import dataclasses
import logging
from datetime import datetime
from typing import List

import dateparser
import interactions
from apscheduler import events
from apscheduler.events import EVENT_JOB_ERROR, EVENT_JOB_MISSED
from apscheduler.jobstores.base import JobLookupError
from apscheduler.triggers.date import DateTrigger
from dateparser.conf import SettingValidationError
from discord_webhook import DiscordWebhook
from interactions import CommandContext, Embed, Option, OptionType, autodefer
from interactions.ext.paginator import Paginator

from discord_reminder_bot.countdown import calculate
from discord_reminder_bot.create_pages import create_pages
from discord_reminder_bot.settings import (
    bot_token,
    config_timezone,
    log_level,
    scheduler,
    sqlite_location,
    webhook_url
)

bot = interactions.Client(token=bot_token)


def send_webhook(url=webhook_url, message: str = "discord-reminder-bot: Empty message."):
    """
    Send a webhook to Discord.

    Args:
        url: Our webhook url, defaults to the one from settings.
        message: The message that will be sent to Discord.
    """
    if not url:
        print("ERROR: Tried to send a webhook but you have no webhook url configured.")
        return
    webhook = DiscordWebhook(url=url, content=message, rate_limit_retry=True)
    webhook.execute()


@bot.command(name="remind")
async def base_command(ctx: interactions.CommandContext):
    """This description isn't seen in the UI (yet?)

    This is the base command for the reminder bot."""
    pass


@dataclasses.dataclass
class ParsedTime:
    """
    This is used when parsing a time or date from a string.

    We use this when adding a job with /reminder add.

    Attributes:
        date_to_parse: The string we parsed the time from.
        err: True if an error was raised when parsing the time.
        err_msg: The error message.
        parsed_time: The parsed time we got from the string.
    """
    date_to_parse: str = None
    err: bool = False
    err_msg: str = ""
    parsed_time: datetime = None


def parse_time(date_to_parse: str, timezone: str = config_timezone) -> ParsedTime:
    """Parse the datetime from a string.

    Args:
        date_to_parse: The string we want to parse.
        timezone: The timezone to use when parsing. This will be used when typing things like "22:00".

    Returns:
        ParsedTime
    """
    try:
        parsed_date = dateparser.parse(
            f"{date_to_parse}",
            settings={
                "PREFER_DATES_FROM": "future",
                "TIMEZONE": f"{timezone}",
                "TO_TIMEZONE": f"{timezone}",
            },
        )
    except SettingValidationError as e:
        return ParsedTime(err=True, err_msg=f"Timezone is possible wrong?: {e}", date_to_parse=date_to_parse)
    except ValueError as e:
        return ParsedTime(err=True, err_msg=f"Failed to parse date. Unknown language: {e}", date_to_parse=date_to_parse)
    except TypeError as e:
        return ParsedTime(err=True, err_msg=f"{e}", date_to_parse=date_to_parse)
    if not parsed_date:
        return ParsedTime(err=True, err_msg=f"Could not parse the date.", date_to_parse=date_to_parse)

    return ParsedTime(parsed_time=parsed_date, date_to_parse=date_to_parse)


@bot.modal("edit_modal")
async def modal_response_edit(ctx: CommandContext, *response: str):
    """This is what gets triggerd when the user clicks the Edit button in /reminder list.

    Args:
        ctx: Context of the slash command. Contains the guild, author and message and more.

    Returns:
        A Discord message with changes.
    """
    job_id = ctx.message.embeds[0].title
    old_date = None
    old_message = None

    try:
        job = scheduler.get_job(job_id)
    except JobLookupError as e:
        return await ctx.send(
            f"Failed to get the job after the modal.\n"
            f"Job ID: {job_id}\n"
            f"Error: {e}",
            ephemeral=True,
        )

    if job is None:
        return await ctx.send("Job not found.", ephemeral=True)

    if not response:
        return await ctx.send("No changes made.", ephemeral=True)

    if type(job.trigger) is DateTrigger:
        new_message = response[0]
        new_date = response[1]
    else:
        new_message = response[0]
        new_date = None

    message_embeds: List[Embed] = ctx.message.embeds
    for embeds in message_embeds:
        for field in embeds.fields:
            if field.name == "**Channel:**":
                continue
            elif field.name == "**Message:**":
                old_message = field.value
            elif field.name == "**Trigger:**":
                old_date = field.value
            else:
                return await ctx.send(
                    f"Unknown field name ({field.name}).", ephemeral=True
                )

    msg = f"Modified job {job_id}.\n"
    if old_date is not None:
        if new_date:
            # Parse the time/date we got from the command.
            parsed = parse_time(date_to_parse=new_date)
            if parsed.err:
                return await ctx.send(parsed.err_msg)
            parsed_date = parsed.parsed_time
            date_new = parsed_date.strftime("%Y-%m-%d %H:%M:%S")

            new_job = scheduler.reschedule_job(job.id, run_date=date_new)
            new_time = calculate(new_job)

            # TODO: old_date and date_new has different precision.
            # Old date: 2032-09-18 00:07
            # New date: 2032-09-18 00:07:13
            msg += (
                f"**Old date**: {old_date}\n"
                f"**New date**: {date_new} (in {new_time})\n"
            )

    if old_message is not None:
        channel_id = job.kwargs.get("channel_id")
        job_author_id = job.kwargs.get("author_id")
        try:
            scheduler.modify_job(
                job.id,
                kwargs={
                    "channel_id": channel_id,
                    "message": f"{new_message}",
                    "author_id": job_author_id,
                },
            )
        except JobLookupError as e:
            return await ctx.send(
                f"Failed to modify the job.\n"
                f"Job ID: {job_id}\n"
                f"Error: {e}",
                ephemeral=True,
            )
        msg += f"**Old message**: {old_message}\n**New message**: {new_message}\n"

    return await ctx.send(msg)


@autodefer()
@bot.command(name="parse", description="Parse the time from a string", options=[
    Option(
        name="time_to_parse",
        description="The string you want to parse.",
        type=OptionType.STRING,
        required=True,
    ),
    Option(
        name="optional_timezone",
        description="Optional time zone, for example Europe/Stockholm",
        type=OptionType.STRING,
        required=False,
    ),
])
async def parse_command(ctx: interactions.CommandContext, time_to_parse: str, optional_timezone: str | None = None):
    """
    Find the date and time from a string.
    Args:
        ctx: Context of the slash command. Contains the guild, author and message and more.
        time_to_parse: The string you want to parse.
        optional_timezone: Optional time zone, for example Europe/Stockholm.
    """
    if optional_timezone:
        parsed = parse_time(date_to_parse=time_to_parse, timezone=optional_timezone)
    else:
        parsed = parse_time(date_to_parse=time_to_parse)
    if parsed.err:
        return await ctx.send(parsed.err_msg)
    parsed_date = parsed.parsed_time

    # Locale’s appropriate date and time representation.
    locale_time = parsed_date.strftime("%c")
    run_date = parsed_date.strftime("%Y-%m-%d %H:%M:%S")
    return await ctx.send(f"**String**: {time_to_parse}\n"
                          f"**Parsed date**: {parsed_date}\n"
                          f"**Formatted**: {run_date}\n"
                          f"**Locale time**: {locale_time}\n")


@autodefer()
@base_command.subcommand(name="list", description="List, pause, unpause, and remove reminders.")
async def list_command(ctx: interactions.CommandContext):
    """List, pause, unpause, and remove reminders.

    Args:
        ctx: Context of the slash command. Contains the guild, author and message and more.
    """

    pages = create_pages(ctx)
    if not pages:
        return await ctx.send("No reminders found.", ephemeral=True)

    if len(pages) == 1:
        for page in pages:
            return await ctx.send(
                content="I haven't added support for buttons if there is only one reminder, "
                        "so you need to add another one to edit/delete this one 🙃",
                embeds=page.embeds,
            )

    paginator: Paginator = Paginator(
        client=bot,
        ctx=ctx,
        pages=pages,
        remove_after_timeout=True,
        author_only=True,
        extended_buttons=False,
        use_buttons=False,
    )

    await paginator.run()


@autodefer()
@base_command.subcommand(
    name="add",
    description="Set a reminder.",
    options=[
        Option(
            name="message_reason",
            description="The message to send.",
            type=OptionType.STRING,
            required=True,
        ),
        Option(
            name="message_date",
            description="The date to send the message.",
            type=OptionType.STRING,
            required=True,
        ),
        Option(
            name="different_channel",
            description="The channel to send the message to.",
            type=OptionType.CHANNEL,
            required=False,
        ),
        Option(
            name="send_dm_to_user",
            description="Send message to a user via DM instead of a channel. Set both_dm_and_channel to send both.",
            type=OptionType.USER,
            required=False,
        ),
        Option(
            name="both_dm_and_channel",
            description="Send both DM and message to the channel, needs send_dm_to_user to be set if you want both.",
            type=OptionType.BOOLEAN,
            required=False,
        ),
    ],
)
async def command_add(
        ctx: interactions.CommandContext,
        message_reason: str,
        message_date: str,
        different_channel: interactions.Channel | None = None,
        send_dm_to_user: interactions.User | None = None,
        both_dm_and_channel: bool | None = None,
):
    """Add a new reminder. You can add a date and message.

    Args:
        ctx: Context of the slash command. Contains the guild, author and message and more.
        message_date: The parsed date and time when you want to get reminded.
        message_reason: The message the bot should write when the reminder is triggered.
        different_channel: The channel the reminder should be sent to.
        send_dm_to_user: Send the message to the user via DM instead of the channel.
        both_dm_and_channel: If we should send both a DM and a message to the channel. Works with different_channel.
    """
    # Parse the time/date we got from the command.
    parsed = parse_time(date_to_parse=message_date)
    if parsed.err:
        return await ctx.send(parsed.err_msg)
    parsed_date = parsed.parsed_time
    run_date = parsed_date.strftime("%Y-%m-%d %H:%M:%S")

    # If we should send the message to a different channel
    channel_id = int(ctx.channel_id)
    if different_channel:
        channel_id = int(different_channel.id)

    dm_message = ""
    where_and_when = "You should never see this message. Please report this to the bot owner if you do. :-)"
    should_send_channel_reminder = True
    try:
        if send_dm_to_user:
            dm_reminder = scheduler.add_job(
                send_to_user,
                run_date=run_date,
                kwargs={
                    "user_id": int(send_dm_to_user.id),
                    "guild_id": int(ctx.guild_id),
                    "message": message_reason,
                },
            )
            dm_message = f"and a DM to {send_dm_to_user.username} "
            if not both_dm_and_channel:
                # If we should send the message to the channel too instead of just a DM.
                should_send_channel_reminder = False
                where_and_when = (f"I will send a DM to {send_dm_to_user.username} at:\n"
                                  f"**{run_date}** (in {calculate(dm_reminder)})\n")

        if should_send_channel_reminder:
            reminder = scheduler.add_job(
                send_to_discord,
                run_date=run_date,
                kwargs={
                    "channel_id": channel_id,
                    "message": message_reason,
                    "author_id": ctx.member.id,
                },
            )
            where_and_when = (f"I will notify you in <#{channel_id}> {dm_message}at:\n"
                              f"**{run_date}** (in {calculate(reminder)})\n")

    except ValueError as e:
        await ctx.send(str(e), ephemeral=True)
        return

    message = (
        f"Hello {ctx.member.name}, "
        f"{where_and_when}"
        f"With the message:\n"
        f"**{message_reason}**."
    )
    await ctx.send(message)


async def send_to_user(user_id: int, guild_id: int, message: str):
    """Send a message to a user via DM.

    Args:
        user_id: The user ID to send the message to.
        guild_id: The guild ID to get the user from.
        message: The message to send.
    """
    member = await interactions.get(bot, interactions.Member, parent_id=guild_id, object_id=user_id, force="http")
    await member.send(message)


@autodefer()
@base_command.subcommand(
    name="cron",
    description="Triggers when current time matches all specified time constraints, similarly to the UNIX cron.",
    options=[
        Option(
            name="message_reason",
            description="The message I'm going to send you.",
            type=OptionType.STRING,
            required=True,
        ),
        Option(
            name="year",
            description="4-digit year. (Example: 2042)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="month",
            description="Month (1-12)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="day",
            description="Day of month (1-31)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="week",
            description="ISO week (1-53)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="day_of_week",
            description="Number or name of weekday (0-6 or mon,tue,wed,thu,fri,sat,sun). The first weekday is monday.",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="hour",
            description="Hour (0-23)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="minute",
            description="Minute (0-59)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="second",
            description="Second (0-59)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="start_date",
            description="Earliest possible time to trigger on, in the ISO 8601 format. (Example: 2010-10-10 09:30:00)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="end_date",
            description="Latest possible time to trigger on, in the ISO 8601 format. (Example: 2010-10-10 09:30:00)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="timezone",
            description="Time zone to use for the date/time calculations (defaults to scheduler timezone)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="jitter",
            description="Delay the job execution by x seconds at most. Adds a random component to the execution time.",
            type=OptionType.INTEGER,
            required=False,
        ),
        Option(
            name="different_channel",
            description="Send the messages to a different channel.",
            type=OptionType.CHANNEL,
            required=False,
        ),
        Option(
            name="send_dm_to_user",
            description="Send message to a user via DM instead of a channel. Set both_dm_and_channel to send both.",
            type=OptionType.USER,
            required=False,
        ),
        Option(
            name="both_dm_and_channel",
            description="Send both DM and message to the channel, needs send_dm_to_user to be set if you want both.",
            type=OptionType.BOOLEAN,
            required=False,
        ),
    ],
)
async def remind_cron(
        ctx: interactions.CommandContext,
        message_reason: str,
        year: int | None = None,
        month: int | None = None,
        day: int | None = None,
        week: int | None = None,
        day_of_week: str | None = None,
        hour: int | None = None,
        minute: int | None = None,
        second: int | None = None,
        start_date: str | None = None,
        end_date: str | None = None,
        timezone: str | None = None,
        jitter: int | None = None,
        different_channel: interactions.Channel | None = None,
        send_dm_to_user: interactions.User | None = None,
        both_dm_and_channel: bool | None = None,
):
    """Create new cron job. Works like UNIX cron.

    https://en.wikipedia.org/wiki/Cron
    Args that are None will be defaulted to *.

    Args:
        ctx: Context of the slash command. Contains the guild, author and message and more.
        message_reason: The message the bot should send every time cron job triggers.
        year: 4-digit year.
        month: Month (1-12).
        day: Day of month (1-31).
        week: ISO week (1-53).
        day_of_week: Number or name of weekday (0-6 or mon,tue,wed,thu,fri,sat,sun).
        hour: Hour (0-23).
        minute: Minute (0-59).
        second: Second (0-59).
        start_date: Earliest possible date/time to trigger on (inclusive).
        end_date: Latest possible date/time to trigger on (inclusive).
        timezone: Time zone to use for the date/time calculations Defaults to scheduler timezone.
        jitter: Delay the job execution by jitter seconds at most.
        different_channel: Send the messages to a different channel.
        send_dm_to_user: Send the message to the user via DM instead of the channel.
        both_dm_and_channel: If we should send both a DM and a message to the channel.
    """
    # If we should send the message to a different channel
    channel_id = int(ctx.channel_id)
    if different_channel:
        channel_id = int(different_channel.id)

    dm_message = ""
    where_and_when = "You should never see this message. Please report this to the bot owner if you do. :-)"
    should_send_channel_reminder = True
    try:
        if send_dm_to_user:
            dm_reminder = scheduler.add_job(
                send_to_user,
                "cron",
                year=year,
                month=month,
                day=day,
                week=week,
                day_of_week=day_of_week,
                hour=hour,
                minute=minute,
                second=second,
                start_date=start_date,
                end_date=end_date,
                timezone=timezone,
                jitter=jitter,
                kwargs={
                    "user_id": int(send_dm_to_user.id),
                    "guild_id": int(ctx.guild_id),
                    "message": message_reason,
                },
            )
            dm_message = f" and a DM to {send_dm_to_user.username}"
            if not both_dm_and_channel:
                # If we should send the message to the channel too instead of just a DM.
                should_send_channel_reminder = False
                where_and_when = (f"I will send a DM to {send_dm_to_user.username} at:\n"
                                  f"First run in {calculate(dm_reminder)} with the message:\n")

        if should_send_channel_reminder:
            job = scheduler.add_job(
                send_to_discord,
                "cron",
                year=year,
                month=month,
                day=day,
                week=week,
                day_of_week=day_of_week,
                hour=hour,
                minute=minute,
                second=second,
                start_date=start_date,
                end_date=end_date,
                timezone=timezone,
                jitter=jitter,
                kwargs={
                    "channel_id": channel_id,
                    "message": message_reason,
                    "author_id": ctx.member.id,
                },
            )
            where_and_when = (f" I will send messages to <#{channel_id}>{dm_message}.\n"
                              f"First run in {calculate(job)} with the message:\n")

    except ValueError as e:
        await ctx.send(str(e), ephemeral=True)
        return

    # TODO: Add what arguments we used in the job to the message
    message = (
        f"Hello {ctx.member.name}, "
        f"{where_and_when}"
        f"**{message_reason}**."
    )
    await ctx.send(message)


@autodefer()
@base_command.subcommand(
    name="interval",
    description="Schedules messages to be run periodically, on selected intervals.",
    options=[
        Option(
            name="message_reason",
            description="The message I'm going to send you.",
            type=OptionType.STRING,
            required=True,
        ),
        Option(
            name="weeks",
            description="Number of weeks to wait",
            type=OptionType.INTEGER,
            required=False,
        ),
        Option(
            name="days",
            description="Number of days to wait",
            type=OptionType.INTEGER,
            required=False,
        ),
        Option(
            name="hours",
            description="Number of hours to wait",
            type=OptionType.INTEGER,
            required=False,
        ),
        Option(
            name="minutes",
            description="Number of minutes to wait",
            type=OptionType.INTEGER,
            required=False,
        ),
        Option(
            name="seconds",
            description="Number of seconds to wait.",
            type=OptionType.INTEGER,
            required=False,
        ),
        Option(
            name="start_date",
            description="When to start, in the ISO 8601 format. (Example: 2010-10-10 09:30:00)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="end_date",
            description="When to stop, in the ISO 8601 format. (Example: 2014-06-15 11:00:00)",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="timezone",
            description="Time zone to use for the date/time calculations",
            type=OptionType.STRING,
            required=False,
        ),
        Option(
            name="jitter",
            description="Delay the job execution by x seconds at most. Adds a random component to the execution time.",
            type=OptionType.INTEGER,
            required=False,
        ),
        Option(
            name="different_channel",
            description="Send the messages to a different channel.",
            type=OptionType.CHANNEL,
            required=False,
        ),
        Option(
            name="send_dm_to_user",
            description="Send message to a user via DM instead of a channel. Set both_dm_and_channel to send both.",
            type=OptionType.USER,
            required=False,
        ),
        Option(
            name="both_dm_and_channel",
            description="Send both DM and message to the channel, needs send_dm_to_user to be set if you want both.",
            type=OptionType.BOOLEAN,
            required=False,
        ),
    ],
)
async def remind_interval(
        ctx: interactions.CommandContext,
        message_reason: str,
        weeks: int = 0,
        days: int = 0,
        hours: int = 0,
        minutes: int = 0,
        seconds: int = 0,
        start_date: str | None = None,
        end_date: str | None = None,
        timezone: str | None = None,
        jitter: int | None = None,
        different_channel: interactions.Channel | None = None,
        send_dm_to_user: interactions.User | None = None,
        both_dm_and_channel: bool | None = None,
):
    """Create a new reminder that triggers based on an interval.

    Args:
        ctx: Context of the slash command. Contains the guild, author and message and more.
        message_reason: The message we should write when triggered.
        weeks: Amount weeks to wait.
        days: Amount days to wait.
        hours: Amount hours to wait.
        minutes: Amount minutes to wait.
        seconds: Amount seconds to wait.
        start_date: Starting point for the interval calculation.
        end_date: Latest possible date/time to trigger on.
        timezone: Time zone to use for the date/time calculations.
        jitter: Delay the job execution by jitter seconds at most.
        different_channel: Send the messages to a different channel.
        send_dm_to_user: Send the message to the user via DM instead of the channel.
        both_dm_and_channel: If we should send both a DM and a message to the channel.
    """
    # If we should send the message to a different channel
    channel_id = int(ctx.channel_id)
    if different_channel:
        channel_id = int(different_channel.id)

    dm_message = ""
    where_and_when = "You should never see this message. Please report this to the bot owner if you do. :-)"
    should_send_channel_reminder = True
    try:
        if send_dm_to_user:
            dm_reminder = scheduler.add_job(
                send_to_user,
                "interval",
                weeks=weeks,
                days=days,
                hours=hours,
                minutes=minutes,
                seconds=seconds,
                start_date=start_date,
                end_date=end_date,
                timezone=timezone,
                jitter=jitter,
                kwargs={
                    "user_id": int(send_dm_to_user.id),
                    "guild_id": int(ctx.guild_id),
                    "message": message_reason,
                },
            )
            dm_message = f"and a DM to {send_dm_to_user.username} "
            if not both_dm_and_channel:
                # If we should send the message to the channel too instead of just a DM.
                should_send_channel_reminder = False
                where_and_when = (f"I will send a DM to {send_dm_to_user.username} at:\n"
                                  f"First run in {calculate(dm_reminder)} with the message:\n")
        if should_send_channel_reminder:
            job = scheduler.add_job(
                send_to_discord,
                "interval",
                weeks=weeks,
                days=days,
                hours=hours,
                minutes=minutes,
                seconds=seconds,
                start_date=start_date,
                end_date=end_date,
                timezone=timezone,
                jitter=jitter,
                kwargs={
                    "channel_id": channel_id,
                    "message": message_reason,
                    "author_id": ctx.member.id,
                },
            )
            where_and_when = (f" I will send messages to <#{channel_id}>{dm_message}.\n"
                              f"First run in {calculate(job)} with the message:\n")

    except ValueError as e:
        await ctx.send(str(e), ephemeral=True)
        return

    # TODO: Add what arguments we used in the job to the message
    message = (
        f"Hello {ctx.member.name}\n"
        f"{where_and_when}"
        f"**{message_reason}**."
    )

    await ctx.send(message)


def my_listener(event):
    """This gets called when something in APScheduler happens."""
    if event.code == events.EVENT_JOB_MISSED:
        # TODO: Is it possible to get the message?
        scheduled_time = event.scheduled_run_time.strftime("%Y-%m-%d %H:%M:%S")
        msg = f"Job {event.job_id} was missed! Was scheduled at {scheduled_time}"
        send_webhook(message=msg)

    if event.exception:
        send_webhook(f"discord-reminder-bot failed to send message to Discord\n"
                     f"{event}")


async def send_to_discord(channel_id: int, message: str, author_id: int):
    """Send a message to Discord.

    Args:
        channel_id: The Discord channel ID.
        message: The message.
        author_id: User we should ping.
    """

    channel = await interactions.get(
        bot,
        interactions.Channel,
        object_id=int(channel_id),
        force=interactions.Force.HTTP,
    )

    await channel.send(f"<@{author_id}>\n{message}")


def start():
    """Start scheduler and log in to Discord."""
    # TODO: Add how many reminders are scheduled.
    # TODO: Make backup of jobs.sqlite before running the bot.
    logging.basicConfig(level=logging.getLevelName(log_level))
    logging.info(
        f"\nsqlite_location = {sqlite_location}\n"
        f"config_timezone = {config_timezone}\n"
        f"log_level = {log_level}"
    )
    scheduler.start()
    scheduler.add_listener(my_listener, EVENT_JOB_MISSED | EVENT_JOB_ERROR)
    bot.start()


if __name__ == "__main__":
    start()