package main

import (
	"log"
	"sort"
	"strings"

	"github.com/diamondburned/arikawa/v3/discord"
	"github.com/gdamore/tcell/v2"
	"github.com/rivo/tview"
)

type GuildsTree struct {
	*tview.TreeView

	root            *tview.TreeNode
	selectedChannel *discord.Channel
}

func newGuildsTree() *GuildsTree {
	gt := &GuildsTree{
		TreeView: tview.NewTreeView(),

		root: tview.NewTreeNode(""),
	}

	gt.SetGraphics(cfg.Theme.GuildsTree.Graphics)
	gt.SetRoot(gt.root)
	gt.SetTopLevel(1)
	gt.SetSelectedFunc(gt.onSelected)

	gt.SetBackgroundColor(tcell.GetColor(cfg.Theme.GuildsTree.BackgroundColor))

	gt.SetTitle("Guilds")
	gt.SetTitleColor(tcell.GetColor(cfg.Theme.GuildsTree.TitleColor))
	gt.SetTitleAlign(tview.AlignLeft)

	padding := cfg.Theme.GuildsTree.BorderPadding
	gt.SetBorder(cfg.Theme.GuildsTree.Border)
	gt.SetBorderPadding(padding[0], padding[1], padding[2], padding[3])

	return gt
}

func (gt *GuildsTree) createGuildNodeFromID(n *tview.TreeNode, gid discord.GuildID) error {
	g, err := discordState.Cabinet.Guild(gid)
	if err != nil {
		return err
	}

	gn := tview.NewTreeNode(g.Name)
	gn.SetReference(g.ID)
	n.AddChild(gn)
	return nil
}

func (gt *GuildsTree) createChannelNode(n *tview.TreeNode, c discord.Channel) {
	cn := tview.NewTreeNode(gt.channelToString(c))
	cn.SetReference(c.ID)
	n.AddChild(cn)
}

func (gt *GuildsTree) channelToString(c discord.Channel) string {
	var s string
	switch c.Type {
	case discord.GuildText:
		s = "#" + c.Name
	case discord.DirectMessage:
		r := c.DMRecipients[0]
		s = r.Tag()
	case discord.GuildVoice:
		s = "v-" + c.Name
	case discord.GroupDM:
		s = c.Name
		// If the name of the channel is empty, use the recipients' tags
		if s == "" {
			rs := make([]string, len(c.DMRecipients))
			for _, r := range c.DMRecipients {
				rs = append(rs, r.Tag())
			}

			s = strings.Join(rs, ", ")
		}
	case discord.GuildNews:
		s = "n-" + c.Name
	case discord.GuildStore:
		s = "s-" + c.Name
	default:
		s = c.Name
	}

	return s
}

func (gt *GuildsTree) createChannelNodes(n *tview.TreeNode, cs []discord.Channel) {
	for _, c := range cs {
		// If the type of the channel is guild category or if the channel is an orphan channel.
		if c.Type == discord.GuildCategory || !c.ParentID.IsValid() {
			gt.createChannelNode(n, c)
		} else {
			var parent *tview.TreeNode
			n.Walk(func(node, _ *tview.TreeNode) bool {
				if node.GetReference() == c.ParentID {
					parent = node
					return false
				}

				return true
			})

			if parent != nil {
				gt.createChannelNode(parent, c)
			}
		}
	}
}

func (gt *GuildsTree) onSelected(n *tview.TreeNode) {
	gt.selectedChannel = nil

	messagesText.reset()
	messageInput.reset()

	if len(n.GetChildren()) != 0 {
		n.SetExpanded(!n.IsExpanded())
		return
	}

	switch ref := n.GetReference().(type) {
	case discord.GuildID:
		cs, err := discordState.Cabinet.Channels(ref)
		if err != nil {
			log.Println(err)
			return
		}

		sort.Slice(cs, func(i, j int) bool {
			return cs[i].Position < cs[j].Position
		})

		gt.createChannelNodes(n, cs)
	case discord.ChannelID:
		c, err := discordState.Cabinet.Channel(ref)
		if err != nil {
			log.Println(err)
			return
		}

		gt.selectedChannel = c
		messagesText.SetTitle(gt.channelToString(*c))

		ms, err := discordState.Messages(ref, cfg.MessagesLimit)
		if err != nil {
			log.Println(err)
			return
		}

		for i := len(ms) - 1; i >= 0; i-- {
			err = messagesText.createMessage(&ms[i])
			if err != nil {
				log.Println(err)
				continue
			}
		}

		app.SetFocus(messageInput)
	case nil: // Direct messages
		cs, err := discordState.Cabinet.PrivateChannels()
		if err != nil {
			log.Println(err)
			return
		}

		sort.Slice(cs, func(i, j int) bool {
			return cs[i].LastMessageID < cs[j].LastMessageID
		})

		for _, c := range cs {
			gt.createChannelNode(n, c)
		}
	}
}