// 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 "vec/exprs/vschema_change_expr.h"

#include <fmt/format.h>
#include <glog/logging.h>

#include <memory>
#include <vector>

#include "runtime/descriptors.h"
#include "runtime/runtime_state.h"
#include "vec/columns/column.h"
#include "vec/columns/column_object.h"
#include "vec/common/assert_cast.h"
#include "vec/common/schema_util.h"
#include "vec/core/block.h"
#include "vec/core/column_with_type_and_name.h"
#include "vec/core/columns_with_type_and_name.h"
#include "vec/json/path_in_data.h"

namespace doris {
namespace vectorized {
class VExprContext;
} // namespace vectorized
} // namespace doris

namespace doris::vectorized {

Status VSchemaChangeExpr::prepare(doris::RuntimeState* state, const doris::RowDescriptor& desc,
                                  VExprContext* context) {
    RETURN_IF_ERROR_OR_PREPARED(VExpr::prepare(state, desc, context));
    // DCHECK_EQ(_children.size(), 1);
    _table_id = _tnode.schema_change_expr.table_id;
    _expr_name = fmt::format("(SCHEMA_CHANGE {})", "VARIANT");
    _slot_id = _tnode.slot_ref.slot_id;
    const SlotDescriptor* slot_desc = state->desc_tbl().get_slot_descriptor(_slot_id);
    if (slot_desc == nullptr) {
        return Status::InternalError("couldn't resolve slot descriptor {}", _slot_id);
    }
    _column_id = desc.get_column_id(_slot_id);
    if (_column_id < 0) {
        return Status::InternalError(
                "VSlotRef have invalid slot id: {}, desc: {}, slot_desc: {}, desc_tbl: {}",
                *"VARIANT", _slot_id, desc.debug_string(), slot_desc->debug_string(),
                state->desc_tbl().debug_string());
    }
    return Status::OK();
}

const std::string& VSchemaChangeExpr::expr_name() const {
    return _expr_name;
}

Status VSchemaChangeExpr::open(doris::RuntimeState* state, VExprContext* context,
                               FunctionContext::FunctionStateScope scope) {
    RETURN_IF_ERROR(VExpr::open(state, context, scope));
    return Status::OK();
}

void VSchemaChangeExpr::close(doris::RuntimeState* state, VExprContext* context,
                              FunctionContext::FunctionStateScope scope) {
    VExpr::close(state, context, scope);
}

Status VSchemaChangeExpr::execute(VExprContext* context, doris::vectorized::Block* block,
                                  int* result_column_id) {
    // Send schema change RPC
    ColumnObject& object_column = *assert_cast<ColumnObject*>(
            block->get_by_position(_column_id).column->assume_mutable().get());
    CHECK(object_column.is_finalized());
    std::unique_ptr<vectorized::schema_util::FullBaseSchemaView> full_base_schema_view =
            vectorized::schema_util::FullBaseSchemaView::create_unique();
    full_base_schema_view->table_id = _table_id;
    vectorized::ColumnsWithTypeAndName cols_with_type_name;
    cols_with_type_name.reserve(object_column.get_subcolumns().size());
    for (auto& entry : object_column.get_subcolumns()) {
        cols_with_type_name.push_back(ColumnWithTypeAndName {entry->data.get_finalized_column_ptr(),
                                                             entry->data.get_least_common_type(),
                                                             entry->path.get_path()});
    }
    if (!cols_with_type_name.empty()) {
        // duplicated columns in full_base_schema_view will be idempotent
        RETURN_IF_ERROR(vectorized::schema_util::send_add_columns_rpc(cols_with_type_name,
                                                                      full_base_schema_view.get()));
    }

    *result_column_id = _column_id;
    return Status::OK();
}

std::string VSchemaChangeExpr::debug_string() const {
    return _expr_name;
}

} // namespace doris::vectorized