#!/usr/bin/env python3

from dataclasses import dataclass
import datetime
import json
from typing import List
import urllib.request

import argparse_utils
import config
import datetime_utils
import list_utils
import persistent

cfg = config.add_commandline_args(
    f'Cached Weather Data List ({__file__})',
    'Arguments controlling cached weather data',
)
cfg.add_argument(
    '--weather_data_cachefile',
    type=str,
    default='/home/scott/.weather_summary_cache',
    metavar='FILENAME',
    help='File in which to cache weather data'
)
cfg.add_argument(
    '--weather_data_stalest_acceptable',
    type=argparse_utils.valid_duration,
    default=datetime.timedelta(seconds=7200),   # 2 hours
    metavar='DURATION',
    help='Maximum acceptable age of cached data.  If zero, forces a refetch'
)


@dataclass
class WeatherData:
    date: datetime.date              # The date
    high: float                      # The predicted high in F
    low: float                       # The predicted low in F
    conditions: List[str]            # Conditions per ~3h window
    most_common_condition: str       # The most common condition
    icon: str                        # An icon to represent it


@persistent.persistent_autoloaded_singleton()
class CachedWeatherData(persistent.Persistent):
    def __init__(self,
                 weather_data = None):
        if weather_data is not None:
            self.weather_data = weather_data
            return
        self.weather_data = {}
        icon_by_condition = {
            "Thunderstorm": "⚡",
            "Drizzle": "",
            "Rain": "☂️",
            "Snow": "❄️",
            "Clear": "☀️",
            "Clouds": "⛅",
            "Mist": "🌫",
            "Smoke": "🚬",
            "Haze": "🌥️",
            "Dust": "💨",
            "Fog": "🌁",
            "Sand": "🏜️",
            "Ash": "🌋",
            "Squall": "🌬",
            "Tornado": "🌪️"
        }
        now = datetime.datetime.now()
        dates = set()
        highs = {}
        lows = {}
        conditions = {}
        param = "id=5786882"   # Bellevue, WA
        key = "c0b160c49743622f62a9cd3cda0270b3"
        www = urllib.request.urlopen(
            f'http://api.openweathermap.org/data/2.5/weather?zip=98005,us&APPID={key}&units=imperial'
        )
        response = www.read()
        www.close()
        parsed_json = json.loads(response)
        dt = datetime.datetime.fromtimestamp(parsed_json["dt"]).date()
        dates.add(dt)
        condition = parsed_json["weather"][0]["main"]
        icon = icon_by_condition.get(condition, '?')
        if dt == now.date() and now.hour > 18 and condition == 'Clear':
            icon = '🌙'
        self.weather_data[dt] = WeatherData(
            date = dt,
            high = float(parsed_json["main"]["temp_max"]),
            low = float(parsed_json["main"]["temp_min"]),
            conditions = [condition],
            most_common_condition = condition,
            icon = icon,
        )

        www = urllib.request.urlopen(
            f"http://api.openweathermap.org/data/2.5/forecast?{param}&APPID={key}&units=imperial"
        )
        response = www.read()
        www.close()
        parsed_json = json.loads(response)
        count = parsed_json["cnt"]
        for x in range(count):
            data = parsed_json["list"][x]
            dt = datetime.datetime.strptime(data['dt_txt'], '%Y-%m-%d %H:%M:%S')
            dt = dt.date()
            dates.add(dt)
            if dt not in highs:
                highs[dt] = None
                lows[dt] = None
                conditions[dt] = []
            temp = data["main"]["temp"]
            if highs[dt] is None or temp > highs[dt]:
                highs[dt] = temp
            if lows[dt] is None or temp < lows[dt]:
                lows[dt] = temp
            cond = data["weather"][0]["main"]
            conditions[dt].append(cond)

        today = datetime_utils.now_pacific().date()
        for dt in sorted(dates):
            if dt == today:
                high = highs.get(dt, None)
                if (
                        high is not None and
                        self.weather_data[today].high < high
                ):
                    self.weather_data[today].high = high
                continue
            most_common_condition = list_utils.most_common_item(conditions[dt])
            icon = icon_by_condition.get(most_common_condition, '?')
            if dt == now.date() and now.hour > 18 and condition == 'Clear':
                icon = '🌙'
            self.weather_data[dt] = WeatherData(
                date = dt,
                high = highs[dt],
                low = lows[dt],
                conditions = conditions[dt],
                most_common_condition = most_common_condition,
                icon = icon
            )

    @classmethod
    def load(cls):
        if persistent.was_file_written_within_n_seconds(
                config.config['weather_data_cachefile'],
                config.config['weather_data_stalest_acceptable'].total_seconds(),
        ):
            import pickle
            with open(config.config['weather_data_cachefile'], 'rb') as rf:
                weather_data = pickle.load(rf)
                return cls(weather_data)
        return None

    def save(self):
        import pickle
        with open(config.config['weather_data_cachefile'], 'wb') as wf:
            pickle.dump(
                self.weather_data,
                wf,
                pickle.HIGHEST_PROTOCOL,
            )