// Client handler
package wsrpc

import (
	"sync"

	"github.com/google/uuid"

	"golang.org/x/net/websocket"
)

// DataObj common structure for dymanic json object
type DataObj map[string]interface{}

// ListenerFunc function type to handle browser events
type ListenerFunc func(...interface{}) interface{}

// Request request type for handling requests channels

// ClientCtx main client struct
type ClientCtx struct {
	locker sync.Mutex

	WS *websocket.Conn
	// stuff
	listeners map[string]ListenerFunc
	requests  map[string]chan interface{}
}

//NewHandler creates a new handler
func NewHandler(id string, ws *websocket.Conn) *ClientCtx {
	var c = ClientCtx{}
	c.WS = ws
	c.listeners = map[string]ListenerFunc{}
	c.requests = map[string]chan interface{}{}
	return &c
}

// Process messages
func (c *ClientCtx) Process(data DataObj) {
	if data["op"].(string) == "call" {
		params := data["param"].([]interface{})
		var idn = data["method"].(string)
		var reqId = data["reqId"].(string)
		var fn, ok = c.listeners[idn]
		if !ok {
			return
		}
		go func() {
			ret := fn(params...)
			var responseObj = DataObj{
				"op":    "response",
				"reqId": reqId,
				"data":  ret,
			}
			//log.Println("Sending response")
			websocket.JSON.Send(c.WS, responseObj)
		}()
	}

	if data["op"].(string) == "response" {
		c.locker.Lock()
		mchan, ok := c.requests[data["reqId"].(string)]
		delete(c.requests, data["reqId"].(string))
		c.locker.Unlock()

		if ok {
			mchan <- data["data"]
		}
	}
}

// Call a client method and estabilishes a request id
func (c *ClientCtx) Call(method string, params ...interface{}) chan interface{} {
	u := uuid.New()
	uuidStr := u.String()

	var callObj = DataObj{
		"op":     "call",
		"reqId":  uuidStr,
		"method": method,
		"param":  params,
	}
	res := make(chan interface{}, 1)
	c.locker.Lock()
	c.requests[uuidStr] = res
	c.locker.Unlock()

	websocket.JSON.Send(c.WS, &callObj)
	return res
}

//Emit emit event listener
/*func (c *ClientCtx) Emit(name string, data DataObj) (interface{}, error) {
	fn, ok := c.listeners[name]
	if !ok {
		return nil, fmt.Errorf("Not found") // Dont execute
	}
	return fn(data), nil

}*/

//On add a event listener on browser
func (c *ClientCtx) Define(name string, listener ListenerFunc) {
	c.listeners[name] = listener
}