# bot.py
import asyncio
import logging
import os
import re
import uuid
import time
from typing import Dict

from aiogram import Bot, Dispatcher, F
from aiogram.filters import CommandStart, Command
from aiogram.types import Message, FSInputFile
from aiogram.enums import ParseMode
from aiogram.exceptions import TelegramBadRequest
from aiogram.client.default import DefaultBotProperties

import config
import terabox_utils as terabox
import db_utils

# --- Setup ---

os.makedirs("logs", exist_ok=True)
os.makedirs("downloads", exist_ok=True)

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
    handlers=[
        logging.StreamHandler(),
        logging.FileHandler("logs/bot.log", mode="a", encoding="utf-8"),
    ],
)
logger = logging.getLogger(__name__)

bot = Bot(
    token=config.BOT_TOKEN,
    default=DefaultBotProperties(parse_mode=ParseMode.HTML),
)

dp = Dispatcher()

TASK_QUEUE = asyncio.Queue()
BATCH_JOBS: Dict[str, Dict] = {}

# --- Worker ---
async def link_processor_worker(worker_id: int):
    logger.info(f"Link worker #{worker_id} started.")
    while True:
        task = await TASK_QUEUE.get()
        batch_id, original_link = task["batch_id"], task["original_link"]
        batch_info = BATCH_JOBS.get(batch_id)

        if not batch_info:
            TASK_QUEUE.task_done()
            continue

        file_info = None
        error_msg = f"Unknown error for link: {original_link}"

        try:
            short_id = await terabox.extract_terabox_short_id(original_link)
            if not short_id:
                raise ValueError("Invalid Terabox link format.")

            cached_file = await db_utils.get_cached_file(short_id)
            if cached_file:
                logger.info(f"Cache hit for {short_id}. Reusing file_id.")
                file_info = {"cached": True, **cached_file}
            else:
                download_url, raw_filename, error = await terabox.get_final_url_and_filename(original_link)
                if error:
                    raise ValueError(error)

                local_filepath, thumb_path, download_error = await terabox.download_terabox_file(
                    bot,
                    batch_info["source_chat_id"],
                    batch_info["status_message"].message_id,
                    download_url,
                    raw_filename,
                )
                if download_error:
                    raise ValueError(download_error)

                file_info = {
                    "cached": False,
                    "path": local_filepath,
                    "name": raw_filename,
                    "size": os.path.getsize(local_filepath),
                    "short_id": short_id,
                    "thumb": thumb_path,
                }

        except Exception as e:
            error_msg = str(e)

        async with batch_info["lock"]:
            batch_info["processed_links"] += 1
            if file_info:
                batch_info["successful_downloads"].append(file_info)
            else:
                batch_info["failed_links"].append({"link": original_link, "error": error_msg})

            processed, total = batch_info["processed_links"], batch_info["total_links"]

            try:
                await batch_info["status_message"].edit_text(
                    f"⚙️ Batch `{batch_id[:6]}` progress: {processed}/{total} links processed.\n"
                    f"ETA: {(total - processed) * 3} sec ⏳"
                )
            except TelegramBadRequest:
                pass

            if processed == total:
                logger.info(f"Batch {batch_id[:6]} complete. Triggering final processing.")
                await handle_batch_completion(batch_id)

        TASK_QUEUE.task_done()

# --- Send & Cache ---
async def send_and_cache_file(chat_id: int, file_info: dict, caption: str) -> Message:
    file_path_or_id = file_info.get("file_id") or FSInputFile(file_info["path"], filename=file_info["name"])
    media_type = file_info.get("type")
    filename = file_info.get("name") or file_info.get("filename")

    video_exts = (".mp4", ".mkv", ".mov", ".avi", ".webm")
    audio_exts = (".mp3", ".flac", ".ogg", ".wav")

    sent_message = None
    if media_type == "video" or filename.lower().endswith(video_exts):
        sent_message = await bot.send_video(chat_id, file_path_or_id, caption=caption, supports_streaming=True)
        media_type = "video"
    elif media_type == "audio" or filename.lower().endswith(audio_exts):
        sent_message = await bot.send_audio(chat_id, file_path_or_id, caption=caption)
        media_type = "audio"
    else:
        sent_message = await bot.send_document(chat_id, file_path_or_id, caption=caption)
        media_type = "document"

    if not file_info.get("cached") and sent_message:
        file_id_to_cache = getattr(sent_message, media_type).file_id
        await db_utils.add_to_cache(
            file_info["short_id"], file_id_to_cache, filename, media_type, file_info["size"]
        )

    return sent_message

# --- Batch Completion ---
async def handle_batch_completion(batch_id: str):
    batch = BATCH_JOBS.get(batch_id)
    if not batch:
        return

    status_msg = batch["status_message"]
    successful_downloads = batch["successful_downloads"]

    try:
        if not successful_downloads:
            failed_links_text = "\n".join([f"- {x['link']} → {x['error']}" for x in batch["failed_links"]])
            await status_msg.edit_text(
                f"❌ Batch `{batch_id[:6]}` failed.\nDetails:\n{failed_links_text}"
            )
            return

        await status_msg.edit_text(
            f"✅ Batch `{batch_id[:6]}` downloaded. Sending {len(successful_downloads)} files..."
        )

        if config.FORWARD_CHANNEL_ID:
            await bot.forward_message(
                config.FORWARD_CHANNEL_ID,
                batch["source_chat_id"],
                batch["source_message_id"],
            )

            for item in successful_downloads:
                caption = f"`{item.get('name') or item.get('filename')}`"
                await send_and_cache_file(config.FORWARD_CHANNEL_ID, item, caption)
                await asyncio.sleep(1)

        for item in successful_downloads:
            caption = f"`{item.get('name') or item.get('filename')}`"
            await send_and_cache_file(batch["source_chat_id"], item, caption)

        summary = f"✅ Batch `{batch_id[:6]}` complete: {len(successful_downloads)} files sent."
        if batch["failed_links"]:
            summary += f"\n❌ {len(batch['failed_links'])} links failed."

        await status_msg.edit_text(summary)

    except Exception as e:
        logger.error(f"Error during batch completion for {batch_id}: {e}", exc_info=True)
        await status_msg.edit_text(
            f"A critical error occurred while sending files for batch `{batch_id[:6]}`."
        )
    finally:
        for item in successful_downloads:
            if not item.get("cached") and os.path.exists(item["path"]):
                os.remove(item["path"])
            if item.get("thumb") and os.path.exists(item["thumb"]):
                os.remove(item["thumb"])

        del BATCH_JOBS[batch_id]

# --- Handlers ---
@dp.message(CommandStart())
async def start_handler(message: Message):
    await message.reply(
        "👋 <b>Welcome to Terabox Bot!</b>\n\n"
        "📥 Send me any <b>Terabox</b> links.\n"
        "✅ I will download and send the files to you.\n\n"
        "ℹ️ Use /status to check current batch progress.\n\n"
        "Happy sharing!"
    )

@dp.message(Command("status"))
async def status_handler(message: Message):
    active_batches = []
    for batch_id, batch in BATCH_JOBS.items():
        processed = batch["processed_links"]
        total = batch["total_links"]
        active_batches.append(f"Batch `{batch_id[:6]}`: {processed}/{total}")

    if not active_batches:
        await message.reply("✅ No active batches. All clear.")
    else:
        await message.reply("📊 Active batches:\n" + "\n".join(active_batches))

@dp.message(F.text | F.caption)
async def message_handler(message: Message):
    if message.text and message.text.startswith("/"):
        return

    await db_utils.add_or_update_user_db(
        message.from_user.id,
        message.from_user.username,
        message.from_user.first_name,
    )

    links = list(set(re.findall(r"https?://[^\s<>'\"]+", message.text or message.caption or "")))
    terabox_links = [
        link
        for link in links
        if any(x in link for x in [
            "terabox.com",
            "teraboxapp.com",
            "terasharelink.com",
            "1024tera.com",
            "freeterabox.com",
            "4funbox.com",
            "box-links.com",
        ])
    ]

    if not terabox_links:
        return

    batch_id = str(uuid.uuid4())
    status_msg = await message.reply(
        f"✅ Found {len(terabox_links)} links. Queued as batch `{batch_id[:6]}`.\nProcessing... ⏳"
    )

    BATCH_JOBS[batch_id] = {
        "total_links": len(terabox_links),
        "processed_links": 0,
        "successful_downloads": [],
        "failed_links": [],
        "source_chat_id": message.chat.id,
        "source_user_id": message.from_user.id,
        "source_message_id": message.message_id,
        "status_message": status_msg,
        "lock": asyncio.Lock(),
    }

    for link in terabox_links:
        await TASK_QUEUE.put({"batch_id": batch_id, "original_link": link})

# --- Startup ---
async def on_startup(dispatcher: Dispatcher):
    await db_utils.initialize_database()
    for i in range(config.CONCURRENT_WORKERS):
        asyncio.create_task(link_processor_worker(i + 1))
    logger.info(f"Bot started with {config.CONCURRENT_WORKERS} concurrent workers.")

# --- Main ---
def setup_dispatcher():
    dp.startup.register(on_startup)
    dp.message.register(start_handler, CommandStart())
    dp.message.register(status_handler, Command("status"))
    dp.message.register(message_handler)
    return dp