import logging
import random
import string
from aiogram import Router, F, types, Bot
from aiogram.filters import StateFilter
from aiogram.fsm.context import FSMContext
from datetime import datetime, timedelta, timezone
from typing import Optional
from sqlalchemy.ext.asyncio import AsyncSession

from config.settings import Settings

from db.dal import promo_code_dal

from bot.states.admin_states import AdminStates
from bot.keyboards.inline.admin_keyboards import get_back_to_admin_panel_keyboard, get_admin_panel_keyboard
from aiogram.utils.keyboard import InlineKeyboardBuilder, InlineKeyboardButton
from bot.middlewares.i18n import JsonI18n

router = Router(name="admin_promo_codes_router")


async def create_promo_prompt_handler(callback: types.CallbackQuery,
                                      state: FSMContext, i18n_data: dict,
                                      settings: Settings,
                                      session: AsyncSession):
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n or not callback.message:
        await callback.answer("Error preparing promo creation.",
                              show_alert=True)
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    prompt_text = _("admin_promo_create_prompt",
                    example_format="MYPROMO20 7 100 30")

    try:
        await callback.message.edit_text(
            prompt_text,
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n))
    except Exception as e:
        logging.warning(
            f"Could not edit message for promo prompt: {e}. Sending new.")
        await callback.message.answer(
            prompt_text,
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n))
    await callback.answer()
    await state.set_state(AdminStates.waiting_for_promo_details)


@router.message(AdminStates.waiting_for_promo_details, F.text)
async def process_promo_code_details_handler(message: types.Message,
                                             state: FSMContext,
                                             i18n_data: dict,
                                             settings: Settings,
                                             session: AsyncSession):
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n:
        await message.reply("Language service error.")
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    if not message.text:
        await message.answer(_("admin_promo_invalid_format"))
        return

    parts = message.text.strip().split()
    if not (3 <= len(parts) <= 4):
        await message.answer(_("admin_promo_invalid_format"))
        return

    try:
        code_str = parts[0].upper()
        if not (3 <= len(code_str) <= 30 and code_str.isalnum()):
            raise ValueError(_("admin_promo_invalid_code_format"))

        bonus_days = int(parts[1])
        max_activations = int(parts[2])

        valid_until_date: Optional[datetime] = None
        valid_until_str_display = _("admin_promo_valid_indefinitely")

        if len(parts) == 4:
            valid_days_from_now = int(parts[3])
            if valid_days_from_now <= 0:
                raise ValueError(_("admin_promo_invalid_validity_days"))
            valid_until_date = datetime.now(
                timezone.utc) + timedelta(days=valid_days_from_now)
            valid_until_str_display = _(
                "admin_promo_valid_until_display",
                date=valid_until_date.strftime('%Y-%m-%d'))

        if bonus_days <= 0 or max_activations <= 0:
            raise ValueError(_("admin_promo_invalid_bonus_or_activations"))

    except ValueError as e:
        await message.answer(_("admin_promo_invalid_values", error=str(e)))
        return
    except Exception as e_parse:
        logging.error(
            f"Error parsing promo details '{message.text}': {e_parse}")
        await message.answer(_("admin_promo_invalid_format_general"))
        return

    admin_id = message.from_user.id if message.from_user else 0

    promo_data_to_create = {
        "code": code_str,
        "bonus_days": bonus_days,
        "max_activations": max_activations,
        "created_by_admin_id": admin_id,
        "valid_until": valid_until_date,
        "is_active": True,
        "current_activations": 0
    }

    try:
        created_promo = await promo_code_dal.create_promo_code(
            session, promo_data_to_create)
        await session.commit()

        if created_promo:
            success_text = _("admin_promo_created_success",
                             code=created_promo.code,
                             bonus_days=created_promo.bonus_days,
                             max_activations=created_promo.max_activations,
                             valid_until_str=valid_until_str_display)
            await message.answer(success_text,
                                 reply_markup=get_back_to_admin_panel_keyboard(
                                     current_lang, i18n))
        else:
            await message.answer(
                _("admin_promo_creation_failed_duplicate", code=code_str))

    except Exception as e_db_create:
        await session.rollback()
        logging.error(
            f"Failed to create promo code '{code_str}' in DB: {e_db_create}",
            exc_info=True)
        await message.answer(_("admin_promo_creation_failed"))

    await state.clear()


async def view_promo_codes_handler(callback: types.CallbackQuery,
                                   i18n_data: dict, settings: Settings,
                                   session: AsyncSession):
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n or not callback.message:
        await callback.answer("Error displaying promo codes.", show_alert=True)
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    promo_models = await promo_code_dal.get_all_active_promo_codes(session,
                                                                   limit=20,
                                                                   offset=0)

    if not promo_models:
        await callback.message.edit_text(
            _("admin_no_active_promos"),
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n))
        await callback.answer()
        return

    response_text_parts = [f"<b>{_('admin_active_promos_list_header')}</b>\n"]
    for promo in promo_models:
        valid_until_display_text = _("admin_promo_valid_indefinitely")
        if promo.valid_until:

            valid_until_display_text = promo.valid_until.strftime('%Y-%m-%d')

        response_text_parts.append(
            _("admin_promo_list_item",
              code=promo.code,
              bonus=promo.bonus_days,
              current=promo.current_activations,
              max=promo.max_activations,
              valid_until=valid_until_display_text))

    final_text = "\n".join(response_text_parts)
    try:
        await callback.message.edit_text(
            final_text,
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n),
            parse_mode="HTML")
    except Exception as e:
        logging.warning(
            f"Failed to edit message for promo list: {e}. Sending new.")
        if callback.message:
            await callback.message.answer(
                final_text,
                reply_markup=get_back_to_admin_panel_keyboard(
                    current_lang, i18n),
                parse_mode="HTML")
    await callback.answer()


@router.callback_query(F.data == "admin_action:manage_promos")
async def manage_promo_codes_handler(callback: types.CallbackQuery,
                                     i18n_data: dict, settings: Settings,
                                     session: AsyncSession):
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n or not callback.message:
        await callback.answer("Error displaying promo codes.", show_alert=True)
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    promo_models = await promo_code_dal.get_all_active_promo_codes(session,
                                                                   limit=20,
                                                                   offset=0)
    if not promo_models:
        await callback.message.edit_text(
            _("admin_no_active_promos"),
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n))
        await callback.answer()
        return

    kb = InlineKeyboardBuilder()
    for promo in promo_models:
        kb.row(
            InlineKeyboardButton(
                text=promo.code,
                callback_data=f"promo_edit:{promo.promo_code_id}"),
            InlineKeyboardButton(
                text=_("admin_promo_delete_button"),
                callback_data=f"promo_delete:{promo.promo_code_id}"),
        )
    kb.row(
        InlineKeyboardButton(text=_("back_to_admin_panel_button"),
                             callback_data="admin_action:main"))

    await callback.message.edit_text(
        _("admin_manage_promos_title"),
        reply_markup=kb.as_markup())
    await callback.answer()


@router.callback_query(F.data.startswith("promo_edit:"))
async def promo_edit_select_handler(callback: types.CallbackQuery, state: FSMContext,
                                    i18n_data: dict, settings: Settings,
                                    session: AsyncSession):
    promo_id = int(callback.data.split(":")[1])
    promo = await promo_code_dal.get_promo_code_by_id(session, promo_id)
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n or not promo or not callback.message:
        await callback.answer("Error", show_alert=True)
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    await state.update_data(edit_promo_id=promo_id)
    await state.set_state(AdminStates.waiting_for_promo_edit_details)
    await callback.message.edit_text(
        _("admin_promo_edit_prompt", code=promo.code),
        reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n),
        parse_mode="HTML")
    await callback.answer()


@router.message(AdminStates.waiting_for_promo_edit_details, F.text)
async def process_promo_edit_details(message: types.Message, state: FSMContext,
                                     i18n_data: dict, settings: Settings,
                                     session: AsyncSession):
    data = await state.get_data()
    promo_id = data.get("edit_promo_id")
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n or not promo_id:
        await message.answer("Error")
        await state.clear()
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    parts = message.text.strip().split()
    if not (3 <= len(parts) <= 4):
        await message.answer(_("admin_promo_invalid_format"))
        return
    try:
        code_str = parts[0].upper()
        bonus = int(parts[1])
        max_act = int(parts[2])
        valid_until = None
        if len(parts) == 4:
            days = int(parts[3])
            valid_until = datetime.now(timezone.utc) + timedelta(days=days)
    except Exception:
        await message.answer(_("admin_promo_invalid_format_general"))
        return

    update_data = {
        "code": code_str,
        "bonus_days": bonus,
        "max_activations": max_act,
        "valid_until": valid_until,
    }
    updated = await promo_code_dal.update_promo_code(session, promo_id, update_data)
    if updated:
        await session.commit()
        await message.answer(
            _("admin_promo_updated_success", code=code_str),
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n),
            parse_mode="HTML",
        )
    else:
        await session.rollback()
        await message.answer(_("admin_promo_not_found"))
    await state.clear()


@router.callback_query(F.data.startswith("promo_delete:"))
async def promo_delete_handler(callback: types.CallbackQuery, i18n_data: dict,
                               settings: Settings, session: AsyncSession):
    promo_id = int(callback.data.split(":")[1])
    promo = await promo_code_dal.delete_promo_code(session, promo_id)
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n or not callback.message:
        await callback.answer("Error", show_alert=True)
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    if promo:
        await session.commit()
        await callback.message.edit_text(
            _("admin_promo_deleted_success", code=promo.code),
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n),
            parse_mode="HTML")
    else:
        await session.rollback()
        await callback.message.edit_text(
            _("admin_promo_not_found"),
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n))
    await callback.answer()


@router.callback_query(
    F.data == "admin_action:main",
    StateFilter(
        AdminStates.waiting_for_promo_details,
        AdminStates.waiting_for_promo_edit_details,
        AdminStates.waiting_for_bulk_promo_details,
    ),
)
async def cancel_promo_creation_state_to_menu(callback: types.CallbackQuery,
                                              state: FSMContext,
                                              settings: Settings,
                                              i18n_data: dict,
                                              session: AsyncSession):
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n or not callback.message:
        await callback.answer("Error cancelling.", show_alert=True)
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    try:
        await callback.message.edit_text(_("admin_action_cancelled_default"),
                                         reply_markup=get_admin_panel_keyboard(
                                             i18n, current_lang, settings))
    except Exception:
        await callback.message.answer(_("admin_action_cancelled_default"),
                                      reply_markup=get_admin_panel_keyboard(
                                          i18n, current_lang, settings))

    await callback.answer(_("admin_action_cancelled_default_alert"))
    await state.clear()


async def create_bulk_promo_prompt_handler(callback: types.CallbackQuery,
                                          state: FSMContext, i18n_data: dict,
                                          settings: Settings,
                                          session: AsyncSession):
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n or not callback.message:
        await callback.answer("Error preparing bulk promo creation.",
                              show_alert=True)
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    prompt_text = _(
        "admin_bulk_promo_create_prompt",
        default="📦 Массовое создание промокодов\n\nВведите данные в формате:\n<количество> <бонусные_дни> <максимальное_использование> [дни_действия]\n\nПример: 50 7 100 30\n(создаст 50 промокодов на 7 дней с лимитом 100 активаций каждый, действующих 30 дней)",
        example_format="50 7 100 30"
    )

    try:
        await callback.message.edit_text(
            prompt_text,
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n))
    except Exception as e:
        logging.warning(
            f"Could not edit message for bulk promo prompt: {e}. Sending new.")
        await callback.message.answer(
            prompt_text,
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n))
    await callback.answer()
    await state.set_state(AdminStates.waiting_for_bulk_promo_details)


def generate_unique_promo_code(length: int = 8) -> str:
    """Generate a unique promotional code"""
    characters = string.ascii_uppercase + string.digits
    # Exclude confusing characters
    characters = characters.replace('0', '').replace('O', '').replace('1', '').replace('I', '').replace('L', '')
    return ''.join(random.choice(characters) for _ in range(length))


@router.message(AdminStates.waiting_for_bulk_promo_details, F.text)
async def process_bulk_promo_details_handler(message: types.Message,
                                            state: FSMContext,
                                            i18n_data: dict,
                                            settings: Settings,
                                            session: AsyncSession):
    current_lang = i18n_data.get("current_language", settings.DEFAULT_LANGUAGE)
    i18n: Optional[JsonI18n] = i18n_data.get("i18n_instance")
    if not i18n:
        await message.reply("Language service error.")
        return
    _ = lambda key, **kwargs: i18n.gettext(current_lang, key, **kwargs)

    if not message.text:
        await message.answer(_("admin_promo_invalid_format"))
        return

    parts = message.text.strip().split()
    if not (3 <= len(parts) <= 4):
        await message.answer(_(
            "admin_bulk_promo_invalid_format",
            default="❌ Неверный формат. Используйте: <количество> <бонусные_дни> <максимальное_использование> [дни_действия]"
        ))
        return

    try:
        count = int(parts[0])
        bonus_days = int(parts[1])
        max_activations = int(parts[2])

        if count <= 0 or count > 1000:
            raise ValueError(_("admin_bulk_promo_invalid_count", default="Количество должно быть от 1 до 1000"))
        
        if bonus_days <= 0 or max_activations <= 0:
            raise ValueError(_("admin_promo_invalid_bonus_or_activations"))

        valid_until_date: Optional[datetime] = None
        valid_until_str_display = _("admin_promo_valid_indefinitely")

        if len(parts) == 4:
            valid_days_from_now = int(parts[3])
            if valid_days_from_now <= 0:
                raise ValueError(_("admin_promo_invalid_validity_days"))
            valid_until_date = datetime.now(
                timezone.utc) + timedelta(days=valid_days_from_now)
            valid_until_str_display = _(
                "admin_promo_valid_until_display",
                date=valid_until_date.strftime('%Y-%m-%d'))

    except ValueError as e:
        await message.answer(_(
            "admin_bulk_promo_invalid_values",
            default="❌ Неверные значения: {error}",
            error=str(e)
        ))
        return
    except Exception as e_parse:
        logging.error(f"Error parsing bulk promo details '{message.text}': {e_parse}")
        await message.answer(_("admin_promo_invalid_format_general"))
        return

    admin_id = message.from_user.id if message.from_user else 0

    # Generate unique codes and create promo codes
    created_codes = []
    failed_codes = []
    
    await message.answer(_(
        "admin_bulk_promo_creating",
        default="🔄 Создаю {count} промокодов...",
        count=count
    ))

    for i in range(count):
        try:
            # Generate unique code
            attempts = 0
            while attempts < 10:  # Max 10 attempts to generate unique code
                code = generate_unique_promo_code()
                
                # Check if code already exists
                existing_promo = await promo_code_dal.get_promo_code_by_code(session, code)
                if not existing_promo:
                    break
                attempts += 1
            
            if attempts >= 10:
                failed_codes.append(f"Failed to generate unique code #{i+1}")
                continue

            promo_data_to_create = {
                "code": code,
                "bonus_days": bonus_days,
                "max_activations": max_activations,
                "created_by_admin_id": admin_id,
                "valid_until": valid_until_date,
                "is_active": True,
                "current_activations": 0
            }

            created_promo = await promo_code_dal.create_promo_code(
                session, promo_data_to_create)
            
            if created_promo:
                created_codes.append(created_promo.code)
            else:
                failed_codes.append(f"Failed to create code #{i+1}")

        except Exception as e:
            logging.error(f"Error creating bulk promo code #{i+1}: {e}")
            failed_codes.append(f"Error creating code #{i+1}: {str(e)}")

    try:
        await session.commit()
        
        # Prepare success message
        success_text_parts = [
            _(
                "admin_bulk_promo_created_success",
                default="✅ Массовое создание завершено!\n\n📦 Создано промокодов: {created_count}\n💎 Бонусных дней: {bonus_days}\n🔄 Макс. активаций каждого: {max_activations}\n⏰ Действительны до: {valid_until}",
                created_count=len(created_codes),
                bonus_days=bonus_days,
                max_activations=max_activations,
                valid_until=valid_until_str_display
            )
        ]

        if failed_codes:
            success_text_parts.append(f"\n❌ Ошибок: {len(failed_codes)}")

        if created_codes:
            # Show first few codes as examples
            codes_to_show = created_codes[:10]  # Show first 10
            success_text_parts.append(f"\n📝 Примеры созданных кодов:")
            success_text_parts.append("\n".join([f"• {code}" for code in codes_to_show]))
            
            if len(created_codes) > 10:
                success_text_parts.append(f"... и еще {len(created_codes) - 10} кодов")

        # Send codes as a file if many were created
        if len(created_codes) > 20:
            try:
                codes_text = "\n".join(created_codes)
                codes_file = types.BufferedInputFile(
                    codes_text.encode('utf-8'),
                    filename=f"promo_codes_{datetime.now().strftime('%Y%m%d_%H%M%S')}.txt"
                )
                await message.answer_document(
                    codes_file,
                    caption=_(
                        "admin_bulk_promo_codes_file",
                        default="📄 Файл со всеми созданными промокодами"
                    )
                )
            except Exception as e:
                logging.error(f"Failed to send codes file: {e}")

        final_text = "\n".join(success_text_parts)
        await message.answer(
            final_text,
            reply_markup=get_back_to_admin_panel_keyboard(current_lang, i18n))

    except Exception as e_db_commit:
        await session.rollback()
        logging.error(f"Failed to commit bulk promo codes creation: {e_db_commit}", exc_info=True)
        await message.answer(_(
            "admin_bulk_promo_creation_failed",
            default="❌ Ошибка при сохранении промокодов в базу данных"
        ))

    await state.clear()