import os
import asyncio
import sys
import concurrent.futures
import logging
import re

from contextlib import suppress
from dotenv import load_dotenv
from functools import wraps
from telegram import Update, InlineKeyboardButton, InlineKeyboardMarkup
from telegram.ext import ApplicationBuilder, CommandHandler, MessageHandler, filters, ContextTypes, CallbackQueryHandler

# Import your existing logic
from agent import parse_page
from database import upload_entry
from scraper import get_clean_content as _get_clean_content


# Run the scraper in a separate thread with its own event loop to avoid
# Windows Selector vs Proactor event loop conflicts between PTB and Playwright.
def _run_scraper_in_thread(url: str) -> str:
    # Proactor is required for subprocesses (Playwright) on Windows
    if sys.platform == 'win32':
        asyncio.set_event_loop_policy(asyncio.WindowsProactorEventLoopPolicy())
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    try:
        return loop.run_until_complete(_get_clean_content(url))
    finally:
        loop.close()


async def get_clean_content(url: str) -> str:
    loop = asyncio.get_event_loop()
    with concurrent.futures.ThreadPoolExecutor() as pool:
        result = await loop.run_in_executor(pool, _run_scraper_in_thread, url)
    return result

load_dotenv()
logging.getLogger("httpx").setLevel(logging.WARNING)

# Configuration
TOKEN = os.getenv("TG_TOKEN")
_allowed_env = os.getenv("ALLOWED_USERS", "")
if _allowed_env:
    try:
        ALLOWED_IDS = [int(x.strip()) for x in _allowed_env.split(',') if x.strip()]
    except Exception:
        logging.warning("Failed to parse ALLOWED_USERS from .env; defaulting to empty list")
        ALLOWED_IDS = []
else:
    ALLOWED_IDS = []

if not TOKEN:
    logging.warning("TG_TOKEN not set in .env; bot will not start without a token")

# Setup Logging
logging.basicConfig(format='%(asctime)s - %(name)s - %(levelname)s - %(message)s', level=logging.INFO)

# --- Retry Function with Exponential Backoff ---
def retry(max_attempts=3, backoff_factor=2, initial_delay=1):
    """
    Decorator for retrying async functions with exponential backoff.
    
    Args:
        max_attempts: Maximum number of retry attempts
        backoff_factor: Multiplier for delay between retries
        initial_delay: Initial delay in seconds
    """
    def decorator(func):
        @wraps(func)
        async def wrapper(*args, **kwargs):
            delay = initial_delay
            last_exception = None
            
            for attempt in range(1, max_attempts + 1):
                try:
                    return await func(*args, **kwargs)
                except Exception as e:
                    last_exception = e
                    if attempt < max_attempts:
                        logging.warning(f"Attempt {attempt}/{max_attempts} failed for {func.__name__}: {str(e)}")
                        await asyncio.sleep(delay)
                        delay *= backoff_factor
                    else:
                        logging.error(f"All {max_attempts} attempts failed for {func.__name__}")
            
            raise last_exception
        return wrapper
    return decorator

# --- The Queue System ---
# This ensures only ONE crawl/parse happens at a time to save RAM
task_queue = asyncio.Queue()


def is_http_url(text: str) -> bool:
    return bool(re.match(r'^https?://\S+$', text.strip()))


def build_url_choice_keyboard(url: str):
    return InlineKeyboardMarkup([
        [InlineKeyboardButton("📅 Process as Event", callback_data='choose_type:event')],
        [InlineKeyboardButton("📋 Process as Opportunity", callback_data='choose_type:opportunity')],
    ])


def build_entry_summary(data, entry_type, saved=False):
    if entry_type == "event":
        event_datetime = data.get('date_time') or data.get('datetime')
        return (
            f"✅ **{data.get('title', 'Unknown')}**\n"
            f"🦆 Org/s: {data.get('org')}\n"
            f"📅 Date & Time: {event_datetime}\n"
            f"📍 Location: {data.get('location')}\n"
            f"🐊 Summary: {data.get('summary')}"
            + ("\n\n💾 **Saved to PocketBase!**" if saved else "")
        )

    return (
        f"✅ **{data.get('title', 'Unknown')}**\n"
        f"🦆 Org/s: {data.get('org')}\n"
        f"📋 Type: {data.get('type')}\n"
        f"🦢 Deadline: {data.get('deadline')}\n"
        f"☁️ Location: {data.get('location')}\n"
        f"🐊 Summary: {data.get('summary')}"
        + ("\n\n💾 **Saved to PocketBase!**" if saved else "")
    )

async def worker():
    while True:
        # Get a 'task' from the queue
        update, context, source_value, entry_type, source_kind = await task_queue.get()
        try:
            await process_link(update, context, source_value, entry_type, source_kind)
        finally:
            task_queue.task_done()

async def process_link(update, context, source_value, entry_type="opportunity", source_kind="url"):
    # Handle both message and callback query contexts
    if update.message:
        status_msg = await update.message.reply_text(f"⏳ Crawling & Analyzing...")
    elif update.callback_query:
        status_msg = update.callback_query.message
        await status_msg.edit_text(f"⏳ Crawling & Analyzing...")
    else:
        logging.error("Could not determine message context for status update")
        return
    
    # Store source and type for potential retry/save
    context.user_data['last_source_value'] = source_value
    context.user_data['last_source_kind'] = source_kind
    context.user_data['last_entry_type'] = entry_type
    
    try:
        if source_kind == "url":
            markdown = await get_clean_content(source_value)
        else:
            markdown = source_value

        extracted_data = await parse_page(markdown, entry_type) 
        
        if not extracted_data:
            await status_msg.edit_text("❌ Failed to extract data from that page.")
            return

        # 2. Store data temporarily in context to 'Save' later
        context.user_data['last_extracted'] = extracted_data
        context.user_data['awaiting_save_url'] = False
        context.user_data['pending_save_url'] = None

        # 3. Show Result with Buttons - format depends on entry type
        summary = build_entry_summary(extracted_data, entry_type)
        
        keyboard = [
            [InlineKeyboardButton("💾 Save to DB", callback_data='save_db')],
            [InlineKeyboardButton("🗑️ Discard", callback_data='discard')],
            [InlineKeyboardButton("🔄️ Retry", callback_data='retry')]
        ]
        reply_markup = InlineKeyboardMarkup(keyboard)
        
        await status_msg.edit_text(summary, reply_markup=reply_markup, parse_mode='Markdown')

    except Exception as e:
        await status_msg.edit_text(f"⚠️ Error: {str(e)}")

# --- Handlers ---

async def start(update: Update, context: ContextTypes.DEFAULT_TYPE):
    if update.effective_user.id not in ALLOWED_IDS:
        return
    await update.message.reply_text(
        "Welcome! I can extract arts opportunities and events.\n\n"
        "📋 **Commands:**\n"
        "/op <url> - Extract an opportunity\n"
        "/ev <url> - Extract an event\n\n"
        "You can also send a URL directly and I will ask whether to process it as an event or opportunity."
    )

async def handle_opportunity(update: Update, context: ContextTypes.DEFAULT_TYPE):
    user_id = update.effective_user.id
    if user_id not in ALLOWED_IDS:
        await update.message.reply_text("Unauthorized. User ID needs to be added!")
        return

    if not context.args:
        await update.message.reply_text("Please provide a URL or paste text. Usage: /op <url or text>")
        return

    input_text = " ".join(context.args).strip()
    if not input_text:
        await update.message.reply_text("Please provide a URL or paste text. Usage: /op <url or text>")
        return

    source_kind = "url" if input_text.startswith("http") else "text"

    await update.message.reply_text("📥 Link queued for processing...")
    await task_queue.put((update, context, input_text, "opportunity", source_kind))

async def handle_event(update: Update, context: ContextTypes.DEFAULT_TYPE):
    user_id = update.effective_user.id
    if user_id not in ALLOWED_IDS:
        await update.message.reply_text("Unauthorized. User ID needs to be added!")
        return

    if not context.args:
        await update.message.reply_text("Please provide a URL or paste text. Usage: /ev <url or text>")
        return

    input_text = " ".join(context.args).strip()
    if not input_text:
        await update.message.reply_text("Please provide a URL or paste text. Usage: /ev <url or text>")
        return

    source_kind = "url" if input_text.startswith("http") else "text"

    await update.message.reply_text("📥 Link queued for processing...")
    await task_queue.put((update, context, input_text, "event", source_kind))

async def handle_followup_text(update: Update, context: ContextTypes.DEFAULT_TYPE):
    if update.effective_user.id not in ALLOWED_IDS:
        return

    if not context.user_data.get('awaiting_save_url'):
        text = (update.message.text or '').strip()
        if not text or not is_http_url(text):
            return

        context.user_data['pending_url_to_process'] = text
        await update.message.reply_text(
            "What should I do with this URL?",
            reply_markup=build_url_choice_keyboard(text)
        )
        return

    text = update.message.text.strip()
    if not text:
        await update.message.reply_text("Please send a URL or type /skip to save without one.")
        return

    if text.lower() == '/skip':
        url = None
    elif text.startswith('http'):
        url = text
    else:
        await update.message.reply_text("Please send a valid URL or type /skip to save without one.")
        return

    data = context.user_data.get('last_extracted')
    entry_type = context.user_data.get('last_entry_type', 'opportunity')
    if data:
        upload_entry(data, entry_type, url)
        context.user_data['awaiting_save_url'] = False
        context.user_data['pending_save_url'] = None
        await update.message.reply_text(build_entry_summary(data, entry_type, saved=True), parse_mode='Markdown')

async def button_handler(update: Update, context: ContextTypes.DEFAULT_TYPE):
    query = update.callback_query
    await query.answer()

    if query.data.startswith('choose_type:'):
        pending_url = context.user_data.get('pending_url_to_process')
        if not pending_url:
            await query.edit_message_text("❌ I couldn't find a pending URL to process.")
            return

        entry_type = query.data.split(':', 1)[1]
        context.user_data['pending_url_to_process'] = None
        await query.edit_message_text(f"📥 Queued URL for {entry_type} processing...")
        await task_queue.put((update, context, pending_url, entry_type, 'url'))
        return

    if query.data == 'save_db':
        data = context.user_data.get('last_extracted')
        entry_type = context.user_data.get('last_entry_type', 'opportunity')
        if data:
            if context.user_data.get('last_source_kind') == 'text':
                context.user_data['awaiting_save_url'] = True
                context.user_data['pending_save_url'] = None
                await query.edit_message_text(
                    build_entry_summary(data, entry_type)
                    + "\n\nSend a source URL to attach it, or type /skip to save without one.",
                    parse_mode='Markdown'
                )
            else:
                url = context.user_data.get('last_source_value')
                upload_entry(data, entry_type, url)  # Pass URL to save with entry
                await query.edit_message_text(build_entry_summary(data, entry_type, saved=True), parse_mode='Markdown')
    elif query.data == 'retry':
        # Retry processing the last URL with the same entry type
        source_value = context.user_data.get('last_source_value')
        source_kind = context.user_data.get('last_source_kind', 'url')
        entry_type = context.user_data.get('last_entry_type', 'opportunity')
        if source_value:
            await query.edit_message_text("⏳ Retrying...")
            await task_queue.put((update, context, source_value, entry_type, source_kind))
        else:
            await query.edit_message_text("❌ No source content to retry.")
    else:
        await query.edit_message_text("🗑️ Discarded.")

# Main Entry Point
async def _main():
    application = ApplicationBuilder().token(TOKEN).build()

    application.add_handler(CommandHandler("start", start))
    application.add_handler(CommandHandler("op", handle_opportunity))
    application.add_handler(CommandHandler("ev", handle_event))
    application.add_handler(MessageHandler(filters.TEXT & (~filters.COMMAND), handle_followup_text))
    application.add_handler(CallbackQueryHandler(button_handler))

    async with application:
        await application.initialize()
        await application.start()

        worker_task = asyncio.create_task(worker())
        print("🤖 Bot is running...")

        await application.updater.start_polling()

        # Keep running until interrupted
        await asyncio.Event().wait()

        # Graceful shutdown
        await application.updater.stop()
        worker_task.cancel()
        with suppress(asyncio.CancelledError):
            await worker_task

        await application.stop()


if __name__ == '__main__':
    import sys
    # if sys.platform == 'win32':
    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
    asyncio.run(_main())