package telegram

import (
	"fmt"
	"strings"

	"tgchanbot/internal/storage"

	tele "gopkg.in/telebot.v3"
)

const (
	cbPrefixCat     = "cat:"
	cbPrefixConfirm = "confirm:"
	cbPrefixTitle   = "title:"
	cbCancel        = "cancel"
)

func (b *Bot) handlePost(c tele.Context) error {
	msg := c.Message()
	payload := strings.TrimSpace(c.Message().Payload)

	// 快捷方式: 回复消息 + /post <分类> /tt <标题>
	if msg.ReplyTo != nil && payload != "" {
		return b.handleQuickPost(c, msg.ReplyTo, payload)
	}

	// 常规交互流程
	b.states.StartPost(c.Sender().ID)
	return c.Reply("📨 请转发需要归档到目录的消息\n\n消息将被同步发送到频道并添加到目录\n\n💡 快捷方式: 回复消息并发送\n`/post <分类> /tt <标题>`", tele.ModeMarkdown)
}

func (b *Bot) handleQuickPost(c tele.Context, replyMsg *tele.Message, payload string) error {
	// 解析: <分类> /tt <标题>
	parts := strings.SplitN(payload, "/tt", 2)
	category := strings.TrimSpace(parts[0])

	var title string
	if len(parts) > 1 {
		title = strings.TrimSpace(parts[1])
	}

	if category == "" {
		return c.Reply("❌ 用法: /post <分类> /tt <标题>\n例如: /post iOS /tt 某个APP推荐")
	}

	// 验证分类存在
	if !b.storage.CategoryExists(category) {
		categories, _ := b.storage.ListCategories()
		var names []string
		for _, cat := range categories {
			names = append(names, cat.Name)
		}
		return c.Reply(fmt.Sprintf("❌ 分类 [%s] 不存在\n\n可用分类: %s", category, strings.Join(names, ", ")))
	}

	// 标题: 优先使用指定标题，否则从回复消息提取
	if title == "" {
		title = extractTitle(replyMsg)
	}

	// 构建链接
	link := buildMessageLinkFromReply(c.Message(), replyMsg)

	// 创建条目
	entry, err := b.storage.CreateEntry(category, title, link)
	if err != nil {
		return c.Reply(fmt.Sprintf("❌ 保存失败: %v", err))
	}

	b.toc.TriggerUpdate()

	return c.Reply(fmt.Sprintf("✅ 已添加\n\nID: `%s`\n分类: %s\n标题: %s\n链接: %s",
		entry.ID, entry.Category, entry.Title, entry.Link), tele.ModeMarkdown)
}

func buildMessageLinkFromReply(currentMsg, replyMsg *tele.Message) string {
	chat := currentMsg.Chat
	msgID := replyMsg.ID

	if chat.Username != "" {
		return fmt.Sprintf("https://t.me/%s/%d", chat.Username, msgID)
	}

	chatID := chat.ID
	if chatID < 0 {
		chatID = -chatID - 1000000000000
	}
	return fmt.Sprintf("https://t.me/c/%d/%d", chatID, msgID)
}

func (b *Bot) handleTextInput(c tele.Context) error {
	msg := c.Message()
	if msg == nil {
		return nil
	}

	// 只处理私聊消息，忽略群组对话
	if c.Chat().Type != tele.ChatPrivate {
		return nil
	}

	// 只处理有活跃投稿状态的用户
	state := b.states.Get(c.Sender().ID)
	if state == nil {
		return nil
	}

	// 转发消息处理 (StepAwaitForward)
	// OriginalChat: 转发自频道/群组; OriginalSender: 转发自个人用户
	isForwarded := msg.OriginalChat != nil || msg.OriginalSender != nil
	if isForwarded && state.Step == StepAwaitForward {
		return b.handleForwarded(c)
	}

	// 自定义标题输入 (StepAwaitTitle)
	if state.Step == StepAwaitTitle {
		return b.handleTitleInput(c)
	}

	return nil
}

func (b *Bot) handleForwarded(c tele.Context) error {
	if !b.cfg.IsAdmin(c.Sender().ID) {
		return nil
	}

	state := b.states.Get(c.Sender().ID)
	if state == nil || state.Step != StepAwaitForward {
		return nil
	}

	msg := c.Message()
	// 检查是否为转发消息（来自频道/群组或个人用户）
	if msg.OriginalChat == nil && msg.OriginalSender == nil {
		return c.Reply("❌ 这不是一条转发消息，请转发一条消息给我")
	}

	b.states.SetForwarded(c.Sender().ID, msg)

	categories, err := b.storage.ListCategories()
	if err != nil {
		b.states.Delete(c.Sender().ID)
		return c.Reply(fmt.Sprintf("❌ 获取分类失败: %v", err))
	}

	if len(categories) == 0 {
		b.states.Delete(c.Sender().ID)
		return c.Reply("❌ 暂无分类，请先使用 /cat_add 创建分类")
	}

	keyboard := b.buildCategoryKeyboard(categories)
	return c.Reply("📁 请选择分类:", keyboard)
}

func (b *Bot) buildCategoryKeyboard(categories []storage.Category) *tele.ReplyMarkup {
	menu := &tele.ReplyMarkup{}
	var rows []tele.Row

	var currentRow []tele.Btn
	for _, cat := range categories {
		btn := menu.Data(cat.Name, cbPrefixCat+cat.Name)
		currentRow = append(currentRow, btn)

		if len(currentRow) == 3 {
			rows = append(rows, menu.Row(currentRow...))
			currentRow = nil
		}
	}

	if len(currentRow) > 0 {
		rows = append(rows, menu.Row(currentRow...))
	}

	cancelBtn := menu.Data("❌ 取消", cbCancel)
	rows = append(rows, menu.Row(cancelBtn))

	menu.Inline(rows...)
	return menu
}

func (b *Bot) handleCallback(c tele.Context) error {
	if !b.cfg.IsAdmin(c.Sender().ID) {
		return c.Respond(&tele.CallbackResponse{Text: "无权限"})
	}

	// telebot v3 会在 data 前加 \f 前缀，需要去掉
	data := strings.TrimPrefix(c.Callback().Data, "\f")
	userID := c.Sender().ID

	switch {
	case data == cbCancel:
		return b.handleCancelCallback(c, userID)

	case strings.HasPrefix(data, cbPrefixCat):
		category := strings.TrimPrefix(data, cbPrefixCat)
		return b.handleCategoryCallback(c, userID, category)

	case strings.HasPrefix(data, cbPrefixTitle):
		action := strings.TrimPrefix(data, cbPrefixTitle)
		return b.handleTitleCallback(c, userID, action)

	case strings.HasPrefix(data, cbPrefixConfirm):
		action := strings.TrimPrefix(data, cbPrefixConfirm)
		return b.handleConfirmCallback(c, userID, action)
	}

	return c.Respond()
}

func (b *Bot) handleCancelCallback(c tele.Context, userID int64) error {
	b.states.Delete(userID)
	c.Edit("❌ 已取消")
	return c.Respond(&tele.CallbackResponse{Text: "已取消"})
}

func (b *Bot) handleTitleCallback(c tele.Context, userID int64, action string) error {
	state := b.states.Get(userID)
	if state == nil || state.Step != StepAwaitTitle {
		return c.Respond(&tele.CallbackResponse{Text: "会话已过期"})
	}

	if action == "default" {
		// 使用默认标题
		title := extractTitle(state.ForwardedMsg)
		b.states.SetTitle(userID, title)
		return b.showConfirmation(c, state, title)
	}

	// 自定义标题 - 提示用户输入
	c.Edit("✏️ 请发送新标题:")
	return c.Respond()
}

func (b *Bot) handleTitleInput(c tele.Context) error {
	state := b.states.Get(c.Sender().ID)
	if state == nil || state.Step != StepAwaitTitle {
		return nil
	}

	title := strings.TrimSpace(c.Message().Text)
	if title == "" {
		return c.Reply("❌ 标题不能为空，请重新输入:")
	}

	if len(title) > 50 {
		title = title[:47] + "..."
	}

	b.states.SetTitle(c.Sender().ID, title)
	return b.showConfirmationMsg(c, state, title)
}

func (b *Bot) showConfirmation(c tele.Context, state *PostState, title string) error {
	channelName := "未知频道"
	if state.ForwardedMsg.OriginalChat != nil {
		channelName = state.ForwardedMsg.OriginalChat.Title
	}

	menu := &tele.ReplyMarkup{}
	confirmBtn := menu.Data("✅ 确认添加", cbPrefixConfirm+"yes")
	cancelBtn := menu.Data("❌ 取消", cbCancel)
	menu.Inline(menu.Row(confirmBtn, cancelBtn))

	text := fmt.Sprintf("📋 确认添加?\n\n频道: %s\n分类: %s\n标题: %s", channelName, state.SelectedCat, title)
	c.Edit(text, menu)
	return c.Respond()
}

func (b *Bot) showConfirmationMsg(c tele.Context, state *PostState, title string) error {
	channelName := "未知频道"
	if state.ForwardedMsg.OriginalChat != nil {
		channelName = state.ForwardedMsg.OriginalChat.Title
	}

	menu := &tele.ReplyMarkup{}
	confirmBtn := menu.Data("✅ 确认添加", cbPrefixConfirm+"yes")
	cancelBtn := menu.Data("❌ 取消", cbCancel)
	menu.Inline(menu.Row(confirmBtn, cancelBtn))

	text := fmt.Sprintf("📋 确认添加?\n\n频道: %s\n分类: %s\n标题: %s", channelName, state.SelectedCat, title)
	return c.Reply(text, menu)
}

func (b *Bot) handleCategoryCallback(c tele.Context, userID int64, category string) error {
	state := b.states.Get(userID)
	if state == nil || state.Step != StepAwaitCategory {
		return c.Respond(&tele.CallbackResponse{Text: "会话已过期"})
	}

	b.states.SetCategory(userID, category)

	// 提取默认标题
	defaultTitle := extractTitle(state.ForwardedMsg)

	menu := &tele.ReplyMarkup{}
	useDefaultBtn := menu.Data("✅ 使用此标题", cbPrefixTitle+"default")
	customBtn := menu.Data("✏️ 自定义标题", cbPrefixTitle+"custom")
	cancelBtn := menu.Data("❌ 取消", cbCancel)
	menu.Inline(
		menu.Row(useDefaultBtn),
		menu.Row(customBtn),
		menu.Row(cancelBtn),
	)

	text := fmt.Sprintf("📝 确认标题\n\n分类: %s\n标题: %s\n\n使用此标题或自定义?", category, defaultTitle)
	c.Edit(text, menu)
	return c.Respond()
}

func (b *Bot) handleConfirmCallback(c tele.Context, userID int64, action string) error {
	if action != "yes" {
		return b.handleCancelCallback(c, userID)
	}

	state := b.states.Get(userID)
	if state == nil || state.Step != StepAwaitConfirm {
		return c.Respond(&tele.CallbackResponse{Text: "会话已过期"})
	}

	defer b.states.Delete(userID)

	msg := state.ForwardedMsg
	title := state.Title

	// 复制消息内容发送到频道（非转发，可编辑）
	channel := &tele.Chat{ID: b.cfg.Channel.ID}
	channelMsg, err := b.sendMessageCopy(channel, msg)
	if err != nil {
		c.Edit(fmt.Sprintf("❌ 发送到频道失败: %v", err))
		return c.Respond(&tele.CallbackResponse{Text: "发送失败"})
	}

	// 使用频道消息的链接
	link := buildChannelLink(b.cfg.Channel.ID, channelMsg.ID)

	entry, err := b.storage.CreateEntry(state.SelectedCat, title, link)
	if err != nil {
		c.Edit(fmt.Sprintf("❌ 保存失败: %v", err))
		return c.Respond(&tele.CallbackResponse{Text: "保存失败"})
	}

	b.toc.TriggerUpdate()

	text := fmt.Sprintf("✅ 已添加\n\nID: %s\n分类: %s\n标题: %s", entry.ID, entry.Category, entry.Title)
	c.Edit(text)
	return c.Respond(&tele.CallbackResponse{Text: "添加成功"})
}

// sendMessageCopy 复制消息内容发送（非转发，可编辑）
func (b *Bot) sendMessageCopy(to *tele.Chat, msg *tele.Message) (*tele.Message, error) {
	// 图片
	if msg.Photo != nil {
		photo := &tele.Photo{File: msg.Photo.File, Caption: msg.Caption}
		return b.bot.Send(to, photo, tele.ModeHTML)
	}

	// 视频
	if msg.Video != nil {
		video := &tele.Video{File: msg.Video.File, Caption: msg.Caption}
		return b.bot.Send(to, video, tele.ModeHTML)
	}

	// 文档
	if msg.Document != nil {
		doc := &tele.Document{File: msg.Document.File, Caption: msg.Caption}
		return b.bot.Send(to, doc, tele.ModeHTML)
	}

	// 音频
	if msg.Audio != nil {
		audio := &tele.Audio{File: msg.Audio.File, Caption: msg.Caption}
		return b.bot.Send(to, audio, tele.ModeHTML)
	}

	// 语音
	if msg.Voice != nil {
		voice := &tele.Voice{File: msg.Voice.File}
		return b.bot.Send(to, voice)
	}

	// 贴纸
	if msg.Sticker != nil {
		sticker := &tele.Sticker{File: msg.Sticker.File}
		return b.bot.Send(to, sticker)
	}

	// 动图
	if msg.Animation != nil {
		anim := &tele.Animation{File: msg.Animation.File, Caption: msg.Caption}
		return b.bot.Send(to, anim, tele.ModeHTML)
	}

	// 纯文本
	if msg.Text != "" {
		return b.bot.Send(to, msg.Text, tele.ModeHTML, tele.NoPreview)
	}

	return nil, fmt.Errorf("不支持的消息类型")
}

func buildChannelLink(channelID int64, msgID int) string {
	chatID := channelID
	if chatID < 0 {
		chatID = -chatID - 1000000000000
	}
	return fmt.Sprintf("https://t.me/c/%d/%d", chatID, msgID)
}

func extractTitle(msg *tele.Message) string {
	text := msg.Text
	if text == "" {
		text = msg.Caption
	}

	lines := strings.Split(text, "\n")
	title := strings.TrimSpace(lines[0])

	if len(title) > 50 {
		title = title[:47] + "..."
	}

	if title == "" {
		title = "无标题"
	}

	return title
}

func buildMessageLink(msg *tele.Message) string {
	if msg.OriginalChat == nil {
		return ""
	}

	chat := msg.OriginalChat
	msgID := msg.OriginalMessageID
	if msgID == 0 {
		msgID = msg.ID
	}

	if chat.Username != "" {
		return fmt.Sprintf("https://t.me/%s/%d", chat.Username, msgID)
	}

	chatID := chat.ID
	if chatID < 0 {
		chatID = -chatID - 1000000000000
	}
	return fmt.Sprintf("https://t.me/c/%d/%d", chatID, msgID)
}