import os
import signal
import socket
import subprocess
import sys
import time
import uuid
from collections.abc import Iterator, Mapping
from contextlib import contextmanager
from dataclasses import dataclass
from pathlib import Path
from types import MappingProxyType
from typing import Final

import httpx
import psutil
from integration._support.client import Gateway


def proxy_database_environment() -> Mapping[str, str]:
    writer: Final = os.environ.get("INTEGRATION_PROXY_DATABASE_URL", "")
    reader: Final = os.environ.get("INTEGRATION_PROXY_READ_REPLICA_URL", "")
    return MappingProxyType(
        {
            **({"DATABASE_URL": writer} if writer else {}),
            **({"DATABASE_URL_READ_REPLICA": reader} if reader else {}),
        }
    )


def in_group(process: psutil.Process, group: int) -> bool:
    try:
        return os.getpgid(process.pid) == group
    except ProcessLookupError:
        return False


def group_members(group: int) -> tuple[psutil.Process, ...]:
    return tuple(process for process in psutil.process_iter() if in_group(process, group))


def signal_group(group: int, action: int) -> None:
    try:
        os.killpg(group, action)
    except ProcessLookupError:
        pass


def stop_root_process(process: subprocess.Popen[bytes]) -> bool:
    if process.poll() is not None:
        return True
    process.terminate()
    try:
        process.wait(timeout=30)
    except subprocess.TimeoutExpired:
        return False
    return True


@dataclass(frozen=True, slots=True)
class OwnedProxy:
    gateway: Gateway
    process: subprocess.Popen[bytes]
    log: Path


@contextmanager
def owned_proxy(
    gateway: Gateway,
    directory: Path,
    overrides: Mapping[str, str],
    *,
    config: Path | None = None,
    remove_environment: tuple[str, ...] = (),
    workers: int = 1,
) -> Iterator[Gateway]:
    with owned_proxy_process(
        gateway, directory, overrides, config=config, remove_environment=remove_environment, workers=workers
    ) as owned:
        yield owned.gateway


@contextmanager
def owned_proxy_process(
    gateway: Gateway,
    directory: Path,
    overrides: Mapping[str, str],
    *,
    config: Path | None = None,
    remove_environment: tuple[str, ...] = (),
    workers: int = 1,
) -> Iterator[OwnedProxy]:
    with socket.socket() as reserve:
        reserve.bind(("127.0.0.1", 0))
        port: Final = reserve.getsockname()[1]
    root: Final = Path(os.environ.get("INTEGRATION_PROXY_ROOT") or Path(__file__).resolve().parents[3])
    environment: Final = {
        **{
            name: value
            for name, value in {**os.environ, **proxy_database_environment()}.items()
            if name not in remove_environment
        },
        "LITELLM_MASTER_KEY": gateway.key,
        "LITELLM_SALT_KEY": os.environ.get("LITELLM_SALT_KEY", "sk-integration-salt"),
        "STORE_MODEL_IN_DB": "True",
        **overrides,
    }
    output: Final = Path(os.environ.get("INTEGRATION_RESULTS_DIR", str(directory)))
    output.mkdir(parents=True, exist_ok=True)
    log_path: Final = output / f"owned-proxy-{uuid.uuid4().hex}.log"
    with log_path.open("w") as log:
        process: Final = subprocess.Popen(
            [
                sys.executable,
                "-m",
                "integration._support.proxy",
                "--config",
                str(config or "tests/integration/proxy_config.yaml"),
                "--host",
                "127.0.0.1",
                "--port",
                str(port),
                "--num_workers",
                str(workers),
                "--use_prisma_db_push",
                "--enforce_prisma_migration_check",
            ],
            cwd=root,
            env=environment,
            stdout=log,
            stderr=subprocess.STDOUT,
            start_new_session=True,
        )
        try:
            with httpx.Client(base_url=f"http://127.0.0.1:{port}", timeout=15, trust_env=False) as client:
                deadline: Final = time.monotonic() + 70
                while True:
                    assert process.poll() is None, "Owned proxy exited before readiness"
                    try:
                        if client.get("/health/readiness", timeout=2).status_code == 200:
                            break
                    except httpx.TransportError:
                        pass
                    assert time.monotonic() < deadline, "Owned proxy readiness deadline exceeded"
                    time.sleep(0.1)
                yield OwnedProxy(Gateway(client, gateway.key, gateway.upstream_url), process, log_path)
        finally:
            root_stopped: Final = stop_root_process(process)
            residual: Final = group_members(process.pid)
            if residual:
                signal_group(process.pid, signal.SIGTERM)
                psutil.wait_procs(residual, timeout=5)
            remaining: Final = group_members(process.pid)
            if remaining:
                signal_group(process.pid, signal.SIGKILL)
                psutil.wait_procs(remaining, timeout=3)
            process.wait(timeout=3)
            survivors: Final = group_members(process.pid)
            assert not survivors, "Owned proxy child survived cleanup"
            assert root_stopped and not remaining, "Owned proxy required forced cleanup"