#!/usr/bin/env python3
"""
Minimal HTTP API server for persisting apartment ratings.

GET  /api/ratings        → returns ratings.json contents
POST /api/ratings        → saves entire ratings object
GET  /api/ratings/export → same as GET, but with download header

Ratings file: /app/data/ratings.json (or ./ratings.json locally)
"""

import json
import logging
import os
import sys
from http.server import BaseHTTPRequestHandler, HTTPServer
from pathlib import Path

PORT = int(os.environ.get("RATINGS_PORT", 8081))
DATA_DIR = Path(os.environ.get("DATA_DIR", "."))
RATINGS_FILE = DATA_DIR / "ratings.json"

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [ratings] %(levelname)s %(message)s",
    datefmt="%Y-%m-%dT%H:%M:%S",
)
log = logging.getLogger(__name__)


def load_ratings() -> dict:
    try:
        if RATINGS_FILE.exists():
            return json.loads(RATINGS_FILE.read_text(encoding="utf-8"))
    except Exception as e:
        log.error("Failed to load ratings: %s", e)
    return {}


def save_ratings(data: dict) -> None:
    RATINGS_FILE.write_text(
        json.dumps(data, ensure_ascii=False, indent=2),
        encoding="utf-8",
    )


class RatingsHandler(BaseHTTPRequestHandler):
    def log_message(self, format, *args):
        # Suppress default HTTP access log (we use our own)
        pass

    def _send_json(self, status: int, body: dict, extra_headers=None):
        payload = json.dumps(body, ensure_ascii=False).encode("utf-8")
        self.send_response(status)
        self.send_header("Content-Type", "application/json; charset=utf-8")
        self.send_header("Content-Length", str(len(payload)))
        self.send_header("Access-Control-Allow-Origin", "*")
        self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
        self.send_header("Access-Control-Allow-Headers", "Content-Type")
        if extra_headers:
            for k, v in extra_headers.items():
                self.send_header(k, v)
        self.end_headers()
        self.wfile.write(payload)

    def do_OPTIONS(self):
        # CORS preflight
        self.send_response(204)
        self.send_header("Access-Control-Allow-Origin", "*")
        self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
        self.send_header("Access-Control-Allow-Headers", "Content-Type")
        self.end_headers()

    def do_GET(self):
        if self.path in ("/api/ratings", "/api/ratings/export"):
            ratings = load_ratings()
            extra = None
            if self.path == "/api/ratings/export":
                extra = {"Content-Disposition": 'attachment; filename="ratings.json"'}
            log.info("GET %s → %d ratings", self.path, len(ratings))
            self._send_json(200, ratings, extra)
        else:
            self._send_json(404, {"error": "not found"})

    def do_POST(self):
        if self.path == "/api/ratings":
            length = int(self.headers.get("Content-Length", 0))
            if length == 0:
                self._send_json(400, {"error": "empty body"})
                return
            try:
                raw = self.rfile.read(length)
                data = json.loads(raw.decode("utf-8"))
            except Exception as e:
                log.warning("Bad request body: %s", e)
                self._send_json(400, {"error": "invalid JSON"})
                return
            if not isinstance(data, dict):
                self._send_json(400, {"error": "expected JSON object"})
                return
            save_ratings(data)
            log.info("POST /api/ratings → saved %d ratings", len(data))
            self._send_json(200, {"ok": True, "count": len(data)})
        else:
            self._send_json(404, {"error": "not found"})


if __name__ == "__main__":
    log.info("Ratings server starting on port %d, data dir: %s", PORT, DATA_DIR)
    log.info("Ratings file: %s", RATINGS_FILE)
    server = HTTPServer(("0.0.0.0", PORT), RatingsHandler)
    try:
        server.serve_forever()
    except KeyboardInterrupt:
        log.info("Stopped.")
        sys.exit(0)