// 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 logic

import (
	"github.com/q191201771/lal/pkg/httpflv"
	"github.com/q191201771/lal/pkg/rtmp"
	log "github.com/q191201771/naza/pkg/nazalog"
	"github.com/q191201771/naza/pkg/unique"
	"sync"
	"time"
)

type Group struct {
	UniqueKey string

	appName    string
	streamName string

	exitChan chan struct{}

	mutex         sync.Mutex
	pubSession    *rtmp.ServerSession
	pullSession   *rtmp.PullSession
	subSessionSet map[*rtmp.ServerSession]struct{}
	// TODO chef:
	metadata        []byte
	avcKeySeqHeader []byte
	aacSeqHeader    []byte
}

var _ rtmp.PubSessionObserver = &Group{}

func NewGroup(appName string, streamName string) *Group {
	uk := unique.GenUniqueKey("RTMPGROUP")
	log.Infof("lifecycle new group. [%s] appName=%s, streamName=%s", uk, appName, streamName)
	return &Group{
		UniqueKey:     uk,
		appName:       appName,
		streamName:    streamName,
		exitChan:      make(chan struct{}, 1),
		subSessionSet: make(map[*rtmp.ServerSession]struct{}),
	}
}

func (group *Group) RunLoop() {
	t := time.NewTicker(200 * time.Millisecond)
	defer t.Stop()

	for {
		select {
		case <-group.exitChan:
			break
		case <-t.C:
			//noop
		}
	}
}

func (group *Group) Dispose(err error) {
	log.Infof("lifecycle dispose group. [%s]", group.UniqueKey)
	group.exitChan <- struct{}{}

	group.mutex.Lock()
	defer group.mutex.Unlock()
	if group.pubSession != nil {
		group.pubSession.Dispose()
	}
	for session := range group.subSessionSet {
		session.Dispose()
	}
}

func (group *Group) AddRTMPPubSession(session *rtmp.ServerSession) bool {
	log.Debugf("add PubSession into group. [%s] [%s]", group.UniqueKey, session.UniqueKey)
	group.mutex.Lock()
	if group.pubSession != nil {
		log.Errorf("PubSession already exist in group. [%s] old=%s, new=%s", group.UniqueKey, group.pubSession.UniqueKey, session.UniqueKey)
		return false
	}

	group.pubSession = session
	group.mutex.Unlock()
	session.SetPubSessionObserver(group)
	return true
}

func (group *Group) AddRTMPSubSession(session *rtmp.ServerSession) {
	log.Debugf("add SubSession into group. [%s] [%s]", group.UniqueKey, session.UniqueKey)
	group.mutex.Lock()
	defer group.mutex.Unlock()
	group.subSessionSet[session] = struct{}{}

	// TODO chef: 多长没有拉流session存在的功能
	//group.turnToEmptyTick = 0
}

func (group *Group) DelRTMPPubSession(session *rtmp.ServerSession) {
	log.Debugf("del PubSession from group. [%s] [%s]", group.UniqueKey, session.UniqueKey)
	group.mutex.Lock()
	defer group.mutex.Unlock()
	group.pubSession = nil
	group.metadata = nil
	group.avcKeySeqHeader = nil
	group.aacSeqHeader = nil

}

func (group *Group) DelRTMPSubSession(session *rtmp.ServerSession) {
	log.Debugf("del SubSession from group. [%s] [%s]", group.UniqueKey, session.UniqueKey)
	group.mutex.Lock()
	defer group.mutex.Unlock()
	delete(group.subSessionSet, session)
}

func (group *Group) AddHTTPFlvSubSession(session *httpflv.SubSession) {
	panic("not impl")
}

func (group *Group) Pull(addr string, connectTimeout int64) {
	// TODO chef: config me,
	// v1.0.0 版本之前先不提供去其他节点回源的功能
	panic("not impl yet")
	//group.pullSession = NewPullSession(group, PullSessionTimeout{
	//	ConnectTimeoutMS: int(connectTimeout),
	//})
	//
	//defer func() {
	//	group.mutex.Lock()
	//	defer group.mutex.Unlock()
	//	log.Infof("del rtmp PullSession out of group. [%s] [%s]", group.UniqueKey, group.pullSession)
	//	group.pullSession = nil
	//}()
	//
	//url := fmt.Sprintf("rtmp://%s/%s/%s", addr, group.appName, group.streamName)
	//if err := group.pullSession.Pull(url); err != nil {
	//	log.Error(err)
	//}
	//if err := group.pullSession.WaitLoop(); err != nil {
	//	log.Debugf("rtmp PullSession loop done. [%s] [%s] err=%v", group.UniqueKey, group.pullSession.UniqueKey, err)
	//	return
	//}
}

func (group *Group) IsTotalEmpty() bool {
	group.mutex.Lock()
	defer group.mutex.Unlock()
	return group.pubSession == nil && len(group.subSessionSet) == 0
}

func (group *Group) IsInExist() bool {
	group.mutex.Lock()
	defer group.mutex.Unlock()
	return group.pubSession != nil
}

// PubSession or PullSession
func (group *Group) ReadRTMPAVMsgCB(header rtmp.Header, timestampAbs uint32, message []byte) {
	group.mutex.Lock()
	defer group.mutex.Unlock()
	group.broadcastRTMP2RTMP(header, timestampAbs, message)
}

func (group *Group) broadcastRTMP2RTMP(header rtmp.Header, timestampAbs uint32, message []byte) {
	//log.Infof("%+v", header)
	// # 1. 设置好头部信息
	var currHeader rtmp.Header
	currHeader.MsgLen = uint32(len(message))
	currHeader.Timestamp = timestampAbs
	currHeader.MsgTypeID = header.MsgTypeID
	currHeader.MsgStreamID = rtmp.MSID1
	switch header.MsgTypeID {
	case rtmp.TypeidDataMessageAMF0:
		currHeader.CSID = rtmp.CSIDAMF
		//prevHeader = nil
	case rtmp.TypeidAudio:
		currHeader.CSID = rtmp.CSIDAudio
		//prevHeader = group.prevAudioHeader
	case rtmp.TypeidVideo:
		currHeader.CSID = rtmp.CSIDVideo
		//prevHeader = group.prevVideoHeader
	}

	var absChunks []byte

	// # 2. 广播。遍历所有sub session，决定是否转发
	for session := range group.subSessionSet {
		// ## 2.1. 一个message广播给多个sub session时，只做一次chunk切割
		if absChunks == nil {
			absChunks = rtmp.Message2Chunks(message, &currHeader)
		}

		// ## 2.2. 如果是新的sub session，发送已缓存的信息
		if session.IsFresh {
			// 发送缓存的头部信息
			if group.metadata != nil {
				session.AsyncWrite(group.metadata)
			}
			if group.avcKeySeqHeader != nil {
				session.AsyncWrite(group.avcKeySeqHeader)
			}
			if group.aacSeqHeader != nil {
				session.AsyncWrite(group.aacSeqHeader)
			}
			session.IsFresh = false
		}

		// ## 2.3. 判断当前包的类型，以及sub session的状态，决定是否发送并更新sub session的状态
		switch header.MsgTypeID {
		case rtmp.TypeidDataMessageAMF0:
			session.AsyncWrite(absChunks)
		case rtmp.TypeidAudio:
			session.AsyncWrite(absChunks)
		case rtmp.TypeidVideo:
			if session.WaitKeyNalu {
				if message[0] == 0x17 && message[1] == 0x0 {
					session.AsyncWrite(absChunks)
				}
				if message[0] == 0x17 && message[1] == 0x1 {
					session.AsyncWrite(absChunks)
					session.WaitKeyNalu = false
				}
			} else {
				session.AsyncWrite(absChunks)
			}

		}

	}

	// # 3. 缓存 metadata 和 avc key seq header 和 aac seq header
	// 由于可能没有订阅者，所以message可能还没做chunk切割，所以这里要做判断是否做chunk切割
	switch header.MsgTypeID {
	case rtmp.TypeidDataMessageAMF0:
		if absChunks == nil {
			absChunks = rtmp.Message2Chunks(message, &currHeader)
		}
		log.Debugf("cache metadata. [%s]", group.UniqueKey)
		group.metadata = absChunks
	case rtmp.TypeidVideo:
		// TODO chef: magic number
		if message[0] == 0x17 && message[1] == 0x0 {
			if absChunks == nil {
				absChunks = rtmp.Message2Chunks(message, &currHeader)
			}
			log.Debugf("cache avc key seq header. [%s]", group.UniqueKey)
			group.avcKeySeqHeader = absChunks
		}
	case rtmp.TypeidAudio:
		if (message[0]>>4) == 0x0a && message[1] == 0x0 {
			if absChunks == nil {
				absChunks = rtmp.Message2Chunks(message, &currHeader)
			}
			log.Debugf("cache aac seq header. [%s]", group.UniqueKey)
			group.aacSeqHeader = absChunks
		}
	}
}

func (group *Group) pullIfNeeded() {
	panic("not impl")
	//if !gm.isInExist() {
	//	switch gm.config.Pull.Type {
	//	case "httpflv":
	//		go gm.httpFlvGroup.Pull(gm.config.Pull.Addr, gm.config.Pull.ConnectTimeout, gm.config.Pull.ReadTimeout)
	//	case "rtmp":
	//		go gm.rtmpGroup.Pull(gm.config.Pull.Addr, gm.config.Pull.ConnectTimeout)
	//	}
	//}
}

func (group *Group) isInExist() bool {
	panic("not impl")
	//return (gm.rtmpGroup != nil && gm.rtmpGroup.IsInExist()) ||
	//	(gm.httpFlvGroup != nil && gm.httpFlvGroup.IsInExist())
}

// GroupObserver of httpflv.Group
func (group *Group) ReadHTTPRespHeaderCB() {
	// noop
}

// GroupObserver of httpflv.Group
func (group *Group) ReadFlvHeaderCB(flvHeader []byte) {
	// noop
}

// GroupObserver of httpflv.Group
func (group *Group) ReadFlvTagCB(tag *httpflv.Tag) {
	log.Info("ReadFlvTagCB")

	// TODO chef: broadcast to rtmp.Group
}