#!/usr/bin/env python3
"""
HTTP-сервер дашборда homelab: статика, /api/containers, прокси к Netdata.
Порт: 19998 (по умолчанию).
"""

import json
import os
import subprocess
import sys
import urllib.request
from http.server import HTTPServer, BaseHTTPRequestHandler
from pathlib import Path

PORT = int(os.environ.get("DASHBOARD_PORT", "19998"))
NETDATA_URL = os.environ.get("NETDATA_URL", "http://127.0.0.1:19999")
SCRIPT_DIR = Path(__file__).resolve().parent
EXPORTER = SCRIPT_DIR / "dashboard-exporter.py"


class DashboardHandler(BaseHTTPRequestHandler):
    def log_message(self, format, *args):
        pass  # подавить вывод в консоль

    def send_json(self, data: dict, status: int = 200):
        self.send_response(status)
        self.send_header("Content-Type", "application/json; charset=utf-8")
        self.send_header("Access-Control-Allow-Origin", "*")
        self.end_headers()
        self.wfile.write(json.dumps(data, ensure_ascii=False).encode("utf-8"))

    def send_html(self, html: bytes, status: int = 200):
        self.send_response(status)
        self.send_header("Content-Type", "text/html; charset=utf-8")
        self.send_header("Cache-Control", "no-cache")
        self.end_headers()
        self.wfile.write(html)

    def do_GET(self):
        path = self.path.split("?")[0].rstrip("/") or "/"
        if path == "/":
            self.serve_index()
        elif path == "/api/containers":
            self.serve_containers()
        elif path.startswith("/api/netdata"):
            self.proxy_netdata()
        else:
            self.send_error(404)

    def serve_index(self):
        html_file = SCRIPT_DIR / "index.html"
        if html_file.exists():
            self.send_html(html_file.read_bytes())
        else:
            self.send_error(404, "index.html not found")

    def serve_containers(self):
        try:
            r = subprocess.run(
                [sys.executable, str(EXPORTER)],
                capture_output=True,
                text=True,
                timeout=30,
                cwd=str(SCRIPT_DIR),
            )
            if r.returncode != 0:
                self.send_json({"ok": False, "error": r.stderr or "exporter failed"}, 500)
                return
            data = json.loads(r.stdout)
            self.send_json(data)
        except subprocess.TimeoutExpired:
            self.send_json({"ok": False, "error": "timeout"}, 504)
        except json.JSONDecodeError as e:
            self.send_json({"ok": False, "error": str(e)}, 500)
        except Exception as e:
            self.send_json({"ok": False, "error": str(e)}, 500)

    def proxy_netdata(self):
        qs = self.path.split("?", 1)[1] if "?" in self.path else ""
        url = f"{NETDATA_URL}/api/v1/data?{qs}" if qs else f"{NETDATA_URL}/api/v1/data"
        try:
            req = urllib.request.Request(url)
            with urllib.request.urlopen(req, timeout=10) as resp:
                data = resp.read()
                self.send_response(200)
                self.send_header("Content-Type", resp.headers.get("Content-Type", "application/json"))
                self.send_header("Access-Control-Allow-Origin", "*")
                self.end_headers()
                self.wfile.write(data)
        except Exception as e:
            self.send_json({"error": str(e)}, 502)


def main():
    server = HTTPServer(("0.0.0.0", PORT), DashboardHandler)
    print(f"Dashboard server on http://0.0.0.0:{PORT}", file=sys.stderr)
    try:
        server.serve_forever()
    except KeyboardInterrupt:
        pass


if __name__ == "__main__":
    main()