#!/usr/bin/env python
#
# 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.

# Script which checks Java API compatibility between two revisions of the
# Java client.
#
# Based on the compatibility checker from the HBase project, but ported to
# Python for better readability.

import logging
import optparse
import os
import re
import shutil
import subprocess
import sys

from kudu_util import check_output

JAVA_ACC_GIT_URL = "https://github.com/lvc/japi-compliance-checker.git"

# The annotations for what we consider our public API.
PUBLIC_ANNOTATIONS = ["InterfaceAudience.LimitedPrivate",
                      "InterfaceAudience.Public"]

# Various relative paths
PATH_TO_REPO_DIR = "../"
PATH_TO_BUILD_DIR = "../build/compat-check"


def get_repo_dir():
  """ Return the path to the top of the repo. """
  dirname, _ = os.path.split(os.path.abspath(__file__))
  return os.path.abspath(os.path.join(dirname, PATH_TO_REPO_DIR))


def get_scratch_dir():
  """ Return the path to the scratch dir that we build within. """
  dirname, _ = os.path.split(os.path.abspath(__file__))
  return os.path.abspath(os.path.join(dirname, PATH_TO_BUILD_DIR))


def get_java_acc_dir():
  """ Return the path where we check out the Java API Compliance Checker. """
  return os.path.join(get_repo_dir(), "thirdparty/java-acc")


def clean_scratch_dir(scratch_dir):
  """ Clean up and re-create the scratch directory. """
  if os.path.exists(scratch_dir):
    logging.info("Removing scratch dir %s...", scratch_dir)
    shutil.rmtree(scratch_dir)
  logging.info("Creating empty scratch dir %s...", scratch_dir)
  os.makedirs(scratch_dir)


def checkout_java_tree(rev, path):
  """ Check out the Java source tree for the given revision into the given path. """
  logging.info("Checking out %s in %s", rev, path)
  os.makedirs(path)
  # Extract java source
  subprocess.check_call(["bash", '-o', 'pipefail', "-c",
                         ("git archive --format=tar %s java/ | " +
                          "tar -C \"%s\" -xf -") % (rev, path)],
                        cwd=get_repo_dir())
  # Extract proto files which the Java build also relies on.
  subprocess.check_call(["bash", '-o', 'pipefail', "-c",
                         ("git archive --format=tar %s src/ | " +
                          "tar -C \"%s\" --wildcards -xf - '*.proto'") % (rev, path)],
                        cwd=get_repo_dir())
  # Symlink thirdparty from the outer build so that protoc is available.
  # This may break at some point in the future if we switch protobuf versions,
  # but for now it's faster than rebuilding protobuf in both trees.
  os.symlink(os.path.join(get_repo_dir(), "thirdparty"),
             os.path.join(path, "thirdparty"))


def get_git_hash(revname):
  """ Convert 'revname' to its SHA-1 hash. """
  return check_output(["git", "rev-parse", revname],
                      cwd=get_repo_dir()).strip()


def build_tree(path):
  """ Run the Java build within 'path'. """
  java_path = os.path.join(path, "java")
  logging.info("Building in %s...", java_path)
  subprocess.check_call(["mvn", "-DskipTests", "-Dmaven.javadoc.skip=true",
                         "package"],
                        cwd=java_path)


def checkout_java_acc(force):
  """
  Check out the Java API Compliance Checker. If 'force' is true, will re-download even if the
  directory exists.
  """
  acc_dir = get_java_acc_dir()
  if os.path.exists(acc_dir):
    logging.info("Java JAVA_ACC is already downloaded.")
    if not force:
      return
    logging.info("Forcing re-download.")
    shutil.rmtree(acc_dir)
  logging.info("Checking out Java JAVA_ACC...")
  subprocess.check_call(["git", "clone", "--depth=1", JAVA_ACC_GIT_URL, acc_dir])


def find_client_jars(path):
  """ Return a list of jars within 'path' to be checked for compatibility. """
  all_jars = set(check_output(["find", path, "-name", "*.jar"]).splitlines())

  # If we see "original-foo.jar", then remove "foo.jar" since that's a post-shading
  # duplicate.
  dups = []
  for j in all_jars:
    dirname, name = os.path.split(j)
    m = re.match("original-(.+)", name)
    if m:
      dups.append(os.path.join(dirname, m.group(1)))
  for d in dups:
    all_jars.remove(d)

  return [j for j in all_jars if (
      "-tests" not in j and
      "-sources" not in j and
      "-with-dependencies" not in j)]


def run_java_acc(src_name, src, dst_name, dst):
  """ Run the compliance checker to compare 'src' and 'dst'. """
  src_jars = find_client_jars(src)
  dst_jars = find_client_jars(dst)
  logging.info("Will check compatibility between original jars:\n%s\n" +
               "and new jars:\n%s",
               "\n".join(src_jars),
               "\n".join(dst_jars))

  annotations_path = os.path.join(get_scratch_dir(), "annotations.txt")
  with file(annotations_path, "w") as f:
    for ann in PUBLIC_ANNOTATIONS:
      print >>f,  ann

  java_acc_path = os.path.join(get_java_acc_dir(), "japi-compliance-checker.pl")

  out_path = os.path.join(get_scratch_dir(), "report.html")
  subprocess.check_call(["perl", java_acc_path,
                         "-l", "Kudu",
                         "-v1", src_name,
                         "-v2", dst_name,
                         "-d1", ",".join(src_jars),
                         "-d2", ",".join(dst_jars),
                         "-report-path", out_path,
                         "-annotations-list", annotations_path])


def main(argv):
  logging.basicConfig(level=logging.INFO)
  parser = optparse.OptionParser(
      usage="usage: %prog SRC..[DST]")
  parser.add_option("-f", "--force-download", dest="force_download_deps",
                    help=("Download dependencies (i.e. Java JAVA_ACC) even if they are " +
                          "already present"))
  opts, args = parser.parse_args()

  if len(args) != 1:
    parser.error("no src/dst revision specified")
    sys.exit(1)

  src_rev, dst_rev = args[0].split("..", 1)
  if dst_rev == "":
    dst_rev = "HEAD"
  src_rev = get_git_hash(src_rev)
  dst_rev = get_git_hash(dst_rev)

  logging.info("Source revision: %s", src_rev)
  logging.info("Destination revision: %s", dst_rev)

  # Download deps.
  checkout_java_acc(opts.force_download_deps)

  # Set up the build.
  scratch_dir = get_scratch_dir()
  clean_scratch_dir(scratch_dir)

  # Check out the src and dst source trees.
  src_dir = os.path.join(scratch_dir, "src")
  dst_dir = os.path.join(scratch_dir, "dst")
  checkout_java_tree(src_rev, src_dir)
  checkout_java_tree(dst_rev, dst_dir)

  # Run the build in each.
  build_tree(src_dir)
  build_tree(dst_dir)

  run_java_acc(src_rev, src_dir,
              dst_rev, dst_dir)


if __name__ == "__main__":
  main(sys.argv)