package misc

import (
	"strconv"
	"fmt"
	"math"
	"image"
)

func mustParseInt(value string, bits int) int64 {
	if parsed, err := strconv.ParseInt(value, 10, bits); err != nil {
		panic(err)
	} else {
		return parsed
	}
}
func mustParseUint(value string, bits int) uint64 {
	if parsed, err := strconv.ParseUint(value, 10, bits); err != nil {
		panic(err)
	} else {
		return parsed
	}
}

func ParseUint8(value string) (ret *uint8) {

	if parsed, err := strconv.ParseUint(value, 10, 8); err == nil {
		ret = new(uint8)
		*ret = uint8(parsed)
	}
	return
}
func ParseUint16(value string) (ret *uint16) {

	if parsed, err := strconv.ParseUint(value, 10, 16); err == nil {
		ret = new(uint16)
		*ret = uint16(parsed)
	}
	return
}
func ParseUint32(value string) (ret *uint32) {

	if parsed, err := strconv.ParseUint(value, 10, 32); err == nil {
		ret = new(uint32)
		*ret = uint32(parsed)
	}
	return
}
func ParseUint64(value string) (ret *uint64) {

	if parsed, err := strconv.ParseUint(value, 10, 64); err == nil {
		ret = new(uint64)
		*ret = uint64(parsed)
	}
	return
}
func ParseUint(value string) (ret *uint) {

	if parsed, err := strconv.ParseUint(value, 10, 0); err == nil {
		ret = new(uint)
		*ret = uint(parsed)
	}
	return
}

func ParseInt8(value string) (ret *int8) {

	if parsed, err := strconv.ParseInt(value, 10, 8); err == nil {
		ret = new(int8)
		*ret = int8(parsed)
	}
	return
}
func ParseInt16(value string) (ret *int16) {

	if parsed, err := strconv.ParseInt(value, 10, 16); err == nil {
		ret = new(int16)
		*ret = int16(parsed)
	}
	return
}
func ParseInt32(value string) (ret *int32) {

	if parsed, err := strconv.ParseInt(value, 10, 32); err == nil {
		ret = new(int32)
		*ret = int32(parsed)
	}
	return
}
func ParseInt64(value string) (ret *int64) {

	if parsed, err := strconv.ParseInt(value, 10, 64); err == nil {
		ret = new(int64)
		*ret = int64(parsed)
	}
	return
}
func ParseInt(value string) (ret *int) {
	if parsed, err := strconv.ParseInt(value, 10, 0); err == nil {
		ret = new(int)
		*ret = int(parsed)
	}
	return
}

func ParseUint8Must(value string) uint8   { return uint8(mustParseUint(value, 8)) }
func ParseUint16Must(value string) uint16 { return uint16(mustParseUint(value, 16)) }
func ParseUint32Must(value string) uint32 { return uint32(mustParseUint(value, 32)) }
func ParseUint64Must(value string) uint64 { return mustParseUint(value, 64) }
func ParseUintMust(value string) uint     { return uint(mustParseUint(value, 0)) }

func ParseInt8Must(value string) int8   { return int8(mustParseInt(value, 8)) }
func ParseInt16Must(value string) int16 { return int16(mustParseInt(value, 16)) }
func ParseInt32Must(value string) int32 { return int32(mustParseInt(value, 32)) }
func ParseInt64Must(value string) int64 { return mustParseInt(value, 64) }
func ParseIntMust(value string) int     { return int(mustParseInt(value, 0)) }

func FormatUint8(value uint8) string   { return strconv.FormatUint(uint64(value), 10) }
func FormatUint16(value uint16) string { return strconv.FormatUint(uint64(value), 10) }
func FormatUint32(value uint32) string { return strconv.FormatUint(uint64(value), 10) }
func FormatUint64(value uint64) string { return strconv.FormatUint(value, 10) }
func FormatUint(value uint) string     { return strconv.FormatUint(uint64(value), 10) }

func FormatInt8(value int8) string   { return strconv.FormatInt(int64(value), 10) }
func FormatInt16(value int16) string { return strconv.FormatInt(int64(value), 10) }
func FormatInt32(value int32) string { return strconv.FormatInt(int64(value), 10) }
func FormatInt64(value int64) string { return strconv.FormatInt(value, 10) }
func FormatInt(value int) string     { return strconv.FormatInt(int64(value), 10) }

var (
	sizesIEC = []string{
		"B",
		"KiB",
		"MiB",
		"GiB",
		"TiB",
		"PiB",
		"EiB",
		"ZiB",
		"YiB",
	}
	sizes = []string{
		"B",
		"KB",
		"MB",
		"GB",
		"TB",
		"PB",
		"EB",
		"ZB",
		"YB",
	}
)

func logn(n, b float64) float64 {
	return math.Log(n) / math.Log(b)
}

func humanateBytes(s uint64, base float64, sizes []string) string {
	if s < 10 {
		return fmt.Sprintf("%dB", s)
	}
	e := math.Floor(logn(float64(s), base))
	suffix := sizes[int(e)]
	val := float64(s) / math.Pow(base, math.Floor(e))
	f := "%.0f"
	if val < 10 {
		f = "%.1f"
	}

	return fmt.Sprintf(f+"%s", val, suffix)
}

// FileSize calculates the file size and generate user-friendly string.
func FileSizeIEC(s uint64) string {
	return humanateBytes(s, 1024, sizesIEC)
}

// FileSize calculates the file size and generate user-friendly string.
func FileSize(s uint64) string {
	return humanateBytes(s, 1000, sizes)
}
func AspectRatio(srcRect image.Point, toResize uint64) image.Point {
	w, h := int(toResize), getRatioSize(int(toResize), srcRect.Y, srcRect.X)
	if srcRect.X < srcRect.Y {
		w, h = getRatioSize(int(toResize), srcRect.X, srcRect.Y), int(toResize)
	}
	return image.Point{w, h}
}

func getRatioSize(a, b, c int) int {
	d := a * b / c
	return (d + 1) & -1
}