// Copyright 2025 Dolthub, Inc.
//
// Licensed 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.

package functions

import (
	"time"

	"github.com/dolthub/go-mysql-server/sql"

	"github.com/dolthub/doltgresql/server/functions/framework"
	pgtypes "github.com/dolthub/doltgresql/server/types"
)

// initToDate registers the functions to the catalog.
func initToDate() {
	framework.RegisterFunction(to_date_text_text)
}

// to_date_text_text represents the PostgreSQL function of the same name, taking text input and format pattern.
var to_date_text_text = framework.Function2{
	Name:       "to_date",
	Return:     pgtypes.Date,
	Parameters: [2]*pgtypes.DoltgresType{pgtypes.Text, pgtypes.Text},
	Strict:     true,
	Callable: func(ctx *sql.Context, _ [3]*pgtypes.DoltgresType, val1, val2 any) (any, error) {
		input := val1.(string)
		format := val2.(string)

		// Parse the date using PostgreSQL format patterns
		t, err := getDateTimeFromFormat(ctx, input, format)
		// We return a version of the time but with the timezone completely stripped since they do not use timezones
		return time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, time.UTC), err
	},
}