#!/usr/bin/env python3
import os
import sys
import json
import time
import socket
import smtplib
from datetime import datetime, timezone
from email.message import EmailMessage

from dotenv import load_dotenv
load_dotenv()

import requests

EPIC_ENDPOINTS = [
    # manchmal zuverlässiger als die ipv4-subdomain
    "https://store-site-backend-static.ak.epicgames.com/freeGamesPromotions",
    "https://store-site-backend-static-ipv4.ak.epicgames.com/freeGamesPromotions",
]

def env(name: str, default: str | None = None, required: bool = False) -> str:
    val = os.getenv(name, default)
    if required and (val is None or val == ""):
        raise SystemExit(f"Missing required env var: {name}")
    return val

def fetch_json_with_retry(locale="de-DE", country="DE", retries=3, timeout=20):
    params = {"locale": locale, "country": country, "allowCountries": country}
    headers = {"Accept": "application/json"}

    last_err = None
    for base in EPIC_ENDPOINTS:
        for attempt in range(1, retries + 1):
            try:
                r = requests.get(base, params=params, headers=headers, timeout=timeout)
                r.raise_for_status()
                return r.json()
            except Exception as e:
                last_err = e
                # kleines Backoff
                time.sleep(1.0 * attempt)

    raise RuntimeError(f"Epic fetch failed after retries. Last error: {last_err}")

def is_active_window(window_obj: dict, now: datetime) -> bool:
    try:
        start = datetime.fromisoformat(window_obj["startDate"].replace("Z", "+00:00"))
        end = datetime.fromisoformat(window_obj["endDate"].replace("Z", "+00:00"))
        return start <= now <= end
    except Exception:
        return False

def extract_free_games(epic_json: dict, locale="de-DE"):
    # Pfad: data.Catalog.searchStore.elements
    elements = (
        epic_json.get("data", {})
        .get("Catalog", {})
        .get("searchStore", {})
        .get("elements", [])
    )

    now = datetime.now(timezone.utc)
    free_now = []

    for e in elements:
        promos = e.get("promotions") or {}
        blocks = promos.get("promotionalOffers") or []
        windows = []
        for b in blocks:
            windows.extend(b.get("promotionalOffers") or [])

        active = [w for w in windows if is_active_window(w, now)]
        if not active:
            continue

        slug = e.get("productSlug") or e.get("urlSlug")
        store_url = None
        if slug:
            store_url = f"https://store.epicgames.com/{locale.lower()}/p/{slug}"

        free_now.append({
            "title": e.get("title"),
            "until": active[0].get("endDate"),
            "store_url": store_url,
        })

    # sortiere nach Titel (optional)
    free_now.sort(key=lambda x: (x["title"] or "").lower())
    return free_now

def format_email_body(free_games: list[dict]) -> tuple[str, str]:
    now = datetime.now(timezone.utc).isoformat()

    if not free_games:
        subject = "Epic Games: Keine aktuellen Gratis-Spiele"
        text = f"Stand: {now}\n\nAktuell wurden keine Gratis-Spiele gefunden."
        html = f"<p><strong>Stand:</strong> {now}</p><p>Aktuell wurden keine Gratis-Spiele gefunden.</p>"
        return subject, text, html

    subject = f"Epic Games: {len(free_games)} Gratis-Spiel(e) verfügbar"
    lines = [f"Stand: {now}", "", "Aktuelle Gratis-Spiele:"]
    for g in free_games:
        lines.append(f"- {g['title']} (bis {g['until']})")
        if g["store_url"]:
            lines.append(f"  {g['store_url']}")
    text = "\n".join(lines)

    items_html = ""
    for g in free_games:
        title = (g["title"] or "").replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
        until = (g["until"] or "")
        if g["store_url"]:
            items_html += f"<li><a href=\"{g['store_url']}\">{title}</a> <small>(bis {until})</small></li>"
        else:
            items_html += f"<li>{title} <small>(bis {until})</small></li>"

    html = f"""
    <p><strong>Stand:</strong> {now}</p>
    <p>Aktuelle Gratis-Spiele:</p>
    <ul>
      {items_html}
    </ul>
    """
    return subject, text, html

def send_email(subject: str, text: str, html: str):
    smtp_host = env("SMTP_HOST", required=True)
    smtp_port = int(env("SMTP_PORT", "587"))
    smtp_user = env("SMTP_USER", required=True)
    smtp_pass = env("SMTP_PASS", required=True)

    mail_from = env("MAIL_FROM", smtp_user)
    mail_to = env("MAIL_TO", required=True)

    use_tls = env("SMTP_TLS", "true").lower() in ("1", "true", "yes", "on")

    msg = EmailMessage()
    msg["Subject"] = subject
    msg["From"] = mail_from
    msg["To"] = mail_to
    msg.set_content(text)
    msg.add_alternative(html, subtype="html")

    with smtplib.SMTP(smtp_host, smtp_port, timeout=30) as server:
        server.ehlo()
        if use_tls:
            server.starttls()
            server.ehlo()
        server.login(smtp_user, smtp_pass)
        server.send_message(msg)

def main():
    locale = env("EPIC_LOCALE", "de-DE")
    country = env("EPIC_COUNTRY", "DE")

    try:
        data = fetch_json_with_retry(locale=locale, country=country)
        free_games = extract_free_games(data, locale=locale)
        subject, text, html = format_email_body(free_games)
        send_email(subject, text, html)
        print(f"OK: Sent mail ({len(free_games)} freebies).")
    except requests.exceptions.RequestException as e:
        print(f"HTTP error: {e}", file=sys.stderr)
        sys.exit(2)
    except (socket.gaierror, RuntimeError) as e:
        print(f"Network/DNS error: {e}", file=sys.stderr)
        sys.exit(3)
    except Exception as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(1)

if __name__ == "__main__":
    main()