package proto

import (
	"encoding"
	"fmt"
	"strconv"

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

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