package extract

import (
	"bufio"
	"fmt"
	"os"
	"path/filepath"
	"sort"

	log "github.com/sirupsen/logrus"

	"github.com/duke-git/lancet/v2/slice"
)

const TransImageFrameLength = 8192
const TransImageFrameHeadLength = 16
const TransImageFrameDataLength = 8176
const ImageFrameHead = 0xE77EE77E

// 智能载荷电箱与数传单机之间图像数据传输帧格式
type TransFrame struct {
	Header     [4]byte // 帧头 E77EE77E
	SNo        uint32  // 序列号 大端序
	Reserved0  [2]byte // 保留字节
	KeyIndex   uint16  // 密钥库索引号 大端序
	SecretFlag byte    // 明密标志 0x55 明传 0xAA 密传
	FrameFlag  byte    // 帧类型 0x00:智能载荷电箱有效帧 0x55: 智能载荷电箱空帧
	FileNo     uint8   // 文件编号
	Reserved1  byte    // 保留字节 0x00
	Data       []byte  // 数据区 8176字节
}

func (t *TransFrame) Decode(frame []byte) {
	if len(frame) < TransImageFrameLength {
		return
	}
	copy(t.Header[:], frame[:4])
	t.SNo = uint32(frame[4])<<24 | uint32(frame[5])<<16 | uint32(frame[6])<<8 | uint32(frame[7])
	copy(t.Reserved0[:], frame[8:10])
	t.KeyIndex = uint16(frame[10])<<8 | uint16(frame[11])
	t.SecretFlag = frame[12]
	t.FrameFlag = frame[13]
	t.FileNo = frame[14]
	t.Reserved1 = frame[15]
	t.Data = append(t.Data, frame[16:8192]...)
}

// 提取图像传输帧中的原始图像数据
func (p *Extractor) ExtractOriginalImageData(aosDataFile string) ([]string, error) {
	var sData []string
	nullFrmCnt := 0

	aosData, err := os.ReadFile(aosDataFile)
	if err != nil {
		log.Println("read data from", aosDataFile, "error:", err.Error())
		return nil, err
	}

	snRange := map[int][]uint32{}
	datSet := map[int][]byte{}

	var i int
	for i < len(aosData) {
		if i+4 > len(aosData) {
			log.Println("end of trans frame data")
			break
		}

		if aosData[i] == 0xE7 && aosData[i+1] == 0x7E && aosData[i+2] == 0xE7 && aosData[i+3] == 0x7E {
			if i+TransImageFrameLength > len(aosData) {
				log.Println("there are not enough data for a trans frame", len(aosData)-i)
				break
			}

			var tf TransFrame
			tf.Decode(aosData[i : i+TransImageFrameLength])
			fileno := int(tf.FileNo)
			snRange[fileno] = append(snRange[fileno], tf.SNo)
			if tf.SecretFlag == 0xAA {
				log.Info("secret frame is not supported")
				// break
			}

			// 只保留非空帧
			if tf.FrameFlag != 0x55 && fileno != 0 {
				datSet[fileno] = append(datSet[fileno], tf.Data...)
			} else {
				nullFrmCnt++
			}

			i += TransImageFrameLength
			continue
		}
		i++
	}

	log.Println("null transfer frame cnt:", nullFrmCnt)
	if len(snRange) == 0 {
		log.Errorf("no valid transfer frame found in %s", aosDataFile)
	}

	for k, v := range snRange {
		vv := slice.Unique(v)
		sort.Slice(vv, func(i, j int) bool { return vv[i] < vv[j] })
		fmt.Println("fileno:", k, ", sn range:", vv[0], "-", vv[len(vv)-1], "len", len(vv))
	}

	for k, v := range datSet {
		frameCnt := slice.Unique(snRange[k])
		if len(frameCnt) < 4096 {
			log.Println("fileno", k, "数据长度不足4096帧")
			continue
		}

		s01 := filepath.Join(p.params.TempPath, fmt.Sprintf("%s_%s_S%d.dat",
			p.params.Satellite,
			p.params.DataId,
			k))
		fo, err := os.OpenFile(s01,
			os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0777)
		if err != nil {
			log.Println("create file", s01, "error:", err.Error())
			return nil, err
		}
		w := bufio.NewWriter(fo)
		w.Write(v)
		w.Flush()
		fo.Close()
		sData = append(sData, s01)
	}

	return sData, nil
}