#!/usr/bin/env python3
"""Flight price monitor.

Reads routes from config.json, searches for round-trip flights via the
selected adapter, and fires an openclaw alert when prices drop below the
configured threshold.

Usage:
    python monitor.py [--adapter kiwi] [--config config.json]
"""

import argparse
import importlib
import json
import logging
import subprocess
import sys
from datetime import date, timedelta
from pathlib import Path

# ---------------------------------------------------------------------------
# Logging — append to monitor.log in same directory as this script
# ---------------------------------------------------------------------------
LOG_FILE = Path(__file__).parent / "monitor.log"

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(message)s",
    handlers=[
        logging.FileHandler(LOG_FILE, encoding="utf-8"),
        logging.StreamHandler(sys.stdout),
    ],
)
logger = logging.getLogger(__name__)


# ---------------------------------------------------------------------------
# Adapter loader
# ---------------------------------------------------------------------------

ADAPTER_MAP = {
    "kiwi": "adapters.kiwi.KiwiAdapter",
}


def load_adapter(name: str):
    """Dynamically load an adapter class by short name."""
    if name not in ADAPTER_MAP:
        raise ValueError(
            f"Unknown adapter '{name}'. Available: {', '.join(ADAPTER_MAP)}"
        )
    module_path, class_name = ADAPTER_MAP[name].rsplit(".", 1)
    module = importlib.import_module(module_path)
    cls = getattr(module, class_name)
    return cls()


# ---------------------------------------------------------------------------
# Date window generation
# ---------------------------------------------------------------------------

def generate_windows(route: dict, horizon_days: int = 365) -> list[tuple[str, str]]:
    """Generate (date_from, date_to) pairs to search.

    Produces one window per fortnight for the next `horizon_days` days.
    Each window spans 2 weeks of possible departure dates.
    """
    today = date.today()
    preferred = set(route.get("preferred_months", []))
    monitor_year_round = route.get("monitor_year_round", True)

    windows = []
    step = timedelta(weeks=2)
    window_span = timedelta(weeks=2)

    cursor = today + timedelta(days=7)  # start one week out
    end_horizon = today + timedelta(days=horizon_days)

    while cursor < end_horizon:
        month = cursor.month
        if monitor_year_round or month in preferred:
            date_from = cursor.strftime("%Y-%m-%d")
            date_to = (cursor + window_span).strftime("%Y-%m-%d")
            windows.append((date_from, date_to))
        cursor += step

    return windows


# ---------------------------------------------------------------------------
# Alerting
# ---------------------------------------------------------------------------

def send_alert(route: dict, result: dict):
    """Fire an openclaw alert for a price hit."""
    msg = (
        f"✈️ Flight alert: {route['origin']}→{route['destination']} "
        f"€{result['price_eur']:.0f} on "
        f"{result['outbound_date']}–{result['return_date']}! "
        f"{result['deep_link']}"
    )
    cmd = ["openclaw", "send", "--text", msg]
    try:
        subprocess.run(cmd, check=True, timeout=30)
        logger.info("ALERT SENT: %s", msg)
    except (subprocess.CalledProcessError, FileNotFoundError, subprocess.TimeoutExpired) as exc:
        logger.error("Failed to send alert: %s | command: %s", exc, " ".join(cmd))


# ---------------------------------------------------------------------------
# Main monitor loop
# ---------------------------------------------------------------------------

def check_route(route: dict, adapter) -> int:
    """Check a single route. Returns number of alerts fired."""
    route_id = route["id"]
    origin = route["origin"]
    destination = route["destination"]
    threshold = route["threshold_eur"]
    min_nights = route["min_nights"]
    max_nights = route["max_nights"]

    logger.info(
        "Checking %s: %s→%s threshold=€%s min=%d max=%d nights",
        route_id, origin, destination, threshold, min_nights, max_nights,
    )

    windows = generate_windows(route)
    logger.info("Generated %d search windows for %s", len(windows), route_id)

    all_results: list[dict] = []

    for date_from, date_to in windows:
        try:
            results = adapter.search(
                origin=origin,
                destination=destination,
                date_from=date_from,
                date_to=date_to,
                min_nights=min_nights,
                max_nights=max_nights,
            )
        except Exception as exc:
            logger.error(
                "Adapter error for %s window %s–%s: %s",
                route_id, date_from, date_to, exc,
            )
            results = []

        logger.debug(
            "Window %s–%s: %d results", date_from, date_to, len(results)
        )
        all_results.extend(results)

    alerts_fired = 0

    if not all_results:
        logger.info("Route %s: no results returned (adapter stub or no flights found)", route_id)
        return 0

    # Sort by price
    all_results.sort(key=lambda r: r["price_eur"])
    best = all_results[0]
    logger.info(
        "Route %s: %d results, best price €%.0f on %s–%s",
        route_id, len(all_results), best["price_eur"], best["outbound_date"], best["return_date"],
    )

    for result in all_results:
        if result["price_eur"] < threshold:
            send_alert(route, result)
            alerts_fired += 1

    if alerts_fired == 0:
        logger.info(
            "Route %s: best price €%.0f is above threshold €%s — no alert",
            route_id, best["price_eur"], threshold,
        )

    return alerts_fired


def main():
    parser = argparse.ArgumentParser(description="Flight price monitor")
    parser.add_argument(
        "--adapter", default="kiwi",
        choices=list(ADAPTER_MAP.keys()),
        help="Price adapter to use (default: kiwi)",
    )
    parser.add_argument(
        "--config", default=Path(__file__).parent / "config.json",
        help="Path to config file (default: config.json)",
    )
    args = parser.parse_args()

    config_path = Path(args.config)
    if not config_path.exists():
        logger.error("Config file not found: %s", config_path)
        sys.exit(1)

    with config_path.open() as f:
        config = json.load(f)

    routes = config.get("routes", [])
    if not routes:
        logger.warning("No routes defined in config — nothing to do.")
        return

    try:
        adapter = load_adapter(args.adapter)
    except ValueError as exc:
        logger.error(str(exc))
        sys.exit(1)

    logger.info("=== Flight monitor run start | adapter=%s | routes=%d ===", args.adapter, len(routes))

    total_alerts = 0
    for route in routes:
        total_alerts += check_route(route, adapter)

    logger.info("=== Run complete | total alerts=%d ===", total_alerts)


if __name__ == "__main__":
    main()