# cogs/backup.py
import discord
from discord.ext import commands, tasks
from discord import app_commands
import asyncio
import os
import datetime
import zipfile
import logging
from config import DB_DSN, BACKUP_CHANNEL_ID

logger = logging.getLogger(__name__)

class BackupCog(commands.Cog):
    def __init__(self, bot):
        self.bot = bot
        self.auto_backup.start()

    def cog_unload(self):
        self.auto_backup.cancel()

    @tasks.loop(hours=12)
    async def auto_backup(self):
        """Automatically runs every 12 hours."""
        await self.bot.wait_until_ready()
        await self._execute_backup("🕒 Automated 12-Hour Backup")

    async def _execute_backup(self, title_prefix: str, interaction: discord.Interaction = None):
        """The core logic for dumping, zipping, and uploading the database."""
        
        # Ensure we have a valid destination
        channel = self.bot.get_channel(BACKUP_CHANNEL_ID)
        if not channel:
            error_msg = "❌ `BACKUP_CHANNEL_ID` is missing or invalid in your .env file! Cannot upload database backup."
            logger.error(error_msg)
            if interaction:
                await interaction.followup.send(error_msg, ephemeral=True)
            return

        now = datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
        sql_filename = f"db_dump_{now}.sql"
        zip_filename = f"Gacha_Backup_{now}.zip"

        logger.info(f"Starting database backup: {sql_filename}")

        try:
            # 1. Run the native PostgreSQL dump command securely
            process = await asyncio.create_subprocess_exec(
                'pg_dump', '--dbname', DB_DSN, '-f', sql_filename,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE
            )
            stdout, stderr = await process.communicate()

            if process.returncode != 0:
                error_msg = f"❌ pg_dump failed: {stderr.decode()}"
                logger.error(error_msg)
                if interaction:
                    await interaction.followup.send(error_msg, ephemeral=True)
                return

            # 2. Compress it heavily so we don't hit Discord's 25MB upload limit
            def zip_file():
                with zipfile.ZipFile(zip_filename, 'w', zipfile.ZIP_DEFLATED) as zipf:
                    zipf.write(sql_filename)

            await asyncio.to_thread(zip_file)

            # 3. Format and Upload to Discord
            file = discord.File(fp=zip_filename, filename=zip_filename)
            embed = discord.Embed(
                title=f"📦 {title_prefix}",
                description=f"Secure database snapshot generated at `<t:{int(datetime.datetime.now().timestamp())}:f>`.",
                color=discord.Color.green()
            )
            embed.set_footer(text="To restore: Extract the .zip and run `psql -d gacha_bot_db -f <filename.sql>` in Termux.")
            
            await channel.send(embed=embed, file=file)
            logger.info("✅ Backup successfully uploaded to Discord Cloud.")

            if interaction:
                await interaction.followup.send("✅ Backup successfully forced and uploaded to the private vault channel!", ephemeral=True)

        except Exception as e:
            logger.error(f"Backup Error: {e}", exc_info=True)
            if interaction:
                await interaction.followup.send("❌ A critical error occurred while generating the backup.", ephemeral=True)
                
        finally:
            # 4. TRASH THE LOCAL FILES: Prevents your Android storage from filling up!
            if os.path.exists(sql_filename):
                os.remove(sql_filename)
            if os.path.exists(zip_filename):
                os.remove(zip_filename)

    # Allow admins to manually force a backup at any time
    @app_commands.command(name="force_backup", description="[ADMIN] Force an immediate database backup to the cloud vault")
    @app_commands.default_permissions(administrator=True)
    async def force_backup(self, interaction: discord.Interaction):
        await interaction.response.defer(ephemeral=True)
        await self._execute_backup("⚙️ Manual Admin Backup", interaction)


async def setup(bot):
    await bot.add_cog(BackupCog(bot))