import json
import os
from datetime import datetime, timedelta


def _years_ago(dt, years):
    try:
        return dt.replace(year=dt.year - years)
    except ValueError:
        return dt.replace(year=dt.year - years, month=2, day=28)


class GunObject:

    def __init__(self, gun_id="", gun_mac=""):
        self.gun_id = gun_id
        self.gun_mac = gun_mac
        self.count = 0
        self.fired = 0
        self.fired_overall = 0
        self.battery = 0
        self.battery_overall = 0
        self.settings_battery_type = 0
        self.settings_battery_changes = 0
        self.settings_battery_life = 0
        self.settings_fired_max = 0
        self.history_battery_changes = 0
        self.history_battery_usage = 0
        self.history_fired = 0
        self.change_history = []
        self._init_dates()

    def _init_dates(self):
        self.last_seen = _years_ago(datetime.now() - timedelta(minutes=3957), 23)
        self.last_count = self.last_seen
        self.battery_last_changed = datetime.min
        self.fired_last = datetime.min

    def to_dict(self):
        return {
            "gun_id": self.gun_id,
            "gun_mac": self.gun_mac,
            "last_seen": self.last_seen.isoformat(),
            "last_count": self.last_count.isoformat(),
            "count": self.count,
            "fired": self.fired,
            "fired_overall": self.fired_overall,
            "battery": self.battery,
            "battery_overall": self.battery_overall,
            "battery_last_changed": self.battery_last_changed.isoformat(),
            "settings_battery_type": self.settings_battery_type,
            "settings_battery_changes": self.settings_battery_changes,
            "settings_battery_life": self.settings_battery_life,
            "settings_fired_max": self.settings_fired_max,
            "history_battery_changes": self.history_battery_changes,
            "history_battery_usage": self.history_battery_usage,
            "history_fired": self.history_fired,
            "fired_last": self.fired_last.isoformat(),
            "change_history": list(self.change_history),
        }

    @classmethod
    def from_dict(cls, data):
        gun = cls()
        gun.gun_id = data.get("gun_id", "")
        gun.gun_mac = data.get("gun_mac", "")
        gun.count = data.get("count", 0)
        gun.fired = data.get("fired", 0)
        gun.fired_overall = data.get("fired_overall", 0)
        gun.battery = data.get("battery", 0)
        gun.battery_overall = data.get("battery_overall", 0)
        gun.settings_battery_type = data.get("settings_battery_type", 0)
        gun.settings_battery_changes = data.get("settings_battery_changes", 0)
        gun.settings_battery_life = data.get("settings_battery_life", 0)
        gun.settings_fired_max = data.get("settings_fired_max", 0)
        gun.history_battery_changes = data.get("history_battery_changes", 0)
        gun.history_battery_usage = data.get("history_battery_usage", 0)
        gun.history_fired = data.get("history_fired", 0)
        gun.change_history = list(data.get("change_history", []))
        for name in ("last_seen", "last_count", "battery_last_changed", "fired_last"):
            raw = data.get(name)
            setattr(gun, name, datetime.fromisoformat(raw) if raw else datetime.min)
        return gun

    def store_gun_info(self):
        try:
            os.makedirs("./items", exist_ok=True)
            path = "./items/{}.cfg".format(self.gun_id)
            with open(path, "w", encoding="utf-8") as f:
                json.dump(self.to_dict(), f, indent=1)
            return True
        except Exception:
            return False

    @classmethod
    def load_gun_info(cls, path):
        with open(path, "r", encoding="utf-8") as f:
            return cls.from_dict(json.load(f))