package main

import (
	"sort"
	"strings"

	"github.com/atotto/clipboard"
	"github.com/gdamore/tcell/v2"
	"github.com/rigormorrtiss/discordgo"
	"github.com/rigormorrtiss/discordo/ui"
	"github.com/rigormorrtiss/discordo/util"
	"github.com/rivo/tview"
)

var (
	app               *tview.Application
	loginForm         *tview.Form
	guildsTreeView    *tview.TreeView
	channelsTreeView  *tview.TreeView
	messagesTextView  *tview.TextView
	messageInputField *tview.InputField
	mainFlex          *tview.Flex

	conf    *util.Config
	session *discordgo.Session
	channel *discordgo.Channel
)

func main() {
	conf = util.NewConfig()

	tview.Styles.PrimitiveBackgroundColor = tcell.GetColor(conf.Theme.Background)

	if !conf.Theme.Borders {
		tview.Borders = struct {
			Horizontal       rune
			Vertical         rune
			TopLeft          rune
			TopRight         rune
			BottomLeft       rune
			BottomRight      rune
			LeftT            rune
			RightT           rune
			TopT             rune
			BottomT          rune
			Cross            rune
			HorizontalFocus  rune
			VerticalFocus    rune
			TopLeftFocus     rune
			TopRightFocus    rune
			BottomLeftFocus  rune
			BottomRightFocus rune
		}{}
	}

	app = tview.NewApplication().
		EnableMouse(conf.Mouse).
		SetInputCapture(onAppInputCapture)
	guildsTreeView = ui.NewGuildsTreeView(onGuildsTreeViewSelected)
	channelsTreeView = ui.NewChannelsTreeView(onChannelsTreeViewSelected)
	messagesTextView = ui.NewMessagesTextView(app)
	messageInputField = ui.NewMessageInputField(onMessageInputFieldInputCapture, conf.Theme)
	mainFlex = ui.NewMainFlex(guildsTreeView, channelsTreeView, messagesTextView, messageInputField)

	token := conf.Token
	if t := util.GetPassword("token"); t != "" {
		token = t
	}

	if token != "" {
		app.
			SetRoot(mainFlex, true).
			SetFocus(guildsTreeView)

		session = newSession()
		session.Token = token
		session.Identify.Token = token
		if err := session.Open(); err != nil {
			panic(err)
		}
	} else {
		loginForm = ui.NewLoginForm(onLoginFormLoginButtonSelected)
		app.SetRoot(loginForm, true)
	}

	if err := app.Run(); err != nil {
		panic(err)
	}
}

func onAppInputCapture(e *tcell.EventKey) *tcell.EventKey {
	switch e.Name() {
	case "Alt+Rune[1]":
		app.SetFocus(guildsTreeView)
	case "Alt+Rune[2]":
		app.SetFocus(channelsTreeView)
	case "Alt+Rune[3]":
		app.SetFocus(messagesTextView)
	case "Alt+Rune[4]":
		app.SetFocus(messageInputField)
	}

	return e
}

func onMessageInputFieldInputCapture(e *tcell.EventKey) *tcell.EventKey {
	switch e.Key() {
	case tcell.KeyEnter:
		t := strings.TrimSpace(messageInputField.GetText())
		if t == "" {
			return nil
		}

		session.ChannelMessageSend(channel.ID, t)
		messageInputField.SetText("")
	case tcell.KeyCtrlV:
		text, _ := clipboard.ReadAll()
		text = messageInputField.GetText() + text
		messageInputField.SetText(text)
	}

	return e
}

func newSession() *discordgo.Session {
	s, err := discordgo.New()
	if err != nil {
		panic(err)
	}

	s.UserAgent = "" +
		"Mozilla/5.0 (X11; Linux x86_64) " +
		"AppleWebKit/537.36 (KHTML, like Gecko) " +
		"Chrome/92.0.4515.131 Safari/537.36"
	s.Identify.Compress = false
	s.Identify.Intents = 0
	s.Identify.LargeThreshold = 0
	s.Identify.Properties.Device = ""
	s.Identify.Properties.Browser = "Chrome"
	s.Identify.Properties.OS = "Linux"

	s.AddHandlerOnce(onSessionReady)
	s.AddHandler(onSessionMessageCreate)

	return s
}

func onSessionReady(_ *discordgo.Session, r *discordgo.Ready) {
	rootN := guildsTreeView.GetRoot()
	for _, g := range r.Guilds {
		gn := tview.NewTreeNode(g.Name).
			SetReference(g.ID)
		rootN.AddChild(gn)
	}

	guildsTreeView.SetCurrentNode(rootN)
}

func onSessionMessageCreate(_ *discordgo.Session, m *discordgo.MessageCreate) {
	if channel != nil && channel.ID == m.ChannelID {
		util.WriteMessage(messagesTextView, m.Message, session.State.Ready.User.ID)
	}
}

func onGuildsTreeViewSelected(gn *tview.TreeNode) {
	app.SetFocus(channelsTreeView)
	messagesTextView.SetTitle("")
	messagesTextView.Clear()

	gID := gn.GetReference().(string)
	g, _ := session.State.Guild(gID)
	cs := g.Channels
	sort.Slice(cs, func(i, j int) bool {
		return cs[i].Position < cs[j].Position
	})

	rootN := channelsTreeView.GetRoot()
	rootN.ClearChildren()
	// Top-level channels
	ui.CreateTopLevelTreeNodes(rootN, cs)
	// Category channels
CategoryLoop:
	for _, c := range cs {
		if c.Type == discordgo.ChannelTypeGuildCategory {
			for _, child := range cs {
				if child.ParentID == c.ID {
					cn := tview.NewTreeNode(c.Name).
						SetReference(c.ID)
					rootN.AddChild(cn)
					continue CategoryLoop
				}
			}

			cn := tview.NewTreeNode(c.Name).
				SetReference(c.ID)
			rootN.AddChild(cn)
		}
	}
	// Second-level channels
	ui.CreateSecondLevelTreeNodes(channelsTreeView, rootN, cs)

	channelsTreeView.SetCurrentNode(rootN)
}

func onChannelsTreeViewSelected(n *tview.TreeNode) {
	cID := n.GetReference().(string)
	c, _ := session.State.Channel(cID)
	switch c.Type {
	case discordgo.ChannelTypeGuildCategory:
		n.SetExpanded(!n.IsExpanded())
	case discordgo.ChannelTypeGuildText, discordgo.ChannelTypeGuildNews:
		if len(n.GetChildren()) == 0 {
			channel = c
			app.SetFocus(messageInputField)
			messagesTextView.Clear()

			title := "#" + c.Name
			if c.Topic != "" {
				title += " - " + c.Topic
			}
			messagesTextView.SetTitle(title)

			go writeMessages(c.ID)
		} else {
			n.SetExpanded(!n.IsExpanded())
		}
	}
}

func writeMessages(cID string) {
	msgs, _ := session.ChannelMessages(cID, conf.GetMessagesLimit, "", "", "")
	for i := len(msgs) - 1; i >= 0; i-- {
		util.WriteMessage(messagesTextView, msgs[i], session.State.Ready.User.ID)
	}
}

func onLoginFormLoginButtonSelected() {
	email := loginForm.GetFormItem(0).(*tview.InputField).GetText()
	password := loginForm.GetFormItem(1).(*tview.InputField).GetText()
	if email == "" || password == "" {
		return
	}

	session = newSession()
	// Try to login without TOTP
	lr, err := util.Login(session, email, password)
	if err != nil {
		panic(err)
	}

	if lr.Token != "" && !lr.MFA {
		app.
			SetRoot(mainFlex, true).
			SetFocus(guildsTreeView)

		session.Token = lr.Token
		session.Identify.Token = lr.Token
		if err = session.Open(); err != nil {
			panic(err)
		}

		go util.SetPassword("token", lr.Token)
	} else if lr.MFA {
		loginForm = ui.NewMfaLoginForm(func() {
			code := loginForm.GetFormItem(0).(*tview.InputField).GetText()
			if code == "" {
				return
			}

			lr, err = util.TOTP(session, code, lr.Ticket)
			if err != nil {
				panic(err)
			}

			app.
				SetRoot(mainFlex, true).
				SetFocus(guildsTreeView)

			session.Token = lr.Token
			session.Identify.Token = lr.Token
			if err = session.Open(); err != nil {
				panic(err)
			}

			go util.SetPassword("token", lr.Token)
		})

		app.SetRoot(loginForm, true)
	}
}