package main

import (
	"fmt"
	"log"
	"os"
	"regexp"
	"strconv"
	"strings"

	"git.zio.sh/astra/bsky2tg/bsky"
	tgbotapi "github.com/OvyFlash/telegram-bot-api"
)

// HandleBotMessage processes incoming bot messages and looks for post URLs
func (h *handler) HandleBotMessage(message *tgbotapi.Message) error {
	// Check if user is a channel admin
	if message.From != nil && !h.isUserAdmin(message.From.ID) {
		log.Printf("User is not an admin: %s", message.From)
		// h.sendMessage(message.Chat.ID, "❌ Only channel admins can use this bot")
		return nil
	}

	// Get text from message or caption
	text := message.Text
	if text == "" {
		text = message.Caption
	}

	if text == "" {
		return nil
	}

	// Look for Bluesky post URLs in the message
	// Format: https://bsky.app/profile/{handle}/post/{rkey}
	var postURL string
	if message.ForwardOrigin != nil {
		if len(message.CaptionEntities) != 0 {
			postURL = message.CaptionEntities[len(message.CaptionEntities)-1].URL
		} else {
			postURL = message.Entities[len(message.Entities)-1].URL
		}
	} else {
		postURL = extractBskyPostURL(text)
		if postURL == "" {
			return nil
		}
	}

	// Extract RKey from the URL (last part after /post/)
	rkey := extractRKeyFromURL(postURL)
	if rkey == "" {
		h.sendMessage(message.Chat.ID, "❌ Could not extract post ID from URL")
		return nil
	}

	// Fetch the post from PDS using the RKey
	post := h.bsky.Bluesky.GetPost(fmt.Sprintf("at://%s/app.bsky.feed.post/%s", h.bsky.Bluesky.Cfg.DID, rkey))
	if post == nil {
		h.sendMessage(message.Chat.ID, "❌ Could not fetch post from Bluesky")
		return nil
	}

	// Format the response
	response := formatPostResponse(post, postURL)

	// Try to find the corresponding channel message
	telegramRecord, err := h.bsky.Bluesky.GetTelegramData(rkey)
	if err == "" && telegramRecord != nil && len(telegramRecord.MessageID) > 0 {
		h.sendMessageWithButtons(message.Chat.ID, response, rkey, postURL, telegramRecord.ChannelID, telegramRecord.MessageID[0])
	} else {
		h.sendMessage(message.Chat.ID, response)
	}

	return nil
}

// extractBskyPostURL finds a Bluesky post URL in text
func extractBskyPostURL(text string) string {
	// Pattern: https://bsky.app/profile/{anything}/post/{rkey}
	pattern := regexp.MustCompile(`https://bsky\.app/profile/[^/]+/post/[a-z0-9]+`)
	matches := pattern.FindString(text)
	return matches
}

// extractRKeyFromURL extracts the post ID (RKey) from a Bluesky URL
// URL format: https://bsky.app/profile/{handle}/post/{rkey}
func extractRKeyFromURL(url string) string {
	// Get the last part after /post/
	parts := strings.Split(url, "/post/")
	if len(parts) < 2 {
		return ""
	}
	return parts[len(parts)-1]
}

// formatPostResponse creates a formatted response message
func formatPostResponse(post *bsky.Post, postURL string) string {
	if post == nil {
		return "❌ Invalid post data"
	}

	return `Post found\!`
}

// escapeMarkdown escapes special markdown characters for Telegram MarkdownV2
func escapeMarkdown(text string) string {
	// Order matters: escape backslash first to avoid double-escaping
	// Telegram MarkdownV2 requires these characters to be escaped:
	replacements := []struct {
		old, new string
	}{
		{`\`, `\\`}, // backslash must be first
		{`_`, `\_`}, // underscore (italic)
		{`*`, `\*`}, // asterisk (bold)
		{`[`, `\[`}, // bracket (link)
		{`]`, `\]`}, // bracket (link)
		{`(`, `\(`}, // parenthesis (link)
		{`)`, `\)`}, // parenthesis (link)
		{`~`, `\~`}, // tilde (strikethrough)
		{"`", "`"},  // backtick (inline code)
		{`>`, `\>`}, // greater-than (blockquote)
		{`#`, `\#`}, // hash (heading)
		{`+`, `\+`}, // plus (list)
		{`-`, `\-`}, // minus (list)
		{`.`, `\.`}, // period (ordered list)
		{`!`, `\!`}, // exclamation (image)
	}

	result := text
	for _, replacement := range replacements {
		result = strings.ReplaceAll(result, replacement.old, replacement.new)
	}

	return result
}

// sendMessage sends a message to a user
func (h *handler) sendMessage(chatID int64, text string) error {
	msg := tgbotapi.NewMessage(chatID, text)
	msg.ParseMode = tgbotapi.ModeMarkdownV2

	_, err := h.tg.Send(msg)
	return err
}

// sendMessageWithButtons sends a message with action buttons for the post
func (h *handler) sendMessageWithButtons(chatID int64, text, rkey, postURL string, channelID int64, messageID int) error {
	msg := tgbotapi.NewMessage(chatID, text)
	msg.LinkPreviewOptions = tgbotapi.LinkPreviewOptions{
		URL:              fmt.Sprintf(embedURL, h.bsky.Bluesky.Cfg.DID, rkey),
		PreferSmallMedia: true,
		ShowAboveText:    true,
	}
	msg.ParseMode = tgbotapi.ModeMarkdownV2

	viewChannel := tgbotapi.NewInlineKeyboardButtonURL(
		"📍 View in Channel",
		fmt.Sprintf("tg://privatepost?channel=%d&post=%d", -channelID-1000000000000, messageID),
	)
	viewBsky := tgbotapi.NewInlineKeyboardButtonURL(
		"🦋 View on Bluesky",
		postURL,
	)
	deleteTG := tgbotapi.NewInlineKeyboardButtonData("🗑 Delete from Channel", "del_tg:"+rkey)
	deleteBsky := tgbotapi.NewInlineKeyboardButtonData("❌ Delete from Bluesky", "del_bsky:"+rkey)
	closeBtn := tgbotapi.NewInlineKeyboardButtonData("✖ Close", "close")

	msg.ReplyMarkup = tgbotapi.NewInlineKeyboardMarkup(
		tgbotapi.NewInlineKeyboardRow(viewChannel, viewBsky),
		tgbotapi.NewInlineKeyboardRow(deleteTG, deleteBsky),
		tgbotapi.NewInlineKeyboardRow(closeBtn),
	)

	_, err := h.tg.Send(msg)
	return err
}

// HandleCallbackQuery processes inline button presses
func (h *handler) HandleCallbackQuery(query *tgbotapi.CallbackQuery) {
	answer := func(text string) {
		h.tg.Send(tgbotapi.NewCallback(query.ID, text))
	}

	editDone := func(text string) {
		if query.Message == nil {
			return
		}
		edit := tgbotapi.NewEditMessageText(query.Message.Chat.ID, query.Message.MessageID, text)
		edit.ParseMode = tgbotapi.ModeMarkdownV2
		edit.LinkPreviewOptions = tgbotapi.LinkPreviewOptions{IsDisabled: true}
		emptyKb := tgbotapi.NewInlineKeyboardMarkup()
		edit.ReplyMarkup = &emptyKb
		h.tg.Send(edit)
	}

	if !h.isUserAdmin(query.From.ID) {
		answer("⛔ Admins only")
		return
	}

	data := query.Data
	switch {
	case data == "close":
		if query.Message != nil {
			h.tg.Send(tgbotapi.NewDeleteMessage(query.Message.Chat.ID, query.Message.MessageID))
		}
		answer("")

	case strings.HasPrefix(data, "del_tg:"):
		rkey := strings.TrimPrefix(data, "del_tg:")
		rec, err := h.bsky.Bluesky.GetTelegramData(rkey)
		if err != "" {
			answer("❌ Post not found in channel records")
			return
		}
		m := tgbotapi.NewDeleteMessages(rec.ChannelID, rec.MessageID)
		if _, e := h.tg.Send(m); e != nil {
			answer("❌ Failed to delete: " + e.Error())
			return
		}
		h.bsky.Bluesky.DeleteRecord([]string{rkey, h.bsky.Bluesky.Cfg.DID, bsky.PostCollection})
		answer("🗑 Deleted from channel")
		editDone("🗑 *Deleted from Telegram channel*")

	case strings.HasPrefix(data, "del_bsky:"):
		rkey := strings.TrimPrefix(data, "del_bsky:")
		h.bsky.Bluesky.DeleteRecord([]string{rkey, h.bsky.Bluesky.Cfg.DID, "app.bsky.feed.post"})
		answer("❌ Deleted from Bluesky")
		editDone("❌ *Deleted from Bluesky*")

	default:
		answer("")
	}
}

// LoadChannelAdmins fetches the list of channel admins from Telegram
func (h *handler) LoadChannelAdmins() error {
	// Get channel admins
	cid, _ := strconv.ParseInt(os.Getenv("TG_CHANNEL_ID"), 10, 64)
	admins, err := h.tg.GetChatAdministrators(
		tgbotapi.ChatAdministratorsConfig{
			ChatConfig: tgbotapi.ChatConfig{
				ChatID: cid,
			},
		},
	)
	if err != nil {
		return fmt.Errorf("failed to get channel admins: %w", err)
	}

	// Store admin IDs in the map
	for _, admin := range admins {
		if admin.User != nil {
			h.channelAdmins[admin.User.ID] = true
		}
	}

	count := len(h.channelAdmins)
	fmt.Printf("Loaded %d channel admins\n", count)
	return nil
}

// isUserAdmin checks if a user ID is a channel admin
func (h *handler) isUserAdmin(userID int64) bool {
	return h.channelAdmins[userID]
}