#!/usr/bin/env python3
"""Measure native upload backlog against a delayed loopback server with fixture data."""
import base64
import http.server
import json
import os
from pathlib import Path
import subprocess
import sys
import threading
import time

root = Path(__file__).resolve().parents[2]
fixture = (root / "internal/docs/seeddata/letter.update.bin").read_bytes()
updates = []
lock = threading.Lock()
fail_once = "--fail-once" in sys.argv

class Handler(http.server.BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path.endswith("/stream"):
            self.send_response(200)
            self.send_header("Content-Type", "text/event-stream")
            self.end_headers()
            self.wfile.write(b"data: 0\n\n")
            self.wfile.flush()
            time.sleep(30)
            return
        if self.path == "/stats":
            with lock:
                data = json.dumps(dict(updates=updates)).encode()
        elif "/updates" in self.path:
            data = fixture
        else:
            data = json.dumps(dict(sqid="fixture", title="Sync fixture", guid="sync-fixture",
                                   can_write=True, can_share=False)).encode()
        self.send_response(200)
        self.send_header("Docs-Seq", "0")
        self.send_header("Content-Length", str(len(data)))
        self.end_headers()
        self.wfile.write(data)

    def do_POST(self):
        body = self.rfile.read(int(self.headers.get("Content-Length", "0")))
        # Deterministic request latency, not an artificial client debounce.
        time.sleep(0.25)
        with lock:
            updates.append(base64.b64encode(body).decode())
        self.send_response(503 if fail_once and len(updates) == 1 else 204)
        self.end_headers()

    def log_message(self, *_):
        pass

with http.server.ThreadingHTTPServer(("127.0.0.1", 0), Handler) as server:
    threading.Thread(target=server.serve_forever, daemon=True).start()
    env = dict(os.environ, DOCS_SYNC_TEST_ORIGIN=f"http://127.0.0.1:{server.server_port}")
    result = subprocess.run(["swift", "test", "--package-path", str(root / "native/apple"),
                             "--filter", "DocumentSyncIntegrationTests"], env=env, timeout=240)
    server.shutdown()
    raise SystemExit(result.returncode)