#!/usr/bin/env python3
"""Athena Deck prototype: loopback API, owned demo process, read-only telemetry."""
import argparse
import json
import signal
import socket
import subprocess
import sys
import threading
import time
import urllib.request
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path

ROOT = Path(__file__).resolve().parent

class DemoService:
    def __init__(self):
        self.lock = threading.RLock()
        self.process = None
        self.port = None

    def status(self):
        with self.lock:
            running = self.process is not None and self.process.poll() is None
            reachable = False
            if running:
                try:
                    with urllib.request.urlopen(f'http://127.0.0.1:{self.port}/health', timeout=.5) as response:
                        reachable = json.load(response).get('service') == 'athena-deck-demo'
                except (OSError, ValueError):
                    pass
            return dict(state='running' if running else 'stopped', reachable=reachable, pid=self.process.pid if running else None, port=self.port if running else None, location='Mac · lokaler Demo-Prozess')

    def start(self):
        with self.lock:
            if self.process is None or self.process.poll() is not None:
                with socket.socket() as sock:
                    sock.bind(('127.0.0.1', 0))
                    sock.listen(8)
                    self.port = sock.getsockname()[1]
                    self.process = subprocess.Popen([sys.executable, str(ROOT/'demo.py'), str(sock.fileno())], pass_fds=(sock.fileno(),), stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
                for _ in range(30):
                    if self.status()['reachable']:
                        break
                    time.sleep(.05)
            return self.status()

    def stop(self):
        with self.lock:
            if self.process is not None and self.process.poll() is None:
                self.process.terminate()
                try:
                    self.process.wait(timeout=3)
                except subprocess.TimeoutExpired:
                    self.process.kill()
                    self.process.wait()
            return self.status()

class HardwareProvider:
    def __init__(self):
        self.lock = threading.Lock()
        self.cached = None
        self.checked = 0

    def snapshot(self):
        with self.lock:
            if time.monotonic() - self.checked < 5 and self.cached is not None:
                return self.cached
            try:
                result = subprocess.run(['ssh', '-i', str(Path.home()/'.ssh/athena_key'), '-o', 'BatchMode=yes', '-o', 'ConnectTimeout=4', '-o', 'StrictHostKeyChecking=yes', 'root@192.168.1.212', 'python3 -'], input=(ROOT/'collect_hardware.py').read_text(), capture_output=True, text=True, timeout=10, check=True)
                self.cached = json.loads(result.stdout)
                self.cached['available'] = True
            except (OSError, subprocess.SubprocessError, ValueError):
                self.cached = dict(available=False, sampled_at=None, cpu={}, ram={}, gpus=[], errors=['Athena per SSH nicht erreichbar oder Messung fehlgeschlagen.'])
            self.checked = time.monotonic()
            return self.cached

class Server(ThreadingHTTPServer):
    daemon_threads = True
    def __init__(self, port):
        super().__init__(('127.0.0.1', port), Handler)
        self.demo = DemoService()
        self.hardware = HardwareProvider()
        self.started = time.time()

class Handler(BaseHTTPRequestHandler):
    def log_message(self, *args):
        pass

    def respond(self, data, status=200, mime='application/json'):
        body = json.dumps(data).encode() if mime == 'application/json' else data
        self.send_response(status)
        self.send_header('Content-Type', mime)
        self.send_header('Content-Length', str(len(body)))
        self.send_header('Cache-Control', 'no-store')
        self.send_header('X-Content-Type-Options', 'nosniff')
        self.send_header('Content-Security-Policy', "default-src 'self'; script-src 'self'; style-src 'self'; frame-ancestors 'none'")
        self.end_headers()
        self.wfile.write(body)

    def valid_host(self):
        return self.headers.get('Host') in (f'127.0.0.1:{self.server.server_port}', f'localhost:{self.server.server_port}')

    def do_GET(self):
        if not self.valid_host():
            return self.respond({'error': 'Host rejected'}, 403)
        routes = {'/': ('index.html', 'text/html; charset=utf-8'), '/app.js': ('app.js', 'text/javascript'), '/style.css': ('style.css', 'text/css')}
        if self.path in routes:
            name, mime = routes[self.path]
            return self.respond((ROOT/name).read_bytes(), mime=mime)
        if self.path == '/api/v1/status':
            return self.respond(dict(name='Athena Deck', version='0.1.0', state='ready', uptime_seconds=round(time.time()-self.server.started), mode='isolated', demo=self.server.demo.status()))
        if self.path == '/api/v1/hardware':
            return self.respond(self.server.hardware.snapshot())
        if self.path == '/api/v1/demo':
            return self.respond(self.server.demo.status())
        return self.respond({'error': 'Not found'}, 404)

    def do_POST(self):
        origin = self.headers.get('Origin')
        if not self.valid_host() or self.headers.get('X-Athena-Deck') != '1' or (origin and origin != 'http://' + self.headers.get('Host', '')):
            return self.respond({'error': 'Same-origin control required'}, 403)
        if self.path not in ('/api/v1/demo/start', '/api/v1/demo/stop'):
            return self.respond({'error': 'Not found'}, 404)
        action = self.server.demo.start if self.path.endswith('/start') else self.server.demo.stop
        result = action()
        self.respond(result, 503 if self.path.endswith('/start') and not result['reachable'] else 200)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--port', type=int, default=8108)
    args = parser.parse_args()
    server = Server(args.port)  # Binding fails rather than taking over an occupied port.
    def shutdown(*_):
        threading.Thread(target=server.shutdown, daemon=True).start()
    signal.signal(signal.SIGTERM, shutdown)
    signal.signal(signal.SIGINT, shutdown)
    print(f'Athena Deck: http://127.0.0.1:{server.server_port}', flush=True)
    try:
        server.serve_forever()
    finally:
        server.demo.stop()
        server.server_close()

if __name__ == '__main__':
    main()