# app.py - Hugging Face Spaces Docker + Persistent Storage Edition
import asyncio
import json
import logging
import os
import random
import re
import signal
import sqlite3
import sys
import time
from contextlib import asynccontextmanager
from datetime import timedelta
from pathlib import Path
from typing import Optional

import aiosqlite
import discord
from discord import app_commands
from discord.ext import commands, tasks

# ============================================================
# CONFIGURATION (Reads from HF Space Environment Variables)
# ============================================================

# Persistent storage path provided by Hugging Face Spaces
STORAGE_PATH = Path(os.environ.get("HF_PERSISTENT_STORAGE", "/data"))
DB_PATH = str(STORAGE_PATH / "database.db")
BACKUP_PATH = str(STORAGE_PATH / "backup.db")

TOKEN = os.environ.get("DISCORD_TOKEN", "")

def _parse_id_set(env_var: str) -> set[int]:
    """Parse comma-separated IDs from environment variable."""
    raw = os.environ.get(env_var, "")
    if not raw:
        return set()
    ids = set()
    for part in raw.split(","):
        part = part.strip()
        if part.isdigit():
            ids.add(int(part))
    return ids

OWNER_USER_IDS = _parse_id_set("OWNER_USER_IDS")
ALLOWED_GUILD_IDS = _parse_id_set("ALLOWED_GUILD_IDS")

BUTTON_REFRESH_SECONDS = 1.0

GIVEAWAY_DESCRIPTION = (
    "You must follow the rules to be eligible to win.\n"
    "You can't be rewarded if you complete the requested requirements after the giveaway ends.\n"
    "Joining multiple times or abusing the bot may disqualify you."
)

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s | %(levelname)-8s | %(name)s | %(message)s",
    stream=sys.stdout,
)
log = logging.getLogger("giveaway-bot")


# ============================================================
# STARTUP VALIDATION
# ============================================================

def validate_environment():
    """Validate all required configuration before starting."""
    errors = []

    if not TOKEN:
        errors.append(
            "DISCORD_TOKEN is not set. "
            "Add it as a secret in your HF Space settings."
        )

    if not OWNER_USER_IDS:
        errors.append(
            "OWNER_USER_IDS is not set or empty. "
            "Add it as a secret in your HF Space settings "
            "(comma-separated Discord user IDs)."
        )

    if not STORAGE_PATH.exists():
        errors.append(
            f"Persistent storage path '{STORAGE_PATH}' does not exist. "
            "Make sure Persistent Storage is enabled in your HF Space settings."
        )
    elif not os.access(STORAGE_PATH, os.W_OK):
        errors.append(
            f"Persistent storage path '{STORAGE_PATH}' is not writable. "
            "Check file permissions on your HF Space volume."
        )

    if errors:
        for err in errors:
            log.critical(err)
        raise SystemExit(1)

    log.info("Environment validated successfully.")
    log.info("  Storage path : %s", STORAGE_PATH)
    log.info("  DB path      : %s", DB_PATH)
    log.info("  Backup path  : %s", BACKUP_PATH)
    log.info("  Owner UIDs   : %s", OWNER_USER_IDS)
    log.info("  Allowed Guilds: %s", ALLOWED_GUILD_IDS or "(owner-only)")


# ============================================================
# UTILS
# ============================================================

def utc_now() -> float:
    return time.time()


def parse_duration(raw: str) -> timedelta:
    text = raw.strip().lower()
    if not re.fullmatch(r"(?:\s*\d+[smhd]\s*)+", text):
        raise ValueError("Use a duration like 30s, 10m, 2h, 1d, or 1h30m.")

    total_seconds = 0
    for value, unit in re.findall(r"(\d+)([smhd])", text):
        value = int(value)
        if unit == "s":
            total_seconds += value
        elif unit == "m":
            total_seconds += value * 60
        elif unit == "h":
            total_seconds += value * 3600
        elif unit == "d":
            total_seconds += value * 86400

    if total_seconds <= 0:
        raise ValueError("Duration must be greater than zero.")
    return timedelta(seconds=total_seconds)


def parse_message_id(raw: str) -> int:
    raw = raw.strip()
    if raw.isdigit():
        return int(raw)
    match = re.search(r"\/(\d+)\/(\d+)\/(\d+)", raw)
    if match:
        return int(match.group(3))
    raise ValueError("Provide a valid message ID or message link.")


def safe_json_list(value: Optional[str]) -> list:
    if not value:
        return []
    try:
        data = json.loads(value)
        return data if isinstance(data, list) else []
    except Exception:
        return []


def format_user_list(user_ids: list, max_shown: int = 20) -> str:
    if not user_ids:
        return "No winners."
    mentions = []
    for uid in user_ids[:max_shown]:
        try:
            mentions.append(f"<@{int(uid)}>")
        except Exception:
            continue
    if len(user_ids) > max_shown:
        mentions.append(f"... and {len(user_ids) - max_shown} more")
    return ", ".join(mentions)


def error_embed(text: str) -> discord.Embed:
    return discord.Embed(description=f"❌ {text}", color=discord.Color.red())


def success_embed(text: str) -> discord.Embed:
    return discord.Embed(description=f"✅ {text}", color=discord.Color.green())


async def send_interaction_message(
    interaction: discord.Interaction,
    embed: discord.Embed,
    *,
    ephemeral: bool = True,
):
    try:
        if interaction.response.is_done():
            await interaction.followup.send(embed=embed, ephemeral=ephemeral)
        else:
            await interaction.response.send_message(embed=embed, ephemeral=ephemeral)
    except Exception:
        pass


# ============================================================
# DATABASE (Fixed async context manager pattern)
# ============================================================

SCHEMA = """
CREATE TABLE IF NOT EXISTS giveaways (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    guild_id INTEGER NOT NULL,
    channel_id INTEGER NOT NULL,
    message_id INTEGER UNIQUE,
    title TEXT NOT NULL,
    winner_count INTEGER NOT NULL CHECK (winner_count > 0),
    ends_at REAL NOT NULL,
    required_roles TEXT NOT NULL DEFAULT '[]',
    creator_id INTEGER NOT NULL,
    created_at REAL NOT NULL,
    ended INTEGER NOT NULL DEFAULT 0,
    participant_count INTEGER NOT NULL DEFAULT 0,
    winners TEXT NOT NULL DEFAULT '[]'
);

CREATE TABLE IF NOT EXISTS entries (
    giveaway_id INTEGER NOT NULL REFERENCES giveaways(id) ON DELETE CASCADE,
    user_id INTEGER NOT NULL,
    joined_at REAL NOT NULL,
    PRIMARY KEY (giveaway_id, user_id)
);

CREATE INDEX IF NOT EXISTS idx_entries_giveaway ON entries(giveaway_id);
CREATE INDEX IF NOT EXISTS idx_giveaways_active ON giveaways(ended, ends_at);
CREATE INDEX IF NOT EXISTS idx_giveaways_message ON giveaways(message_id);
"""


class Database:
    def __init__(self):
        self._write_lock = asyncio.Lock()
        self._restore_lock = asyncio.Lock()

    @asynccontextmanager
    async def _connect(self, path: Optional[str] = None):
        conn = await aiosqlite.connect(path or DB_PATH, timeout=30)
        try:
            await conn.execute("PRAGMA journal_mode=WAL;")
            await conn.execute("PRAGMA synchronous=NORMAL;")
            await conn.execute("PRAGMA foreign_keys=ON;")
            await conn.execute("PRAGMA busy_timeout=10000;")
            conn.row_factory = sqlite3.Row
            yield conn
        finally:
            await conn.close()

    def _integrity_check(self, path: str) -> bool:
        conn = None
        try:
            conn = sqlite3.connect(path)
            cursor = conn.execute("PRAGMA integrity_check;")
            result = cursor.fetchone()
            return bool(result and str(result[0]).lower() == "ok")
        except Exception:
            return False
        finally:
            if conn:
                try:
                    conn.close()
                except Exception:
                    pass

    def _sqlite_backup(self, source_path: str, destination_path: str):
        source = sqlite3.connect(source_path)
        destination = sqlite3.connect(destination_path)
        try:
            source.backup(destination)
        finally:
            try:
                destination.close()
            except Exception:
                pass
            try:
                source.close()
            except Exception:
                pass

    def _remove_db_files(self):
        for suffix in ("", "-wal", "-shm"):
            path = DB_PATH + suffix
            try:
                os.remove(path)
            except FileNotFoundError:
                pass
            except Exception:
                log.exception("Failed removing database file: %s", path)

    async def initialize(self):
        if not os.path.exists(DB_PATH):
            if os.path.exists(BACKUP_PATH) and await asyncio.to_thread(
                self._integrity_check, BACKUP_PATH
            ):
                log.info("database.db missing. Restoring from backup.db.")
                await asyncio.to_thread(self._sqlite_backup, BACKUP_PATH, DB_PATH)
            else:
                log.info("Creating fresh database.db.")
                self._remove_db_files()
                async with self._connect():
                    pass
        else:
            if not await asyncio.to_thread(self._integrity_check, DB_PATH):
                await self._handle_corruption()

        await self._create_schema()
        await self.backup_now()
        log.info("Database initialized successfully.")

    async def _handle_corruption(self):
        log.error("database.db failed integrity check. Attempting recovery.")
        stamp = int(time.time())

        if os.path.exists(DB_PATH):
            try:
                os.replace(DB_PATH, str(STORAGE_PATH / f"corrupt_database_{stamp}.db"))
            except Exception:
                self._remove_db_files()

        for suffix in ("-wal", "-shm"):
            try:
                os.remove(DB_PATH + suffix)
            except FileNotFoundError:
                pass
            except Exception:
                pass

        if os.path.exists(BACKUP_PATH) and await asyncio.to_thread(
            self._integrity_check, BACKUP_PATH
        ):
            log.info("Restoring database.db from backup.db.")
            await asyncio.to_thread(self._sqlite_backup, BACKUP_PATH, DB_PATH)
        else:
            log.warning("No valid backup.db found. Creating fresh database.db.")
            async with self._connect():
                pass

    async def _create_schema(self):
        async with self._write_lock:
            async with self._connect() as conn:
                await conn.executescript(SCHEMA)
                await conn.commit()

    async def backup_now(self) -> bool:
        try:
            if not os.path.exists(DB_PATH):
                return False
            if not await asyncio.to_thread(self._integrity_check, DB_PATH):
                log.warning("Skipping backup: database.db failed integrity check.")
                return False
            await asyncio.to_thread(self._sqlite_backup, DB_PATH, BACKUP_PATH)
            return True
        except Exception:
            log.exception("Backup failed.")
            return False

    async def fetch_one(self, query: str, params: tuple = ()) -> Optional[dict]:
        async with self._connect() as conn:
            cursor = await conn.execute(query, params)
            row = await cursor.fetchone()
            return dict(row) if row else None

    async def fetch_all(self, query: str, params: tuple = ()) -> list[dict]:
        async with self._connect() as conn:
            cursor = await conn.execute(query, params)
            rows = await cursor.fetchall()
            return [dict(row) for row in rows]

    async def create_giveaway(
        self, guild_id: int, channel_id: int, title: str,
        winner_count: int, ends_at: float, required_roles: list[int],
        creator_id: int,
    ) -> int:
        async with self._write_lock:
            async with self._connect() as conn:
                cursor = await conn.execute(
                    """INSERT INTO giveaways (
                        guild_id, channel_id, message_id, title, winner_count,
                        ends_at, required_roles, creator_id, created_at,
                        ended, participant_count, winners
                    ) VALUES (?, ?, NULL, ?, ?, ?, ?, ?, ?, 0, 0, '[]')""",
                    (guild_id, channel_id, title, winner_count, ends_at,
                     json.dumps(required_roles), creator_id, utc_now()),
                )
                await conn.commit()
                return int(cursor.lastrowid)

    async def delete_giveaway(self, giveaway_id: int):
        async with self._write_lock:
            async with self._connect() as conn:
                await conn.execute("DELETE FROM giveaways WHERE id = ?", (giveaway_id,))
                await conn.commit()

    async def bind_message(self, giveaway_id: int, message_id: int):
        async with self._write_lock:
            async with self._connect() as conn:
                await conn.execute(
                    "UPDATE giveaways SET message_id = ? WHERE id = ?",
                    (message_id, giveaway_id),
                )
                await conn.commit()

    async def get_giveaway(self, giveaway_id: int) -> Optional[dict]:
        return await self.fetch_one("SELECT * FROM giveaways WHERE id = ?", (giveaway_id,))

    async def get_giveaway_by_message(self, message_id: int) -> Optional[dict]:
        return await self.fetch_one("SELECT * FROM giveaways WHERE message_id = ?", (message_id,))

    async def add_entry(self, giveaway_id: int, user_id: int) -> tuple[bool, int, str]:
        async with self._write_lock:
            async with self._connect() as conn:
                cursor = await conn.execute(
                    "SELECT ended, ends_at, participant_count FROM giveaways WHERE id = ?",
                    (giveaway_id,),
                )
                row = await cursor.fetchone()
                if not row:
                    return False, 0, "missing"

                ended = bool(row["ended"])
                ends_at = float(row["ends_at"])
                participant_count = int(row["participant_count"])

                if ended or ends_at <= utc_now():
                    return False, participant_count, "ended"

                cursor = await conn.execute(
                    "INSERT OR IGNORE INTO entries (giveaway_id, user_id, joined_at) VALUES (?, ?, ?)",
                    (giveaway_id, user_id, utc_now()),
                )
                if cursor.rowcount == 0:
                    await conn.rollback()
                    return False, participant_count, "already"

                await conn.execute(
                    "UPDATE giveaways SET participant_count = participant_count + 1 WHERE id = ?",
                    (giveaway_id,),
                )
                await conn.commit()
                return True, participant_count + 1, "ok"

    async def get_due_active_ids(self) -> list[int]:
        rows = await self.fetch_all(
            "SELECT id FROM giveaways WHERE ended = 0 AND ends_at <= ?", (utc_now(),)
        )
        return [int(row["id"]) for row in rows]

    async def active_giveaways_for_views(self) -> list[dict]:
        return await self.fetch_all(
            "SELECT id, participant_count FROM giveaways WHERE ended = 0 AND ends_at > ?",
            (utc_now(),),
        )

    async def _random_winners_conn(
        self, conn: aiosqlite.Connection, giveaway_id: int,
        limit: int, exclude_user_ids: list[int],
    ) -> list[int]:
        limit = int(limit)
        if limit <= 0:
            return []

        exclude_user_ids = list({int(u) for u in exclude_user_ids if u})

        if not exclude_user_ids:
            cursor = await conn.execute(
                "SELECT user_id FROM entries WHERE giveaway_id = ? ORDER BY RANDOM() LIMIT ?",
                (giveaway_id, limit),
            )
        else:
            await conn.execute(
                "CREATE TEMP TABLE IF NOT EXISTS temp_excluded_winners (user_id INTEGER PRIMARY KEY)"
            )
            await conn.execute("DELETE FROM temp_excluded_winners")
            await conn.executemany(
                "INSERT OR IGNORE INTO temp_excluded_winners (user_id) VALUES (?)",
                [(u,) for u in exclude_user_ids],
            )
            cursor = await conn.execute(
                """SELECT e.user_id FROM entries AS e
                   WHERE e.giveaway_id = ?
                     AND NOT EXISTS (SELECT 1 FROM temp_excluded_winners AS x WHERE x.user_id = e.user_id)
                   ORDER BY RANDOM() LIMIT ?""",
                (giveaway_id, limit),
            )

        rows = await cursor.fetchall()
        return [int(row["user_id"]) for row in rows]

    async def end_giveaway_and_choose_winners(self, giveaway_id: int) -> Optional[dict]:
        async with self._write_lock:
            async with self._connect() as conn:
                cursor = await conn.execute("SELECT * FROM giveaways WHERE id = ?", (giveaway_id,))
                row = await cursor.fetchone()
                if not row:
                    return None

                giveaway = dict(row)
                if giveaway["ended"]:
                    return {"already": True, "giveaway": giveaway}

                existing = safe_json_list(giveaway.get("winners"))
                winners = await self._random_winners_conn(conn, giveaway_id, giveaway["winner_count"], existing)

                await conn.execute(
                    "UPDATE giveaways SET ended = 1, winners = ? WHERE id = ?",
                    (json.dumps(winners), giveaway_id),
                )
                await conn.commit()

                giveaway["ended"] = 1
                giveaway["winners"] = json.dumps(winners)
                return {"already": False, "giveaway": giveaway, "winners": winners}

    async def reroll_giveaway(self, giveaway_id: int) -> Optional[dict]:
        async with self._write_lock:
            async with self._connect() as conn:
                cursor = await conn.execute("SELECT * FROM giveaways WHERE id = ?", (giveaway_id,))
                row = await cursor.fetchone()
                if not row:
                    return None

                giveaway = dict(row)
                if not giveaway["ended"]:
                    return {"not_ended": True, "giveaway": giveaway}

                existing = safe_json_list(giveaway.get("winners"))
                new_winners = await self._random_winners_conn(conn, giveaway_id, giveaway["winner_count"], existing)

                if not new_winners:
                    return {"not_ended": False, "giveaway": giveaway, "new_winners": [], "all_winners": existing}

                combined = list(existing)
                for w in new_winners:
                    if w not in combined:
                        combined.append(w)

                await conn.execute(
                    "UPDATE giveaways SET winners = ? WHERE id = ?",
                    (json.dumps(combined), giveaway_id),
                )
                await conn.commit()

                giveaway["winners"] = json.dumps(combined)
                return {"not_ended": False, "giveaway": giveaway, "new_winners": new_winners, "all_winners": combined}


# ============================================================
# BOT SETUP
# ============================================================

intents = discord.Intents.default()
intents.members = True

db = Database()


class GiveawayBot(commands.Bot):
    def __init__(self):
        super().__init__(command_prefix="!", intents=intents, help_command=None)

    async def setup_hook(self):
        await db.initialize()


bot = GiveawayBot()


def guild_is_allowed(guild: Optional[discord.Guild]) -> bool:
    if not guild:
        return False
    if guild.id in ALLOWED_GUILD_IDS:
        return True
    return guild.owner_id in OWNER_USER_IDS


def owner_only():
    async def predicate(interaction: discord.Interaction) -> bool:
        if interaction.guild is None:
            raise app_commands.CheckFailure("This command can only be used in a server.")
        if interaction.user.id not in OWNER_USER_IDS:
            raise app_commands.CheckFailure("This command is private.")
        if not guild_is_allowed(interaction.guild):
            raise app_commands.CheckFailure("This bot is not authorized in this server.")
        return True
    return app_commands.check(predicate)


# ============================================================
# EMBED BUILDING
# ============================================================

def build_giveaway_embed(giveaway: dict, *, ended: bool = False) -> discord.Embed:
    embed = discord.Embed(title=giveaway["title"], description=GIVEAWAY_DESCRIPTION, color=discord.Color.blurple())
    ends_at = int(giveaway["ends_at"])

    if ended:
        embed.add_field(name="Status", value=f"Ended <t:{ends_at}:R>", inline=False)
    else:
        embed.add_field(name="Ends", value=f"<t:{ends_at}:R> • <t:{ends_at}:F>", inline=False)

    roles = safe_json_list(giveaway.get("required_roles"))
    if roles:
        embed.add_field(name="Required role(s)", value=" ".join(f"<@&{r}>" for r in roles), inline=False)

    embed.add_field(name="Winners", value=str(giveaway["winner_count"]), inline=True)
    embed.add_field(name="Entries", value=str(giveaway["participant_count"]), inline=True)

    if ended:
        winners = safe_json_list(giveaway.get("winners"))
        embed.add_field(name="Winner(s)", value=format_user_list(winners) if winners else "No eligible entries.", inline=False)

    embed.set_footer(text="Join once. You cannot unjoin. You must hold required role(s) when joining.")
    return embed


# ============================================================
# VIEWS / BUTTONS
# ============================================================

class GiveawayView(discord.ui.View):
    def __init__(self, giveaway_id: int, count: int = 0):
        super().__init__(timeout=None)
        self.giveaway_id = int(giveaway_id)
        button = discord.ui.Button(
            label=f"{count} | Join", style=discord.ButtonStyle.success,
            custom_id=f"giveaway_join:{self.giveaway_id}", emoji="🎉",
        )
        button.callback = self.join_button
        self.add_item(button)

    async def join_button(self, interaction: discord.Interaction):
        try:
            if interaction.guild is None:
                await send_interaction_message(interaction, error_embed("This button only works inside a server."))
                return
            if interaction.message is None:
                await send_interaction_message(interaction, error_embed("This giveaway message is invalid."))
                return

            giveaway = await db.get_giveaway(self.giveaway_id)
            if not giveaway:
                await send_interaction_message(interaction, error_embed("This giveaway no longer exists."))
                return
            if giveaway.get("message_id") != interaction.message.id:
                await send_interaction_message(interaction, error_embed("This giveaway card is no longer valid."))
                return
            if giveaway["ended"] or giveaway["ends_at"] <= utc_now():
                await send_interaction_message(interaction, error_embed("This giveaway has ended."))
                return

            member = interaction.user
            if not isinstance(member, discord.Member):
                await send_interaction_message(interaction, error_embed("Could not verify your server roles."))
                return

            required_roles = safe_json_list(giveaway.get("required_roles"))
            if required_roles:
                member_role_ids = {role.id for role in member.roles}
                missing = [r for r in required_roles if r not in member_role_ids]
                if missing:
                    await send_interaction_message(
                        interaction,
                        error_embed(f"You need these role(s) to join:\n{' '.join(f'<@&{r}>' for r in missing)}"),
                    )
                    return

            inserted, _, status = await db.add_entry(self.giveaway_id, member.id)
            if status == "missing":
                await send_interaction_message(interaction, error_embed("This giveaway no longer exists."))
            elif status == "ended":
                await send_interaction_message(interaction, error_embed("This giveaway has ended."))
            elif status == "already":
                await send_interaction_message(interaction, error_embed("You already joined this giveaway."))
            else:
                await send_interaction_message(interaction, success_embed("You joined the giveaway!"))
                await queue_button_refresh(interaction.client, self.giveaway_id)

        except Exception:
            log.exception("Button join failed.")
            await send_interaction_message(interaction, error_embed("Something went wrong while joining."))


class EndedGiveawayView(discord.ui.View):
    def __init__(self, giveaway_id: int, count: int = 0):
        super().__init__(timeout=None)
        self.add_item(discord.ui.Button(
            label=f"{count} | Ended", style=discord.ButtonStyle.secondary,
            custom_id=f"giveaway_join:{int(giveaway_id)}", disabled=True, emoji="🔒",
        ))


ACTIVE_VIEWS: dict[int, GiveawayView] = {}


def register_giveaway_view(client: discord.Client, giveaway_id: int, count: int) -> GiveawayView:
    view = ACTIVE_VIEWS.get(giveaway_id)
    if view is None:
        view = GiveawayView(giveaway_id, count)
        ACTIVE_VIEWS[giveaway_id] = view
        client.add_view(view)
    else:
        if view.children:
            view.children[0].label = f"{count} | Join"
    return view


# ============================================================
# CHANNEL / MESSAGE HELPERS
# ============================================================

async def get_channel_safe(guild: discord.Guild, channel_id: int):
    if guild is None:
        return None
    channel = None
    if hasattr(guild, "get_channel_or_thread"):
        channel = guild.get_channel_or_thread(channel_id)
    else:
        channel = guild.get_channel(channel_id)
    if channel:
        return channel
    try:
        return await guild.fetch_channel(channel_id)
    except Exception:
        return None


async def safe_fetch_message(client: discord.Client, giveaway: dict):
    guild = client.get_guild(giveaway["guild_id"])
    if not guild:
        return None
    channel = await get_channel_safe(guild, giveaway["channel_id"])
    if not channel:
        return None
    try:
        return await channel.fetch_message(giveaway["message_id"])
    except Exception:
        return None


# ============================================================
# BUTTON REFRESH / DEBOUNCE
# ============================================================

_button_last_update: dict[int, float] = {}
_button_update_tasks: dict[int, asyncio.Task] = {}


async def refresh_button_message(client: discord.Client, giveaway_id: int):
    try:
        giveaway = await db.get_giveaway(giveaway_id)
        if not giveaway or giveaway["ended"]:
            return
        message = await safe_fetch_message(client, giveaway)
        if not message:
            return
        view = register_giveaway_view(client, giveaway_id, giveaway["participant_count"])
        await message.edit(view=view)
    except Exception:
        log.exception("Failed refreshing giveaway button.")


async def queue_button_refresh(client: discord.Client, giveaway_id: int):
    now = time.monotonic()
    last = _button_last_update.get(giveaway_id, 0.0)
    if now - last >= BUTTON_REFRESH_SECONDS:
        _button_last_update[giveaway_id] = now
        await refresh_button_message(client, giveaway_id)
        return
    if giveaway_id in _button_update_tasks:
        return
    delay = BUTTON_REFRESH_SECONDS - (now - last)

    async def delayed_refresh():
        await asyncio.sleep(delay)
        _button_update_tasks.pop(giveaway_id, None)
        _button_last_update[giveaway_id] = time.monotonic()
        await refresh_button_message(client, giveaway_id)

    _button_update_tasks[giveaway_id] = asyncio.create_task(delayed_refresh())


# ============================================================
# ANNOUNCE / FINALIZE
# ============================================================

async def announce_winners(giveaway: dict, winners: list[int], *, title: str):
    guild = bot.get_guild(giveaway["guild_id"])
    if not guild:
        return
    channel = await get_channel_safe(guild, giveaway["channel_id"])
    if not channel:
        return

    if winners:
        all_winners = safe_json_list(giveaway.get("winners"))
        content = (
            f"🎉 **{title}**: {giveaway['title']}\n"
            f"Winner(s): {format_user_list(winners)}\n"
            f"Total winner(s) recorded: {len(all_winners)}"
        )
    else:
        content = f"🎉 **{title}**: {giveaway['title']}\nNo eligible entries were available."

    try:
        await channel.send(content)
    except Exception:
        log.exception("Failed sending winner announcement.")


async def refresh_message_ended(giveaway_id: int):
    try:
        giveaway = await db.get_giveaway(giveaway_id)
        if not giveaway:
            return
        message = await safe_fetch_message(bot, giveaway)
        if not message:
            return
        embed = build_giveaway_embed(giveaway, ended=True)
        view = EndedGiveawayView(giveaway_id, giveaway["participant_count"])
        ACTIVE_VIEWS.pop(giveaway_id, None)
        await message.edit(embed=embed, view=view)
    except Exception:
        log.exception("Failed updating ended giveaway message.")


async def process_end(giveaway_id: int) -> Optional[dict]:
    result = await db.end_giveaway_and_choose_winners(giveaway_id)
    if not result or result.get("already"):
        return result
    giveaway = await db.get_giveaway(giveaway_id)
    if not giveaway:
        return result
    guild = bot.get_guild(giveaway["guild_id"])
    if guild and guild_is_allowed(guild):
        await announce_winners(giveaway, result["winners"], title="Giveaway ended")
    await refresh_message_ended(giveaway_id)
    return result


async def process_reroll(giveaway_id: int) -> Optional[dict]:
    result = await db.reroll_giveaway(giveaway_id)
    if not result or result.get("not_ended"):
        return result
    giveaway = await db.get_giveaway(giveaway_id)
    if giveaway:
        await announce_winners(giveaway, result["new_winners"], title="Giveaway reroll")
        await refresh_message_ended(giveaway_id)
    return result


# ============================================================
# SLASH COMMANDS
# ============================================================

@bot.tree.command(name="giveaway", description="Create a giveaway. Owner UID only.")
@app_commands.guild_only()
@owner_only()
@app_commands.describe(
    name="Giveaway title", amount="Number of winners",
    duration="Duration: 30s, 10m, 2h, 1d, 1h30m",
    role1="Optional required role 1", role2="Optional required role 2",
    role3="Optional required role 3", role4="Optional required role 4",
    role5="Optional required role 5",
)
@app_commands.rename(duration="time")
async def giveaway_cmd(
    interaction: discord.Interaction,
    name: app_commands.Range[str, 1, 200],
    amount: app_commands.Range[int, 1, 100],
    duration: str,
    role1: Optional[discord.Role] = None, role2: Optional[discord.Role] = None,
    role3: Optional[discord.Role] = None, role4: Optional[discord.Role] = None,
    role5: Optional[discord.Role] = None,
):
    await interaction.response.defer(ephemeral=True, thinking=True)

    channel = interaction.channel
    if not isinstance(channel, discord.abc.Messageable):
        await interaction.followup.send(embed=error_embed("Giveaways can only be created in a text channel."), ephemeral=True)
        return

    me = interaction.guild.me
    if hasattr(channel, "permissions_for"):
        perms = channel.permissions_for(me)
        if not (perms.view_channel and perms.send_messages and perms.embed_links):
            await interaction.followup.send(
                embed=error_embed("I need View Channel, Send Messages, and Embed Links in this channel."), ephemeral=True
            )
            return

    try:
        parsed_duration = parse_duration(duration)
    except ValueError as e:
        await interaction.followup.send(embed=error_embed(str(e)), ephemeral=True)
        return

    role_ids = []
    for role in (role1, role2, role3, role4, role5):
        if role and role.id not in role_ids:
            role_ids.append(role.id)

    ends_at = utc_now() + parsed_duration.total_seconds()
    giveaway_id = await db.create_giveaway(
        guild_id=interaction.guild.id, channel_id=channel.id, title=name,
        winner_count=amount, ends_at=ends_at, required_roles=role_ids,
        creator_id=interaction.user.id,
    )

    view = register_giveaway_view(bot, giveaway_id, 0)
    temp = {
        "title": name, "ends_at": ends_at, "winner_count": amount,
        "participant_count": 0, "required_roles": json.dumps(role_ids), "winners": "[]",
    }
    embed = build_giveaway_embed(temp, ended=False)

    try:
        message = await channel.send(embed=embed, view=view)
    except Exception:
        await db.delete_giveaway(giveaway_id)
        log.exception("Failed sending giveaway message.")
        await interaction.followup.send(embed=error_embed("I could not send the giveaway message."), ephemeral=True)
        return

    await db.bind_message(giveaway_id, message.id)
    await interaction.followup.send(embed=success_embed(f"Giveaway created: {message.jump_url}"), ephemeral=True)


@bot.tree.command(name="end", description="End a giveaway now. Owner UID only.")
@app_commands.guild_only()
@owner_only()
@app_commands.describe(id="Giveaway message ID or message link")
async def end_cmd(interaction: discord.Interaction, id: str):
    await interaction.response.defer(ephemeral=True, thinking=True)
    try:
        message_id = parse_message_id(id)
    except ValueError as e:
        await interaction.followup.send(embed=error_embed(str(e)), ephemeral=True)
        return

    giveaway = await db.get_giveaway_by_message(message_id)
    if not giveaway or giveaway["guild_id"] != interaction.guild.id:
        await interaction.followup.send(embed=error_embed("No giveaway found for that message in this server."), ephemeral=True)
        return
    if giveaway["ended"]:
        await interaction.followup.send(embed=error_embed("That giveaway has already ended."), ephemeral=True)
        return

    result = await process_end(giveaway["id"])
    if not result:
        await interaction.followup.send(embed=error_embed("Could not end that giveaway."), ephemeral=True)
        return
    if result.get("already"):
        await interaction.followup.send(embed=error_embed("That giveaway has already ended."), ephemeral=True)
        return

    await interaction.followup.send(
        embed=success_embed(f"Giveaway ended.\nWinner(s): {format_user_list(result.get('winners', []))}"), ephemeral=True
    )


@bot.tree.command(name="reroll", description="Reroll a finished giveaway. Owner UID only.")
@app_commands.guild_only()
@owner_only()
@app_commands.describe(id="Giveaway message ID or message link")
async def reroll_cmd(interaction: discord.Interaction, id: str):
    await interaction.response.defer(ephemeral=True, thinking=True)
    try:
        message_id = parse_message_id(id)
    except ValueError as e:
        await interaction.followup.send(embed=error_embed(str(e)), ephemeral=True)
        return

    giveaway = await db.get_giveaway_by_message(message_id)
    if not giveaway or giveaway["guild_id"] != interaction.guild.id:
        await interaction.followup.send(embed=error_embed("No giveaway found for that message in this server."), ephemeral=True)
        return
    if not giveaway["ended"]:
        await interaction.followup.send(embed=error_embed("End the giveaway first before rerolling."), ephemeral=True)
        return

    result = await process_reroll(giveaway["id"])
    if not result:
        await interaction.followup.send(embed=error_embed("Could not reroll that giveaway."), ephemeral=True)
        return
    if result.get("not_ended"):
        await interaction.followup.send(embed=error_embed("End the giveaway first before rerolling."), ephemeral=True)
        return

    new_winners = result.get("new_winners", [])
    if not new_winners:
        await interaction.followup.send(
            embed=error_embed("No new eligible entries were available for reroll.\nPrevious winners are excluded."), ephemeral=True
        )
        return

    await interaction.followup.send(
        embed=success_embed(f"Reroll complete.\nNew winner(s): {format_user_list(new_winners)}"), ephemeral=True
    )


# Hide commands from non-owners as much as Discord allows
for _cmd_name in ("giveaway", "end", "reroll"):
    _cmd = bot.tree.get_command(_cmd_name)
    if _cmd is not None:
        _cmd.default_member_permissions = discord.Permissions.none()


# ============================================================
# ERROR HANDLER
# ============================================================

@bot.tree.error
async def app_command_error(interaction: discord.Interaction, error: app_commands.AppCommandError):
    if isinstance(error, app_commands.CheckFailure):
        msg = "You are not authorized to use this command."
    elif isinstance(error, app_commands.CommandInvokeError):
        msg = str(error.original) if error.original else "Unexpected command error."
    else:
        msg = str(error)
    await send_interaction_message(interaction, error_embed(msg))


# ============================================================
# PRIVATE SYNC / GUILD ENFORCEMENT
# ============================================================

async def enforce_allowed_guilds():
    for guild in list(bot.guilds):
        if not guild_is_allowed(guild):
            log.info("Leaving unauthorized guild: %s (%s)", guild.name, guild.id)
            try:
                await guild.leave()
            except Exception:
                log.exception("Failed leaving unauthorized guild: %s", guild.id)


async def load_active_views():
    rows = await db.active_giveaways_for_views()
    for row in rows:
        register_giveaway_view(bot, int(row["id"]), int(row["participant_count"]))


async def sync_private_commands():
    allowed_guilds = [g for g in bot.guilds if guild_is_allowed(g)]

    for guild in allowed_guilds:
        try:
            bot.tree.copy_global_to(guild=guild)
        except Exception:
            log.exception("Failed copying commands to guild %s", guild.id)

    bot.tree.clear_commands(guild=None)
    try:
        await bot.tree.sync(guild=None)
    except Exception:
        log.exception("Failed clearing global commands.")

    for guild in allowed_guilds:
        try:
            synced = await bot.tree.sync(guild=guild)
            permissions = {}
            for cmd in synced:
                permissions[cmd.id] = [
                    app_commands.AppCommandPermissions(
                        id=uid, type=app_commands.AppCommandPermissionsType.user, permission=True
                    )
                    for uid in OWNER_USER_IDS
                ]
            if permissions:
                await guild.edit_command_permissions(permissions)
        except Exception:
            log.exception("Failed syncing/locking commands for guild %s", guild.id)


# ============================================================
# BACKGROUND TASKS
# ============================================================

@tasks.loop(seconds=20)
async def expire_loop():
    try:
        due_ids = await db.get_due_active_ids()
        for gid in due_ids:
            try:
                await process_end(gid)
            except Exception:
                log.exception("Failed ending giveaway %s", gid)
    except Exception:
        log.exception("Expire loop failure.")


@expire_loop.before_loop
async def before_expire_loop():
    await bot.wait_until_ready()


@tasks.loop(minutes=5)
async def backup_loop():
    try:
        await db.backup_now()
    except Exception:
        log.exception("Backup loop failure.")


@backup_loop.before_loop
async def before_backup_loop():
    await bot.wait_until_ready()


# ============================================================
# EVENTS
# ============================================================

@bot.event
async def on_ready():
    log.info("Logged in as %s (%s)", bot.user, bot.user.id)
    try:
        await load_active_views()
        await enforce_allowed_guilds()
        await sync_private_commands()
    except Exception:
        log.exception("Startup setup failed.")

    if not expire_loop.is_running():
        expire_loop.start()
    if not backup_loop.is_running():
        backup_loop.start()


@bot.event
async def on_guild_join(guild: discord.Guild):
    if not guild_is_allowed(guild):
        log.info("Joined unauthorized guild %s (%s). Leaving.", guild.name, guild.id)
        try:
            await guild.leave()
        except Exception:
            log.exception("Failed leaving unauthorized guild on join.")


# ============================================================
# GRACEFUL SHUTDOWN FOR DOCKER
# ============================================================

def _shutdown_handler(signum, frame):
    log.info("Received shutdown signal (%s). Closing gracefully...", signum)
    asyncio.get_event_loop().create_task(bot.close())


signal.signal(signal.SIGTERM, _shutdown_handler)
signal.signal(signal.SIGINT, _shutdown_handler)


# ============================================================
# RUN
# ============================================================

if __name__ == "__main__":
    validate_environment()
    bot.run(TOKEN)