// Package laniakea provides a high-level context-based API for handling Telegram
// bot interactions, including message responses, callback queries, inline keyboards,
// localization, and message drafting. It wraps tgapi and adds convenience methods
// with built-in rate limiting, error handling, and i18n support.
//
// The core type is MsgContext, which encapsulates the state of a Telegram update
// and provides methods to respond, edit, delete, and translate messages.
//
// # Markdown Safety Warning
//
// All methods that accept MarkdownV2 formatting (e.g., AnswerMarkdown, EditCallbackfMarkdown)
// require that user-provided text be escaped using laniakea.EscapeMarkdownV2().
// Failure to escape user input may result in Telegram API errors, malformed messages,
// or security issues.
//
// Example:
//
//	text := laniakea.EscapeMarkdownV2(userInput)
//	ctx.AnswerMarkdown("You said: " + text)
package laniakea

import (
	"context"
	"fmt"
	"time"

	"git.nix13.pw/scuroneko/laniakea/tgapi"
	"git.nix13.pw/scuroneko/slog"
)

// MsgContext holds the context for handling a Telegram message or callback query.
// It provides methods to respond, edit, delete, and translate messages, as well as
// manage inline keyboards and message drafts.
type MsgContext struct {
	Api    *tgapi.API
	Update tgapi.Update

	Msg  *tgapi.Message
	From *tgapi.User

	CallbackMsgId   int
	CallbackQueryId string
	FromID          int
	Prefix          string
	Text            string
	Args            []string

	errorTemplate string
	botLogger     *slog.Logger
	l10n          *L10n
	draftProvider *DraftProvider
	payloadType   BotPayloadType
}

// AnswerMessage represents a message sent or edited via MsgContext.
// It holds metadata to allow further editing or deletion.
type AnswerMessage struct {
	MessageID int
	Text      string
	IsMedia   bool
	ctx       *MsgContext // internal back-reference
}

// edit is an internal helper to edit a message's text with optional keyboard and parse mode.
// Used by Edit, EditMarkdown, EditCallback, etc.
func (ctx *MsgContext) edit(messageId int, text string, keyboard *InlineKeyboard, parseMode tgapi.ParseMode) *AnswerMessage {
	params := tgapi.EditMessageTextP{
		MessageID: messageId,
		ChatID:    ctx.Msg.Chat.ID,
		Text:      text,
		ParseMode: parseMode,
	}
	if keyboard != nil {
		params.ReplyMarkup = keyboard.Get()
	}
	msg, _, err := ctx.Api.EditMessageText(params)
	if err != nil {
		ctx.botLogger.Errorln(err)
		return nil
	}
	return &AnswerMessage{
		MessageID: msg.MessageID, ctx: ctx, Text: text, IsMedia: false,
	}
}

// Edit replaces the text of the message without changing the keyboard or parse mode.
// Uses ParseNone (plain text).
func (m *AnswerMessage) Edit(text string) *AnswerMessage {
	return m.ctx.edit(m.MessageID, text, nil, tgapi.ParseNone)
}

// EditMarkdown replaces the text of the message using MarkdownV2 formatting.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
// Unescaped input may cause Telegram API errors or broken formatting.
func (m *AnswerMessage) EditMarkdown(text string) *AnswerMessage {
	return m.ctx.edit(m.MessageID, text, nil, tgapi.ParseMDV2)
}

// editCallback is an internal helper to edit the message associated with a callback query.
// Returns nil if CallbackMsgId is 0 (not a callback context).
func (ctx *MsgContext) editCallback(text string, keyboard *InlineKeyboard, parseMode tgapi.ParseMode) *AnswerMessage {
	if ctx.CallbackMsgId == 0 {
		ctx.botLogger.Errorln("Can't edit non-callback update message")
		return nil
	}
	return ctx.edit(ctx.CallbackMsgId, text, keyboard, parseMode)
}

// EditCallback edits the callback message using plain text (ParseNone).
func (ctx *MsgContext) EditCallback(text string, keyboard *InlineKeyboard) *AnswerMessage {
	return ctx.editCallback(text, keyboard, tgapi.ParseNone)
}

// EditCallbackMarkdown edits the callback message using MarkdownV2.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (ctx *MsgContext) EditCallbackMarkdown(text string, keyboard *InlineKeyboard) *AnswerMessage {
	return ctx.editCallback(text, keyboard, tgapi.ParseMDV2)
}

// EditCallbackf formats a string using fmt.Sprintf and edits the callback message with plain text.
func (ctx *MsgContext) EditCallbackf(format string, keyboard *InlineKeyboard, args ...any) *AnswerMessage {
	return ctx.editCallback(fmt.Sprintf(format, args...), keyboard, tgapi.ParseNone)
}

// EditCallbackfMarkdown formats a string using fmt.Sprintf and edits the callback message with MarkdownV2.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (ctx *MsgContext) EditCallbackfMarkdown(format string, keyboard *InlineKeyboard, args ...any) *AnswerMessage {
	return ctx.editCallback(fmt.Sprintf(format, args...), keyboard, tgapi.ParseMDV2)
}

// editPhotoText edits the caption of a photo/video message.
// Returns nil if messageId is 0.
func (ctx *MsgContext) editPhotoText(messageId int, text string, kb *InlineKeyboard, parseMode tgapi.ParseMode) *AnswerMessage {
	if messageId == 0 {
		ctx.botLogger.Errorln("Can't edit caption message, message ID zero")
		return nil
	}
	params := tgapi.EditMessageCaptionP{
		ChatID:    ctx.Msg.Chat.ID,
		MessageID: messageId,
		Caption:   text,
		ParseMode: parseMode,
	}
	if kb != nil {
		params.ReplyMarkup = kb.Get()
	}

	msg, _, err := ctx.Api.EditMessageCaption(params)
	if err != nil {
		ctx.botLogger.Errorln(err)
	}
	return &AnswerMessage{
		MessageID: msg.MessageID, ctx: ctx, Text: text, IsMedia: true,
	}
}

// EditCaption edits the caption of a media message using plain text.
func (m *AnswerMessage) EditCaption(text string) *AnswerMessage {
	return m.ctx.editPhotoText(m.MessageID, text, nil, tgapi.ParseNone)
}

// EditCaptionMarkdown edits the caption of a media message using MarkdownV2.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (m *AnswerMessage) EditCaptionMarkdown(text string) *AnswerMessage {
	return m.ctx.editPhotoText(m.MessageID, text, nil, tgapi.ParseMDV2)
}

// EditCaptionKeyboard edits the caption of a media message with a new inline keyboard (plain text).
func (m *AnswerMessage) EditCaptionKeyboard(text string, kb *InlineKeyboard) *AnswerMessage {
	return m.ctx.editPhotoText(m.MessageID, text, kb, tgapi.ParseNone)
}

// EditCaptionKeyboardMarkdown edits the caption of a media message with a new inline keyboard using MarkdownV2.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (m *AnswerMessage) EditCaptionKeyboardMarkdown(text string, kb *InlineKeyboard) *AnswerMessage {
	return m.ctx.editPhotoText(m.MessageID, text, kb, tgapi.ParseMDV2)
}

// answer sends a new message with optional keyboard and parse mode.
// Uses API limiter to respect Telegram rate limits per chat.
func (ctx *MsgContext) answer(text string, keyboard *InlineKeyboard, parseMode tgapi.ParseMode) *AnswerMessage {
	params := tgapi.SendMessageP{
		ChatID:    ctx.Msg.Chat.ID,
		Text:      text,
		ParseMode: parseMode,
	}
	if keyboard != nil {
		params.ReplyMarkup = keyboard.Get()
	}
	if ctx.Msg.MessageThreadID > 0 {
		params.MessageThreadID = ctx.Msg.MessageThreadID
	}
	if ctx.Msg.DirectMessageTopic != nil {
		params.DirectMessagesTopicID = ctx.Msg.DirectMessageTopic.TopicID
	}

	cont := context.Background()
	if err := ctx.Api.Limiter.Wait(cont, ctx.Msg.Chat.ID); err != nil {
		ctx.botLogger.Errorln(err)
		return nil
	}
	msg, err := ctx.Api.SendMessage(params)
	if err != nil {
		ctx.botLogger.Errorln(err)
		return nil
	}
	return &AnswerMessage{
		MessageID: msg.MessageID, ctx: ctx, IsMedia: false, Text: text,
	}
}

// Answer sends a plain text message (ParseNone).
func (ctx *MsgContext) Answer(text string) *AnswerMessage {
	return ctx.answer(text, nil, tgapi.ParseNone)
}

// AnswerMarkdown sends a message using MarkdownV2 formatting.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (ctx *MsgContext) AnswerMarkdown(text string) *AnswerMessage {
	return ctx.answer(text, nil, tgapi.ParseMDV2)
}

// Answerf formats a string using fmt.Sprintf and sends it as a plain text message.
func (ctx *MsgContext) Answerf(template string, args ...any) *AnswerMessage {
	return ctx.answer(fmt.Sprintf(template, args...), nil, tgapi.ParseNone)
}

// AnswerfMarkdown formats a string using fmt.Sprintf and sends it using MarkdownV2.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (ctx *MsgContext) AnswerfMarkdown(template string, args ...any) *AnswerMessage {
	return ctx.answer(fmt.Sprintf(template, args...), nil, tgapi.ParseMDV2)
}

// Keyboard sends a message with an inline keyboard (plain text).
func (ctx *MsgContext) Keyboard(text string, kb *InlineKeyboard) *AnswerMessage {
	return ctx.answer(text, kb, tgapi.ParseNone)
}

// KeyboardMarkdown sends a message with an inline keyboard using MarkdownV2.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (ctx *MsgContext) KeyboardMarkdown(text string, keyboard *InlineKeyboard) *AnswerMessage {
	return ctx.answer(text, keyboard, tgapi.ParseMDV2)
}

// answerPhoto sends a photo with optional caption and keyboard.
func (ctx *MsgContext) answerPhoto(photoId, text string, kb *InlineKeyboard, parseMode tgapi.ParseMode) *AnswerMessage {
	params := tgapi.SendPhotoP{
		ChatID:    ctx.Msg.Chat.ID,
		Caption:   text,
		ParseMode: parseMode,
		Photo:     photoId,
	}
	if kb != nil {
		params.ReplyMarkup = kb.Get()
	}
	if ctx.Msg.MessageThreadID > 0 {
		params.MessageThreadID = ctx.Msg.MessageThreadID
	}

	msg, err := ctx.Api.SendPhoto(params)
	if err != nil {
		ctx.botLogger.Errorln(err)
		return nil
	}
	return &AnswerMessage{
		MessageID: msg.MessageID, ctx: ctx, Text: text, IsMedia: true,
	}
}

// AnswerPhoto sends a photo with plain text caption.
func (ctx *MsgContext) AnswerPhoto(photoId, text string) *AnswerMessage {
	return ctx.answerPhoto(photoId, text, nil, tgapi.ParseNone)
}

// AnswerPhotoMarkdown sends a photo with MarkdownV2 caption.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (ctx *MsgContext) AnswerPhotoMarkdown(photoId, text string) *AnswerMessage {
	return ctx.answerPhoto(photoId, text, nil, tgapi.ParseMDV2)
}

// AnswerPhotoKeyboard sends a photo with caption and inline keyboard (plain text).
func (ctx *MsgContext) AnswerPhotoKeyboard(photoId, text string, kb *InlineKeyboard) *AnswerMessage {
	return ctx.answerPhoto(photoId, text, kb, tgapi.ParseNone)
}

// AnswerPhotoKeyboardMarkdown sends a photo with caption and inline keyboard using MarkdownV2.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (ctx *MsgContext) AnswerPhotoKeyboardMarkdown(photoId, text string, kb *InlineKeyboard) *AnswerMessage {
	return ctx.answerPhoto(photoId, text, kb, tgapi.ParseMDV2)
}

// AnswerPhotof formats a string and sends it as a photo caption (plain text).
func (ctx *MsgContext) AnswerPhotof(photoId, template string, args ...any) *AnswerMessage {
	return ctx.answerPhoto(photoId, fmt.Sprintf(template, args...), nil, tgapi.ParseNone)
}

// AnswerPhotofMarkdown formats a string and sends it as a photo caption using MarkdownV2.
//
// ⚠️ WARNING: User input must be escaped with laniakea.EscapeMarkdownV2() before passing here.
func (ctx *MsgContext) AnswerPhotofMarkdown(photoId, template string, args ...any) *AnswerMessage {
	return ctx.answerPhoto(photoId, fmt.Sprintf(template, args...), nil, tgapi.ParseMDV2)
}

// delete removes a message by ID.
func (ctx *MsgContext) delete(messageId int) {
	_, err := ctx.Api.DeleteMessage(tgapi.DeleteMessageP{
		ChatID:    ctx.Msg.Chat.ID,
		MessageID: messageId,
	})
	if err != nil {
		ctx.botLogger.Errorln(err)
	}
}

// Delete removes the message associated with this AnswerMessage.
func (m *AnswerMessage) Delete() { m.ctx.delete(m.MessageID) }

// CallbackDelete deletes the message that triggered the callback query.
func (ctx *MsgContext) CallbackDelete() { ctx.delete(ctx.CallbackMsgId) }

// answerCallbackQuery sends a response to a callback query (optional text/alert/url).
// Does nothing if CallbackQueryId is empty.
func (ctx *MsgContext) answerCallbackQuery(url, text string, showAlert bool) {
	if len(ctx.CallbackQueryId) == 0 {
		return
	}
	_, err := ctx.Api.AnswerCallbackQuery(tgapi.AnswerCallbackQueryP{
		CallbackQueryID: ctx.CallbackQueryId,
		Text:            text, ShowAlert: showAlert, URL: url,
	})
	if err != nil {
		ctx.botLogger.Errorln(err)
	}
}

// AnswerCbQuery answers the callback query with no text or alert.
func (ctx *MsgContext) AnswerCbQuery() { ctx.answerCallbackQuery("", "", false) }

// AnswerCbQueryText answers the callback query with a text notification.
func (ctx *MsgContext) AnswerCbQueryText(text string) { ctx.answerCallbackQuery("", text, false) }

// AnswerCbQueryAlert answers the callback query with a user-visible alert.
func (ctx *MsgContext) AnswerCbQueryAlert(text string) { ctx.answerCallbackQuery("", text, true) }

// AnswerCbQueryUrl answers the callback query with a URL redirect.
func (ctx *MsgContext) AnswerCbQueryUrl(u string) { ctx.answerCallbackQuery(u, "", false) }

// SendAction sends a chat action (typing, uploading_photo, etc.) to indicate bot activity.
func (ctx *MsgContext) SendAction(action tgapi.ChatActionType) {
	params := tgapi.SendChatActionP{
		ChatID: ctx.Msg.Chat.ID, Action: action,
	}
	if ctx.Msg.MessageThreadID > 0 {
		params.MessageThreadID = ctx.Msg.MessageThreadID
	}
	_, err := ctx.Api.SendChatAction(params)
	if err != nil {
		ctx.botLogger.Errorln(err)
	}
}

// error sends an error message to the user and logs it.
// Uses errorTemplate to format the message.
// For callbacks: sends as callback answer (no alert).
// For regular messages: sends as plain text.
func (ctx *MsgContext) error(err error) {
	text := fmt.Sprintf(ctx.errorTemplate, err.Error())

	if ctx.CallbackQueryId != "" {
		ctx.answerCallbackQuery("", text, false)
	} else {
		ctx.answer(text, nil, tgapi.ParseNone)
	}
	ctx.botLogger.Errorln(err)
}

// Error is an alias for error().
func (ctx *MsgContext) Error(err error) { ctx.error(err) }

func (ctx *MsgContext) newDraft(parseMode tgapi.ParseMode) *Draft {
	if ctx.Msg == nil {
		ctx.botLogger.Errorln("can't create draft: ctx.Msg is nil")
		return nil
	}

	c, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	if err := ctx.Api.Limiter.Wait(c, ctx.Msg.Chat.ID); err != nil {
		ctx.botLogger.Errorln(err)
		return nil
	}

	draft := ctx.draftProvider.NewDraft(parseMode).SetChat(ctx.Msg.Chat.ID, ctx.Msg.MessageThreadID)
	return draft
}

// NewDraft creates a new message draft associated with the current chat.
// Uses the API limiter to avoid rate limiting.
func (ctx *MsgContext) NewDraft() *Draft {
	return ctx.newDraft(tgapi.ParseNone)
}

func (ctx *MsgContext) NewDraftMarkdown() *Draft {
	return ctx.newDraft(tgapi.ParseMDV2)
}

// Translate looks up a key in the current user's language.
// Falls back to the bot's default language if user's language is unknown or unsupported.
func (ctx *MsgContext) Translate(key string) string {
	if ctx.From == nil {
		return key
	}
	lang := Val(ctx.From.LanguageCode, ctx.l10n.GetFallbackLanguage())
	return ctx.l10n.Translate(lang, key)
}