package ui

import (
	"cmp"
	"net/url"
	"path"
	"slices"
	"strings"

	"github.com/ayn2op/discordo/internal/config"
	"github.com/ayn2op/tview"
	"github.com/diamondburned/arikawa/v3/discord"
	"github.com/diamondburned/ningen/v3"
	"github.com/gdamore/tcell/v3"
)

// ConfigureBox configures the provided box according to the provided theme.
func ConfigureBox(box *tview.Box, cfg *config.Theme) *tview.Box {
	border := cfg.Border
	normalBorderStyle, activeBorderStyle := border.NormalStyle.Style, border.ActiveStyle.Style
	normalBorderSet, activeBorderSet := border.NormalSet.BorderSet, border.ActiveSet.BorderSet

	title := cfg.Title
	normalTitleStyle, activeTitleStyle := title.NormalStyle.Style, title.ActiveStyle.Style

	footer := cfg.Footer
	normalFooterStyle, activeFooterStyle := footer.NormalStyle.Style, footer.ActiveStyle.Style

	padding := border.Padding

	box.
		SetBorderStyle(normalBorderStyle).
		SetBorderSet(normalBorderSet).
		SetBorderPadding(padding[0], padding[1], padding[2], padding[3]).
		SetTitleStyle(normalTitleStyle).
		SetTitleAlignment(title.Alignment.Alignment).
		SetFooterStyle(normalFooterStyle).
		SetFooterAlignment(footer.Alignment.Alignment).
		SetBlurFunc(func() {
			box.
				SetBorderStyle(normalBorderStyle).
				SetBorderSet(normalBorderSet)
			box.SetTitleStyle(normalTitleStyle).SetFooterStyle(normalFooterStyle)
		}).
		SetFocusFunc(func() {
			box.
				SetBorderStyle(activeBorderStyle).
				SetBorderSet(activeBorderSet)
			box.SetTitleStyle(activeTitleStyle).SetFooterStyle(activeFooterStyle)
		})

	if border.Enabled {
		box.SetBorders(tview.BordersAll)
	}

	return box
}

// Centered creates a new grid with provided primitive aligned in the center.
func Centered(m tview.Model, width, height int) tview.Model {
	return tview.NewGrid().
		SetColumns(0, width, 0).
		SetRows(0, height, 0).
		AddItem(m, 1, 1, 1, 1, 0, 0, true)
}

func ChannelToString(channel discord.Channel, icons config.Icons, state *ningen.State) string {
	var icon string
	switch channel.Type {
	case discord.DirectMessage, discord.GroupDM:
		if channel.Name != "" {
			return channel.Name
		}

		recipients := make([]string, len(channel.DMRecipients))
		for i, r := range channel.DMRecipients {
			if state != nil && channel.Type == discord.DirectMessage {
				if rel, ok := state.RelationshipState.FullRelationship(r.ID); ok && rel.Type == discord.FriendRelationship {
					if rel.Nickname != nil && *rel.Nickname != "" {
						recipients[i] = *rel.Nickname
						continue
					}
				}
			}
			recipients[i] = r.DisplayOrUsername()
		}

		return strings.Join(recipients, ", ")

	case discord.GuildCategory:
		icon = icons.GuildCategory
	case discord.GuildText:
		icon = icons.GuildText
	case discord.GuildVoice:
		icon = icons.GuildVoice
	case discord.GuildStageVoice:
		icon = icons.GuildStageVoice

	case discord.GuildAnnouncementThread:
		icon = icons.GuildAnnouncementThread
	case discord.GuildPublicThread:
		icon = icons.GuildPublicThread
	case discord.GuildPrivateThread:
		icon = icons.GuildPrivateThread

	case discord.GuildAnnouncement:
		icon = icons.GuildAnnouncement
	case discord.GuildForum:
		icon = icons.GuildForum
	case discord.GuildStore:
		icon = icons.GuildStore
	}

	return icon + channel.Name
}

func SortGuildChannels(channels []discord.Channel) {
	slices.SortFunc(channels, func(a, b discord.Channel) int {
		return cmp.Compare(a.Position, b.Position)
	})
}

func SortPrivateChannels(channels []discord.Channel) {
	slices.SortFunc(channels, func(a, b discord.Channel) int {
		// Descending order
		return cmp.Compare(getMessageIDFromChannel(b), getMessageIDFromChannel(a))
	})
}

func getMessageIDFromChannel(channel discord.Channel) discord.MessageID {
	if channel.LastMessageID.IsValid() {
		return channel.LastMessageID
	}
	return discord.MessageID(channel.ID)
}

// LinkDisplayText returns a short, human-friendly label for a URL.
// Known hosts get special treatment; everything else shows host + truncated path.
func LinkDisplayText(raw string) string {
	parsed, err := url.Parse(raw)
	if err != nil || parsed.Host == "" {
		return raw
	}

	host := strings.ToLower(parsed.Host)
	p := strings.TrimRight(parsed.EscapedPath(), "/")
	segments := strings.Split(strings.TrimLeft(p, "/"), "/")

	// Discord CDN / media — show cleaned filename
	if host == "cdn.discordapp.com" || host == "media.discordapp.net" {
		if base := path.Base(p); base != "" && base != "." && base != "/" {
			return cdnDisplayName(base)
		}
	}

	// Tenor GIFs
	if host == "tenor.com" || strings.HasSuffix(host, ".tenor.com") {
		return "Tenor GIF"
	}

	// Substack: open.substack.com/pub/{author} or {author}.substack.com
	switch {
	case host == "open.substack.com" || host == "substack.com":
		if len(segments) >= 2 && segments[0] == "pub" && segments[1] != "" {
			return "Substack - " + segments[1]
		}
		return "Substack"
	case strings.HasSuffix(host, ".substack.com"):
		return "Substack - " + strings.TrimSuffix(host, ".substack.com")
	}

	// YouTube
	if host == "youtube.com" || host == "www.youtube.com" || host == "m.youtube.com" || host == "youtu.be" {
		return "YouTube"
	}

	// Twitter / X
	if host == "twitter.com" || host == "www.twitter.com" || host == "x.com" || host == "www.x.com" {
		return "X (Twitter)"
	}

	// Reddit
	if host == "reddit.com" || host == "www.reddit.com" || host == "old.reddit.com" {
		if len(segments) >= 2 && segments[0] == "r" {
			return "Reddit - r/" + segments[1]
		}
		return "Reddit"
	}

	// GitHub
	if host == "github.com" || host == "www.github.com" {
		if len(segments) >= 2 && segments[0] != "" && segments[1] != "" {
			return "GitHub - " + segments[0] + "/" + segments[1]
		}
		return "GitHub"
	}

	// Generic fallback: host + truncated path
	switch {
	case p == "", p == "/":
		return parsed.Host
	case len(p) > 48:
		return parsed.Host + p[:45] + "..."
	default:
		return parsed.Host + p
	}
}

// cdnDisplayName cleans up Discord CDN filenames for display.
// Handles URL-encoded URLs used as filenames and UUID filenames.
func cdnDisplayName(name string) string {
	ext := path.Ext(name)
	stem := strings.TrimSuffix(name, ext)

	// URL-encoded URL as filename (e.g., "https3A2F2F...512x512.png")
	if strings.HasPrefix(stem, "http") && strings.Contains(stem, "2F") {
		return "image" + ext
	}

	// UUID filename (e.g., "c02b97b3-813f-4c03-904a-0bd4240f2c10.jpg")
	if isUUID(stem) {
		return "image" + ext
	}

	// Truncate long filenames
	if len(name) > 40 {
		return name[:37] + "..." + ext
	}

	return name
}

func isUUID(s string) bool {
	if len(s) != 36 {
		return false
	}
	for i, c := range s {
		if i == 8 || i == 13 || i == 18 || i == 23 {
			if c != '-' {
				return false
			}
		} else if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')) {
			return false
		}
	}
	return true
}

func MergeStyle(base, overlay tcell.Style) tcell.Style {
	fg := overlay.GetForeground()
	if fg == tcell.ColorDefault {
		fg = base.GetForeground()
	}
	bg := overlay.GetBackground()
	if bg == tcell.ColorDefault {
		bg = base.GetBackground()
	}
	style := base.Foreground(fg).Background(bg)
	style = style.Bold(base.HasBold() || overlay.HasBold())
	style = style.Dim(base.HasDim() || overlay.HasDim())
	style = style.Italic(base.HasItalic() || overlay.HasItalic())
	style = style.Blink(base.HasBlink() || overlay.HasBlink())
	style = style.Reverse(base.HasReverse() || overlay.HasReverse())
	style = style.StrikeThrough(base.HasStrikeThrough() || overlay.HasStrikeThrough())
	if base.HasUnderline() || overlay.HasUnderline() {
		style = style.Underline(true)
	}
	return style
}