// Copyright 2024 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 (
	"github.com/dolthub/go-mysql-server/sql"

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

// initText registers the functions to the catalog.
func initText() {
	framework.RegisterFunction(textin)
	framework.RegisterFunction(textout)
	framework.RegisterFunction(textrecv)
	framework.RegisterFunction(textsend)
	framework.RegisterFunction(bttextcmp)
	framework.RegisterFunction(bttextnamecmp)
}

// textin represents the PostgreSQL function of text type IO input.
var textin = framework.Function1{
	Name:       "textin",
	Return:     pgtypes.Text,
	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Cstring},
	Strict:     true,
	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
		return val.(string), nil
	},
}

// textout represents the PostgreSQL function of text type IO output.
var textout = framework.Function1{
	Name:       "textout",
	Return:     pgtypes.Cstring,
	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Text},
	Strict:     true,
	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
		return val, nil
	},
}

// textrecv represents the PostgreSQL function of text type IO receive.
var textrecv = framework.Function1{
	Name:       "textrecv",
	Return:     pgtypes.Text,
	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Internal},
	Strict:     true,
	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
		data := val.([]byte)
		if data == nil {
			return nil, nil
		}
		return string(data), nil
	},
}

// textsend represents the PostgreSQL function of text type IO send.
var textsend = framework.Function1{
	Name:       "textsend",
	Return:     pgtypes.Bytea,
	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Text},
	Strict:     true,
	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
		if wrapper, ok := val.(sql.AnyWrapper); ok {
			var err error
			val, err = wrapper.UnwrapAny(ctx)
			if err != nil {
				return nil, err
			}
			if val == nil {
				return nil, nil
			}
		}
		writer := utils.NewWireWriter()
		writer.WriteString(val.(string))
		return writer.BufferData(), nil
	},
}

// bttextcmp represents the PostgreSQL function of text type compare.
var bttextcmp = framework.Function2{
	Name:       "bttextcmp",
	Return:     pgtypes.Int32,
	Parameters: [2]*pgtypes.DoltgresType{pgtypes.Text, pgtypes.Text},
	Strict:     true,
	Callable: func(ctx *sql.Context, _ [3]*pgtypes.DoltgresType, val1, val2 any) (any, error) {
		ab := val1.(string)
		bb := val2.(string)
		if ab == bb {
			return int32(0), nil
		} else if ab < bb {
			return int32(-1), nil
		} else {
			return int32(1), nil
		}
	},
}

// bttextnamecmp represents the PostgreSQL function of text type compare with name.
var bttextnamecmp = framework.Function2{
	Name:       "bttextnamecmp",
	Return:     pgtypes.Int32,
	Parameters: [2]*pgtypes.DoltgresType{pgtypes.Text, pgtypes.Text},
	Strict:     true,
	Callable: func(ctx *sql.Context, _ [3]*pgtypes.DoltgresType, val1, val2 any) (any, error) {
		ab := val1.(string)
		bb := val2.(string)
		if ab == bb {
			return int32(0), nil
		} else if ab < bb {
			return int32(-1), nil
		} else {
			return int32(1), nil
		}
	},
}