import http.client
import json
import os
import threading
import unittest
from unittest.mock import patch

from server import ProxyStaticHandler
from http.server import ThreadingHTTPServer

RealHTTPConnection = http.client.HTTPConnection


class FakeUpstream:
    def __init__(self, *args, **kwargs):
        self.response = type('Response', (), {
            'status': 200,
            'reason': 'OK',
            'getheaders': lambda self: [('Content-Type', 'application/json'), ('Set-Cookie', 'session=abc; Path=/')],
            'read': lambda self: b'{"status":"ok"}',
        })()
    def request(self, method, path, body=None, headers=None):
        self.method, self.path, self.body, self.headers = method, path, body, headers
    def getresponse(self):
        return self.response
    def close(self):
        pass


class ProxyServerTests(unittest.TestCase):
    def test_api_requests_are_forwarded_to_internal_upstream(self):
        server = ProxyStaticHandler
        self.assertTrue(hasattr(server, 'proxy_api'))
        with patch('server.http.client.HTTPConnection', FakeUpstream):
            self.assertTrue(server.proxy_api)

    def test_upstream_failure_is_structured_json(self):
        httpd = ThreadingHTTPServer(("127.0.0.1", 0), ProxyStaticHandler)
        thread = threading.Thread(target=httpd.serve_forever, daemon=True)
        thread.start()
        try:
            with patch('server.http.client.HTTPConnection', side_effect=OSError('connection refused')):
                conn = RealHTTPConnection('127.0.0.1', httpd.server_port, timeout=3)
                conn.request('GET', '/api/v1/dashboard/summary')
                response = conn.getresponse()
                body = response.read()
            self.assertEqual(response.status, 502)
            self.assertEqual(response.getheader('Content-Type'), 'application/json; charset=utf-8')
            self.assertEqual(json.loads(body), {'error': 'api_upstream_unavailable'})
        finally:
            httpd.shutdown(); httpd.server_close(); thread.join(timeout=2)


if __name__ == '__main__':
    unittest.main()