package main

import (
	"bytes"
	"encoding/json"
	"git.ailur.dev/ailur/jsFetch"
	"syscall/js"
	"time"
)

var messageDivs = make(map[string]js.Value)

func refreshMessages(localStorage js.Value, messageBox js.Value, userId string) {
	jsonBody, err := json.Marshal(map[string]interface{}{
		"token": localStorage.Call("getItem", "token").String(),
	})
	if err != nil {
		alert("Failed to encode request: " + err.Error())
		return
	}
	response, err := jsFetch.Post(localStorage.Call("getItem", "server").String()+"/api/messages", "application/json", bytes.NewReader(jsonBody))
	if err != nil {
		alert("Failed to contact server: " + err.Error())
		return
	}

	if response.StatusCode != 200 {
		if response.StatusCode == 500 {
			alert("Something went wrong on our end. Please try again later.")
		} else {
			var body map[string]interface{}
			err := json.NewDecoder(response.Body).Decode(&body)
			if err != nil {
				alert("Failed to decode response: " + err.Error())
			} else {
				alert(body["error"].(string))
			}
		}
		return
	}

	var body map[string]interface{}
	err = json.NewDecoder(response.Body).Decode(&body)
	if err != nil {
		alert("Failed to decode response: " + err.Error())
		return
	}

	if !messageBox.Get("lastChild").IsNull() {
		messageBox.Get("lastChild").Get("style").Set("margin-bottom", "15px")
	}

	if len(messageDivs) > len(body) {
		for id, _ := range messageDivs {
			_, exists := body[id]
			if !exists {
				messageDivs[id].Call("remove")
				delete(messageDivs, id)
			}
		}
	}

	for id, message := range body {
		_, exists := messageDivs[id]
		if !exists {
			messageDiv := createMessage(message.(map[string]interface{})["message"].(string), message.(map[string]interface{})["name"].(string), message.(map[string]interface{})["sender"].(string) == userId, message.(map[string]interface{})["id"].(string), time.Unix(int64(message.(map[string]interface{})["sent"].(float64)), 0))
			messageBox.Call("appendChild", messageDiv)
			messageDivs[id] = messageDiv
		}
	}

	if !messageBox.Get("lastChild").IsNull() {
		messageBox.Get("lastChild").Get("style").Set("margin-bottom", "22.5px")
	}
	messageBox.Set("scrollTop", messageBox.Get("scrollTopMax").Float())
}

func alert(message string) {
	js.Global().Call("alert", message)
}

func createMessage(message string, user string, delete bool, id string, timestamp time.Time) js.Value {
	div := js.Global().Get("document").Call("createElement", "div")

	author := js.Global().Get("document").Call("createElement", "span")
	author.Get("classList").Call("add", "author")
	author.Set("innerText", user)

	content := js.Global().Get("document").Call("createElement", "span")
	content.Get("classList").Call("add", "content")
	content.Set("innerText", message)

	timestampSpan := js.Global().Get("document").Call("createElement", "span")
	timestampSpan.Get("classList").Call("add", "timestamp")
	timestampSpan.Set("innerText", timestamp.Format("15:04"))

	if delete {
		div.Get("style").Set("padding-bottom", "55px")
		deleteButton := js.Global().Get("document").Call("createElement", "button")
		deleteButton.Set("innerText", "Delete")
		deleteButton.Call("addEventListener", "click", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
			go func() {
				jsonBody, err := json.Marshal(map[string]interface{}{
					"id":    id,
					"token": js.Global().Get("localStorage").Call("getItem", "token").String(),
				})
				if err != nil {
					alert("Failed to encode request: " + err.Error())
					return
				}

				response, err := jsFetch.Post(js.Global().Get("localStorage").Call("getItem", "server").String()+"/api/delete", "application/json", bytes.NewReader(jsonBody))
				if err != nil {
					alert("Failed to contact server: " + err.Error())
					return
				}

				if response.StatusCode != 200 {
					if response.StatusCode == 500 {
						alert("Something went wrong on our end. Please try again later.")
					} else {
						var body map[string]interface{}
						err := json.NewDecoder(response.Body).Decode(&body)
						if err != nil {
							alert("Failed to decode response: " + err.Error())
						} else {
							alert(body["error"].(string))
						}
					}
					return
				}

				div.Call("remove")
			}()
			return nil
		}))
		div.Call("appendChild", deleteButton)
	}

	div.Call("appendChild", author)
	div.Call("appendChild", content)

	return div
}

func main() {
	localStorage := js.Global().Get("localStorage")
	login := js.Global().Get("document").Call("getElementById", "login")
	app := js.Global().Get("document").Call("getElementById", "app")
	logout := js.Global().Get("document").Call("getElementById", "logout")
	sendField := js.Global().Get("document").Call("getElementById", "sendField")
	send := js.Global().Get("document").Call("getElementById", "send")
	messageBox := js.Global().Get("document").Call("getElementById", "messageBox")

	if localStorage.Call("getItem", "server").IsNull() {
		localStorage.Call("setItem", "server", "https://chat.ailur.dev:1974")
	}

	if localStorage.Call("getItem", "token").IsNull() {
		return
	}

	userId := localStorage.Call("getItem", "userId").String()

	login.Get("style").Set("display", "none")
	app.Get("style").Set("display", "initial")

	logout.Call("addEventListener", "click", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
		go func() {
			localStorage.Call("removeItem", "token")
			js.Global().Get("location").Set("href", "login")
		}()
		return nil
	}))

	send.Call("addEventListener", "click", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
		go func() {
			jsonBody, err := json.Marshal(map[string]interface{}{
				"message": sendField.Get("value").String(),
				"token":   localStorage.Call("getItem", "token").String(),
			})
			if err != nil {
				alert("Failed to encode request: " + err.Error())
				return
			}

			response, err := jsFetch.Post(localStorage.Call("getItem", "server").String()+"/api/send", "application/json", bytes.NewReader(jsonBody))
			if err != nil {
				alert("Failed to contact server: " + err.Error())
				return
			}

			if response.StatusCode != 200 {
				if response.StatusCode == 500 {
					alert("Something went wrong on our end. Please try again later.")
				} else {
					var body map[string]interface{}
					err := json.NewDecoder(response.Body).Decode(&body)
					if err != nil {
						alert("Failed to decode response: " + err.Error())
					} else {
						alert(body["error"].(string))
					}
				}
				return
			}
		}()
		return nil
	}))

	go refreshMessages(localStorage, messageBox, userId)

	go func() {
		webSocket := js.Global().Get("WebSocket").New(localStorage.Call("getItem", "server").String() + "/api/ping")
		webSocket.Set("onmessage", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
			go refreshMessages(localStorage, messageBox, userId)
			return nil
		}))
	}()

	select {}
}