// 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 "exprs/vslot_ref.h"

#include <gen_cpp/Exprs_types.h>
#include <glog/logging.h>

#include <ostream>

#include "common/status.h"
#include "core/block/block.h"
#include "exprs/vexpr_context.h"
#include "runtime/descriptors.h"
#include "runtime/runtime_state.h"

namespace doris {
class VExprContext;

VSlotRef::VSlotRef(const doris::TExprNode& node)
        : VExpr(node),
          _slot_id(node.slot_ref.slot_id),
          _column_id(-1),
          _column_name(nullptr),
          _column_label(node.label) {}

VSlotRef::VSlotRef(const SlotDescriptor* desc)
        : VExpr(desc->type(), true), _slot_id(desc->id()), _column_id(-1), _column_name(nullptr) {}

Status VSlotRef::prepare(doris::RuntimeState* state, const doris::RowDescriptor& desc,
                         VExprContext* context) {
    RETURN_IF_ERROR_OR_PREPARED(VExpr::prepare(state, desc, context));
    DCHECK_EQ(_children.size(), 0);
    if (_slot_id == -1) {
        _prepare_finished = true;
        return Status::OK();
    }
    const SlotDescriptor* slot_desc = state->desc_tbl().get_slot_descriptor(_slot_id);
    if (slot_desc == nullptr) {
        return Status::Error<ErrorCode::INTERNAL_ERROR>(
                "couldn't resolve slot descriptor {}, desc: {}", _slot_id,
                state->desc_tbl().debug_string());
    }
    _column_name = &slot_desc->col_name();
    _column_uniq_id = slot_desc->col_unique_id();
    _column_id = desc.get_column_id(_slot_id);
    if (_column_id < 0) {
        return Status::Error<ErrorCode::INTERNAL_ERROR>(
                "VSlotRef {} have invalid slot id: {}, desc: {}, slot_desc: {}, desc_tbl: {}",
                *_column_name, _slot_id, desc.debug_string(), slot_desc->debug_string(),
                state->desc_tbl().debug_string());
    }
    _prepare_finished = true;
    return Status::OK();
}

Status VSlotRef::open(RuntimeState* state, VExprContext* context,
                      FunctionContext::FunctionStateScope scope) {
    DCHECK(_prepare_finished);
    RETURN_IF_ERROR(VExpr::open(state, context, scope));
    _open_finished = true;
    return Status::OK();
}

Status VSlotRef::execute(VExprContext* context, Block* block, int* result_column_id) const {
    if (_column_id >= 0 && _column_id >= block->columns()) {
        return Status::Error<ErrorCode::INTERNAL_ERROR>(
                "input block not contain slot column {}, column_id={}, block={}", *_column_name,
                _column_id, block->dump_structure());
    }
    *result_column_id = _column_id;
    return Status::OK();
}

Status VSlotRef::execute_column_impl(VExprContext* context, const Block* block,
                                     const Selector* selector, size_t count,
                                     ColumnPtr& result_column) const {
    if (_column_id >= 0 && _column_id >= block->columns()) {
        return Status::Error<ErrorCode::INTERNAL_ERROR>(
                "input block not contain slot column {}, column_id={}, block={}", *_column_name,
                _column_id, block->dump_structure());
    }
    result_column =
            filter_column_with_selector(block->get_by_position(_column_id).column, selector, count);
    DCHECK_EQ(result_column->size(), count);
    return Status::OK();
}

DataTypePtr VSlotRef::execute_type(const Block* block) const {
    if (_column_id >= 0 && _column_id >= block->columns()) {
        throw doris::Exception(ErrorCode::INTERNAL_ERROR,
                               "input block not contain slot column {}, column_id={}, block={}",
                               *_column_name, _column_id, block->dump_structure());
    }
    return block->get_by_position(_column_id).type;
}

const std::string& VSlotRef::expr_name() const {
    return *_column_name;
}
std::string VSlotRef::expr_label() {
    return _column_label;
}

std::string VSlotRef::debug_string() const {
    std::stringstream out;
    out << "SlotRef(slot_id=" << _slot_id << VExpr::debug_string() << ")";
    return out.str();
}

bool VSlotRef::equals(const VExpr& other) {
    if (!VExpr::equals(other)) {
        return false;
    }
    const auto* other_ptr = dynamic_cast<const VSlotRef*>(&other);
    if (!other_ptr) {
        return false;
    }
    if (this->_slot_id != other_ptr->_slot_id || this->_column_id != other_ptr->_column_id ||
        this->_column_name != other_ptr->_column_name ||
        this->_column_label != other_ptr->_column_label) {
        return false;
    }
    return true;
}

uint64_t VSlotRef::get_digest(uint64_t seed) const {
    seed = HashUtil::hash64(&_column_uniq_id, sizeof(int), seed);
    return HashUtil::hash64(_column_name->c_str(), _column_name->size(), seed);
}

} // namespace doris