package proto

import (
	"encoding"
	"fmt"
	"strconv"

	"gopkg.in/redis.v5/internal"
)

const (
	ErrorReply  = '-'
	StatusReply = '+'
	IntReply    = ':'
	StringReply = '$'
	ArrayReply  = '*'
)

const defaultBufSize = 4096

const errScanNil = internal.RedisError("redis: Scan(nil)")

func Scan(b []byte, val interface{}) error {
	switch v := val.(type) {
	case nil:
		return errScanNil
	case *string:
		*v = string(b)
		return nil
	case *[]byte:
		*v = b
		return nil
	case *int:
		var err error
		*v, err = strconv.Atoi(string(b))
		return err
	case *int8:
		n, err := strconv.ParseInt(string(b), 10, 8)
		if err != nil {
			return err
		}
		*v = int8(n)
		return nil
	case *int16:
		n, err := strconv.ParseInt(string(b), 10, 16)
		if err != nil {
			return err
		}
		*v = int16(n)
		return nil
	case *int32:
		n, err := strconv.ParseInt(string(b), 10, 32)
		if err != nil {
			return err
		}
		*v = int32(n)
		return nil
	case *int64:
		n, err := strconv.ParseInt(string(b), 10, 64)
		if err != nil {
			return err
		}
		*v = n
		return nil
	case *uint:
		n, err := strconv.ParseUint(string(b), 10, 64)
		if err != nil {
			return err
		}
		*v = uint(n)
		return nil
	case *uint8:
		n, err := strconv.ParseUint(string(b), 10, 8)
		if err != nil {
			return err
		}
		*v = uint8(n)
		return nil
	case *uint16:
		n, err := strconv.ParseUint(string(b), 10, 16)
		if err != nil {
			return err
		}
		*v = uint16(n)
		return nil
	case *uint32:
		n, err := strconv.ParseUint(string(b), 10, 32)
		if err != nil {
			return err
		}
		*v = uint32(n)
		return nil
	case *uint64:
		n, err := strconv.ParseUint(string(b), 10, 64)
		if err != nil {
			return err
		}
		*v = n
		return nil
	case *float32:
		n, err := strconv.ParseFloat(string(b), 32)
		if err != nil {
			return err
		}
		*v = float32(n)
		return err
	case *float64:
		var err error
		*v, err = strconv.ParseFloat(string(b), 64)
		return err
	case *bool:
		*v = len(b) == 1 && b[0] == '1'
		return nil
	default:
		if bu, ok := val.(encoding.BinaryUnmarshaler); ok {
			return bu.UnmarshalBinary(b)
		}
		err := fmt.Errorf(
			"redis: can't unmarshal %T (consider implementing BinaryUnmarshaler)", val)
		return err
	}
}