package chat

import (
	"log/slog"
	"strings"

	"github.com/ayn2op/discordo/internal/config"
	"github.com/ayn2op/discordo/internal/ui"
	"github.com/ayn2op/discordo/pkg/picker"
	"github.com/ayn2op/tview"
	"github.com/ayn2op/tview/help"
	"github.com/ayn2op/tview/keybind"
	"github.com/diamondburned/arikawa/v3/discord"
	"github.com/gdamore/tcell/v3"
)

type channelsPicker struct {
	*picker.Model
	chatView *Model
}

var _ help.KeyMap = (*channelsPicker)(nil)

func newChannelsPicker(cfg *config.Config, chatView *Model) *channelsPicker {
	cp := &channelsPicker{picker.NewModel(), chatView}
	cp.Box = ui.ConfigureBox(tview.NewBox(), &cfg.Theme)
	// When a child of the parent flex is focused, the parent layout itself is not reported as focused.
	// Instead, the focused child (picker) is considered focused.
	// Therefore, we manually set the active border style on the picker to ensure it displays the correct focused appearance.
	cp.
		SetBlurFunc(nil).
		SetFocusFunc(nil).
		SetBorderSet(cfg.Theme.Border.ActiveSet.BorderSet).
		SetBorderStyle(cfg.Theme.Border.ActiveStyle.Style).
		SetTitleStyle(cfg.Theme.Title.ActiveStyle.Style).
		SetFooterStyle(cfg.Theme.Footer.ActiveStyle.Style)

	cp.SetTitle("Channels")
	cp.SetScrollBarVisibility(cfg.Theme.ScrollBar.Visibility.ScrollBarVisibility)
	cp.SetScrollBar(tview.NewScrollBar().
		SetTrackStyle(cfg.Theme.ScrollBar.TrackStyle.Style).
		SetThumbStyle(cfg.Theme.ScrollBar.ThumbStyle.Style).
		SetGlyphSet(cfg.Theme.ScrollBar.GlyphSet.GlyphSet))
	cp.SetKeyMap(&picker.KeyMap{
		Cancel: cfg.Keybinds.Picker.Cancel.Keybind,
		Up:     cfg.Keybinds.Picker.Up.Keybind,
		Down:   cfg.Keybinds.Picker.Down.Keybind,
		Top:    cfg.Keybinds.Picker.Top.Keybind,
		Bottom: cfg.Keybinds.Picker.Bottom.Keybind,
		Select: cfg.Keybinds.Picker.Select.Keybind,
	})
	return cp
}

func (cp *channelsPicker) HandleEvent(event tcell.Event) tview.Command {
	switch event := event.(type) {
	case *picker.SelectedEvent:
		channelID, ok := event.Reference.(discord.ChannelID)
		if !ok || !channelID.IsValid() {
			return nil
		}

		channel, err := cp.chatView.state.Cabinet.Channel(channelID)
		if err != nil {
			slog.Error("failed to get channel from state", "err", err, "channel_id", channelID)
			return nil
		}

		node := cp.chatView.guildsTree.findNodeByChannelID(channel.ID)
		if node == nil {
			slog.Error("failed to locate channel in tree", "channel_id", channel.ID)
			return nil
		}

		cp.chatView.guildsTree.expandPathToNode(node)
		cp.chatView.guildsTree.SetCurrentNode(node)
		if channel.Type != discord.GuildCategory {
			cp.chatView.guildsTree.onSelected(node)
		}
		cp.chatView.closePicker()
		cp.chatView.focusMessageInput()
		return nil
	case *picker.CancelEvent:
		cp.chatView.closePicker()
		return nil
	}
	return cp.Model.HandleEvent(event)
}

func (cp *channelsPicker) update() {
	cp.ClearItems()
	state := cp.chatView.state

	privateChannels, err := state.Cabinet.PrivateChannels()
	if err != nil {
		slog.Error("failed to get private channels from state", "err", err)
		return
	}

	ui.SortPrivateChannels(privateChannels)
	for _, channel := range privateChannels {
		cp.addChannel(nil, channel)
	}

	guilds, err := state.Cabinet.Guilds()
	if err != nil {
		slog.Error("failed to get guilds from state", "err", err)
		return
	}

	for _, guild := range guilds {
		channels, err := state.Cabinet.Channels(guild.ID)
		if err != nil {
			slog.Error("failed to get channels from state", "err", err, "guild_id", guild.ID)
			continue
		}

		for _, channel := range channels {
			cp.addChannel(&guild, channel)
		}
	}

	cp.Update()
}

func (cp *channelsPicker) addChannel(guild *discord.Guild, channel discord.Channel) {
	var b strings.Builder
	b.WriteString(ui.ChannelToString(channel, cp.chatView.cfg.Icons, cp.chatView.state))

	if guild != nil {
		b.WriteString(" - ")
		b.WriteString(guild.Name)
	}

	name := b.String()
	cp.AddItem(picker.Item{Text: name, FilterText: name, Reference: channel.ID})
}

func (cp *channelsPicker) ShortHelp() []keybind.Keybind {
	cfg := cp.chatView.cfg.Keybinds.Picker
	return []keybind.Keybind{cfg.Up.Keybind, cfg.Down.Keybind, cfg.Select.Keybind, cfg.Cancel.Keybind}
}

func (cp *channelsPicker) FullHelp() [][]keybind.Keybind {
	cfg := cp.chatView.cfg.Keybinds.Picker
	return [][]keybind.Keybind{
		{cfg.Up.Keybind, cfg.Down.Keybind, cfg.Top.Keybind, cfg.Bottom.Keybind},
		{cfg.Select.Keybind, cfg.Cancel.Keybind},
	}
}