package main

import (
	"encoding/base64"
	"flag"
	"fmt"
	"net/http"
	"strconv"
	"time"

	"github.com/gin-gonic/gin"
	"yumc.pw/cloud/clipboard-sync/lib/clipboard"
)

func main() {
	t := flag.String("t", "c", "Type c(client) or s(server)")
	a := flag.String("a", "http://127.0.0.1:8080", "Server Address")
	b := flag.String("b", ":8080", "Server Listen Port")
	flag.Parse()
	if *t == "c" {
		if clipboard.Unsupported {
			panic("Unsupported On This Machine")
		}
		readClipboard(*a)
	} else {
		startServer(*b)
	}
}

const (
	textHeader = "Go-Clipboard-Text"
	timeHeader = "Go-Clipboard-Time"
)

func startServer(b string) {
	text := ""
	time := time.Now().Unix()
	g := gin.New()
	g.GET("/", func(c *gin.Context) {
		c.Header(textHeader, text)
		c.Header(timeHeader, strconv.FormatInt(time, 10))
	})
	g.POST("/", func(c *gin.Context) {
		text = c.Query("text")
		time, _ = strconv.ParseInt(c.Query("time"), 10, 64)
	})
	g.Run(b)
}

func readClipboard(a string) {
	old, _ := clipboard.ReadAll()
	updateTime := time.Now().Unix()
	client := &http.Client{}
	address := a + "?text=%s&time=%s"
	for {
		time.Sleep(100 * time.Millisecond)
		text, _ := clipboard.ReadAll()
		if old != text {
			old = text
			updateTime = time.Now().Unix()
			request, _ := http.NewRequest("POST",
				fmt.Sprintf(address, encode(text), strconv.FormatInt(updateTime, 10)), nil)
			client.Do(request)
		} else {
			response, _ := http.Get(a)
			texts, ok := response.Header[textHeader]
			if ok {
				sText := decode(texts[0])
				sTime, _ := strconv.ParseInt(response.Header[timeHeader][0], 10, 64)
				if sTime > updateTime && sText != old {
					old = sText
					updateTime = sTime
					clipboard.WriteAll(sText)
				}
			}
		}
	}
}

func encode(text string) string {
	return base64.URLEncoding.EncodeToString([]byte(text))
}

func decode(text string) string {
	origin, _ := base64.URLEncoding.DecodeString(text)
	return string(origin)
}