package main

import (
	"container/ring"
	"net/http"
	"time"

	"github.com/gin-gonic/gin"
	melody "gopkg.in/olahol/melody.v1"
)

func main() {
	gin.SetMode(gin.ReleaseMode)

	r := gin.Default()
	m := melody.New()

	history := ring.New(10)
	pub := ring.New(10)

	r.Static("/assets", "./assets")
	r.StaticFile("/", "./index.html")

	r.GET("/ws", func(c *gin.Context) {
		m.HandleRequest(c.Writer, c.Request)
	})

	r.POST("/update", func(c *gin.Context) {
		metadata := c.PostForm("metadata")

		c.JSON(http.StatusOK, gin.H{
			"status": "ok",
		})

		if metadata == "" {
			return
		}

		for i := 0; i < history.Len(); i++ {
			history = history.Next()

			if history.Value == metadata {
				return
			}
		}

		history.Value = metadata
		history = history.Next()

		go func() {
			time.Sleep(time.Second * 10)
			for i := 0; i < pub.Len(); i++ {
				pub = pub.Next()

				if pub.Value == metadata {
					return
				}
			}
			pub.Value = metadata
			pub = pub.Next()
			m.Broadcast([]byte(metadata))
		}()
	})

	m.HandleConnect(func(s *melody.Session) {
		for i := 0; i < pub.Len(); i++ {
			if pub.Value != nil {
				s.Write([]byte(pub.Value.(string)))
			}
			pub = pub.Next()
		}
	})

	r.Run(":1338")
}