package smart

import (
	"errors"
	"gitea.unprism.ru/KRBL/n9m/v2/pkg/models"
	"gitea.unprism.ru/KRBL/n9m/v2/pkg/protocol"
	"gitea.unprism.ru/KRBL/n9m/v2/pkg/utils"
	"net"
	"sync"
)

const (
	charset = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
	length  = 6
)

func NewSmartChannelPackage(conn net.Conn, mainSmartPackage *SmartPackage) (*SmartChannelPackage, error) {
	pack := NewSmartPackage(conn)
	pack.pack.Payload.Session = mainSmartPackage.pack.Payload.Session

	channelName, err := registerChannelHandles(pack)

	if err != nil {
		return nil, err
	}

	smartChannelPackage := &SmartChannelPackage{
		pack:     pack,
		mainPack: mainSmartPackage,

		channelName: channelName,

		mutex: sync.RWMutex{},
		ssrc:  make(map[uint16][]func([]byte) error),
	}

	pack.AddPayloadHandler(protocol.PayloadTypeLive, smartChannelPackage.handleLiveVideo)

	return smartChannelPackage, nil
}

func (channelPack *SmartChannelPackage) Run() error {
	for {
		if err := channelPack.pack.Handle(); err != nil {
			return err
		}
	}
}

func (channelPack *SmartChannelPackage) GetChannelName() string {
	return channelPack.channelName
}

func (channelPack *SmartChannelPackage) AddLiveSource(ssrc uint16, source func([]byte) error) {
	channelPack.mutex.Lock()
	defer channelPack.mutex.Unlock()

	channelPack.ssrc[ssrc] = append(channelPack.ssrc[ssrc], source)
}

func (channelPack *SmartChannelPackage) handleLiveVideo(sPack *SmartPackage, pack protocol.Package) error {
	channelPack.mutex.RLock()

	sources, ok := channelPack.ssrc[uint16(pack.SSRC)]

	if !ok || len(sources) == 0 {
		channelPack.mutex.RUnlock()

		var request = models.MediaStreamModelControlStreamRequest{
			PayloadType: protocol.PayloadTypeLive,
			SSRC:        uint16(pack.SSRC),
			StreamName:  channelPack.channelName,
			Command:     models.MediaStreamCommandStop,
		}

		pack.PayloadType = protocol.PayloadTypeData
		pack.Payload.Module = "MEDIASTREAMMODEL"
		pack.Payload.Operation = "CONTROLSTREAM"
		pack.SetParameters(request)

		if _, err := channelPack.mainPack.Write(pack.PackPackage()); err != nil {
			panic(err)
		}

		return nil
	}

	var errorMask = map[int]bool{}

	for i, source := range sources {
		if err := source(pack.RawPayload); err != nil {
			errorMask[i] = true
		}
	}

	channelPack.mutex.RUnlock()

	if len(errorMask) > 0 {
		newSources := make([]func([]byte) error, 0, len(sources))

		for i, source := range sources {
			if !errorMask[i] {
				newSources = append(newSources, source)
			}
		}

		channelPack.mutex.Lock()
		channelPack.ssrc[uint16(pack.SSRC)] = newSources
		channelPack.mutex.Unlock()
	}

	return nil
}

func registerChannelHandles(pack *SmartPackage) (string, error) {
	res := make(chan error, 1)

	pack.AddJSONHandler("CERTIFICATE", "CREATESTREAM", func(smartPackage *SmartPackage, p protocol.Package) error {
		var params models.CertificateCreateStreamResponse

		if err := p.GetResponseAs(&params); err != nil {
			return err
		}

		if params.ErrorCode != 0 {
			res <- errors.New(params.ErrorCause)
		} else {
			res <- nil
		}

		return nil
	})

	channelName := utils.RandomString(length, charset)

	var request = models.CertificateCreateStreamRequest{
		StreamName: channelName,
	}

	pack.pack.Payload.Module = "CERTIFICATE"
	pack.pack.Payload.Operation = "CREATESTREAM"
	pack.pack.SetParameters(request)

	pack.Write(pack.pack.PackPackage())

	for {
		if err := pack.Handle(); err != nil {
			return "", err
		}

		select {
		case err := <-res:
			close(res)

			if err != nil {
				return "", err
			}

			pack.AddJSONHandler("CERTIFICATE", "CREATESTREAM", func(smartPackage *SmartPackage, p protocol.Package) error {
				return errors.New("stream already exists")
			})

			return channelName, nil
		default:
		}
	}
}