package pgtype

import (
	"errors"
	"io"

	"github.com/jackc/pgx/pgio"
)

// PostgreSQL oids for common types
const (
	BoolOID             = 16
	ByteaOID            = 17
	CharOID             = 18
	NameOID             = 19
	Int8OID             = 20
	Int2OID             = 21
	Int4OID             = 23
	TextOID             = 25
	OIDOID              = 26
	TidOID              = 27
	XidOID              = 28
	CidOID              = 29
	JSONOID             = 114
	CidrOID             = 650
	CidrArrayOID        = 651
	Float4OID           = 700
	Float8OID           = 701
	UnknownOID          = 705
	InetOID             = 869
	BoolArrayOID        = 1000
	Int2ArrayOID        = 1005
	Int4ArrayOID        = 1007
	TextArrayOID        = 1009
	ByteaArrayOID       = 1001
	VarcharArrayOID     = 1015
	Int8ArrayOID        = 1016
	Float4ArrayOID      = 1021
	Float8ArrayOID      = 1022
	AclItemOID          = 1033
	AclItemArrayOID     = 1034
	InetArrayOID        = 1041
	VarcharOID          = 1043
	DateOID             = 1082
	TimestampOID        = 1114
	TimestampArrayOID   = 1115
	DateArrayOID        = 1182
	TimestamptzOID      = 1184
	TimestamptzArrayOID = 1185
	RecordOID           = 2249
	UUIDOID             = 2950
	JSONBOID            = 3802
)

type Status byte

const (
	Undefined Status = iota
	Null
	Present
)

type InfinityModifier int8

const (
	Infinity         InfinityModifier = 1
	None             InfinityModifier = 0
	NegativeInfinity InfinityModifier = -Infinity
)

type Value interface {
	ConvertFrom(src interface{}) error
	AssignTo(dst interface{}) error
}

type BinaryDecoder interface {
	DecodeBinary(r io.Reader) error
}

type TextDecoder interface {
	DecodeText(r io.Reader) error
}

type BinaryEncoder interface {
	EncodeBinary(w io.Writer) error
}

type TextEncoder interface {
	EncodeText(w io.Writer) error
}

var errUndefined = errors.New("cannot encode status undefined")

func encodeNotPresent(w io.Writer, status Status) (done bool, err error) {
	switch status {
	case Undefined:
		return true, errUndefined
	case Null:
		_, err = pgio.WriteInt32(w, -1)
		return true, err
	}
	return false, nil
}