/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#include <string>
#include <fstream>
#include <iostream>
#include <vector>

#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sstream>
#include <algorithm>
#include "t_generator.h"
#include "platform.h"
using namespace std;


/**
 * Python code generator.
 *
 */
class t_py_generator : public t_generator {
 public:
  t_py_generator(
      t_program* program,
      const std::map<std::string, std::string>& parsed_options,
      const std::string& option_string)
    : t_generator(program)
  {
    std::map<std::string, std::string>::const_iterator iter;

    iter = parsed_options.find("new_style");
    gen_newstyle_ = (iter != parsed_options.end());

    iter = parsed_options.find("twisted");
    gen_twisted_ = (iter != parsed_options.end());

    out_dir_base_ = "gen-py";
  }

  /**
   * Init and close methods
   */

  void init_generator();
  void close_generator();

  /**
   * Program-level generation functions
   */

  void generate_typedef  (t_typedef*  ttypedef);
  void generate_enum     (t_enum*     tenum);
  void generate_const    (t_const*    tconst);
  void generate_struct   (t_struct*   tstruct);
  void generate_xception (t_struct*   txception);
  void generate_service  (t_service*  tservice);

  std::string render_const_value(t_type* type, t_const_value* value);

  /**
   * Struct generation code
   */

  void generate_py_struct(t_struct* tstruct, bool is_exception);
  void generate_py_struct_definition(std::ofstream& out, t_struct* tstruct, bool is_xception=false, bool is_result=false);
  void generate_py_struct_reader(std::ofstream& out, t_struct* tstruct);
  void generate_py_struct_writer(std::ofstream& out, t_struct* tstruct);
  void generate_py_function_helpers(t_function* tfunction);

  /**
   * Service-level generation functions
   */

  void generate_service_helpers   (t_service*  tservice);
  void generate_service_interface (t_service* tservice);
  void generate_service_client    (t_service* tservice);
  void generate_service_remote    (t_service* tservice);
  void generate_service_server    (t_service* tservice);
  void generate_process_function  (t_service* tservice, t_function* tfunction);

  /**
   * Serialization constructs
   */

  void generate_deserialize_field        (std::ofstream &out,
                                          t_field*    tfield,
                                          std::string prefix="",
                                          bool inclass=false);

  void generate_deserialize_struct       (std::ofstream &out,
                                          t_struct*   tstruct,
                                          std::string prefix="");

  void generate_deserialize_container    (std::ofstream &out,
                                          t_type*     ttype,
                                          std::string prefix="");

  void generate_deserialize_set_element  (std::ofstream &out,
                                          t_set*      tset,
                                          std::string prefix="");

  void generate_deserialize_map_element  (std::ofstream &out,
                                          t_map*      tmap,
                                          std::string prefix="");

  void generate_deserialize_list_element (std::ofstream &out,
                                          t_list*     tlist,
                                          std::string prefix="");

  void generate_serialize_field          (std::ofstream &out,
                                          t_field*    tfield,
                                          std::string prefix="");

  void generate_serialize_struct         (std::ofstream &out,
                                          t_struct*   tstruct,
                                          std::string prefix="");

  void generate_serialize_container      (std::ofstream &out,
                                          t_type*     ttype,
                                          std::string prefix="");

  void generate_serialize_map_element    (std::ofstream &out,
                                          t_map*      tmap,
                                          std::string kiter,
                                          std::string viter);

  void generate_serialize_set_element    (std::ofstream &out,
                                          t_set*      tmap,
                                          std::string iter);

  void generate_serialize_list_element   (std::ofstream &out,
                                          t_list*     tlist,
                                          std::string iter);

  void generate_python_docstring         (std::ofstream& out,
                                          t_struct* tstruct);

  void generate_python_docstring         (std::ofstream& out,
                                          t_function* tfunction);

  void generate_python_docstring         (std::ofstream& out,
                                          t_doc*    tdoc,
                                          t_struct* tstruct,
                                          const char* subheader);

  void generate_python_docstring         (std::ofstream& out,
                                          t_doc* tdoc);

  /**
   * Helper rendering functions
   */

  std::string py_autogen_comment();
  std::string py_imports();
  std::string render_includes();
  std::string render_fastbinary_includes();
  std::string declare_argument(t_field* tfield);
  std::string render_field_default_value(t_field* tfield);
  std::string type_name(t_type* ttype);
  std::string function_signature(t_function* tfunction, std::string prefix="");
  std::string function_signature_if(t_function* tfunction, std::string prefix="");
  std::string argument_list(t_struct* tstruct);
  std::string type_to_enum(t_type* ttype);
  std::string type_to_spec_args(t_type* ttype);

  static std::string get_real_py_module(const t_program* program) {
    std::string real_module = program->get_namespace("py");
    if (real_module.empty()) {
      return program->get_name();
    }
    return real_module;
  }

 private:

  /**
   * True iff we should generate new-style classes.
   */
  bool gen_newstyle_;

  /**
   * True iff we should generate Twisted-friendly RPC services.
   */
  bool gen_twisted_;

  /**
   * File streams
   */

  std::ofstream f_types_;
  std::ofstream f_consts_;
  std::ofstream f_service_;

  std::string package_dir_;

};


/**
 * Prepares for file generation by opening up the necessary file output
 * streams.
 *
 * @param tprogram The program to generate
 */
void t_py_generator::init_generator() {
  // Make output directory
  string module = get_real_py_module(program_);
  package_dir_ = get_out_dir();
  while (true) {
    // TODO: Do better error checking here.
    MKDIR(package_dir_.c_str());
    std::ofstream init_py((package_dir_+"/__init__.py").c_str());
    init_py.close();
    if (module.empty()) {
      break;
    }
    string::size_type pos = module.find('.');
    if (pos == string::npos) {
      package_dir_ += "/";
      package_dir_ += module;
      module.clear();
    } else {
      package_dir_ += "/";
      package_dir_ += module.substr(0, pos);
      module.erase(0, pos+1);
    }
  }

  // Make output file
  string f_types_name = package_dir_+"/"+"ttypes.py";
  f_types_.open(f_types_name.c_str());

  string f_consts_name = package_dir_+"/"+"constants.py";
  f_consts_.open(f_consts_name.c_str());

  string f_init_name = package_dir_+"/__init__.py";
  ofstream f_init;
  f_init.open(f_init_name.c_str());
  f_init  <<
    "__all__ = ['ttypes', 'constants'";
  vector<t_service*> services = program_->get_services();
  vector<t_service*>::iterator sv_iter;
  for (sv_iter = services.begin(); sv_iter != services.end(); ++sv_iter) {
    f_init << ", '" << (*sv_iter)->get_name() << "'";
  }
  f_init << "]" << endl;
  f_init.close();

  // Print header
  f_types_ <<
    py_autogen_comment() << endl <<
    py_imports() << endl <<
    render_includes() << endl <<
    render_fastbinary_includes() <<
    endl << endl;

  f_consts_ <<
    py_autogen_comment() << endl <<
    py_imports() << endl <<
    "from ttypes import *" << endl <<
    endl;
}

/**
 * Renders all the imports necessary for including another Thrift program
 */
string t_py_generator::render_includes() {
  const vector<t_program*>& includes = program_->get_includes();
  string result = "";
  for (size_t i = 0; i < includes.size(); ++i) {
    result += "import " + get_real_py_module(includes[i]) + ".ttypes\n";
  }
  if (includes.size() > 0) {
    result += "\n";
  }
  return result;
}

/**
 * Renders all the imports necessary to use the accelerated TBinaryProtocol
 */
string t_py_generator::render_fastbinary_includes() {
  return
    "from thrift.transport import TTransport\n"
    "from thrift.protocol import TBinaryProtocol\n"
    "try:\n"
    "  from thrift.protocol import fastbinary\n"
    "except:\n"
    "  fastbinary = None\n";
}

/**
 * Autogen'd comment
 */
string t_py_generator::py_autogen_comment() {
  return
    std::string("#\n") +
    "# Autogenerated by Thrift\n" +
    "#\n" +
    "# DO NOT EDIT UNLESS YOU ARE SURE THAT YOU KNOW WHAT YOU ARE DOING\n" +
    "#\n";
}

/**
 * Prints standard thrift imports
 */
string t_py_generator::py_imports() {
  return
    string("from thrift.Thrift import *");
}

/**
 * Closes the type files
 */
void t_py_generator::close_generator() {
  // Close types file
  f_types_.close();
  f_consts_.close();
}

/**
 * Generates a typedef. This is not done in Python, types are all implicit.
 *
 * @param ttypedef The type definition
 */
void t_py_generator::generate_typedef(t_typedef* ttypedef) {}

/**
 * Generates code for an enumerated type. Done using a class to scope
 * the values.
 *
 * @param tenum The enumeration
 */
void t_py_generator::generate_enum(t_enum* tenum) {
  f_types_ <<
    "class " << tenum->get_name() <<
    (gen_newstyle_ ? "(object)" : "") <<
    ":" << endl;
  indent_up();
  generate_python_docstring(f_types_, tenum);

  vector<t_enum_value*> constants = tenum->get_constants();
  vector<t_enum_value*>::iterator c_iter;
  int value = -1;
  for (c_iter = constants.begin(); c_iter != constants.end(); ++c_iter) {
    if ((*c_iter)->has_value()) {
      value = (*c_iter)->get_value();
    } else {
      ++value;
    }

    f_types_ <<
      indent() << (*c_iter)->get_name() << " = " << value << endl;
  }

  indent_down();
  f_types_ << endl;
}

/**
 * Generate a constant value
 */
void t_py_generator::generate_const(t_const* tconst) {
  t_type* type = tconst->get_type();
  string name = tconst->get_name();
  t_const_value* value = tconst->get_value();

  indent(f_consts_) << name << " = " << render_const_value(type, value);
  f_consts_ << endl << endl;
}

/**
 * Prints the value of a constant with the given type. Note that type checking
 * is NOT performed in this function as it is always run beforehand using the
 * validate_types method in main.cc
 */
string t_py_generator::render_const_value(t_type* type, t_const_value* value) {
  type = get_true_type(type);
  std::ostringstream out;

  if (type->is_base_type()) {
    t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
    switch (tbase) {
    case t_base_type::TYPE_STRING:
      out << '"' << get_escaped_string(value) << '"';
      break;
    case t_base_type::TYPE_BOOL:
      out << (value->get_integer() > 0 ? "True" : "False");
      break;
    case t_base_type::TYPE_BYTE:
    case t_base_type::TYPE_I16:
    case t_base_type::TYPE_I32:
    case t_base_type::TYPE_I64:
      out << value->get_integer();
      break;
    case t_base_type::TYPE_DOUBLE:
      if (value->get_type() == t_const_value::CV_INTEGER) {
        out << value->get_integer();
      } else {
        out << value->get_double();
      }
      break;
    default:
      throw "compiler error: no const of base type " + t_base_type::t_base_name(tbase);
    }
  } else if (type->is_enum()) {
    indent(out) << value->get_integer();
  } else if (type->is_struct() || type->is_xception()) {
    out << type->get_name() << "(**{" << endl;
    indent_up();
    const vector<t_field*>& fields = ((t_struct*)type)->get_members();
    vector<t_field*>::const_iterator f_iter;
    const map<t_const_value*, t_const_value*>& val = value->get_map();
    map<t_const_value*, t_const_value*>::const_iterator v_iter;
    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
      t_type* field_type = NULL;
      for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
        if ((*f_iter)->get_name() == v_iter->first->get_string()) {
          field_type = (*f_iter)->get_type();
        }
      }
      if (field_type == NULL) {
        throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
      }
      out << indent();
      out << render_const_value(g_type_string, v_iter->first);
      out << " : ";
      out << render_const_value(field_type, v_iter->second);
      out << "," << endl;
    }
    indent_down();
    indent(out) << "})";
  } else if (type->is_map()) {
    t_type* ktype = ((t_map*)type)->get_key_type();
    t_type* vtype = ((t_map*)type)->get_val_type();
    out << "{" << endl;
    indent_up();
    const map<t_const_value*, t_const_value*>& val = value->get_map();
    map<t_const_value*, t_const_value*>::const_iterator v_iter;
    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
      out << indent();
      out << render_const_value(ktype, v_iter->first);
      out << " : ";
      out << render_const_value(vtype, v_iter->second);
      out << "," << endl;
    }
    indent_down();
    indent(out) << "}";
  } else if (type->is_list() || type->is_set()) {
    t_type* etype;
    if (type->is_list()) {
      etype = ((t_list*)type)->get_elem_type();
    } else {
      etype = ((t_set*)type)->get_elem_type();
    }
    if (type->is_set()) {
      out << "set(";
    }
    out << "[" << endl;
    indent_up();
    const vector<t_const_value*>& val = value->get_list();
    vector<t_const_value*>::const_iterator v_iter;
    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
      out << indent();
      out << render_const_value(etype, *v_iter);
      out << "," << endl;
    }
    indent_down();
    indent(out) << "]";
    if (type->is_set()) {
      out << ")";
    }
  } else {
    throw "CANNOT GENERATE CONSTANT FOR TYPE: " + type->get_name();
  }

  return out.str();
}

/**
 * Generates a python struct
 */
void t_py_generator::generate_struct(t_struct* tstruct) {
  generate_py_struct(tstruct, false);
}

/**
 * Generates a struct definition for a thrift exception. Basically the same
 * as a struct but extends the Exception class.
 *
 * @param txception The struct definition
 */
void t_py_generator::generate_xception(t_struct* txception) {
  generate_py_struct(txception, true);
}

/**
 * Generates a python struct
 */
void t_py_generator::generate_py_struct(t_struct* tstruct,
                                        bool is_exception) {
  generate_py_struct_definition(f_types_, tstruct, is_exception);
}

/**
 * Generates a struct definition for a thrift data type.
 *
 * @param tstruct The struct definition
 */
void t_py_generator::generate_py_struct_definition(ofstream& out,
                                                   t_struct* tstruct,
                                                   bool is_exception,
                                                   bool is_result) {

  const vector<t_field*>& members = tstruct->get_members();
  const vector<t_field*>& sorted_members = tstruct->get_sorted_members();
  vector<t_field*>::const_iterator m_iter;

  out <<
    "class " << tstruct->get_name();
  if (is_exception) {
    out << "(Exception)";
  } else if (gen_newstyle_) {
    out << "(object)";
  }
  out <<
    ":" << endl;
  indent_up();
  generate_python_docstring(out, tstruct);

  out << endl;

  /*
     Here we generate the structure specification for the fastbinary codec.
     These specifications have the following structure:
     thrift_spec -> tuple of item_spec
     item_spec -> None | (tag, type_enum, name, spec_args, default)
     tag -> integer
     type_enum -> TType.I32 | TType.STRING | TType.STRUCT | ...
     name -> string_literal
     default -> None  # Handled by __init__
     spec_args -> None  # For simple types
                | (type_enum, spec_args)  # Value type for list/set
                | (type_enum, spec_args, type_enum, spec_args)
                  # Key and value for map
                | (class_name, spec_args_ptr) # For struct/exception
     class_name -> identifier  # Basically a pointer to the class
     spec_args_ptr -> expression  # just class_name.spec_args

     TODO(dreiss): Consider making this work for structs with negative tags.
  */

  // TODO(dreiss): Look into generating an empty tuple instead of None
  // for structures with no members.
  // TODO(dreiss): Test encoding of structs where some inner structs
  // don't have thrift_spec.
  if (sorted_members.empty() || (sorted_members[0]->get_key() >= 0)) {
    indent(out) << "thrift_spec = (" << endl;
    indent_up();

    int sorted_keys_pos = 0;
    for (m_iter = sorted_members.begin(); m_iter != sorted_members.end(); ++m_iter) {

      for (; sorted_keys_pos != (*m_iter)->get_key(); sorted_keys_pos++) {
        indent(out) << "None, # " << sorted_keys_pos << endl;
      }

      indent(out) << "(" << (*m_iter)->get_key() << ", "
            << type_to_enum((*m_iter)->get_type()) << ", "
            << "'" << (*m_iter)->get_name() << "'" << ", "
            << type_to_spec_args((*m_iter)->get_type()) << ", "
            << render_field_default_value(*m_iter) << ", "
            << "),"
            << " # " << sorted_keys_pos
            << endl;

      sorted_keys_pos ++;
    }

    indent_down();
    indent(out) << ")" << endl << endl;
  } else {
    indent(out) << "thrift_spec = None" << endl;
  }


  if (members.size() > 0) {
    out <<
      indent() << "def __init__(self,";

    for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
      // This fills in default values, as opposed to nulls
      out << " " << declare_argument(*m_iter) << ",";
    }

    out << "):" << endl;

    indent_up();

    for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
      // Initialize fields
      t_type* type = (*m_iter)->get_type();
      if (!type->is_base_type() && !type->is_enum() && (*m_iter)->get_value() != NULL) {
        indent(out) <<
          "if " << (*m_iter)->get_name() << " is " << "self.thrift_spec[" <<
            (*m_iter)->get_key() << "][4]:" << endl;
        indent(out) << "  " << (*m_iter)->get_name() << " = " <<
          render_field_default_value(*m_iter) << endl;
      }
      indent(out) <<
        "self." << (*m_iter)->get_name() << " = " << (*m_iter)->get_name() << endl;
    }

    indent_down();

    out << endl;
  }

  generate_py_struct_reader(out, tstruct);
  generate_py_struct_writer(out, tstruct);

  // For exceptions only, generate a __str__ method. This is
  // because when raised exceptions are printed to the console, __repr__
  // isn't used. See python bug #5882
  if (is_exception) {
    out <<
      indent() << "def __str__(self):" << endl <<
      indent() << "  return repr(self)" << endl <<
      endl;
  }

  // Printing utilities so that on the command line thrift
  // structs look pretty like dictionaries
  out <<
    indent() << "def __repr__(self):" << endl <<
    indent() << "  L = ['%s=%r' % (key, value)" << endl <<
    indent() << "    for key, value in self.__dict__.iteritems()]" << endl <<
    indent() << "  return '%s(%s)' % (self.__class__.__name__, ', '.join(L))" << endl <<
    endl;

  // Equality and inequality methods that compare by value
  out <<
    indent() << "def __eq__(self, other):" << endl;
  indent_up();
  out <<
    indent() << "return isinstance(other, self.__class__) and "
                "self.__dict__ == other.__dict__" << endl;
  indent_down();
  out << endl;

  out <<
    indent() << "def __ne__(self, other):" << endl;
  indent_up();
  out <<
    indent() << "return not (self == other)" << endl;
  indent_down();
  out << endl;

  indent_down();
}

/**
 * Generates the read method for a struct
 */
void t_py_generator::generate_py_struct_reader(ofstream& out,
                                                t_struct* tstruct) {
  const vector<t_field*>& fields = tstruct->get_members();
  vector<t_field*>::const_iterator f_iter;

  indent(out) <<
    "def read(self, iprot):" << endl;
  indent_up();

  indent(out) <<
    "if iprot.__class__ == TBinaryProtocol.TBinaryProtocolAccelerated "
    "and isinstance(iprot.trans, TTransport.CReadableTransport) "
    "and self.thrift_spec is not None "
    "and fastbinary is not None:" << endl;
  indent_up();

  indent(out) <<
    "fastbinary.decode_binary(self, iprot.trans, (self.__class__, self.thrift_spec))" << endl;
  indent(out) <<
    "return" << endl;
  indent_down();

  indent(out) <<
    "iprot.readStructBegin()" << endl;

  // Loop over reading in fields
  indent(out) <<
    "while True:" << endl;
    indent_up();

    // Read beginning field marker
    indent(out) <<
      "(fname, ftype, fid) = iprot.readFieldBegin()" << endl;

    // Check for field STOP marker and break
    indent(out) <<
      "if ftype == TType.STOP:" << endl;
    indent_up();
    indent(out) <<
      "break" << endl;
    indent_down();

    // Switch statement on the field we are reading
    bool first = true;

    // Generate deserialization code for known cases
    for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
      if (first) {
        first = false;
        out <<
          indent() << "if ";
      } else {
        out <<
          indent() << "elif ";
      }
      out << "fid == " << (*f_iter)->get_key() << ":" << endl;
      indent_up();
      indent(out) << "if ftype == " << type_to_enum((*f_iter)->get_type()) << ":" << endl;
      indent_up();
      generate_deserialize_field(out, *f_iter, "self.");
      indent_down();
      out <<
        indent() << "else:" << endl <<
        indent() << "  iprot.skip(ftype)" << endl;
      indent_down();
    }

    // In the default case we skip the field
    out <<
      indent() <<  "else:" << endl <<
      indent() <<  "  iprot.skip(ftype)" << endl;

    // Read field end marker
    indent(out) <<
      "iprot.readFieldEnd()" << endl;

    indent_down();

    indent(out) <<
      "iprot.readStructEnd()" << endl;

    indent_down();
  out << endl;
}

void t_py_generator::generate_py_struct_writer(ofstream& out,
                                               t_struct* tstruct) {
  string name = tstruct->get_name();
  const vector<t_field*>& fields = tstruct->get_sorted_members();
  vector<t_field*>::const_iterator f_iter;

  indent(out) <<
    "def write(self, oprot):" << endl;
  indent_up();

  indent(out) <<
    "if oprot.__class__ == TBinaryProtocol.TBinaryProtocolAccelerated "
    "and self.thrift_spec is not None "
    "and fastbinary is not None:" << endl;
  indent_up();

  indent(out) <<
    "oprot.trans.write(fastbinary.encode_binary(self, (self.__class__, self.thrift_spec)))" << endl;
  indent(out) <<
    "return" << endl;
  indent_down();

  indent(out) <<
    "oprot.writeStructBegin('" << name << "')" << endl;

  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
    // Write field header
    indent(out) <<
      "if self." << (*f_iter)->get_name() << " != None:" << endl;
    indent_up();
    indent(out) <<
      "oprot.writeFieldBegin(" <<
      "'" << (*f_iter)->get_name() << "', " <<
      type_to_enum((*f_iter)->get_type()) << ", " <<
      (*f_iter)->get_key() << ")" << endl;

    // Write field contents
    generate_serialize_field(out, *f_iter, "self.");

    // Write field closer
    indent(out) <<
      "oprot.writeFieldEnd()" << endl;

    indent_down();
  }

  // Write the struct map
  out <<
    indent() << "oprot.writeFieldStop()" << endl <<
    indent() << "oprot.writeStructEnd()" << endl;

  indent_down();
  out <<
    endl;
}

/**
 * Generates a thrift service.
 *
 * @param tservice The service definition
 */
void t_py_generator::generate_service(t_service* tservice) {
  string f_service_name = package_dir_+"/"+service_name_+".py";
  f_service_.open(f_service_name.c_str());

  f_service_ <<
    py_autogen_comment() << endl <<
    py_imports() << endl;

  if (tservice->get_extends() != NULL) {
    f_service_ <<
      "import " << get_real_py_module(tservice->get_extends()->get_program()) <<
      "." << tservice->get_extends()->get_name() << endl;
  }

  f_service_ <<
    "from ttypes import *" << endl <<
    "from thrift.Thrift import TProcessor" << endl <<
    render_fastbinary_includes() << endl;

  if (gen_twisted_) {
    f_service_ <<
      "from zope.interface import Interface, implements" << endl <<
      "from twisted.internet import defer" << endl <<
      "from thrift.transport import TTwisted" << endl;
  }

  f_service_ << endl;

  // Generate the three main parts of the service (well, two for now in PHP)
  generate_service_interface(tservice);
  generate_service_client(tservice);
  generate_service_server(tservice);
  generate_service_helpers(tservice);
  generate_service_remote(tservice);

  // Close service file
  f_service_ << endl;
  f_service_.close();
}

/**
 * Generates helper functions for a service.
 *
 * @param tservice The service to generate a header definition for
 */
void t_py_generator::generate_service_helpers(t_service* tservice) {
  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::iterator f_iter;

  f_service_ <<
    "# HELPER FUNCTIONS AND STRUCTURES" << endl << endl;

  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    t_struct* ts = (*f_iter)->get_arglist();
    generate_py_struct_definition(f_service_, ts, false);
    generate_py_function_helpers(*f_iter);
  }
}

/**
 * Generates a struct and helpers for a function.
 *
 * @param tfunction The function
 */
void t_py_generator::generate_py_function_helpers(t_function* tfunction) {
  if (!tfunction->is_oneway()) {
    t_struct result(program_, tfunction->get_name() + "_result");
    t_field success(tfunction->get_returntype(), "success", 0);
    if (!tfunction->get_returntype()->is_void()) {
      result.append(&success);
    }

    t_struct* xs = tfunction->get_xceptions();
    const vector<t_field*>& fields = xs->get_members();
    vector<t_field*>::const_iterator f_iter;
    for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
      result.append(*f_iter);
    }
    generate_py_struct_definition(f_service_, &result, false, true);
  }
}

/**
 * Generates a service interface definition.
 *
 * @param tservice The service to generate a header definition for
 */
void t_py_generator::generate_service_interface(t_service* tservice) {
  string extends = "";
  string extends_if = "";
  if (tservice->get_extends() != NULL) {
    extends = type_name(tservice->get_extends());
    extends_if = "(" + extends + ".Iface)";
  } else {
    if (gen_twisted_) {
      extends_if = "(Interface)";
    }
  }

  f_service_ <<
    "class Iface" << extends_if << ":" << endl;
  indent_up();
  generate_python_docstring(f_service_, tservice);
  vector<t_function*> functions = tservice->get_functions();
  if (functions.empty()) {
    f_service_ <<
      indent() << "pass" << endl;
  } else {
    vector<t_function*>::iterator f_iter;
    for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
      f_service_ <<
        indent() << "def " << function_signature_if(*f_iter) << ":" << endl;
      indent_up();
      generate_python_docstring(f_service_, (*f_iter));
      f_service_ <<
        indent() << "pass" << endl << endl;
      indent_down();
    }
  }

  indent_down();
  f_service_ <<
    endl;
}

/**
 * Generates a service client definition.
 *
 * @param tservice The service to generate a server for.
 */
void t_py_generator::generate_service_client(t_service* tservice) {
  string extends = "";
  string extends_client = "";
  if (tservice->get_extends() != NULL) {
    extends = type_name(tservice->get_extends());
    if (gen_twisted_) {
      extends_client = "(" + extends + ".Client)";
    } else {
      extends_client = extends + ".Client, ";
    }
  } else {
    if (gen_twisted_ && gen_newstyle_) {
        extends_client = "(object)";
    }
  }

  if (gen_twisted_) {
    f_service_ <<
      "class Client" << extends_client << ":" << endl <<
      "  implements(Iface)" << endl << endl;
  } else {
    f_service_ <<
      "class Client(" << extends_client << "Iface):" << endl;
  }
  indent_up();
  generate_python_docstring(f_service_, tservice);

  // Constructor function
  if (gen_twisted_) {
    f_service_ <<
      indent() << "def __init__(self, transport, oprot_factory):" << endl;
  } else {
    f_service_ <<
      indent() << "def __init__(self, iprot, oprot=None):" << endl;
  }
  if (extends.empty()) {
    if (gen_twisted_) {
      f_service_ <<
        indent() << "  self._transport = transport" << endl <<
        indent() << "  self._oprot_factory = oprot_factory" << endl <<
        indent() << "  self._seqid = 0" << endl <<
        indent() << "  self._reqs = {}" << endl <<
        endl;
    } else {
      f_service_ <<
        indent() << "  self._iprot = self._oprot = iprot" << endl <<
        indent() << "  if oprot != None:" << endl <<
        indent() << "    self._oprot = oprot" << endl <<
        indent() << "  self._seqid = 0" << endl <<
        endl;
    }
  } else {
    if (gen_twisted_) {
      f_service_ <<
        indent() << "  " << extends << ".Client.__init__(self, transport, oprot_factory)" << endl <<
        endl;
    } else {
      f_service_ <<
        indent() << "  " << extends << ".Client.__init__(self, iprot, oprot)" << endl <<
        endl;
    }
  }

  // Generate client method implementations
  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::const_iterator f_iter;
  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    t_struct* arg_struct = (*f_iter)->get_arglist();
    const vector<t_field*>& fields = arg_struct->get_members();
    vector<t_field*>::const_iterator fld_iter;
    string funname = (*f_iter)->get_name();

    // Open function
    indent(f_service_) <<
      "def " << function_signature(*f_iter) << ":" << endl;
    indent_up();
    generate_python_docstring(f_service_, (*f_iter));
    if (gen_twisted_) {
      indent(f_service_) << "self._seqid += 1" << endl;
      if (!(*f_iter)->is_oneway()) {
        indent(f_service_) <<
          "d = self._reqs[self._seqid] = defer.Deferred()" << endl;
      }
    }

    indent(f_service_) <<
      "self.send_" << funname << "(";

    bool first = true;
    for (fld_iter = fields.begin(); fld_iter != fields.end(); ++fld_iter) {
      if (first) {
        first = false;
      } else {
        f_service_ << ", ";
      }
      f_service_ << (*fld_iter)->get_name();
    }
    f_service_ << ")" << endl;

    if (!(*f_iter)->is_oneway()) {
      f_service_ << indent();
      if (gen_twisted_) {
        f_service_ << "return d" << endl;
      } else {
        if (!(*f_iter)->get_returntype()->is_void()) {
          f_service_ << "return ";
        }
        f_service_ <<
          "self.recv_" << funname << "()" << endl;
      }
    } else {
      if (gen_twisted_) {
        f_service_ <<
          indent() << "return defer.succeed(None)" << endl;
      }
    }
    indent_down();
    f_service_ << endl;

    indent(f_service_) <<
      "def send_" << function_signature(*f_iter) << ":" << endl;

    indent_up();

    std::string argsname = (*f_iter)->get_name() + "_args";

    // Serialize the request header
    if (gen_twisted_) {
      f_service_ <<
        indent() << "oprot = self._oprot_factory.getProtocol(self._transport)" << endl <<
        indent() <<
          "oprot.writeMessageBegin('" << (*f_iter)->get_name() << "', TMessageType.CALL, self._seqid)"
        << endl;
    } else {
      f_service_ <<
        indent() << "self._oprot.writeMessageBegin('" << (*f_iter)->get_name() << "', TMessageType.CALL, self._seqid)" << endl;
    }

    f_service_ <<
      indent() << "args = " << argsname << "()" << endl;

    for (fld_iter = fields.begin(); fld_iter != fields.end(); ++fld_iter) {
      f_service_ <<
        indent() << "args." << (*fld_iter)->get_name() << " = " << (*fld_iter)->get_name() << endl;
    }

    // Write to the stream
    if (gen_twisted_) {
      f_service_ <<
        indent() << "args.write(oprot)" << endl <<
        indent() << "oprot.writeMessageEnd()" << endl <<
        indent() << "oprot.trans.flush()" << endl;
    } else {
      f_service_ <<
        indent() << "args.write(self._oprot)" << endl <<
        indent() << "self._oprot.writeMessageEnd()" << endl <<
        indent() << "self._oprot.trans.flush()" << endl;
    }

    indent_down();

    if (!(*f_iter)->is_oneway()) {
      std::string resultname = (*f_iter)->get_name() + "_result";
      // Open function
      f_service_ <<
        endl;
      if (gen_twisted_) {
        f_service_ <<
          indent() << "def recv_" << (*f_iter)->get_name() <<
              "(self, iprot, mtype, rseqid):" << endl;
      } else {
        t_struct noargs(program_);
        t_function recv_function((*f_iter)->get_returntype(),
                               string("recv_") + (*f_iter)->get_name(),
                               &noargs);
        f_service_ <<
          indent() << "def " << function_signature(&recv_function) << ":" << endl;
      }
      indent_up();

      // TODO(mcslee): Validate message reply here, seq ids etc.

      if (gen_twisted_) {
        f_service_ <<
          indent() << "d = self._reqs.pop(rseqid)" << endl;
      } else {
        f_service_ <<
          indent() << "(fname, mtype, rseqid) = self._iprot.readMessageBegin()" << endl;
      }

      f_service_ <<
        indent() << "if mtype == TMessageType.EXCEPTION:" << endl <<
        indent() << "  x = TApplicationException()" << endl;

      if (gen_twisted_) {
        f_service_ <<
          indent() << "  x.read(iprot)" << endl <<
          indent() << "  iprot.readMessageEnd()" << endl <<
          indent() << "  return d.errback(x)" << endl <<
          indent() << "result = " << resultname << "()" << endl <<
          indent() << "result.read(iprot)" << endl <<
          indent() << "iprot.readMessageEnd()" << endl;
      } else {
        f_service_ <<
          indent() << "  x.read(self._iprot)" << endl <<
          indent() << "  self._iprot.readMessageEnd()" << endl <<
          indent() << "  raise x" << endl <<
          indent() << "result = " << resultname << "()" << endl <<
          indent() << "result.read(self._iprot)" << endl <<
          indent() << "self._iprot.readMessageEnd()" << endl;
      }

      // Careful, only return _result if not a void function
      if (!(*f_iter)->get_returntype()->is_void()) {
        f_service_ <<
          indent() << "if result.success != None:" << endl;
          if (gen_twisted_) {
            f_service_ <<
              indent() << "  return d.callback(result.success)" << endl;
          } else {
            f_service_ <<
              indent() << "  return result.success" << endl;
          }
      }

      t_struct* xs = (*f_iter)->get_xceptions();
      const std::vector<t_field*>& xceptions = xs->get_members();
      vector<t_field*>::const_iterator x_iter;
      for (x_iter = xceptions.begin(); x_iter != xceptions.end(); ++x_iter) {
        f_service_ <<
          indent() << "if result." << (*x_iter)->get_name() << " != None:" << endl;
          if (gen_twisted_) {
            f_service_ <<
              indent() << "  return d.errback(result." << (*x_iter)->get_name() << ")" << endl;

          } else {
            f_service_ <<
              indent() << "  raise result." << (*x_iter)->get_name() << "" << endl;
          }
      }

      // Careful, only return _result if not a void function
      if ((*f_iter)->get_returntype()->is_void()) {
        if (gen_twisted_) {
          indent(f_service_) <<
            "return d.callback(None)" << endl;
        } else {
          indent(f_service_) <<
            "return" << endl;
        }
      } else {
        if (gen_twisted_) {
          f_service_ <<
            indent() << "return d.errback(TApplicationException(TApplicationException.MISSING_RESULT, \"" << (*f_iter)->get_name() << " failed: unknown result\"))" << endl;
        } else {
          f_service_ <<
            indent() << "raise TApplicationException(TApplicationException.MISSING_RESULT, \"" << (*f_iter)->get_name() << " failed: unknown result\");" << endl;
        }
      }

      // Close function
      indent_down();
      f_service_ << endl;
    }
  }

  indent_down();
  f_service_ <<
    endl;
}

/**
 * Generates a command line tool for making remote requests
 *
 * @param tservice The service to generate a remote for.
 */
void t_py_generator::generate_service_remote(t_service* tservice) {
  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::iterator f_iter;

  string f_remote_name = package_dir_+"/"+service_name_+"-remote";
  ofstream f_remote;
  f_remote.open(f_remote_name.c_str());

  f_remote <<
    "#!/usr/bin/env python" << endl <<
    py_autogen_comment() << endl <<
    "import sys" << endl <<
    "import pprint" << endl <<
    "from urlparse import urlparse" << endl <<
    "from thrift.transport import TTransport" << endl <<
    "from thrift.transport import TSocket" << endl <<
    "from thrift.transport import THttpClient" << endl <<
    "from thrift.protocol import TBinaryProtocol" << endl <<
    endl;

  f_remote <<
    "import " << service_name_ << endl <<
    "from ttypes import *" << endl <<
    endl;

  f_remote <<
    "if len(sys.argv) <= 1 or sys.argv[1] == '--help':" << endl <<
    "  print ''" << endl <<
    "  print 'Usage: ' + sys.argv[0] + ' [-h host:port] [-u url] [-f[ramed]] function [arg1 [arg2...]]'" << endl <<
    "  print ''" << endl <<
    "  print 'Functions:'" << endl;
  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    f_remote <<
      "  print '  " << (*f_iter)->get_returntype()->get_name() << " " << (*f_iter)->get_name() << "(";
    t_struct* arg_struct = (*f_iter)->get_arglist();
    const std::vector<t_field*>& args = arg_struct->get_members();
    vector<t_field*>::const_iterator a_iter;
    int num_args = args.size();
    bool first = true;
    for (int i = 0; i < num_args; ++i) {
      if (first) {
        first = false;
      } else {
        f_remote << ", ";
      }
      f_remote <<
        args[i]->get_type()->get_name() << " " << args[i]->get_name();
    }
    f_remote << ")'" << endl;
  }
  f_remote <<
    "  print ''" << endl <<
    "  sys.exit(0)" << endl <<
    endl;

  f_remote <<
    "pp = pprint.PrettyPrinter(indent = 2)" << endl <<
    "host = 'localhost'" << endl <<
    "port = 9090" << endl <<
    "uri = ''" << endl <<
    "framed = False" << endl <<
    "http = False" << endl <<
    "argi = 1" << endl <<
    endl <<
    "if sys.argv[argi] == '-h':" << endl <<
    "  parts = sys.argv[argi+1].split(':') " << endl <<
    "  host = parts[0]" << endl <<
    "  port = int(parts[1])" << endl <<
    "  argi += 2" << endl <<
    endl <<
    "if sys.argv[argi] == '-u':" << endl <<
    "  url = urlparse(sys.argv[argi+1])" << endl <<
    "  parts = url[1].split(':') " << endl <<
    "  host = parts[0]" << endl <<
    "  if len(parts) > 1:" << endl <<
    "    port = int(parts[1])" << endl <<
    "  else:" << endl <<
    "    port = 80" << endl <<
    "  uri = url[2]" << endl <<
    "  http = True" << endl <<
    "  argi += 2" << endl <<
    endl <<
    "if sys.argv[argi] == '-f' or sys.argv[argi] == '-framed':" << endl <<
    "  framed = True" << endl <<
    "  argi += 1" << endl <<
    endl <<
    "cmd = sys.argv[argi]" << endl <<
    "args = sys.argv[argi+1:]" << endl <<
    endl <<
    "if http:" << endl <<
    "  transport = THttpClient.THttpClient(host, port, uri)" << endl <<
    "else:" << endl <<
    "  socket = TSocket.TSocket(host, port)" << endl <<
    "  if framed:" << endl <<
    "    transport = TTransport.TFramedTransport(socket)" << endl <<
    "  else:" << endl <<
    "    transport = TTransport.TBufferedTransport(socket)" << endl <<
    "protocol = TBinaryProtocol.TBinaryProtocol(transport)" << endl <<
    "client = " << service_name_ << ".Client(protocol)" << endl <<
    "transport.open()" << endl <<
    endl;

  // Generate the dispatch methods
  bool first = true;

  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    if (first) {
      first = false;
    } else {
      f_remote << "el";
    }

    t_struct* arg_struct = (*f_iter)->get_arglist();
    const std::vector<t_field*>& args = arg_struct->get_members();
    vector<t_field*>::const_iterator a_iter;
    int num_args = args.size();

    f_remote <<
      "if cmd == '" << (*f_iter)->get_name() << "':" << endl <<
      "  if len(args) != " << num_args << ":" << endl <<
      "    print '" << (*f_iter)->get_name() << " requires " << num_args << " args'" << endl <<
      "    sys.exit(1)" << endl <<
      "  pp.pprint(client." << (*f_iter)->get_name() << "(";
    for (int i = 0; i < num_args; ++i) {
      if (args[i]->get_type()->is_string()) {
        f_remote << "args[" << i << "],";
      } else {
        f_remote << "eval(args[" << i << "]),";
      }
    }
    f_remote << "))" << endl;

    f_remote << endl;
  }

  f_remote << "transport.close()" << endl;

  // Close service file
  f_remote.close();

  // Make file executable, love that bitwise OR action
  chmod(f_remote_name.c_str(),
          S_IRUSR
        | S_IWUSR
        | S_IXUSR
#ifndef MINGW
        | S_IRGRP
        | S_IXGRP
        | S_IROTH
        | S_IXOTH
#endif
  );
}

/**
 * Generates a service server definition.
 *
 * @param tservice The service to generate a server for.
 */
void t_py_generator::generate_service_server(t_service* tservice) {
  // Generate the dispatch methods
  vector<t_function*> functions = tservice->get_functions();
  vector<t_function*>::iterator f_iter;

  string extends = "";
  string extends_processor = "";
  if (tservice->get_extends() != NULL) {
    extends = type_name(tservice->get_extends());
    extends_processor = extends + ".Processor, ";
  }

  // Generate the header portion
  if (gen_twisted_) {
    f_service_ <<
      "class Processor(" << extends_processor << "TProcessor):" << endl <<
      "  implements(Iface)" << endl << endl;
  } else {
    f_service_ <<
      "class Processor(" << extends_processor << "Iface, TProcessor):" << endl;
  }

  indent_up();

  indent(f_service_) <<
    "def __init__(self, handler):" << endl;
  indent_up();
  if (extends.empty()) {
    if (gen_twisted_) {
      f_service_ <<
        indent() << "self._handler = Iface(handler)" << endl;
    } else {
      f_service_ <<
        indent() << "self._handler = handler" << endl;
    }

    f_service_ <<
      indent() << "self._processMap = {}" << endl;
  } else {
    if (gen_twisted_) {
      f_service_ <<
        indent() << extends << ".Processor.__init__(self, Iface(handler))" << endl;
    } else {
      f_service_ <<
        indent() << extends << ".Processor.__init__(self, handler)" << endl;
    }
  }
  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    f_service_ <<
      indent() << "self._processMap[\"" << (*f_iter)->get_name() << "\"] = Processor.process_" << (*f_iter)->get_name() << endl;
  }
  indent_down();
  f_service_ << endl;

  // Generate the server implementation
  indent(f_service_) <<
    "def process(self, iprot, oprot):" << endl;
  indent_up();

  f_service_ <<
    indent() << "(name, type, seqid) = iprot.readMessageBegin()" << endl;

  // TODO(mcslee): validate message

  // HOT: dictionary function lookup
  f_service_ <<
    indent() << "if name not in self._processMap:" << endl <<
    indent() << "  iprot.skip(TType.STRUCT)" << endl <<
    indent() << "  iprot.readMessageEnd()" << endl <<
    indent() << "  x = TApplicationException(TApplicationException.UNKNOWN_METHOD, 'Unknown function %s' % (name))" << endl <<
    indent() << "  oprot.writeMessageBegin(name, TMessageType.EXCEPTION, seqid)" << endl <<
    indent() << "  x.write(oprot)" << endl <<
    indent() << "  oprot.writeMessageEnd()" << endl <<
    indent() << "  oprot.trans.flush()" << endl;

  if (gen_twisted_) {
    f_service_ <<
      indent() << "  return defer.succeed(None)" << endl;
  } else {
    f_service_ <<
      indent() << "  return" << endl;
  }

  f_service_ <<
    indent() << "else:" << endl;

  if (gen_twisted_) {
    f_service_ <<
      indent() << "  return self._processMap[name](self, seqid, iprot, oprot)" << endl;
  } else {
    f_service_ <<
      indent() << "  self._processMap[name](self, seqid, iprot, oprot)" << endl;

    // Read end of args field, the T_STOP, and the struct close
    f_service_ <<
      indent() << "return True" << endl;
  }

  indent_down();
  f_service_ << endl;

  // Generate the process subfunctions
  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
    generate_process_function(tservice, *f_iter);
  }

  indent_down();
  f_service_ << endl;
}

/**
 * Generates a process function definition.
 *
 * @param tfunction The function to write a dispatcher for
 */
void t_py_generator::generate_process_function(t_service* tservice,
                                               t_function* tfunction) {
  // Open function
  indent(f_service_) <<
    "def process_" << tfunction->get_name() <<
    "(self, seqid, iprot, oprot):" << endl;
  indent_up();

  string argsname = tfunction->get_name() + "_args";
  string resultname = tfunction->get_name() + "_result";

  f_service_ <<
    indent() << "args = " << argsname << "()" << endl <<
    indent() << "args.read(iprot)" << endl <<
    indent() << "iprot.readMessageEnd()" << endl;

  t_struct* xs = tfunction->get_xceptions();
  const std::vector<t_field*>& xceptions = xs->get_members();
  vector<t_field*>::const_iterator x_iter;

  // Declare result for non oneway function
  if (!tfunction->is_oneway()) {
    f_service_ <<
      indent() << "result = " << resultname << "()" << endl;
  }

  if (gen_twisted_) {
    // Generate the function call
    t_struct* arg_struct = tfunction->get_arglist();
    const std::vector<t_field*>& fields = arg_struct->get_members();
    vector<t_field*>::const_iterator f_iter;

    f_service_ <<
      indent() << "d = defer.maybeDeferred(self._handler." <<
        tfunction->get_name() << ", ";
    bool first = true;
    for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
      if (first) {
        first = false;
      } else {
        f_service_ << ", ";
      }
      f_service_ << "args." << (*f_iter)->get_name();
    }
    f_service_ << ")" << endl;

    // Shortcut out here for oneway functions
    if (tfunction->is_oneway()) {
      f_service_ <<
        indent() << "return d" << endl;
      indent_down();
      f_service_ << endl;
      return;
    }

    f_service_ <<
      indent() <<
        "d.addCallback(self.write_results_success_" <<
          tfunction->get_name() << ", result, seqid, oprot)" << endl;

    if (xceptions.size() > 0) {
      f_service_ <<
        indent() <<
          "d.addErrback(self.write_results_exception_" <<
            tfunction->get_name() << ", result, seqid, oprot)" << endl;
    }

    f_service_ <<
      indent() << "return d" << endl;

    indent_down();
    f_service_ << endl;

    indent(f_service_) <<
        "def write_results_success_" << tfunction->get_name() <<
        "(self, success, result, seqid, oprot):" << endl;
    indent_up();
    f_service_ <<
      indent() << "result.success = success" << endl <<
      indent() << "oprot.writeMessageBegin(\"" << tfunction->get_name() <<
        "\", TMessageType.REPLY, seqid)" << endl <<
      indent() << "result.write(oprot)" << endl <<
      indent() << "oprot.writeMessageEnd()" << endl <<
      indent() << "oprot.trans.flush()" << endl;
    indent_down();
    f_service_ << endl;

    // Try block for a function with exceptions
    if (!tfunction->is_oneway() && xceptions.size() > 0) {
      indent(f_service_) <<
        "def write_results_exception_" << tfunction->get_name() <<
        "(self, error, result, seqid, oprot):" << endl;
      indent_up();
      f_service_ <<
        indent() << "try:" << endl;

      // Kinda absurd
      f_service_ <<
        indent() << "  error.raiseException()" << endl;
      for (x_iter = xceptions.begin(); x_iter != xceptions.end(); ++x_iter) {
        f_service_ <<
          indent() << "except " << type_name((*x_iter)->get_type()) << ", " << (*x_iter)->get_name() << ":" << endl;
        if (!tfunction->is_oneway()) {
          indent_up();
          f_service_ <<
            indent() << "result." << (*x_iter)->get_name() << " = " << (*x_iter)->get_name() << endl;
          indent_down();
        } else {
          f_service_ <<
            indent() << "pass" << endl;
        }
      }
      f_service_ <<
        indent() << "oprot.writeMessageBegin(\"" << tfunction->get_name() <<
          "\", TMessageType.REPLY, seqid)" << endl <<
        indent() << "result.write(oprot)" << endl <<
        indent() << "oprot.writeMessageEnd()" << endl <<
        indent() << "oprot.trans.flush()" << endl;
      indent_down();
      f_service_ << endl;
    }
  } else {

    // Try block for a function with exceptions
    if (xceptions.size() > 0) {
      f_service_ <<
        indent() << "try:" << endl;
      indent_up();
    }

    // Generate the function call
    t_struct* arg_struct = tfunction->get_arglist();
    const std::vector<t_field*>& fields = arg_struct->get_members();
    vector<t_field*>::const_iterator f_iter;

    f_service_ << indent();
    if (!tfunction->is_oneway() && !tfunction->get_returntype()->is_void()) {
      f_service_ << "result.success = ";
    }
    f_service_ <<
      "self._handler." << tfunction->get_name() << "(";
    bool first = true;
    for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
      if (first) {
        first = false;
      } else {
        f_service_ << ", ";
      }
      f_service_ << "args." << (*f_iter)->get_name();
    }
    f_service_ << ")" << endl;

    if (!tfunction->is_oneway() && xceptions.size() > 0) {
      indent_down();
      for (x_iter = xceptions.begin(); x_iter != xceptions.end(); ++x_iter) {
        f_service_ <<
          indent() << "except " << type_name((*x_iter)->get_type()) << ", " << (*x_iter)->get_name() << ":" << endl;
        if (!tfunction->is_oneway()) {
          indent_up();
          f_service_ <<
            indent() << "result." << (*x_iter)->get_name() << " = " << (*x_iter)->get_name() << endl;
          indent_down();
        } else {
          f_service_ <<
            indent() << "pass" << endl;
        }
      }
    }

    // Shortcut out here for oneway functions
    if (tfunction->is_oneway()) {
      f_service_ <<
        indent() << "return" << endl;
      indent_down();
      f_service_ << endl;
      return;
    }

    f_service_ <<
      indent() << "oprot.writeMessageBegin(\"" << tfunction->get_name() << "\", TMessageType.REPLY, seqid)" << endl <<
      indent() << "result.write(oprot)" << endl <<
      indent() << "oprot.writeMessageEnd()" << endl <<
      indent() << "oprot.trans.flush()" << endl;

    // Close function
    indent_down();
    f_service_ << endl;
  }
}

/**
 * Deserializes a field of any type.
 */
void t_py_generator::generate_deserialize_field(ofstream &out,
                                                t_field* tfield,
                                                string prefix,
                                                bool inclass) {
  t_type* type = get_true_type(tfield->get_type());

  if (type->is_void()) {
    throw "CANNOT GENERATE DESERIALIZE CODE FOR void TYPE: " +
      prefix + tfield->get_name();
  }

  string name = prefix + tfield->get_name();

  if (type->is_struct() || type->is_xception()) {
    generate_deserialize_struct(out,
                                (t_struct*)type,
                                 name);
  } else if (type->is_container()) {
    generate_deserialize_container(out, type, name);
  } else if (type->is_base_type() || type->is_enum()) {
    indent(out) <<
      name << " = iprot.";

    if (type->is_base_type()) {
      t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
      switch (tbase) {
      case t_base_type::TYPE_VOID:
        throw "compiler error: cannot serialize void field in a struct: " +
          name;
        break;
      case t_base_type::TYPE_STRING:
        out << "readString();";
        break;
      case t_base_type::TYPE_BOOL:
        out << "readBool();";
        break;
      case t_base_type::TYPE_BYTE:
        out << "readByte();";
        break;
      case t_base_type::TYPE_I16:
        out << "readI16();";
        break;
      case t_base_type::TYPE_I32:
        out << "readI32();";
        break;
      case t_base_type::TYPE_I64:
        out << "readI64();";
        break;
      case t_base_type::TYPE_DOUBLE:
        out << "readDouble();";
        break;
      default:
        throw "compiler error: no PHP name for base type " + t_base_type::t_base_name(tbase);
      }
    } else if (type->is_enum()) {
      out << "readI32();";
    }
    out << endl;

  } else {
    printf("DO NOT KNOW HOW TO DESERIALIZE FIELD '%s' TYPE '%s'\n",
           tfield->get_name().c_str(), type->get_name().c_str());
  }
}

/**
 * Generates an unserializer for a struct, calling read()
 */
void t_py_generator::generate_deserialize_struct(ofstream &out,
                                                  t_struct* tstruct,
                                                  string prefix) {
  out <<
    indent() << prefix << " = " << type_name(tstruct) << "()" << endl <<
    indent() << prefix << ".read(iprot)" << endl;
}

/**
 * Serialize a container by writing out the header followed by
 * data and then a footer.
 */
void t_py_generator::generate_deserialize_container(ofstream &out,
                                                    t_type* ttype,
                                                    string prefix) {
  string size = tmp("_size");
  string ktype = tmp("_ktype");
  string vtype = tmp("_vtype");
  string etype = tmp("_etype");

  t_field fsize(g_type_i32, size);
  t_field fktype(g_type_byte, ktype);
  t_field fvtype(g_type_byte, vtype);
  t_field fetype(g_type_byte, etype);

  // Declare variables, read header
  if (ttype->is_map()) {
    out <<
      indent() << prefix << " = {}" << endl <<
      indent() << "(" << ktype << ", " << vtype << ", " << size << " ) = iprot.readMapBegin() " << endl;
  } else if (ttype->is_set()) {
    out <<
      indent() << prefix << " = set()" << endl <<
      indent() << "(" << etype << ", " << size << ") = iprot.readSetBegin()" << endl;
  } else if (ttype->is_list()) {
    out <<
      indent() << prefix << " = []" << endl <<
      indent() << "(" << etype << ", " << size << ") = iprot.readListBegin()" << endl;
  }

  // For loop iterates over elements
  string i = tmp("_i");
  indent(out) <<
    "for " << i << " in xrange(" << size << "):" << endl;

    indent_up();

    if (ttype->is_map()) {
      generate_deserialize_map_element(out, (t_map*)ttype, prefix);
    } else if (ttype->is_set()) {
      generate_deserialize_set_element(out, (t_set*)ttype, prefix);
    } else if (ttype->is_list()) {
      generate_deserialize_list_element(out, (t_list*)ttype, prefix);
    }

    indent_down();

  // Read container end
  if (ttype->is_map()) {
    indent(out) << "iprot.readMapEnd()" << endl;
  } else if (ttype->is_set()) {
    indent(out) << "iprot.readSetEnd()" << endl;
  } else if (ttype->is_list()) {
    indent(out) << "iprot.readListEnd()" << endl;
  }
}


/**
 * Generates code to deserialize a map
 */
void t_py_generator::generate_deserialize_map_element(ofstream &out,
                                                       t_map* tmap,
                                                       string prefix) {
  string key = tmp("_key");
  string val = tmp("_val");
  t_field fkey(tmap->get_key_type(), key);
  t_field fval(tmap->get_val_type(), val);

  generate_deserialize_field(out, &fkey);
  generate_deserialize_field(out, &fval);

  indent(out) <<
    prefix << "[" << key << "] = " << val << endl;
}

/**
 * Write a set element
 */
void t_py_generator::generate_deserialize_set_element(ofstream &out,
                                                       t_set* tset,
                                                       string prefix) {
  string elem = tmp("_elem");
  t_field felem(tset->get_elem_type(), elem);

  generate_deserialize_field(out, &felem);

  indent(out) <<
    prefix << ".add(" << elem << ")" << endl;
}

/**
 * Write a list element
 */
void t_py_generator::generate_deserialize_list_element(ofstream &out,
                                                        t_list* tlist,
                                                        string prefix) {
  string elem = tmp("_elem");
  t_field felem(tlist->get_elem_type(), elem);

  generate_deserialize_field(out, &felem);

  indent(out) <<
    prefix << ".append(" << elem << ")" << endl;
}


/**
 * Serializes a field of any type.
 *
 * @param tfield The field to serialize
 * @param prefix Name to prepend to field name
 */
void t_py_generator::generate_serialize_field(ofstream &out,
                                               t_field* tfield,
                                               string prefix) {
  t_type* type = get_true_type(tfield->get_type());

  // Do nothing for void types
  if (type->is_void()) {
    throw "CANNOT GENERATE SERIALIZE CODE FOR void TYPE: " +
      prefix + tfield->get_name();
  }

  if (type->is_struct() || type->is_xception()) {
    generate_serialize_struct(out,
                              (t_struct*)type,
                              prefix + tfield->get_name());
  } else if (type->is_container()) {
    generate_serialize_container(out,
                                 type,
                                 prefix + tfield->get_name());
  } else if (type->is_base_type() || type->is_enum()) {

    string name = prefix + tfield->get_name();

    indent(out) <<
      "oprot.";

    if (type->is_base_type()) {
      t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
      switch (tbase) {
      case t_base_type::TYPE_VOID:
        throw
          "compiler error: cannot serialize void field in a struct: " + name;
        break;
      case t_base_type::TYPE_STRING:
        out << "writeString(" << name << ")";
        break;
      case t_base_type::TYPE_BOOL:
        out << "writeBool(" << name << ")";
        break;
      case t_base_type::TYPE_BYTE:
        out << "writeByte(" << name << ")";
        break;
      case t_base_type::TYPE_I16:
        out << "writeI16(" << name << ")";
        break;
      case t_base_type::TYPE_I32:
        out << "writeI32(" << name << ")";
        break;
      case t_base_type::TYPE_I64:
        out << "writeI64(" << name << ")";
        break;
      case t_base_type::TYPE_DOUBLE:
        out << "writeDouble(" << name << ")";
        break;
      default:
        throw "compiler error: no PHP name for base type " + t_base_type::t_base_name(tbase);
      }
    } else if (type->is_enum()) {
      out << "writeI32(" << name << ")";
    }
    out << endl;
  } else {
    printf("DO NOT KNOW HOW TO SERIALIZE FIELD '%s%s' TYPE '%s'\n",
           prefix.c_str(),
           tfield->get_name().c_str(),
           type->get_name().c_str());
  }
}

/**
 * Serializes all the members of a struct.
 *
 * @param tstruct The struct to serialize
 * @param prefix  String prefix to attach to all fields
 */
void t_py_generator::generate_serialize_struct(ofstream &out,
                                               t_struct* tstruct,
                                               string prefix) {
  indent(out) <<
    prefix << ".write(oprot)" << endl;
}

void t_py_generator::generate_serialize_container(ofstream &out,
                                                  t_type* ttype,
                                                  string prefix) {
  if (ttype->is_map()) {
    indent(out) <<
      "oprot.writeMapBegin(" <<
      type_to_enum(((t_map*)ttype)->get_key_type()) << ", " <<
      type_to_enum(((t_map*)ttype)->get_val_type()) << ", " <<
      "len(" << prefix << "))" << endl;
  } else if (ttype->is_set()) {
    indent(out) <<
      "oprot.writeSetBegin(" <<
      type_to_enum(((t_set*)ttype)->get_elem_type()) << ", " <<
      "len(" << prefix << "))" << endl;
  } else if (ttype->is_list()) {
    indent(out) <<
      "oprot.writeListBegin(" <<
      type_to_enum(((t_list*)ttype)->get_elem_type()) << ", " <<
      "len(" << prefix << "))" << endl;
  }

  if (ttype->is_map()) {
    string kiter = tmp("kiter");
    string viter = tmp("viter");
    indent(out) <<
      "for " << kiter << "," << viter << " in " << prefix << ".items():" << endl;
    indent_up();
    generate_serialize_map_element(out, (t_map*)ttype, kiter, viter);
    indent_down();
  } else if (ttype->is_set()) {
    string iter = tmp("iter");
    indent(out) <<
      "for " << iter << " in " << prefix << ":" << endl;
    indent_up();
    generate_serialize_set_element(out, (t_set*)ttype, iter);
    indent_down();
  } else if (ttype->is_list()) {
    string iter = tmp("iter");
    indent(out) <<
      "for " << iter << " in " << prefix << ":" << endl;
    indent_up();
    generate_serialize_list_element(out, (t_list*)ttype, iter);
    indent_down();
  }

  if (ttype->is_map()) {
    indent(out) <<
      "oprot.writeMapEnd()" << endl;
  } else if (ttype->is_set()) {
    indent(out) <<
      "oprot.writeSetEnd()" << endl;
  } else if (ttype->is_list()) {
    indent(out) <<
      "oprot.writeListEnd()" << endl;
  }
}

/**
 * Serializes the members of a map.
 *
 */
void t_py_generator::generate_serialize_map_element(ofstream &out,
                                                     t_map* tmap,
                                                     string kiter,
                                                     string viter) {
  t_field kfield(tmap->get_key_type(), kiter);
  generate_serialize_field(out, &kfield, "");

  t_field vfield(tmap->get_val_type(), viter);
  generate_serialize_field(out, &vfield, "");
}

/**
 * Serializes the members of a set.
 */
void t_py_generator::generate_serialize_set_element(ofstream &out,
                                                     t_set* tset,
                                                     string iter) {
  t_field efield(tset->get_elem_type(), iter);
  generate_serialize_field(out, &efield, "");
}

/**
 * Serializes the members of a list.
 */
void t_py_generator::generate_serialize_list_element(ofstream &out,
                                                      t_list* tlist,
                                                      string iter) {
  t_field efield(tlist->get_elem_type(), iter);
  generate_serialize_field(out, &efield, "");
}

/**
 * Generates the docstring for a given struct.
 */
void t_py_generator::generate_python_docstring(ofstream& out,
                                               t_struct* tstruct) {
  generate_python_docstring(out, tstruct, tstruct, "Attributes");
}

/**
 * Generates the docstring for a given function.
 */
void t_py_generator::generate_python_docstring(ofstream& out,
                                               t_function* tfunction) {
  generate_python_docstring(out, tfunction, tfunction->get_arglist(), "Parameters");
}

/**
 * Generates the docstring for a struct or function.
 */
void t_py_generator::generate_python_docstring(ofstream& out,
                                               t_doc*    tdoc,
                                               t_struct* tstruct,
                                               const char* subheader) {
  bool has_doc = false;
  stringstream ss;
  if (tdoc->has_doc()) {
    has_doc = true;
    ss << tdoc->get_doc();
  }

  const vector<t_field*>& fields = tstruct->get_members();
  if (fields.size() > 0) {
    if (has_doc) {
      ss << endl;
    }
    has_doc = true;
    ss << subheader << ":\n";
    vector<t_field*>::const_iterator p_iter;
    for (p_iter = fields.begin(); p_iter != fields.end(); ++p_iter) {
      t_field* p = *p_iter;
      ss << " - " << p->get_name();
      if (p->has_doc()) {
        ss << ": " << p->get_doc();
      } else {
        ss << endl;
      }
    }
  }

  if (has_doc) {
    generate_docstring_comment(out,
      "\"\"\"\n",
      "", ss.str(),
      "\"\"\"\n");
  }
}

/**
 * Generates the docstring for a generic object.
 */
void t_py_generator::generate_python_docstring(ofstream& out,
                                               t_doc* tdoc) {
  if (tdoc->has_doc()) {
    generate_docstring_comment(out,
      "\"\"\"\n",
      "", tdoc->get_doc(),
      "\"\"\"\n");
  }
}

/**
 * Declares an argument, which may include initialization as necessary.
 *
 * @param tfield The field
 */
string t_py_generator::declare_argument(t_field* tfield) {
  std::ostringstream result;
  result << tfield->get_name() << "=";
  if (tfield->get_value() != NULL) {
    result << "thrift_spec[" <<
      tfield->get_key() << "][4]";
  } else {
    result << "None";
  }
  return result.str();
}

/**
 * Renders a field default value, returns None otherwise.
 *
 * @param tfield The field
 */
string t_py_generator::render_field_default_value(t_field* tfield) {
  t_type* type = get_true_type(tfield->get_type());
  if (tfield->get_value() != NULL) {
    return render_const_value(type, tfield->get_value());
  } else {
    return "None";
  }
}

/**
 * Renders a function signature of the form 'type name(args)'
 *
 * @param tfunction Function definition
 * @return String of rendered function definition
 */
string t_py_generator::function_signature(t_function* tfunction,
                                           string prefix) {
  // TODO(mcslee): Nitpicky, no ',' if argument_list is empty
  return
    prefix + tfunction->get_name() +
    "(self, " + argument_list(tfunction->get_arglist()) + ")";
}

/**
 * Renders an interface function signature of the form 'type name(args)'
 *
 * @param tfunction Function definition
 * @return String of rendered function definition
 */
string t_py_generator::function_signature_if(t_function* tfunction,
                                           string prefix) {
  // TODO(mcslee): Nitpicky, no ',' if argument_list is empty
  string signature = prefix + tfunction->get_name() + "(";
  if (!gen_twisted_) {
    signature += "self, ";
  }
  signature += argument_list(tfunction->get_arglist()) + ")";
  return signature;
}


/**
 * Renders a field list
 */
string t_py_generator::argument_list(t_struct* tstruct) {
  string result = "";

  const vector<t_field*>& fields = tstruct->get_members();
  vector<t_field*>::const_iterator f_iter;
  bool first = true;
  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
    if (first) {
      first = false;
    } else {
      result += ", ";
    }
    result += (*f_iter)->get_name();
  }
  return result;
}

string t_py_generator::type_name(t_type* ttype) {
  t_program* program = ttype->get_program();
  if (ttype->is_service()) {
    return get_real_py_module(program) + "." + ttype->get_name();
  }
  if (program != NULL && program != program_) {
    return get_real_py_module(program) + ".ttypes." + ttype->get_name();
  }
  return ttype->get_name();
}

/**
 * Converts the parse type to a Python tyoe
 */
string t_py_generator::type_to_enum(t_type* type) {
  type = get_true_type(type);

  if (type->is_base_type()) {
    t_base_type::t_base tbase = ((t_base_type*)type)->get_base();
    switch (tbase) {
    case t_base_type::TYPE_VOID:
      throw "NO T_VOID CONSTRUCT";
    case t_base_type::TYPE_STRING:
      return "TType.STRING";
    case t_base_type::TYPE_BOOL:
      return "TType.BOOL";
    case t_base_type::TYPE_BYTE:
      return "TType.BYTE";
    case t_base_type::TYPE_I16:
      return "TType.I16";
    case t_base_type::TYPE_I32:
      return "TType.I32";
    case t_base_type::TYPE_I64:
      return "TType.I64";
    case t_base_type::TYPE_DOUBLE:
      return "TType.DOUBLE";
    }
  } else if (type->is_enum()) {
    return "TType.I32";
  } else if (type->is_struct() || type->is_xception()) {
    return "TType.STRUCT";
  } else if (type->is_map()) {
    return "TType.MAP";
  } else if (type->is_set()) {
    return "TType.SET";
  } else if (type->is_list()) {
    return "TType.LIST";
  }

  throw "INVALID TYPE IN type_to_enum: " + type->get_name();
}

/** See the comment inside generate_py_struct_definition for what this is. */
string t_py_generator::type_to_spec_args(t_type* ttype) {
  while (ttype->is_typedef()) {
    ttype = ((t_typedef*)ttype)->get_type();
  }

  if (ttype->is_base_type() || ttype->is_enum()) {
    return "None";
  } else if (ttype->is_struct() || ttype->is_xception()) {
    return "(" + type_name(ttype) + ", " + type_name(ttype) + ".thrift_spec)";
  } else if (ttype->is_map()) {
    return "(" +
      type_to_enum(((t_map*)ttype)->get_key_type()) + "," +
      type_to_spec_args(((t_map*)ttype)->get_key_type()) + "," +
      type_to_enum(((t_map*)ttype)->get_val_type()) + "," +
      type_to_spec_args(((t_map*)ttype)->get_val_type()) +
      ")";

  } else if (ttype->is_set()) {
    return "(" +
      type_to_enum(((t_set*)ttype)->get_elem_type()) + "," +
      type_to_spec_args(((t_set*)ttype)->get_elem_type()) +
      ")";

  } else if (ttype->is_list()) {
    return "(" +
      type_to_enum(((t_list*)ttype)->get_elem_type()) + "," +
      type_to_spec_args(((t_list*)ttype)->get_elem_type()) +
      ")";
  }

  throw "INVALID TYPE IN type_to_spec_args: " + ttype->get_name();
}


THRIFT_REGISTER_GENERATOR(py, "Python",
"    new_style:       Generate new-style classes.\n" \
"    twisted:         Generate Twisted-friendly RPC services.\n"
);