"""
Land Weather extension for qrm
---
Copyright (C) 2019-2020 Abigail Gold, 0x5c  (as weather.py)
Copyright (C) 2021 Abigail Gold, 0x5c

This file is part of qrm2 and is released under the terms of
the GNU General Public License, version 2.
"""


import re
from typing import List

import aiohttp

from discord import Embed
import discord.ext.commands as commands

import common as cmn


class WeatherCog(commands.Cog):
    wttr_units_regex = re.compile(r"\B-([cCfF])\b")

    def __init__(self, bot: commands.Bot):
        self.bot = bot
        self.session = aiohttp.ClientSession(connector=bot.qrm.connector)

    @commands.group(name="weather", aliases=["wttr"], case_insensitive=True, category=cmn.Cats.WEATHER)
    async def _weather_conditions(self, ctx: commands.Context):
        """Gets local weather conditions from [wttr.in](http://wttr.in/).

        *Supported location types:*
        city name: `paris`
        any location: `~Eiffel Tower`
        Unicode name of any location in any language: `Москва`
        airport code (3 letters): `muc`
        domain name `@stackoverflow.com`
        area codes: `12345`
        GPS coordinates: `-78.46,106.79`

        Add a `-c` or `-f` to use Celcius or Fahrenheit: `-c YSC`"""
        if ctx.invoked_subcommand is None:
            await ctx.send_help(ctx.command)

    @_weather_conditions.command(name="forecast", aliases=["fc", "future"], category=cmn.Cats.WEATHER)
    async def _weather_conditions_forecast(self, ctx: commands.Context, *, location: str):
        """Gets local weather forecast for the next three days from [wttr.in](http://wttr.in/).
        See help of the `weather` command for possible location types and options."""
        try:
            units_arg = re.search(self.wttr_units_regex, location).group(1)
        except AttributeError:
            units_arg = ""
        if units_arg.lower() == "f":
            units = "u"
        elif units_arg.lower() == "c":
            units = "m"
        else:
            units = ""

        loc = self.wttr_units_regex.sub("", location).strip()

        embed = cmn.embed_factory(ctx)
        embed.title = f"Weather Forecast for {loc}"
        embed.description = "Data from [wttr.in](http://wttr.in/)."
        embed.colour = cmn.colours.good

        loc = loc.replace(" ", "+")
        embed.set_image(url=f"http://wttr.in/{loc}_{units}pnFQ.png")
        await ctx.send(embed=embed)

    @_weather_conditions.command(name="now", aliases=["n"], category=cmn.Cats.WEATHER)
    async def _weather_conditions_now(self, ctx: commands.Context, *, location: str):
        """Gets current local weather conditions from [wttr.in](http://wttr.in/).
        See help of the `weather` command for possible location types and options."""
        try:
            units_arg = re.search(self.wttr_units_regex, location).group(1)
        except AttributeError:
            units_arg = ""
        if units_arg.lower() == "f":
            units = "u"
        elif units_arg.lower() == "c":
            units = "m"
        else:
            units = ""

        loc = self.wttr_units_regex.sub("", location).strip()

        embed = cmn.embed_factory(ctx)
        embed.title = f"Current Weather for {loc}"
        embed.description = "Data from [wttr.in](http://wttr.in/)."
        embed.colour = cmn.colours.good

        loc = loc.replace(" ", "+")
        embed.set_image(url=f"http://wttr.in/{loc}_0{units}pnFQ.png")
        await ctx.send(embed=embed)

    @commands.command(name="metar", category=cmn.Cats.WEATHER)
    async def metar(self, ctx: commands.Context, airport: str, hours: int = 0):
        """Gets current raw METAR (Meteorological Terminal Aviation Routine Weather Report) for an airport. \
        Optionally, a number of hours can be given to show a number of hours of historical METAR data.

        Airports should be given as an \
        [ICAO code](https://en.wikipedia.org/wiki/List_of_airports_by_IATA_and_ICAO_code)."""
        await ctx.send(embed=await self.gen_metar_taf_embed(ctx, airport, hours, False))

    @commands.command(name="taf", category=cmn.Cats.WEATHER)
    async def taf(self, ctx: commands.Context, airport: str):
        """Gets forecasted raw TAF (Terminal Aerodrome Forecast) data for an airport. Includes the latest METAR data.

        Airports should be given as an \
        [ICAO code](https://en.wikipedia.org/wiki/List_of_airports_by_IATA_and_ICAO_code)."""
        await ctx.send(embed=await self.gen_metar_taf_embed(ctx, airport, 0, True))

    async def gen_metar_taf_embed(self, ctx: commands.Context, airport: str, hours: int, taf: bool) -> Embed:
        embed = cmn.embed_factory(ctx)
        airport = airport.upper()

        if re.fullmatch(r"\w(\w|\d){2,3}", airport):
            metar = await self.get_metar_taf_data(airport, hours, taf)

            if taf:
                embed.title = f"Current TAF for {airport}"
            elif hours > 0:
                embed.title = f"METAR for {airport} for the last {hours} hour{'s' if hours > 1 else ''}"
            else:
                embed.title = f"Current METAR for {airport}"

            embed.description = "Data from [aviationweather.gov](https://www.aviationweather.gov/metar/data)."
            embed.colour = cmn.colours.good

            data = "\n".join(metar)
            embed.description += f"\n\n```\n{data}\n```"
        else:
            embed.title = "Invalid airport given!"
            embed.colour = cmn.colours.bad
        return embed

    async def get_metar_taf_data(self, airport: str, hours: int, taf: bool) -> List[str]:
        url = (f"https://www.aviationweather.gov/metar/data?ids={airport}&format=raw&hours={hours}"
               f"&taf={'on' if taf else 'off'}&layout=off")
        async with self.session.get(url) as r:
            if r.status != 200:
                raise cmn.BotHTTPError(r)
            page = await r.text()

        # pare down to just the data
        page = page.split("<!-- Data starts here -->")[1].split("<!-- Data ends here -->")[0].strip()
        # split at <hr>s
        data = re.split(r"<hr.*>", page, maxsplit=len(airport))

        parsed = []
        for sec in data:
            if sec.strip():
                for line in sec.split("\n"):
                    line = line.strip()
                    # remove HTML stuff
                    line = line.replace("<code>", "").replace("</code>", "")
                    line = line.replace("<strong>", "").replace("</strong>", "")
                    line = line.replace("<br/>", "\n").replace("&nbsp;", " ")
                    line = line.strip("\n")
                    parsed.append(line)
        return parsed


def setup(bot: commands.Bot):
    bot.add_cog(WeatherCog(bot))