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// 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 "format_v2/expr/cast.h"

#include <fmt/format.h>

#include <gen_cpp/Exprs_types.h>

#include <glog/logging.h>

#include <ostream>

#include "common/status.h"

#include "core/block/block.h"

#include "core/block/column_with_type_and_name.h"

#include "core/block/columns_with_type_and_name.h"

#include "exprs/function/simple_function_factory.h"

#include "exprs/vexpr_context.h"

#include "exprs/vliteral.h"

namespace doris::format {

Status Cast::prepare(RuntimeState* state, const RowDescriptor& desc, VExprContext* context) {

    RETURN_IF_ERROR_OR_PREPARED(VExpr::prepare(state, desc, context));

    if (_children.size() != 1) {

        return Status::InternalError(

                fmt::format("Cast should have exactly 1 child expr, but got {}", _children.size()));

    }

    ColumnsWithTypeAndName argument_template;

    argument_template.reserve(_children.size());

    if (_children[0]->is_literal()) {

        // For some functions, he needs some literal columns to derive the return type.

        auto literal_node = std::dynamic_pointer_cast<VLiteral>(_children[0]);

        argument_template.emplace_back(literal_node->get_column_ptr(), _children[0]->data_type(),

                                       _children[0]->expr_name());

    } else {

        argument_template.emplace_back(nullptr, _children[0]->data_type(),

                                       _children[0]->expr_name());

    }

    _expr_name = fmt::format("CAST(arguments={},return={})", _children[0]->data_type()->get_name(),

                             _data_type->get_name());

    // get the function. won't prepare function.

    _function = SimpleFunctionFactory::instance().get_function(

            "CAST", argument_template, _data_type,

            {.new_version_unix_timestamp = state->query_options().new_version_unix_timestamp,

             .new_version_bitmap_op_count =

                     state->query_options().__isset.new_version_bitmap_op_count &&

                     state->query_options().new_version_bitmap_op_count},

            state->be_exec_version());

    if (_function == nullptr) {

        return Status::InternalError("Could not find function {} ", _expr_name);

    }

    VExpr::register_function_context(state, context);

    _prepare_finished = true;

    return Status::OK();

}

Status Cast::open(RuntimeState* state, VExprContext* context,

                  FunctionContext::FunctionStateScope scope) {

    DCHECK(_prepare_finished);

    for (auto& i : _children) {

        RETURN_IF_ERROR(i->open(state, context, scope));

    }

    RETURN_IF_ERROR(VExpr::init_function_context(state, context, scope, _function));

    if (scope == FunctionContext::FRAGMENT_LOCAL) {

        RETURN_IF_ERROR(VExpr::get_const_col(context, nullptr));

    }

    _open_finished = true;

    return Status::OK();

}

void Cast::close(VExprContext* context, FunctionContext::FunctionStateScope scope) {

    VExpr::close_function_context(context, scope, _function);

    VExpr::close(context, scope);

}

Status Cast::execute_column_impl(VExprContext* context, const Block* block,

                                 const Selector* selector, size_t count,

                                 ColumnPtr& result_column) const {

    return _do_execute(context, block, selector, count, result_column);

}

std::string Cast::debug_string() const {

    return _expr_name;

}

Status Cast::_do_execute(VExprContext* context, const Block* block, const Selector* selector,

                         size_t count, ColumnPtr& result_column) const {

    DCHECK(_open_finished || block == nullptr) << debug_string();

    if (_children.size() != 1) {

        return Status::InternalError(

                fmt::format("Cast should have exactly 1 child expr, but got {}", _children.size()));

    }

    if (is_const_and_have_executed()) { // const have executed in open function

        result_column = get_result_from_const(count);

        return Status::OK();

    }

    Block temp_block;

    ColumnNumbers args(1);

    ColumnPtr tmp_arg_column;

    RETURN_IF_ERROR(_children[0]->execute_column(context, block, selector, count, tmp_arg_column));

    auto arg_type = _children[0]->execute_type(block);

    temp_block.insert({tmp_arg_column, arg_type, _children[0]->expr_name()});

    args[0] = 0;

    uint32_t num_columns_without_result = temp_block.columns();

    // prepare a column to save result

    temp_block.insert({nullptr, _data_type, _expr_name});

    RETURN_IF_ERROR(_function->execute(context->fn_context(_fn_context_index), temp_block, args,

                                       num_columns_without_result, count));

    result_column = temp_block.get_by_position(num_columns_without_result).column;

    DCHECK_EQ(result_column->size(), count);

    RETURN_IF_ERROR(result_column->column_self_check());

    return Status::OK();

}

} // namespace doris::format