// pgm
//
// A simple PG query builder
//
// Author: Ankit Patial

package pgm

import (
	"errors"
	"strings"
	"sync"
	"time"

	"github.com/jackc/pgx/v5/pgtype"
)

var poolStringBuilder = sync.Pool{
	New: func() any {
		return new(strings.Builder)
	},
}

// Errors
var (
	ErrInitTX   = errors.New("failed to init db.tx")
	ErrCommitTX = errors.New("failed to commit db.tx")
	ErrNoRows   = errors.New("no data found")
)

// get string builder from pool
func getSB() *strings.Builder {
	return poolStringBuilder.Get().(*strings.Builder)
}

// put string builder back to pool
func putSB(sb *strings.Builder) {
	sb.Reset()
	poolStringBuilder.Put(sb)
}

// PgTime as in UTC
func PgTime(t time.Time) pgtype.Timestamptz {
	return pgtype.Timestamptz{Time: t, Valid: true}
}

func PgTimeNow() pgtype.Timestamptz {
	return pgtype.Timestamptz{Time: time.Now(), Valid: true}
}

func ConcatWs(sep string, fields ...Field) Field {
	return Field("concat_ws('" + sep + "'," + joinFileds(fields) + ")")
}

func StringAgg(exp, sep string) Field {
	return Field("string_agg(" + exp + ",'" + sep + "')")
}

func StringAggCast(exp, sep string) Field {
	return Field("string_agg(cast(" + exp + " as varchar),'" + sep + "')")
}