import discord
from discord.ext import commands, tasks
from discord import app_commands
import json
import asyncio
from datetime import datetime, timedelta
import os

TIMER_FILE = "data/timers.json"


class TimerCog(commands.Cog):
    def __init__(self, bot):
        self.bot = bot
        self.timers = []
        self.load_timers()
        self.timer_check_task.start()

    def load_timers(self):
        if not os.path.exists("data"):
            os.makedirs("data")
        if os.path.exists(TIMER_FILE):
            with open(TIMER_FILE, "r") as f:
                try:
                    data = json.load(f)
                    # Convert string timestamps back to datetime objects
                    for timer_data in data:
                        timer_data["expires_at"] = datetime.fromisoformat(
                            timer_data["expires_at"]
                        )
                        self.timers.append(timer_data)
                except json.JSONDecodeError:
                    self.timers = []
        else:
            self.timers = []
        print(f"Loaded {len(self.timers)} timers.")

    def save_timers(self):
        # Convert datetime objects to ISO format strings for JSON serialization
        serializable_timers = []
        for timer in self.timers:
            timer_copy = timer.copy()
            timer_copy["expires_at"] = timer_copy["expires_at"].isoformat()
            serializable_timers.append(timer_copy)

        with open(TIMER_FILE, "w") as f:
            json.dump(serializable_timers, f, indent=4)
        print(f"Saved {len(self.timers)} timers.")

    @tasks.loop(seconds=10)  # Check every 10 seconds
    async def timer_check_task(self):
        now = datetime.now()
        expired_timers = []
        for timer in self.timers:
            if timer["expires_at"] <= now:
                expired_timers.append(timer)

        for timer in expired_timers:
            self.timers.remove(timer)
            try:
                channel = self.bot.get_channel(timer["channel_id"])
                if channel:
                    user = self.bot.get_user(timer["user_id"])
                    if user:
                        message_content = f"{user.mention}, your timer for '{timer['message']}' has expired!"
                        if timer.get(
                            "ephemeral", True
                        ):  # Default to True if not specified
                            # Ephemeral messages require interaction context, which we don't have here.
                            # For now, we'll send non-ephemeral if it was originally ephemeral.
                            # A better solution would be to store interaction context or use webhooks.
                            await channel.send(message_content)
                        else:
                            await channel.send(message_content)
                    else:
                        print(f"Could not find user {timer['user_id']} for timer.")
                else:
                    print(f"Could not find channel {timer['channel_id']} for timer.")
            except Exception as e:
                print(f"Error sending timer message: {e}")

        if expired_timers:
            self.save_timers()

    @timer_check_task.before_loop
    async def before_timer_check_task(self):
        await self.bot.wait_until_ready()

    @app_commands.command(name="timer", description="Sets a timer, reminder, or alarm.")
    @app_commands.describe(
        time_str="Duration for the timer (e.g., 1h30m, 5m, 2d). Supports s, m, h, d.",
        message="The message for your reminder.",
        ephemeral="Whether the response should only be visible to you (defaults to True).",
    )
    async def timer_slash(
        self,
        interaction: discord.Interaction,
        time_str: str,
        message: str = "a reminder",
        ephemeral: bool = True,
    ):
        """
        Sets a timer, reminder, or alarm as a slash command.
        Usage: /timer time_str:1h30m message:Your reminder message ephemeral:False
        Supports: s (seconds), m (minutes), h (hours), d (days)
        """
        duration_seconds = 0
        time_str = time_str.lower()

        # Parse time string (e.g., 1h30m, 5m, 2d)
        current_num = ""
        for char in time_str:
            if char.isdigit():
                current_num += char
            else:
                if current_num:
                    num = int(current_num)
                    if char == "s":
                        duration_seconds += num
                    elif char == "m":
                        duration_seconds += num * 60
                    elif char == "h":
                        duration_seconds += num * 60 * 60
                    elif char == "d":
                        duration_seconds += num * 60 * 60 * 24
                    else:
                        await interaction.response.send_message(
                            "Invalid time unit. Use s, m, h, or d.", ephemeral=ephemeral
                        )
                        return
                    current_num = ""
                else:
                    await interaction.response.send_message(
                        "Invalid time format. Example: `1h30m` or `5m`.",
                        ephemeral=ephemeral,
                    )
                    return

        if current_num:  # Handle cases like "30s" without a unit at the end
            await interaction.response.send_message(
                "Invalid time format. Please specify a unit (s, m, h, d) for all numbers.",
                ephemeral=ephemeral,
            )
            return

        if duration_seconds <= 0:
            await interaction.response.send_message(
                "Duration must be a positive value.", ephemeral=ephemeral
            )
            return

        expires_at = datetime.now() + timedelta(seconds=duration_seconds)

        timer_data = {
            "user_id": interaction.user.id,
            "channel_id": interaction.channel_id,
            "message": message,
            "expires_at": expires_at,
            "ephemeral": ephemeral,
        }
        self.timers.append(timer_data)
        self.save_timers()

        await interaction.response.send_message(
            f"Timer set for {timedelta(seconds=duration_seconds)} from now for '{message}'.",
            ephemeral=ephemeral,
        )

    def cog_unload(self):
        self.timer_check_task.cancel()
        self.save_timers()  # Ensure timers are saved on unload


async def setup(bot: commands.Bot):
    await bot.add_cog(TimerCog(bot))