package websocket

import (
	"github.com/olahol/melody"
	"github.com/pkg/errors"
	"net/http"
	"sync"
	"time"
)

type HandleConnectFunc func(context map[string]any)
type HandleDisconnectFunc func(context map[string]any)
type HandleErrorFunc func(err error, context map[string]any)
type HandleCloseFunc func(i int, s string, context map[string]any) error
type HandlePongFunc func(context map[string]any)
type HandleMessageFunc func(message []byte, context map[string]any)
type BroadCastFilterCallback func(context map[string]any) bool

var managerInstance *Manager

func Init() {
	if managerInstance == nil {
		managerInstance = &Manager{
			melodyMapMutex: &sync.RWMutex{},
			melodyMap:      make(map[string]*melody.Melody),
		}
	}
}

func Destroy() {
	if managerInstance != nil {
		managerInstance.melodyMapMutex.Lock()
		defer managerInstance.melodyMapMutex.Unlock()

		for _, melodyInstance := range managerInstance.melodyMap {
			err := melodyInstance.Close()
			if err != nil {
				panic(err)
			}
		}

		managerInstance.melodyMap = nil
		managerInstance = nil
	}

	managerInstance = nil
}

func GetInstance() *Manager {
	return managerInstance
}

type Manager struct {
	melodyMapMutex *sync.RWMutex
	melodyMap      map[string]*melody.Melody
}

func (m *Manager) RegisterHub(groupID string, opts ...InitOption) {
	m.melodyMapMutex.Lock()
	defer m.melodyMapMutex.Unlock()

	_, ok := m.melodyMap[groupID]
	if ok {
		return
	}

	melodyInstance := melody.New()

	options := new(InitOptions)
	for _, opt := range opts {
		opt(options)
	}

	if options.writeWaitSec != 0 {
		melodyInstance.Config.WriteWait = time.Duration(options.writeWaitSec) * time.Second
	}

	if options.pongWaitSec != 0 {
		melodyInstance.Config.PongWait = time.Duration(options.pongWaitSec) * time.Second
	}

	if options.pingPeriodSec != 0 {
		melodyInstance.Config.PingPeriod = time.Duration(options.pingPeriodSec) * time.Second
	}

	if options.maxMessageSize != 0 {
		melodyInstance.Config.MaxMessageSize = options.maxMessageSize
	}

	if options.messageBufferSize != 0 {
		melodyInstance.Config.MessageBufferSize = options.messageBufferSize
	}

	melodyInstance.Config.ConcurrentMessageHandling = options.concurrentMessageHandling

	melodyInstance.Upgrader.CheckOrigin = func(r *http.Request) bool { return true }

	m.melodyMap[groupID] = melodyInstance
}

func (m *Manager) UnregisterHub(groupID string) {
	m.melodyMapMutex.Lock()
	defer m.melodyMapMutex.Unlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return
	}

	err := melodyInstance.Close()
	if err != nil {
		panic(err)
	}

	melodyInstance = nil

	delete(m.melodyMap, groupID)
}

func (m *Manager) HandleConnect(groupID string, handleConnectFunc HandleConnectFunc) {
	m.melodyMapMutex.RLock()
	defer m.melodyMapMutex.RUnlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return
	}

	melodyInstance.HandleConnect(func(session *melody.Session) {
		if handleConnectFunc != nil {
			handleConnectFunc(session.Keys)
		}
	})
}

func (m *Manager) HandleDisconnect(groupID string, handleDisconnectFunc HandleDisconnectFunc) {
	m.melodyMapMutex.Lock()
	defer m.melodyMapMutex.Unlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return
	}

	melodyInstance.HandleDisconnect(func(session *melody.Session) {
		if handleDisconnectFunc != nil {
			handleDisconnectFunc(session.Keys)
		}
	})
}

func (m *Manager) HandleError(groupID string, handleErrorFunc HandleErrorFunc) {
	m.melodyMapMutex.RLock()
	defer m.melodyMapMutex.RUnlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return
	}

	melodyInstance.HandleError(func(session *melody.Session, err error) {
		if handleErrorFunc != nil {
			handleErrorFunc(err, session.Keys)
		}
	})
}

func (m *Manager) HandleClose(groupID string, handleCloseFunc HandleCloseFunc) {
	m.melodyMapMutex.RLock()
	defer m.melodyMapMutex.RUnlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return
	}

	melodyInstance.HandleClose(func(session *melody.Session, i int, s string) error {
		if handleCloseFunc != nil {
			err := handleCloseFunc(i, s, session.Keys)
			if err != nil {
				return err
			}
		}

		return nil
	})
}

func (m *Manager) HandlePong(groupID string, handlePongFunc HandlePongFunc) {
	m.melodyMapMutex.RLock()
	defer m.melodyMapMutex.RUnlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return
	}

	melodyInstance.HandlePong(func(session *melody.Session) {
		if handlePongFunc != nil {
			handlePongFunc(session.Keys)
		}
	})
}

func (m *Manager) HandleRequest(groupID string, w http.ResponseWriter, r *http.Request, opts ...ConnectionOption) error {
	m.melodyMapMutex.RLock()
	defer m.melodyMapMutex.RUnlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return errors.New("groupID尚未注册")
	}

	sessionMap := make(map[string]any)

	for _, opt := range opts {
		opt(&sessionMap)
	}

	err := melodyInstance.HandleRequestWithKeys(w, r, sessionMap)
	if err != nil {
		return err
	}

	return nil
}

func (m *Manager) HandleMessage(groupID string, handleMessageFunc HandleMessageFunc) error {
	m.melodyMapMutex.RLock()
	defer m.melodyMapMutex.RUnlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return errors.New("groupID尚未注册")
	}

	melodyInstance.HandleMessage(func(session *melody.Session, bytes []byte) {
		if handleMessageFunc != nil {
			handleMessageFunc(bytes, session.Keys)
		}
	})

	return nil
}

func (m *Manager) BroadCast(groupID string, msg []byte) error {
	m.melodyMapMutex.RLock()
	defer m.melodyMapMutex.RUnlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return errors.New("groupID尚未注册")
	}

	return melodyInstance.Broadcast(msg)
}

func (m *Manager) BroadCastFilter(groupID string, msg []byte, filterCallback BroadCastFilterCallback) error {
	m.melodyMapMutex.RLock()
	defer m.melodyMapMutex.RUnlock()

	melodyInstance, ok := m.melodyMap[groupID]
	if !ok {
		return errors.New("groupID尚未注册")
	}

	return melodyInstance.BroadcastFilter(msg, func(session *melody.Session) bool {
		return filterCallback(session.Keys)
	})
}

type InitOption func(*InitOptions)

type InitOptions struct {
	writeWaitSec              int64
	pongWaitSec               int64
	pingPeriodSec             int64
	maxMessageSize            int64
	messageBufferSize         int
	concurrentMessageHandling bool
}

func InitWithWriteWaitSec(writeWaitSec int64) InitOption {
	return func(options *InitOptions) {
		options.writeWaitSec = writeWaitSec
	}
}

func InitWithPongWaitSec(pongWaitSec int64) InitOption {
	return func(options *InitOptions) {
		options.pongWaitSec = pongWaitSec
	}
}

func InitWithPingPeriodSec(pingPeriodSec int64) InitOption {
	return func(options *InitOptions) {
		options.pingPeriodSec = pingPeriodSec
	}
}

func InitWithMaxMessageSize(maxMessageSize int64) InitOption {
	return func(options *InitOptions) {
		options.maxMessageSize = maxMessageSize
	}
}

func InitWithMaxMessageBufferSize(messageBufferSize int) InitOption {
	return func(options *InitOptions) {
		options.messageBufferSize = messageBufferSize
	}
}

func InitWithConcurrentMessageHandling(concurrentMessageHandling bool) InitOption {
	return func(options *InitOptions) {
		options.concurrentMessageHandling = concurrentMessageHandling
	}
}

type ConnectionOption func(sessionMap *map[string]any)

func WithConnectionContext(context map[string]any) ConnectionOption {
	return func(sessionMap *map[string]any) {
		*sessionMap = context
	}
}