// Package websocket...
//
// Description : websocket...
//
// Author : go_developer@163.com<张德满>
//
// Date : 2021-03-27 6:49 下午
package websocket

import (
	"encoding/json"
	"fmt"
	"sync"

	"github.com/go-developer/websocket/context"

	"gopkg.in/olahol/melody.v1"

	"github.com/go-developer/gopkg/easylock"

	"github.com/gin-gonic/gin"
	"github.com/go-developer/websocket/abstract"
	"github.com/pkg/errors"
)

// Server ...
//
// Author : go_developer@163.com<张德满>
//
// Date : 8:04 下午 2021/3/27
type Server struct {
	ginRouter *gin.Engine
	wsServer  *melody.Melody
}

var (
	// ginRouterTable 表
	ginRouterTable map[int]*Server
	// commandTable 指令表
	commandTable map[string]map[string]abstract.ICommand
	// 服务启停的信号
	sigChan = make(chan int, 0)
)

// NewWebsocketServe 启动websocket服务
//
// Author : go_developer@163.com<张德满>
//
// Date : 6:49 下午 2021/3/27
func NewWebsocketServe(wsInstanceList ...abstract.IWebsocket) error {
	if len(wsInstanceList) == 0 {
		return errors.WithStack(errors.New("register websocket server list is empty"))
	}
	lock := easylock.NewLock()
	ginRouterTable = make(map[int]*Server)
	commandTable = make(map[string]map[string]abstract.ICommand)
	wg := &sync.WaitGroup{}
	wg.Add(len(wsInstanceList))
	for _, wsInstance := range wsInstanceList {
		go func(wsInstance abstract.IWebsocket) {
			defer wg.Done()
			// 初始化ws server
			_ = lock.Lock()
			if _, exist := ginRouterTable[wsInstance.GetServerPort()]; !exist {
				ginRouterTable[wsInstance.GetServerPort()] = &Server{
					ginRouter: gin.Default(),
					wsServer:  melody.New(),
				}
			}
			if _, exist := commandTable[wsInstance.GetModuleFlag()]; !exist {
				commandTable[wsInstance.GetModuleFlag()] = make(map[string]abstract.ICommand)
			}
			_ = lock.Unlock()
			routerGroup := ginRouterTable[wsInstance.GetServerPort()].ginRouter.Group(wsInstance.GetModuleFlag())
			// 注册路由
			for _, path := range wsInstance.HandshakeURL() {
				routerGroup.GET(path, func(ctx *gin.Context) {
					parameter := map[string]interface{}{
						"ws_context": context.NewContext(ctx, wsInstance.GetModuleFlag(), nil),
					}
					_ = ginRouterTable[wsInstance.GetServerPort()].wsServer.HandleRequestWithKeys(ctx.Writer, ctx.Request, parameter)
				})
			}
			// 注册回调函数
			// 1. 建立连接的函数
			ginRouterTable[wsInstance.GetServerPort()].wsServer.HandleConnect(func(session *melody.Session) {
				ctxInterface, _ := session.Get("ws_context")
				ctx := ctxInterface.(*context.WSContext)
				ctx.Session = session
				wsInstance.Connect(ctx)
			})
			// 2. 指令处理的函数
			ginRouterTable[wsInstance.GetServerPort()].wsServer.HandleMessage(func(session *melody.Session, bytes []byte) {
				// TODO : 增加指令回调失败的callback
				ctxInterface, _ := session.Get("ws_context")
				ctx := ctxInterface.(*context.WSContext)
				_ = dispatchCommand(ctx, bytes)
			})
			// 3, 关闭连接的处理函数
			ginRouterTable[wsInstance.GetServerPort()].wsServer.HandleClose(func(session *melody.Session, i int, s string) error {
				ctxInterface, _ := session.Get("ws_context")
				ctx := ctxInterface.(*context.WSContext)
				return wsInstance.Close(ctx, i, s)
			})
			// 4. 断开连接的处理函数
			ginRouterTable[wsInstance.GetServerPort()].wsServer.HandleDisconnect(func(session *melody.Session) {
				ctxInterface, _ := session.Get("ws_context")
				ctx := ctxInterface.(*context.WSContext)
				wsInstance.Disconnect(ctx)
			})
			// 注册指令
			for _, cmd := range wsInstance.GetCommandList() {
				commandTable[wsInstance.GetModuleFlag()][cmd.GetCommand()] = cmd
			}
			go func() {
				if err := ginRouterTable[wsInstance.GetServerPort()].ginRouter.Run(fmt.Sprintf(":%d", wsInstance.GetServerPort())); nil != err {
					panic(err)
				}
			}()
		}(wsInstance)
	}
	wg.Wait()
	run()
	return nil
}

// dispatchCommand 调度command ...
//
// Author : go_developer@163.com<张德满>
//
// Date : 3:36 下午 2021/3/28
func dispatchCommand(ctx *context.WSContext, data []byte) error {
	var command struct {
		Command string `json:"command"`
	}
	if err := json.Unmarshal(data, &command); nil != err {
		return err
	}
	if _, exist := commandTable[ctx.Flag]; !exist {
		return errors.WithStack(errors.New("未注册【" + ctx.Flag + "】长连接模块"))
	}

	if _, exist := commandTable[ctx.Flag][command.Command]; !exist {
		return errors.WithStack(errors.New("【" + ctx.Flag + "】长连接模块未注册【" + command.Command + "】指令"))
	}
	return nil
}

func run() {
	<-sigChan
	// TODO : 增加后置hook
}

// Stop 停止服务
//
// Author : go_developer@163.com<张德满>
//
// Date : 3:55 下午 2021/3/28
func Stop() {
	sigChan <- 1
}