import json
import os
import stat
import subprocess
import sys
import textwrap
from pathlib import Path
from typing import Final, cast

import pytest

HARNESS: Final = Path(__file__).parents[2] / ".github" / "scripts" / "run_merge_smoke.py"


def _run(root: Path, *argv: str) -> subprocess.CompletedProcess[str]:
    return subprocess.run(
        [sys.executable, "-I", str(HARNESS), *argv],
        cwd=root,
        capture_output=True,
        text=True,
        timeout=120,
    )


def _fake_litellm(tmp_path: Path, script: str) -> Path:
    path: Final = tmp_path / "fake-litellm"
    path.write_text(f"#!{sys.executable}\n" + textwrap.dedent(script))
    path.chmod(path.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
    return path


def test_proxy_startup_exits_early_fails(tmp_path: Path) -> None:
    fake: Final = _fake_litellm(tmp_path, "import sys\nsys.exit(1)\n")
    diagnostics: Final = tmp_path / "diag"

    proc: Final = _run(
        tmp_path,
        "proxy-startup",
        "--diagnostics-dir",
        str(diagnostics),
        "--litellm-bin",
        str(fake),
    )

    assert proc.returncode != 0
    assert "exited early" in proc.stderr
    assert (diagnostics / "proxy.log").exists()


def test_proxy_startup_readiness_timeout_fails(tmp_path: Path) -> None:
    fake: Final = _fake_litellm(
        tmp_path,
        "import os, pathlib, sys, time\npathlib.Path(sys.argv[0]).with_name('fake.pid').write_text(str(os.getpid()))\ntime.sleep(3600)\n",
    )
    diagnostics: Final = tmp_path / "diag"

    proc: Final = _run(
        tmp_path,
        "proxy-startup",
        "--diagnostics-dir",
        str(diagnostics),
        "--litellm-bin",
        str(fake),
        "--ready-deadline",
        "3",
        "--shutdown-deadline",
        "2",
    )

    assert proc.returncode != 0
    assert "readiness" in proc.stderr
    assert (diagnostics / "proxy.log").exists()
    with pytest.raises(ProcessLookupError):
        os.kill(int((tmp_path / "fake.pid").read_text()), 0)


def test_proxy_startup_healthy_succeeds(tmp_path: Path) -> None:
    fake: Final = _fake_litellm(
        tmp_path,
        """
        import http.server, json, sys
        port = int(sys.argv[sys.argv.index("--port") + 1])
        class H(http.server.BaseHTTPRequestHandler):
            def do_GET(self):
                body = json.dumps({"status": "healthy", "db": "Not connected"}).encode()
                self.send_response(200)
                self.send_header("content-type", "application/json")
                self.end_headers()
                self.wfile.write(body)
            def log_message(self, *a):
                pass
        http.server.HTTPServer(("127.0.0.1", port), H).serve_forever()
        """,
    )
    diagnostics: Final = tmp_path / "diag"

    proc: Final = _run(
        tmp_path,
        "proxy-startup",
        "--diagnostics-dir",
        str(diagnostics),
        "--litellm-bin",
        str(fake),
        "--ready-deadline",
        "15",
    )

    assert proc.returncode == 0, proc.stderr
    result: Final = cast(dict[str, object], json.loads((diagnostics / "result.json").read_text()))
    assert result["outcome"] == "ok"
    assert result["readiness"] == '{"status": "healthy", "db": "Not connected"}'


def test_proxy_startup_sigterm_ignored_forces_kill(tmp_path: Path) -> None:
    fake: Final = _fake_litellm(
        tmp_path,
        """
        import http.server, json, os, pathlib, signal, sys
        port = int(sys.argv[sys.argv.index("--port") + 1])
        pathlib.Path(sys.argv[0]).with_name("fake.pid").write_text(str(os.getpid()))
        signal.signal(signal.SIGTERM, signal.SIG_IGN)
        class H(http.server.BaseHTTPRequestHandler):
            def do_GET(self):
                body = json.dumps({"status": "healthy", "db": "Not connected"}).encode()
                self.send_response(200)
                self.send_header("content-type", "application/json")
                self.end_headers()
                self.wfile.write(body)
            def log_message(self, *a):
                pass
        http.server.HTTPServer(("127.0.0.1", port), H).serve_forever()
        """,
    )
    diagnostics: Final = tmp_path / "diag"

    proc: Final = _run(
        tmp_path,
        "proxy-startup",
        "--diagnostics-dir",
        str(diagnostics),
        "--litellm-bin",
        str(fake),
        "--ready-deadline",
        "15",
        "--shutdown-deadline",
        "2",
    )

    assert proc.returncode != 0
    assert "forced kill" in proc.stderr
    result: Final = cast(dict[str, object], json.loads((diagnostics / "result.json").read_text()))
    assert result["outcome"] == "failed"
    with pytest.raises(ProcessLookupError):
        os.kill(int((tmp_path / "fake.pid").read_text()), 0)


def test_proxy_startup_waits_through_not_ready_status(tmp_path: Path) -> None:
    fake: Final = _fake_litellm(
        tmp_path,
        """
        import http.server, json, sys
        port = int(sys.argv[sys.argv.index("--port") + 1])
        hits = [0]
        class H(http.server.BaseHTTPRequestHandler):
            def do_GET(self):
                hits[0] += 1
                if hits[0] <= 2:
                    self.send_response(503)
                    self.end_headers()
                    return
                body = json.dumps({"status": "healthy", "db": "Not connected"}).encode()
                self.send_response(200)
                self.send_header("content-type", "application/json")
                self.end_headers()
                self.wfile.write(body)
            def log_message(self, *a):
                pass
        http.server.HTTPServer(("127.0.0.1", port), H).serve_forever()
        """,
    )
    diagnostics: Final = tmp_path / "diag"

    proc: Final = _run(
        tmp_path,
        "proxy-startup",
        "--diagnostics-dir",
        str(diagnostics),
        "--litellm-bin",
        str(fake),
        "--ready-deadline",
        "15",
    )

    assert proc.returncode == 0, proc.stderr


def test_proxy_startup_wrong_body_fails(tmp_path: Path) -> None:
    fake: Final = _fake_litellm(
        tmp_path,
        """
        import http.server, json, sys
        port = int(sys.argv[sys.argv.index("--port") + 1])
        class H(http.server.BaseHTTPRequestHandler):
            def do_GET(self):
                body = json.dumps({"status": "healthy", "db": "connected"}).encode()
                self.send_response(200)
                self.send_header("content-type", "application/json")
                self.end_headers()
                self.wfile.write(body)
            def log_message(self, *a):
                pass
        http.server.HTTPServer(("127.0.0.1", port), H).serve_forever()
        """,
    )
    diagnostics: Final = tmp_path / "diag"

    proc: Final = _run(
        tmp_path,
        "proxy-startup",
        "--diagnostics-dir",
        str(diagnostics),
        "--litellm-bin",
        str(fake),
        "--ready-deadline",
        "15",
    )

    assert proc.returncode != 0
    assert "connected" in proc.stderr


def test_interpreter_expect_mismatch_fails() -> None:
    proc: Final = _run(Path.cwd(), "interpreter", "--expect", "9.99")

    assert proc.returncode != 0
    assert "9.99" in proc.stderr


def test_interpreter_expect_match_passes() -> None:
    expect: Final = f"{sys.version_info.major}.{sys.version_info.minor}"

    proc: Final = _run(Path.cwd(), "interpreter", "--expect", expect)

    assert proc.returncode == 0
    assert f"OK interpreter {expect}" in proc.stdout