#!/usr/bin/env python3
"""SSE smoke test with active event trigger via /api/v1/trace/append."""

import http.client
import json
import os
import sys
import threading
import time
from urllib.parse import urlparse

API_URL = os.environ.get("API_URL", "http://127.0.0.1:8080")
TIMEOUT = float(os.environ.get("EVENTS_TIMEOUT_SEC", "12"))
EVENT_REQUIRED = "trace_append"


def parse_base(api_url: str):
    parsed = urlparse(api_url)
    if parsed.scheme != "http":
        raise ValueError("only http API_URL is supported for this smoke test")
    host = parsed.hostname or "127.0.0.1"
    port = parsed.port or 80
    base_path = parsed.path.rstrip("/")
    return host, port, base_path


def post_trace_append(host: str, port: int, base_path: str):
    # Small delay to ensure SSE subscription is active before trigger.
    time.sleep(1.0)
    conn = http.client.HTTPConnection(host, port, timeout=8)
    body = json.dumps({"kind": "gui", "line": f"sse-probe-{int(time.time())}"})
    path = f"{base_path}/api/v1/trace/append"
    conn.request("POST", path, body=body, headers={"Content-Type": "application/json"})
    resp = conn.getresponse()
    payload = resp.read().decode("utf-8", errors="ignore")
    if resp.status != 200:
        raise RuntimeError(f"trace/append failed: HTTP {resp.status}, body={payload}")
    conn.close()


def main():
    host, port, base_path = parse_base(API_URL)
    stream_path = f"{base_path}/api/v1/events/stream"
    conn = http.client.HTTPConnection(host, port, timeout=TIMEOUT)
    conn.putrequest("GET", stream_path)
    conn.putheader("Accept", "text/event-stream")
    conn.putheader("Cache-Control", "no-cache")
    conn.putheader("Connection", "keep-alive")
    conn.endheaders()

    resp = conn.getresponse()
    if resp.status != 200:
        print(f"[events] unexpected HTTP {resp.status}", file=sys.stderr)
        sys.exit(1)
    content_type = resp.getheader("Content-Type", "")
    if "text/event-stream" not in content_type:
        print(f"[events] bad Content-Type: {content_type}", file=sys.stderr)
        sys.exit(1)

    trigger_err = []

    def trigger():
        try:
            post_trace_append(host, port, base_path)
        except Exception as exc:
            trigger_err.append(str(exc))

    t = threading.Thread(target=trigger, daemon=True)
    t.start()

    got_id = False
    got_required = False
    deadline = time.time() + TIMEOUT
    while time.time() < deadline:
        raw = resp.readline()
        if not raw:
            break
        line = raw.decode("utf-8", errors="ignore").strip()
        if line.startswith("id:"):
            got_id = True
        if line.startswith("event:"):
            event = line.split(":", 1)[1].strip()
            if event == EVENT_REQUIRED:
                got_required = True
                print(f"[events] got required event: {event}")
                break

    resp.close()
    conn.close()
    t.join(timeout=0.5)

    if trigger_err:
        print(f"[events] trigger failed: {trigger_err[0]}", file=sys.stderr)
        sys.exit(1)
    if not got_id:
        print("[events] no SSE event id observed", file=sys.stderr)
        sys.exit(1)
    if not got_required:
        print(f"[events] missing required event: {EVENT_REQUIRED}", file=sys.stderr)
        sys.exit(1)
    print("[events] stream smoke passed")


if __name__ == "__main__":
    main()