// Copyright 2019, Chef.  All rights reserved.
// https://github.com/q191201771/lal
//
// Use of this source code is governed by a MIT-style license
// that can be found in the License file.
//
// Author: Chef (191201771@qq.com)

package main

import (
	"bytes"
	"encoding/hex"
	"flag"
	"fmt"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/q191201771/naza/pkg/nazastring"

	"github.com/q191201771/lal/pkg/rtmp"

	"github.com/q191201771/lal/pkg/avc"
	"github.com/q191201771/lal/pkg/hevc"
	"github.com/q191201771/naza/pkg/bele"
	"github.com/q191201771/naza/pkg/bitrate"

	"github.com/q191201771/lal/pkg/httpflv"
	"github.com/q191201771/naza/pkg/nazalog"
)

// 分析诊断HTTP-FLV流的时间戳。注意，这个程序还没有完成。
// 功能：
// - 时间戳回退检查
//     - 当音频时间戳出现回退时打error日志
//     - 当视频时间戳出现回退时打error日志
//     - 将音频和视频时间戳看成一个整体，出现回退时打error日志
// - 定时打印：
//     - 总体带宽
//     - 音频带宽
//     - 视频带宽
//     - 视频DTS和PTS不相等的计数
//     - I帧间隔时间
// - H264
//     - 打印每个tag的类型：key seq header...
//     - 打印每个tag中有多少个帧：SPS PPS SEI IDR SLICE...
//     - 打印每个SLICE的类型：I、P、B...
// 解析metadata信息，并打印

// TODO
// - 检查时间戳正向大的跳跃
// - 打印GOP中帧数量？
// - slice_num?
// - 输入源可以是httpflv，也可以是flv文件

var (
	timestampCheckFlag   = true
	printStatFlag        = true
	printEveryTagFlag    = false
	printMetaData        = true
	analysisVideoTagFlag = true
)

var (
	prevAudioTS = int64(-1)
	prevVideoTS = int64(-1)
	prevTS      = int64(-1)
	prevIDRTS   = int64(-1)
	diffIDRTS   = int64(-1)
)

func main() {
	url := parseFlag()
	session := httpflv.NewPullSession()

	brTotal := bitrate.New()
	brAudio := bitrate.New()
	brVideo := bitrate.New()

	videoCTSNotZeroCount := 0

	go func() {
		for {
			time.Sleep(1 * time.Second)
			if printStatFlag {
				nazalog.Debugf("stat. total=%dKb/s, audio=%dKb/s, video=%dKb/s, videoCTSNotZeroCount=%d, diffIDRTS=%d",
					int(brTotal.Rate()), int(brAudio.Rate()), int(brVideo.Rate()), videoCTSNotZeroCount, diffIDRTS)
			}
		}
	}()

	err := session.Pull(url, func(tag httpflv.Tag) {
		if printEveryTagFlag {
			debugLength := 32
			if len(tag.Raw) < 32 {
				debugLength = len(tag.Raw)
			}
			nazalog.Debugf("header=%+v, hex=%s", tag.Header, hex.Dump(tag.Raw[11:debugLength]))
		}

		brTotal.Add(len(tag.Raw))

		switch tag.Header.Type {
		case httpflv.TagTypeMetadata:
			if printMetaData {
				nazalog.Debugf("----------\n%s", hex.Dump(tag.Raw[11:]))

				opa, err := rtmp.ParseMetadata(tag.Raw[11 : len(tag.Raw)-4])
				nazalog.Assert(nil, err)
				var buf bytes.Buffer
				buf.WriteString(fmt.Sprintf("-----\ncount:%d\n", len(opa)))
				for _, op := range opa {
					buf.WriteString(fmt.Sprintf("  %s: %+v\n", op.Key, op.Value))
				}
				nazalog.Debugf("%+v", buf.String())
			}
		case httpflv.TagTypeAudio:
			brAudio.Add(len(tag.Raw))

			if timestampCheckFlag {
				if prevAudioTS != -1 && int64(tag.Header.Timestamp) < prevAudioTS {
					nazalog.Errorf("audio timestamp error, less than prev audio timestamp. header=%+v, prevAudioTS=%d, diff=%d", tag.Header, prevAudioTS, int64(tag.Header.Timestamp)-prevAudioTS)
				}
				if prevTS != -1 && int64(tag.Header.Timestamp) < prevTS {
					nazalog.Warnf("audio timestamp error. less than prev global timestamp. header=%+v, prevTS=%d, diff=%d", tag.Header, prevTS, int64(tag.Header.Timestamp)-prevTS)
				}
			}
			prevAudioTS = int64(tag.Header.Timestamp)
			prevTS = int64(tag.Header.Timestamp)
		case httpflv.TagTypeVideo:
			analysisVideoTag(tag)

			videoCTS := bele.BEUint24(tag.Raw[13:])
			if videoCTS != 0 {
				videoCTSNotZeroCount++
			}

			brVideo.Add(len(tag.Raw))

			if timestampCheckFlag {
				if prevVideoTS != -1 && int64(tag.Header.Timestamp) < prevVideoTS {
					nazalog.Errorf("video timestamp error, less than prev video timestamp. header=%+v, prevVideoTS=%d, diff=%d", tag.Header, prevVideoTS, int64(tag.Header.Timestamp)-prevVideoTS)
				}
				if prevTS != -1 && int64(tag.Header.Timestamp) < prevTS {
					nazalog.Warnf("video timestamp error, less than prev global timestamp. header=%+v, prevTS=%d, diff=%d", tag.Header, prevTS, int64(tag.Header.Timestamp)-prevTS)
				}
			}
			prevVideoTS = int64(tag.Header.Timestamp)
			prevTS = int64(tag.Header.Timestamp)
		}
	})
	nazalog.Warn(err)
}

const (
	typeUnknown uint8 = 1
	typeAVC     uint8 = 2
	typeHEVC    uint8 = 3
)

var t uint8 = typeUnknown

func analysisVideoTag(tag httpflv.Tag) {
	var buf bytes.Buffer
	if tag.IsVideoKeySeqHeader() {
		if tag.IsAVCKeySeqHeader() {
			t = typeAVC
			buf.WriteString(" [AVC SeqHeader] ")
			if _, _, err := avc.ParseSPSPPSFromSeqHeader(tag.Raw[11:]); err != nil {
				buf.WriteString(" parse sps pps failed.")
			}
		} else if tag.IsHEVCKeySeqHeader() {
			t = typeHEVC
			//nazalog.Debugf("%s", nazastring.DumpSliceByte(tag.Raw[11:]))
			vps, sps, pps, _ := hevc.ParseVPSSPSPPSFromSeqHeader(tag.Raw[11:])
			nazalog.Debugf("%s", nazastring.DumpSliceByte(vps))
			nazalog.Debugf("%s", nazastring.DumpSliceByte(sps))
			nazalog.Debugf("%s", nazastring.DumpSliceByte(pps))
			//nazalog.Debugf("%s %s %s %+v", hex.Dump(vps), hex.Dump(sps), hex.Dump(pps), err)
			buf.WriteString(" [HEVC SeqHeader] ")
		}
	} else {
		body := tag.Raw[11:]

		i := 5
		for i != int(tag.Header.DataSize) {
			if i+4 > int(tag.Header.DataSize) {
				nazalog.Errorf("invalid nalu size. i=%d, tag size=%d", i, int(tag.Header.DataSize))
				break
			}
			naluLen := bele.BEUint32(body[i:])
			if i+int(naluLen) > int(tag.Header.DataSize) {
				nazalog.Errorf("invalid nalu size. i=%d, naluLen=%d, tag size=%d", i, naluLen, int(tag.Header.DataSize))
				break
			}
			switch t {
			case typeAVC:
				if avc.ParseNALUType(body[i+4]) == avc.NALUTypeIDRSlice {
					if prevIDRTS != int64(-1) {
						diffIDRTS = int64(tag.Header.Timestamp) - prevIDRTS
					}
					prevIDRTS = int64(tag.Header.Timestamp)
				}
				if avc.ParseNALUType(body[i+4]) == avc.NALUTypeSEI {
					delay := SEIDelayMS(body[i+4 : i+4+int(naluLen)])
					if delay != -1 {
						buf.WriteString(fmt.Sprintf("delay: %dms", delay))
					}
				}
				sliceTypeReadable, _ := avc.ParseSliceTypeReadable(body[i+4:])
				buf.WriteString(fmt.Sprintf(" [%s(%s)] ", avc.ParseNALUTypeReadable(body[i+4]), sliceTypeReadable))
			case typeHEVC:
				if hevc.ParseNALUType(body[i+4]) == hevc.NALUTypeSEI {
					delay := SEIDelayMS(body[i+4 : i+4+int(naluLen)])
					if delay != -1 {
						buf.WriteString(fmt.Sprintf("delay: %dms", delay))
					}
				}
				buf.WriteString(fmt.Sprintf(" [%s] ", hevc.ParseNALUTypeReadable(body[i+4])))
			}
			i = i + 4 + int(naluLen)
		}
	}
	if analysisVideoTagFlag {
		nazalog.Debug(buf.String())
	}
}

// 注意，SEI的内容是自定义格式，解析的代码不具有通用性
func SEIDelayMS(seiNALU []byte) int {
	//nazalog.Debugf("sei: %s", hex.Dump(seiNALU))
	items := strings.Split(string(seiNALU), ":")
	if len(items) != 3 {
		return -1
	}

	a, err := strconv.ParseInt(items[1], 10, 64)
	if err != nil {
		return -1
	}
	t := time.Unix(a/1e3, a%1e3)
	d := time.Now().Sub(t)
	return int(d.Nanoseconds() / 1e6)
}

func parseFlag() string {
	url := flag.String("i", "", "specify http-flv url")
	flag.Parse()
	if *url == "" {
		flag.Usage()
		os.Exit(1)
	}
	return *url
}