package starcrypto

import (
	"crypto/rand"
	"encoding/binary"
	"encoding/hex"
	"io"
	"os"
)

func String(bstr []byte) string {
	return hex.EncodeToString(bstr)
}

func VicqueEncodeV1(srcdata []byte, key string) []byte {
	var keys []int
	var randCode1, randCode2 uint8
	data := make([]byte, len(srcdata))
	copy(data, srcdata)
	binary.Read(rand.Reader, binary.LittleEndian, &randCode1)
	binary.Read(rand.Reader, binary.LittleEndian, &randCode2)
	keys = append(keys, len(key)+int(randCode1))
	lens := len(data)
	for _, v := range key {
		keys = append(keys, int(byte(v))+int(randCode1)-int(randCode2))
	}
	lenkey := len(keys)
	for k, v := range data {
		if k == lens/2 {
			break
		}
		nv := int(v)
		t := 0
		if k%2 == 0 {
			nv += keys[k%lenkey]
			if nv > 255 {
				nv -= 256
			}
			t = int(data[lens-1-k])
			t += keys[k%lenkey]
			if t > 255 {
				t -= 256
			}
		} else {
			nv -= keys[k%lenkey]
			if nv < 0 {
				nv += 256
			}
			t = int(data[lens-1-k])
			t -= keys[k%lenkey]
			if t > 255 {
				t += 256
			}
		}
		data[k] = byte(t)
		data[lens-1-k] = byte(nv)
	}
	data = append(data, byte(randCode1), byte(randCode2))
	return data
}

func VicqueDecodeV1(srcdata []byte, key string) []byte {
	var keys []int
	var randCode1, randCode2 int
	data := make([]byte, len(srcdata))
	copy(data, srcdata)
	lens := len(data)
	randCode1 = int(data[lens-2])
	randCode2 = int(data[lens-1])
	keys = append(keys, len(key)+int(randCode1))
	for _, v := range key {
		keys = append(keys, int(byte(v))+int(randCode1)-int(randCode2))
	}
	lenkey := len(keys)
	lens -= 2
	for k, v := range data {
		if k == lens/2 {
			break
		}
		nv := int(v)
		t := 0
		if k%2 == 0 {
			nv -= keys[k%lenkey]
			if nv < 0 {
				nv += 256
			}
			t = int(data[lens-1-k])
			t -= keys[k%lenkey]
			if t > 255 {
				t += 256
			}
		} else {
			nv += keys[k%lenkey]
			if nv > 255 {
				nv -= 256
			}
			t = int(data[lens-1-k])
			t += keys[k%lenkey]
			if t > 255 {
				t -= 256
			}
		}
		data[k] = byte(t)
		data[lens-1-k] = byte(nv)
	}
	return data[:lens]
}

func VicqueEncodeV1File(src, dst, pwd string, shell func(float64)) error {
	fpsrc, err := os.Open(src)
	if err != nil {
		return err
	}
	defer fpsrc.Close()
	stat, _ := os.Stat(src)
	filebig := float64(stat.Size())
	var sum int64
	defer fpsrc.Close()
	fpdst, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer fpdst.Close()
	for {
		buf := make([]byte, 1048576)
		n, err := fpsrc.Read(buf)
		if err != nil {
			if err == io.EOF {
				break
			}
			return err
		}
		sum += int64(n)
		go shell(float64(sum) / filebig * 100)
		data := VicqueEncodeV1(buf[0:n], pwd)
		fpdst.Write(data)
	}
	return nil
}

func VicqueDecodeV1File(src, dst, pwd string, shell func(float64)) error {
	fpsrc, err := os.Open(src)
	if err != nil {
		return err
	}
	defer fpsrc.Close()
	stat, _ := os.Stat(src)
	filebig := float64(stat.Size())
	var sum int64
	defer fpsrc.Close()
	fpdst, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer fpdst.Close()
	for {
		buf := make([]byte, 1048578)
		n, err := fpsrc.Read(buf)
		if err != nil {
			if err == io.EOF {
				break
			}
			return err
		}
		sum += int64(n)
		go shell(float64(sum) / filebig * 100)
		data := VicqueDecodeV1(buf[0:n], pwd)
		fpdst.Write(data)
	}
	return nil
}