import os
import time
import json
import requests
from datetime import datetime
from pathlib import Path

# ===== SMS GATEWAY =====
SMS_USER = os.getenv("SMS_USER", "weatherbot")
SMS_PASS = os.getenv("SMS_PASS", "Cupakabra17")

RECEIVE_URL = "https://sms.internet-master.cz/receive/"
SEND_URL    = "https://sms.internet-master.cz/send/"

# ===== TIMING =====
POLL_INTERVAL = 1  # seconds (low latency)

# ===== STATE =====
STATE_FILE = Path("weatherbot_state.json")
MAX_SEEN_OFFSETS = 5000

# ===== OPEN-METEO =====
GEO_URL = "https://geocoding-api.open-meteo.com/v1/search"
WEATHER_URL = "https://api.open-meteo.com/v1/forecast"

# city -> (lat, lon)
GEO_CACHE = {}

HEADERS = {
    "User-Agent": "weatherbot/1.0 (jakub@jimbuntu)"
}

session = requests.Session()
session.headers.update(HEADERS)

# =========================================================
# SMS API
# =========================================================

def fetch_inbox(limit=5):
    r = session.get(
        RECEIVE_URL,
        params={
            "username": SMS_USER,
            "password": SMS_PASS,
            "limit": limit
        },
        timeout=5
    )
    r.raise_for_status()
    return r.json()

def send_sms(number, message):
    r = session.get(
        SEND_URL,
        params={
            "number": number,
            "message": message,
            "username": SMS_USER,
            "password": SMS_PASS
        },
        timeout=5
    )
    r.raise_for_status()
    print("📤 SEND:", r.text)

# =========================================================
# WEATHER (Open-Meteo, no registration)
# =========================================================

CODE_MAP = {
    0: "Clear",
    1: "Mostly clear",
    2: "Partly cloudy",
    3: "Cloudy",
    45: "Fog",
    48: "Fog",
    51: "Drizzle",
    53: "Drizzle",
    55: "Drizzle",
    61: "Rain",
    63: "Rain",
    65: "Heavy rain",
    71: "Snow",
    73: "Snow",
    75: "Heavy snow",
    80: "Showers",
    81: "Showers",
    82: "Heavy showers",
    95: "Storm"
}

def get_weather(city):
    city = city.strip()
    if not city:
        return "❌ Send a city name."

    try:
        key = city.lower()

        # --- GEO ---
        if key in GEO_CACHE:
            lat, lon = GEO_CACHE[key]
        else:
            r = session.get(
                GEO_URL,
                params={"name": city, "count": 1},
                timeout=2
            )
            r.raise_for_status()
            data = r.json()
            results = data.get("results")

            if not results:
                return f"❌ Unknown city: {city}"

            lat = results[0]["latitude"]
            lon = results[0]["longitude"]
            GEO_CACHE[key] = (lat, lon)

        # --- WEATHER ---
        r = session.get(
            WEATHER_URL,
            params={
                "latitude": lat,
                "longitude": lon,
                "daily": "temperature_2m_mean,weathercode",
                "timezone": "auto"
            },
            timeout=2
        )
        r.raise_for_status()
        data = r.json()

        daily = data.get("daily", {})
        dates = daily.get("time", [])[:3]
        temps = daily.get("temperature_2m_mean", [])[:3]
        codes = daily.get("weathercode", [])[:3]

        if not dates:
            return f"❌ Weather unavailable for {city}"

        msg = f"🌦 {city}:\n"
        for d, t, c in zip(dates, temps, codes):
            wd = datetime.strptime(d, "%Y-%m-%d").strftime("%a")
            desc = CODE_MAP.get(c, "Weather")
            msg += f"{wd}: {round(t)}°C {desc}\n"

        return msg.strip()

    except Exception:
        return f"⚠ Weather service error for {city}"

# =========================================================
# STATE HANDLING
# =========================================================

def load_state():
    if not STATE_FILE.exists():
        return {"seen_offsets": []}
    try:
        with STATE_FILE.open("r", encoding="utf-8") as f:
            data = json.load(f)
        return data if isinstance(data, dict) else {"seen_offsets": []}
    except Exception:
        return {"seen_offsets": []}

def save_state(state):
    seen = state.get("seen_offsets", [])
    if len(seen) > MAX_SEEN_OFFSETS:
        state["seen_offsets"] = seen[-MAX_SEEN_OFFSETS:]

    tmp = STATE_FILE.with_suffix(".tmp")
    with tmp.open("w", encoding="utf-8") as f:
        json.dump(state, f, ensure_ascii=False)
    tmp.replace(STATE_FILE)

def prime_seen_offsets(seen_set):
    try:
        data = fetch_inbox(limit=20)
        for sms in data.get("inbox", []):
            offset = sms.get("offset")
            if offset is not None:
                seen_set.add(offset)
        print("🧹 Inbox primed (no backlog replies).")
    except Exception as e:
        print("⚠ Prime failed:", e)

# =========================================================
# MAIN LOOP
# =========================================================

print("📡 SMS Weather Bot started (Open-Meteo, no registration)")

state = load_state()
seen_list = state.get("seen_offsets", [])
seen_set = set(seen_list)

prime_seen_offsets(seen_set)
state["seen_offsets"] = list(seen_set)
save_state(state)

while True:
    try:
        data = fetch_inbox(limit=5)

        for sms in data.get("inbox", []):
            offset = sms.get("offset")
            if offset in seen_set or offset is None:
                continue

            phone = sms.get("phone", "")
            text = (sms.get("message") or "").strip()

            seen_set.add(offset)
            seen_list.append(offset)
            state["seen_offsets"] = seen_list
            save_state(state)

            print(f"📨 {phone}: {text}")

            reply = get_weather(text)
            send_sms(phone, reply)

            print(f"✅ Replied to {phone}")

    except Exception as e:
        print("⚠ ERROR:", e)

    time.sleep(POLL_INTERVAL)