from aiogram import Router, F
from aiogram.filters import Command
from aiogram.types import Message, InlineKeyboardMarkup, InlineKeyboardButton, CallbackQuery
from aiogram.fsm.context import FSMContext
from aiogram.fsm.state import State, StatesGroup

from database.db import async_session_maker
from database.models import WordSource
from services.user_service import UserService
from services.task_service import TaskService
from services.vocabulary_service import VocabularyService
from services.ai_service import ai_service
from utils.i18n import t, get_user_lang, get_user_translation_lang
from utils.levels import get_user_level_for_language

router = Router()


class TaskStates(StatesGroup):
    """Состояния для прохождения заданий"""
    choosing_mode = State()
    choosing_type = State()  # Выбор типа заданий
    doing_tasks = State()
    waiting_for_answer = State()


# Типы заданий
TASK_TYPES = ['mix', 'word_translate', 'fill_blank', 'sentence_translate']


def get_task_type_keyboard(lang: str) -> InlineKeyboardMarkup:
    """Клавиатура выбора типа заданий"""
    return InlineKeyboardMarkup(inline_keyboard=[
        [InlineKeyboardButton(text=t(lang, 'tasks.type_mix'), callback_data="task_type_mix")],
        [InlineKeyboardButton(text=t(lang, 'tasks.type_word_translate'), callback_data="task_type_word_translate")],
        [InlineKeyboardButton(text=t(lang, 'tasks.type_fill_blank'), callback_data="task_type_fill_blank")],
        [InlineKeyboardButton(text=t(lang, 'tasks.type_sentence_translate'), callback_data="task_type_sentence_translate")],
    ])


@router.message(Command("task"))
async def cmd_task(message: Message, state: FSMContext):
    """Обработчик команды /task — показываем меню выбора режима"""
    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, message.from_user.id)

        if not user:
            await message.answer(t('ru', 'common.start_first'))
            return

        lang = get_user_lang(user)

        keyboard = InlineKeyboardMarkup(inline_keyboard=[
            [InlineKeyboardButton(
                text=t(lang, 'tasks.mode_vocabulary'),
                callback_data="task_mode_vocabulary"
            )],
            [InlineKeyboardButton(
                text=t(lang, 'tasks.mode_new_words'),
                callback_data="task_mode_new"
            )]
        ])

        await state.update_data(user_id=user.id)
        await state.set_state(TaskStates.choosing_mode)
        await message.answer(t(lang, 'tasks.choose_mode'), reply_markup=keyboard)


@router.callback_query(F.data == "task_mode_vocabulary", TaskStates.choosing_mode)
async def choose_vocabulary_task_type(callback: CallbackQuery, state: FSMContext):
    """Показать выбор типа заданий для режима vocabulary"""
    await callback.answer()

    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, callback.from_user.id)

        if not user:
            await callback.message.edit_text(t('ru', 'common.start_first'))
            return

        lang = get_user_lang(user)

        # Сохраняем режим и переходим к выбору типа
        await state.update_data(user_id=user.id, mode='vocabulary')
        await state.set_state(TaskStates.choosing_type)

        await callback.message.edit_text(
            t(lang, 'tasks.choose_type'),
            reply_markup=get_task_type_keyboard(lang)
        )


@router.callback_query(F.data.startswith("task_type_"), TaskStates.choosing_type)
async def start_tasks_with_type(callback: CallbackQuery, state: FSMContext):
    """Начать задания выбранного типа"""
    await callback.answer()

    task_type = callback.data.replace("task_type_", "")  # mix, word_translate, fill_blank, sentence_translate
    data = await state.get_data()
    mode = data.get('mode', 'vocabulary')

    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, callback.from_user.id)

        if not user:
            await callback.message.edit_text(t('ru', 'common.start_first'))
            return

        lang = get_user_lang(user)

        # Получаем количество заданий из настроек пользователя
        tasks_count = getattr(user, 'tasks_count', 5) or 5

        if mode == 'vocabulary':
            # Генерируем задания по словам из словаря
            tasks = await TaskService.generate_tasks_by_type(
                session, user.id, count=tasks_count,
                task_type=task_type,
                learning_lang=user.learning_language,
                translation_lang=get_user_translation_lang(user),
            )

            if not tasks:
                await callback.message.edit_text(t(lang, 'tasks.no_words'))
                await state.clear()
                return

            # Сохраняем задания в состоянии
            await state.update_data(
                tasks=tasks,
                current_task_index=0,
                correct_count=0,
                user_id=user.id,
                mode='vocabulary',
                task_type=task_type
            )
            await state.set_state(TaskStates.doing_tasks)

            await callback.message.delete()
            await show_current_task(callback.message, state)

        else:
            # Режим new_words - генерируем новые слова
            await generate_new_words_tasks(callback, state, user, task_type)


async def generate_new_words_tasks(callback: CallbackQuery, state: FSMContext, user, task_type: str):
    """Генерация заданий с новыми словами"""
    lang = get_user_lang(user)
    level = get_user_level_for_language(user)
    tasks_count = getattr(user, 'tasks_count', 5) or 5

    # Показываем индикатор загрузки
    await callback.message.edit_text(t(lang, 'tasks.generating_new'))

    async with async_session_maker() as session:
        # Получаем слова для исключения
        vocab_words = await VocabularyService.get_all_user_word_strings(
            session, user.id, learning_lang=user.learning_language
        )
        correct_task_words = await TaskService.get_correctly_answered_words(
            session, user.id
        )
        exclude_words = list(set(vocab_words + correct_task_words))

    # Генерируем новые слова через AI
    translation_lang = get_user_translation_lang(user)
    words = await ai_service.generate_thematic_words(
        theme="random everyday vocabulary",
        level=level,
        count=tasks_count,
        learning_lang=user.learning_language,
        translation_lang=translation_lang,
        exclude_words=exclude_words if exclude_words else None,
        user_id=user.id
    )

    if not words:
        await callback.message.edit_text(t(lang, 'tasks.generate_failed'))
        await state.clear()
        return

    # Преобразуем слова в задания нужного типа
    tasks = await create_tasks_from_words(
        words, task_type, lang, user.learning_language, translation_lang,
        level=level, user_id=user.id
    )

    await state.update_data(
        tasks=tasks,
        current_task_index=0,
        correct_count=0,
        user_id=user.id,
        mode='new_words',
        task_type=task_type
    )
    await state.set_state(TaskStates.doing_tasks)

    await callback.message.delete()
    await show_current_task(callback.message, state)


async def create_tasks_from_words(
    words: list,
    task_type: str,
    lang: str,
    learning_lang: str,
    translation_lang: str,
    level: str = None,
    user_id: int = None
) -> list:
    """Создать задания из списка слов в зависимости от типа (оптимизировано - 1 запрос к AI)"""
    import random

    # 1. Определяем типы заданий для всех слов
    word_tasks = []
    for word in words:
        if task_type == 'mix':
            chosen_type = random.choice(['word_translate', 'fill_blank', 'sentence_translate'])
        else:
            chosen_type = task_type
        word_tasks.append({
            'word_data': word,
            'chosen_type': chosen_type
        })

    # 2. Собираем задания, требующие генерации предложений
    ai_tasks = []
    ai_task_indices = []  # Индексы в word_tasks для сопоставления результатов

    for i, wt in enumerate(word_tasks):
        if wt['chosen_type'] in ('fill_blank', 'sentence_translate'):
            ai_tasks.append({
                'word': wt['word_data'].get('word', ''),
                'task_type': wt['chosen_type']
            })
            ai_task_indices.append(i)

    # 3. Один запрос к AI для всех предложений (если нужно)
    ai_results = []
    if ai_tasks:
        ai_results = await ai_service.generate_task_sentences_batch(
            ai_tasks,
            learning_lang=learning_lang,
            translation_lang=translation_lang,
            user_id=user_id
        )

    # Создаём маппинг: индекс в word_tasks -> результат AI
    ai_results_map = {}
    for idx, result in zip(ai_task_indices, ai_results):
        ai_results_map[idx] = result

    # 4. Собираем финальные задания
    tasks = []
    for i, wt in enumerate(word_tasks):
        word = wt['word_data']
        chosen_type = wt['chosen_type']

        word_text = word.get('word', '')
        translation = word.get('translation', '')
        transcription = word.get('transcription', '')
        example = word.get('example', '')
        example_translation = word.get('example_translation', '')

        if chosen_type == 'word_translate':
            translate_prompt = t(lang, 'tasks.translate_to', lang_name=t(lang, f'lang.{translation_lang}'))
            tasks.append({
                'type': 'translate',
                'question': f"{translate_prompt}: <b>{word_text}</b>",
                'word': word_text,
                'correct_answer': translation,
                'transcription': transcription,
                'example': example,
                'example_translation': example_translation,
                'difficulty_level': level
            })

        elif chosen_type == 'fill_blank':
            sentence_data = ai_results_map.get(i, {})
            if translation_lang == 'en':
                fill_title = "Fill in the blank:"
            elif translation_lang == 'ja':
                fill_title = "空欄を埋めてください:"
            else:
                fill_title = "Заполни пропуск:"

            tasks.append({
                'type': 'fill_in',
                'question': f"{fill_title}\n\n<b>{sentence_data.get('sentence', '___')}</b>\n\n<i>{sentence_data.get('translation', '')}</i>",
                'word': word_text,
                'correct_answer': sentence_data.get('answer', word_text),
                'transcription': transcription,
                'example': example,
                'example_translation': example_translation,
                'difficulty_level': level
            })

        elif chosen_type == 'sentence_translate':
            sentence_data = ai_results_map.get(i, {})
            if translation_lang == 'en':
                sentence_title = "Translate the sentence:"
                word_hint = "Word"
            elif translation_lang == 'ja':
                sentence_title = "文を翻訳してください:"
                word_hint = "単語"
            else:
                sentence_title = "Переведи предложение:"
                word_hint = "Слово"

            tasks.append({
                'type': 'sentence_translate',
                'question': f"{sentence_title}\n\n<b>{sentence_data.get('sentence', word_text)}</b>\n\n📝 {word_hint}: <code>{word_text}</code> — {translation}",
                'word': word_text,
                'correct_answer': sentence_data.get('translation', translation),
                'transcription': transcription,
                'example': example,
                'example_translation': example_translation,
                'difficulty_level': level
            })

    return tasks


@router.callback_query(F.data == "task_mode_new", TaskStates.choosing_mode)
async def choose_new_words_task_type(callback: CallbackQuery, state: FSMContext):
    """Показать выбор типа заданий для режима new_words"""
    await callback.answer()

    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, callback.from_user.id)

        if not user:
            await callback.message.edit_text(t('ru', 'common.start_first'))
            return

        lang = get_user_lang(user)

        # Сохраняем режим и переходим к выбору типа
        await state.update_data(user_id=user.id, mode='new_words')
        await state.set_state(TaskStates.choosing_type)

        await callback.message.edit_text(
            t(lang, 'tasks.choose_type'),
            reply_markup=get_task_type_keyboard(lang)
        )


async def show_current_task(message: Message, state: FSMContext):
    """Показать текущее задание"""
    data = await state.get_data()
    tasks = data.get('tasks', [])
    current_index = data.get('current_task_index', 0)
    user_id = data.get('user_id')

    if current_index >= len(tasks):
        # Все задания выполнены
        await finish_tasks(message, state)
        return

    task = tasks[current_index]

    # Определяем язык пользователя (берём user_id из state, т.к. message может быть от бота)
    async with async_session_maker() as session:
        user = await UserService.get_user_by_id(session, user_id)
    lang = (user.language_interface if user else 'ru') or 'ru'

    task_text = (
        t(lang, 'tasks.header', i=current_index + 1, n=len(tasks)) + "\n\n" +
        f"{task['question']}\n"
    )

    if task.get('transcription'):
        task_text += f"🔊 [{task['transcription']}]\n"

    task_text += t(lang, 'tasks.write_answer')

    await state.set_state(TaskStates.waiting_for_answer)
    await message.answer(task_text)


@router.message(TaskStates.waiting_for_answer)
async def process_answer(message: Message, state: FSMContext):
    """Обработка ответа пользователя"""
    user_answer = message.text.strip()
    data = await state.get_data()

    tasks = data.get('tasks', [])
    current_index = data.get('current_task_index', 0)
    correct_count = data.get('correct_count', 0)
    user_id = data.get('user_id')

    task = tasks[current_index]

    # Показываем индикатор проверки
    # Язык пользователя
    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, message.from_user.id)
    lang = (user.language_interface if user else 'ru') or 'ru'

    checking_msg = await message.answer(t(lang, 'tasks.checking'))

    # Проверяем ответ через AI
    check_result = await ai_service.check_answer(
        question=task['question'],
        correct_answer=task['correct_answer'],
        user_answer=user_answer,
        user_id=user.id if user else None
    )

    await checking_msg.delete()

    is_correct = check_result.get('is_correct', False)
    feedback = check_result.get('feedback', '')

    # Формируем ответ
    if is_correct:
        result_text = t(lang, 'tasks.correct') + "\n\n"
        correct_count += 1
    else:
        result_text = t(lang, 'tasks.incorrect') + "\n\n"

    result_text += f"{t(lang, 'tasks.your_answer')}: <i>{user_answer}</i>\n"
    result_text += f"{t(lang, 'tasks.right_answer')}: <b>{task['correct_answer']}</b>\n\n"

    if feedback:
        result_text += f"💬 {feedback}\n\n"

    # Показываем пример использования если есть
    example = task.get('example', '')
    example_translation = task.get('example_translation', '')
    if example:
        result_text += f"📖 {t(lang, 'tasks.example_label')}:\n"
        result_text += f"<i>{example}</i>\n"
        if example_translation:
            result_text += f"<i>({example_translation})</i>\n"
        result_text += "\n"

    # Сохраняем результат в БД
    async with async_session_maker() as session:
        await TaskService.save_task_result(
            session=session,
            user_id=user_id,
            task_type=task['type'],
            content={
                'question': task['question'],
                'word': task['word']
            },
            user_answer=user_answer,
            correct_answer=task['correct_answer'],
            is_correct=is_correct,
            ai_feedback=feedback
        )

        # Обновляем статистику слова
        if 'word_id' in task:
            await TaskService.update_word_statistics(
                session=session,
                word_id=task['word_id'],
                is_correct=is_correct
            )

    # Обновляем счетчик
    await state.update_data(
        current_task_index=current_index + 1,
        correct_count=correct_count
    )

    # Показываем результат и кнопку "Далее"
    mode = data.get('mode')
    buttons = [[InlineKeyboardButton(text=t(lang, 'tasks.next_btn'), callback_data="next_task")]]

    # Для режима new_words добавляем кнопку "Добавить слово"
    if mode == 'new_words':
        buttons.append([InlineKeyboardButton(
            text=t(lang, 'tasks.add_word_btn'),
            callback_data=f"add_task_word_{current_index}"
        )])

    buttons.append([InlineKeyboardButton(text=t(lang, 'tasks.stop_btn'), callback_data="stop_tasks")])
    keyboard = InlineKeyboardMarkup(inline_keyboard=buttons)

    await message.answer(result_text, reply_markup=keyboard)
    # После показа результата ждём нажатия кнопки – переключаемся в состояние doing_tasks
    await state.set_state(TaskStates.doing_tasks)


@router.callback_query(F.data == "next_task", TaskStates.doing_tasks)
async def next_task(callback: CallbackQuery, state: FSMContext):
    """Переход к следующему заданию"""
    await callback.message.delete()
    await show_current_task(callback.message, state)
    await callback.answer()


@router.callback_query(F.data.startswith("add_task_word_"), TaskStates.doing_tasks)
async def add_task_word(callback: CallbackQuery, state: FSMContext):
    """Добавить слово из задания в словарь"""
    task_index = int(callback.data.split("_")[-1])
    data = await state.get_data()
    tasks = data.get('tasks', [])

    if task_index >= len(tasks):
        await callback.answer()
        return

    task = tasks[task_index]
    word = task.get('word', '')
    translation = task.get('correct_answer', '')
    transcription = task.get('transcription', '')
    example = task.get('example', '')  # Пример использования как контекст
    example_translation = task.get('example_translation', '')  # Перевод примера
    difficulty_level = task.get('difficulty_level')  # Уровень сложности

    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, callback.from_user.id)

        if not user:
            await callback.answer()
            return

        lang = get_user_lang(user)
        translation_lang = get_user_translation_lang(user)

        # Проверяем, есть ли слово уже в словаре
        existing = await VocabularyService.get_word_by_original(session, user.id, word, source_lang=user.learning_language)

        if existing:
            await callback.answer(t(lang, 'tasks.word_already_exists', word=word), show_alert=True)
            return

        # Добавляем слово в словарь
        new_word = await VocabularyService.add_word(
            session=session,
            user_id=user.id,
            word_original=word,
            word_translation=translation,
            source_lang=user.learning_language,
            translation_lang=translation_lang,
            transcription=transcription,
            difficulty_level=difficulty_level,
            source=WordSource.AI_TASK
        )

        # Сохраняем перевод в таблицу word_translations
        await VocabularyService.add_translations_bulk(
            session=session,
            vocabulary_id=new_word.id,
            translations=[{
                'translation': translation,
                'context': example if example else None,
                'context_translation': example_translation if example_translation else None,
                'is_primary': True
            }]
        )

    await callback.answer(t(lang, 'tasks.word_added', word=word), show_alert=True)


@router.callback_query(F.data == "stop_tasks", TaskStates.doing_tasks)
async def stop_tasks_callback(callback: CallbackQuery, state: FSMContext):
    """Остановить выполнение заданий через кнопку"""
    await state.clear()
    await callback.message.edit_reply_markup(reply_markup=None)
    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, callback.from_user.id)
    lang = (user.language_interface if user else 'ru') or 'ru'
    await callback.message.answer(t(lang, 'tasks.finished'))
    await callback.answer()


@router.message(Command("stop"), TaskStates.doing_tasks)
@router.message(Command("stop"), TaskStates.waiting_for_answer)
async def stop_tasks(message: Message, state: FSMContext):
    """Остановить выполнение заданий командой /stop"""
    await state.clear()
    # Определяем язык пользователя
    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, message.from_user.id)
    await message.answer(t((user.language_interface if user else 'ru') or 'ru', 'tasks.stopped'))


@router.message(Command("cancel"), TaskStates.doing_tasks)
@router.message(Command("cancel"), TaskStates.waiting_for_answer)
async def cancel_tasks(message: Message, state: FSMContext):
    """Отмена выполнения заданий командой /cancel"""
    await state.clear()
    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, message.from_user.id)
    lang = (user.language_interface if user else 'ru') or 'ru'
    await message.answer(t(lang, 'tasks.cancelled'))


async def finish_tasks(message: Message, state: FSMContext):
    """Завершение всех заданий"""
    data = await state.get_data()
    tasks = data.get('tasks', [])
    correct_count = data.get('correct_count', 0)
    total_count = len(tasks)
    user_id = data.get('user_id')

    accuracy = int((correct_count / total_count) * 100) if total_count > 0 else 0

    # Определяем эмодзи на основе результата
    if accuracy >= 90:
        emoji = "🏆"
        comment_key = 'excellent'
    elif accuracy >= 70:
        emoji = "👍"
        comment_key = 'good'
    elif accuracy >= 50:
        emoji = "📚"
        comment_key = 'average'
    else:
        emoji = "💪"
        comment_key = 'poor'

    # Язык пользователя (берём user_id из state, т.к. message может быть от бота)
    async with async_session_maker() as session:
        user = await UserService.get_user_by_id(session, user_id)
    lang = (user.language_interface if user else 'ru') or 'ru'

    result_text = (
        t(lang, 'tasks.finish_title', emoji=emoji) + "\n\n" +
        t(lang, 'tasks.correct_of', correct=correct_count, total=total_count) + "\n" +
        t(lang, 'tasks.accuracy', accuracy=accuracy) + "\n\n" +
        t(lang, f"tasks.comment.{comment_key}") + "\n\n" +
        t(lang, 'tasks.use_task') + "\n" +
        t(lang, 'tasks.use_stats')
    )

    await state.clear()
    await message.answer(result_text)


@router.message(Command("stats"))
async def cmd_stats(message: Message):
    """Обработчик команды /stats"""
    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, message.from_user.id)

        if not user:
            await message.answer(t('ru', 'common.start_first'))
            return

        # Получаем статистику
        stats = await TaskService.get_user_stats(session, user.id)
        lang = (user.language_interface if user else 'ru') or 'ru'

        stats_text = (
            t(lang, 'stats.header') + "\n\n" +
            t(lang, 'stats.total_words', n=stats['total_words']) + "\n" +
            t(lang, 'stats.studied_words', n=stats['reviewed_words']) + "\n" +
            t(lang, 'stats.total_tasks', n=stats['total_tasks']) + "\n" +
            t(lang, 'stats.correct_tasks', n=stats['correct_tasks']) + "\n" +
            t(lang, 'stats.accuracy', n=stats['accuracy']) + "\n\n"
        )

        if stats['total_words'] == 0:
            stats_text += t(lang, 'stats.hint_add_words')
        elif stats['total_tasks'] == 0:
            stats_text += t(lang, 'stats.hint_first_task')
        else:
            stats_text += t(lang, 'stats.hint_keep_practice')

        # Кнопка "Слово дня"
        keyboard = InlineKeyboardMarkup(inline_keyboard=[
            [InlineKeyboardButton(
                text=t(lang, 'stats.word_of_day_btn'),
                callback_data="stats_word_of_day"
            )]
        ])

        await message.answer(stats_text, reply_markup=keyboard)


@router.callback_query(F.data == "stats_word_of_day")
async def stats_word_of_day(callback: CallbackQuery):
    """Показать слово дня из статистики"""
    await callback.answer()

    from services.wordofday_service import wordofday_service
    from bot.handlers.wordofday import format_word_of_day

    async with async_session_maker() as session:
        user = await UserService.get_user_by_telegram_id(session, callback.from_user.id)

        if not user:
            return

        lang = get_user_lang(user)
        learning_lang = user.learning_language or 'en'
        level = get_user_level_for_language(user)

        wod = await wordofday_service.get_word_of_day(
            learning_lang=learning_lang,
            level=level
        )

        if not wod:
            await callback.message.answer(t(lang, 'wod.not_available'))
            return

        text = format_word_of_day(wod, lang)

        keyboard = InlineKeyboardMarkup(inline_keyboard=[
            [InlineKeyboardButton(
                text=t(lang, 'wod.add_btn'),
                callback_data=f"wod_add_{wod.id}"
            )]
        ])

        await callback.message.answer(text, reply_markup=keyboard)