// 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.

#pragma once

#include <cctz/time_zone.h>
#include <stddef.h>
#include <stdint.h>

#include <map>
#include <memory>
#include <string>
#include <type_traits>
#include <utility>

#include "common/status.h"
#include "udf/udf.h"
#include "util/binary_cast.hpp"
#include "util/timezone_utils.h"
#include "vec/aggregate_functions/aggregate_function.h"
#include "vec/columns/column.h"
#include "vec/columns/column_const.h"
#include "vec/columns/column_nullable.h"
#include "vec/columns/column_string.h"
#include "vec/columns/column_vector.h"
#include "vec/columns/columns_number.h"
#include "vec/common/assert_cast.h"
#include "vec/common/string_ref.h"
#include "vec/core/block.h"
#include "vec/core/column_numbers.h"
#include "vec/core/column_with_type_and_name.h"
#include "vec/core/types.h"
#include "vec/data_types/data_type.h"
#include "vec/data_types/data_type_date_time.h"
#include "vec/data_types/data_type_nullable.h"
#include "vec/data_types/data_type_string.h"
#include "vec/data_types/data_type_time_v2.h"
#include "vec/functions/function.h"

namespace doris {
namespace vectorized {
class DataTypeDate;
class VecDateTimeValue;
struct DateTimeV2ValueType;
struct DateV2ValueType;
template <typename T>
class DateV2Value;
} // namespace vectorized
} // namespace doris

namespace doris::vectorized {

struct ConvertTzCtx {
    std::map<std::string, cctz::time_zone> time_zone_cache;
};

template <typename DateValueType, typename ArgType>
struct ConvertTZImpl {
    using ColumnType = std::conditional_t<
            std::is_same_v<DateV2Value<DateV2ValueType>, DateValueType>, ColumnDateV2,
            std::conditional_t<std::is_same_v<DateV2Value<DateTimeV2ValueType>, DateValueType>,
                               ColumnDateTimeV2, ColumnDateTime>>;
    using NativeType = std::conditional_t<
            std::is_same_v<DateV2Value<DateV2ValueType>, DateValueType>, UInt32,
            std::conditional_t<std::is_same_v<DateV2Value<DateTimeV2ValueType>, DateValueType>,
                               UInt64, Int64>>;
    using ReturnDateType = std::conditional_t<std::is_same_v<VecDateTimeValue, DateValueType>,
                                              VecDateTimeValue, DateV2Value<DateTimeV2ValueType>>;
    using ReturnNativeType =
            std::conditional_t<std::is_same_v<VecDateTimeValue, DateValueType>, Int64, UInt64>;
    using ReturnColumnType = std::conditional_t<std::is_same_v<VecDateTimeValue, DateValueType>,
                                                ColumnDateTime, ColumnDateTimeV2>;

    static void execute(FunctionContext* context, const ColumnType* date_column,
                        const ColumnString* from_tz_column, const ColumnString* to_tz_column,
                        ReturnColumnType* result_column, NullMap& result_null_map,
                        size_t input_rows_count) {
        auto convert_ctx = reinterpret_cast<ConvertTzCtx*>(
                context->get_function_state(FunctionContext::FunctionStateScope::THREAD_LOCAL));
        std::map<std::string, cctz::time_zone> time_zone_cache_;
        auto& time_zone_cache = convert_ctx ? convert_ctx->time_zone_cache : time_zone_cache_;
        for (size_t i = 0; i < input_rows_count; i++) {
            if (result_null_map[i]) {
                result_column->insert_default();
                continue;
            }
            auto from_tz = from_tz_column->get_data_at(i).to_string();
            auto to_tz = to_tz_column->get_data_at(i).to_string();
            execute_inner_loop(date_column, time_zone_cache, from_tz, to_tz, result_column,
                               result_null_map, i);
        }
    }

    static void execute_tz_const(FunctionContext* context, const ColumnType* date_column,
                                 const ColumnString* from_tz_column,
                                 const ColumnString* to_tz_column, ReturnColumnType* result_column,
                                 NullMap& result_null_map, size_t input_rows_count) {
        auto convert_ctx = reinterpret_cast<ConvertTzCtx*>(
                context->get_function_state(FunctionContext::FunctionStateScope::THREAD_LOCAL));
        std::map<std::string, cctz::time_zone> time_zone_cache_;
        auto& time_zone_cache = convert_ctx ? convert_ctx->time_zone_cache : time_zone_cache_;

        auto from_tz = from_tz_column->get_data_at(0).to_string();
        auto to_tz = to_tz_column->get_data_at(0).to_string();
        for (size_t i = 0; i < input_rows_count; i++) {
            if (result_null_map[i]) {
                result_column->insert_default();
                continue;
            }
            execute_inner_loop(date_column, time_zone_cache, from_tz, to_tz, result_column,
                               result_null_map, i);
        }
    }

    static void execute_inner_loop(const ColumnType* date_column,
                                   std::map<std::string, cctz::time_zone>& time_zone_cache,
                                   const std::string& from_tz, const std::string& to_tz,
                                   ReturnColumnType* result_column, NullMap& result_null_map,
                                   const size_t index_now) {
        DateValueType ts_value =
                binary_cast<NativeType, DateValueType>(date_column->get_element(index_now));
        int64_t timestamp;

        if (time_zone_cache.find(from_tz) == time_zone_cache.cend()) {
            if (!TimezoneUtils::find_cctz_time_zone(from_tz, time_zone_cache[from_tz])) {
                result_null_map[index_now] = true;
                result_column->insert_default();
                return;
            }
        }

        if (time_zone_cache.find(to_tz) == time_zone_cache.cend()) {
            if (!TimezoneUtils::find_cctz_time_zone(to_tz, time_zone_cache[to_tz])) {
                result_null_map[index_now] = true;
                result_column->insert_default();
                return;
            }
        }

        if (!ts_value.unix_timestamp(&timestamp, time_zone_cache[from_tz])) {
            result_null_map[index_now] = true;
            result_column->insert_default();
            return;
        }

        ReturnDateType ts_value2;
        if (!ts_value2.from_unixtime(timestamp, time_zone_cache[to_tz])) {
            result_null_map[index_now] = true;
            result_column->insert_default();
            return;
        }

        result_column->insert(binary_cast<ReturnDateType, ReturnNativeType>(ts_value2));
    }

    static DataTypes get_variadic_argument_types() {
        return {std::make_shared<ArgType>(), std::make_shared<DataTypeString>(),
                std::make_shared<DataTypeString>()};
    }
};

template <typename Transform, typename DateType>
class FunctionConvertTZ : public IFunction {
public:
    static constexpr auto name = "convert_tz";

    static FunctionPtr create() { return std::make_shared<FunctionConvertTZ>(); }

    String get_name() const override { return name; }

    size_t get_number_of_arguments() const override { return 3; }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {
        if constexpr (std::is_same_v<DateType, DataTypeDateTime> ||
                      std::is_same_v<DateType, DataTypeDate>) {
            return make_nullable(std::make_shared<DataTypeDateTime>());
        } else {
            return make_nullable(std::make_shared<DataTypeDateTimeV2>());
        }
    }

    bool is_variadic() const override { return true; }

    DataTypes get_variadic_argument_types_impl() const override {
        return Transform::get_variadic_argument_types();
    }

    bool use_default_implementation_for_nulls() const override { return false; }

    Status open(FunctionContext* context, FunctionContext::FunctionStateScope scope) override {
        if (scope != FunctionContext::THREAD_LOCAL) {
            return Status::OK();
        }
        context->set_function_state(scope, std::make_shared<ConvertTzCtx>());
        return Status::OK();
    }

    Status close(FunctionContext* context, FunctionContext::FunctionStateScope scope) override {
        return Status::OK();
    }

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
                        size_t result, size_t input_rows_count) override {
        auto result_null_map_column = ColumnUInt8::create(input_rows_count, 0);

        bool col_const[3];
        ColumnPtr argument_columns[3];
        for (int i = 0; i < 3; ++i) {
            col_const[i] = is_column_const(*block.get_by_position(arguments[i]).column);
        }
        argument_columns[0] = col_const[0] ? static_cast<const ColumnConst&>(
                                                     *block.get_by_position(arguments[0]).column)
                                                     .convert_to_full_column()
                                           : block.get_by_position(arguments[0]).column;

        default_preprocess_parameter_columns(argument_columns, col_const, {1, 2}, block, arguments);

        for (int i = 0; i < 3; i++) {
            check_set_nullable(argument_columns[i], result_null_map_column, col_const[i]);
        }

        if (col_const[1] && col_const[2]) {
            if constexpr (std::is_same_v<DateType, DataTypeDateTime> ||
                          std::is_same_v<DateType, DataTypeDate>) {
                auto result_column = ColumnDateTime::create();
                Transform::execute_tz_const(
                        context, assert_cast<const ColumnDateTime*>(argument_columns[0].get()),
                        assert_cast<const ColumnString*>(argument_columns[1].get()),
                        assert_cast<const ColumnString*>(argument_columns[2].get()),
                        assert_cast<ColumnDateTime*>(result_column.get()),
                        assert_cast<ColumnUInt8*>(result_null_map_column.get())->get_data(),
                        input_rows_count);
                block.get_by_position(result).column = ColumnNullable::create(
                        std::move(result_column), std::move(result_null_map_column));
            } else if constexpr (std::is_same_v<DateType, DataTypeDateV2>) {
                auto result_column = ColumnDateTimeV2::create();
                Transform::execute_tz_const(
                        context, assert_cast<const ColumnDateV2*>(argument_columns[0].get()),
                        assert_cast<const ColumnString*>(argument_columns[1].get()),
                        assert_cast<const ColumnString*>(argument_columns[2].get()),
                        assert_cast<ColumnDateTimeV2*>(result_column.get()),
                        assert_cast<ColumnUInt8*>(result_null_map_column.get())->get_data(),
                        input_rows_count);
                block.get_by_position(result).column = ColumnNullable::create(
                        std::move(result_column), std::move(result_null_map_column));
            } else {
                auto result_column = ColumnDateTimeV2::create();
                Transform::execute_tz_const(
                        context, assert_cast<const ColumnDateTimeV2*>(argument_columns[0].get()),
                        assert_cast<const ColumnString*>(argument_columns[1].get()),
                        assert_cast<const ColumnString*>(argument_columns[2].get()),
                        assert_cast<ColumnDateTimeV2*>(result_column.get()),
                        assert_cast<ColumnUInt8*>(result_null_map_column.get())->get_data(),
                        input_rows_count);
                block.get_by_position(result).column = ColumnNullable::create(
                        std::move(result_column), std::move(result_null_map_column));
            }
        } else {
            if constexpr (std::is_same_v<DateType, DataTypeDateTime> ||
                          std::is_same_v<DateType, DataTypeDate>) {
                auto result_column = ColumnDateTime::create();
                Transform::execute(
                        context, assert_cast<const ColumnDateTime*>(argument_columns[0].get()),
                        assert_cast<const ColumnString*>(argument_columns[1].get()),
                        assert_cast<const ColumnString*>(argument_columns[2].get()),
                        assert_cast<ColumnDateTime*>(result_column.get()),
                        assert_cast<ColumnUInt8*>(result_null_map_column.get())->get_data(),
                        input_rows_count);
                block.get_by_position(result).column = ColumnNullable::create(
                        std::move(result_column), std::move(result_null_map_column));
            } else if constexpr (std::is_same_v<DateType, DataTypeDateV2>) {
                auto result_column = ColumnDateTimeV2::create();
                Transform::execute(
                        context, assert_cast<const ColumnDateV2*>(argument_columns[0].get()),
                        assert_cast<const ColumnString*>(argument_columns[1].get()),
                        assert_cast<const ColumnString*>(argument_columns[2].get()),
                        assert_cast<ColumnDateTimeV2*>(result_column.get()),
                        assert_cast<ColumnUInt8*>(result_null_map_column.get())->get_data(),
                        input_rows_count);
                block.get_by_position(result).column = ColumnNullable::create(
                        std::move(result_column), std::move(result_null_map_column));
            } else {
                auto result_column = ColumnDateTimeV2::create();
                Transform::execute(
                        context, assert_cast<const ColumnDateTimeV2*>(argument_columns[0].get()),
                        assert_cast<const ColumnString*>(argument_columns[1].get()),
                        assert_cast<const ColumnString*>(argument_columns[2].get()),
                        assert_cast<ColumnDateTimeV2*>(result_column.get()),
                        assert_cast<ColumnUInt8*>(result_null_map_column.get())->get_data(),
                        input_rows_count);
                block.get_by_position(result).column = ColumnNullable::create(
                        std::move(result_column), std::move(result_null_map_column));
            } //if datatype
        }     //if const
        return Status::OK();
    }
};

} // namespace doris::vectorized