"""Shared pytest fixtures.

Tests run on a throwaway SQLite file (no external database required).
`DATABASE_URL` and `FLOWS_DIR` are pointed at a session temp dir *before* any
app module is imported, so settings pick them up at import time. The app
schema is migrated to head once per session via Alembic.
"""

import os
import tempfile
from pathlib import Path

import pytest

TEST_AREA = Path(tempfile.mkdtemp(prefix="kirche-tests-"))

# Must precede all `app.*` imports: Settings is instantiated at import time.
os.environ["DATABASE_URL"] = f"sqlite:///{TEST_AREA / 'test.db'}"
os.environ["FLOWS_DIR"] = str(TEST_AREA / "flows")

BACKEND_DIR = Path(__file__).resolve().parent.parent


@pytest.fixture(scope="session")
def db_engine():
    """Engine on the test DB, migrated to head once per session."""
    from alembic import command as alembic_command
    from alembic.config import Config

    from app import db as app_db

    app_db.reset_engine()
    engine = app_db.get_engine()

    cfg = Config()
    cfg.set_main_option("script_location", str(BACKEND_DIR / "migrations"))
    alembic_command.upgrade(cfg, "head")

    yield engine

    engine.dispose()
    app_db.reset_engine()


@pytest.fixture()
def session(db_engine):
    """Function-scoped session for direct DB access in tests."""
    from sqlmodel import Session

    with Session(db_engine) as s:
        yield s


@pytest.fixture(autouse=True)
def _clean_tables(db_engine):
    """Truncate all domain tables before and after every test (isolation)."""
    from sqlmodel import SQLModel

    def _truncate() -> None:
        with db_engine.begin() as conn:
            for table in reversed(SQLModel.metadata.sorted_tables):
                conn.execute(table.delete())

    _truncate()
    yield
    _truncate()


@pytest.fixture()
async def client():
    """ASGI test client for the FastAPI app."""
    from httpx import ASGITransport, AsyncClient

    from app.main import app

    transport = ASGITransport(app=app)
    async with AsyncClient(transport=transport, base_url="http://test") as c:
        yield c


@pytest.fixture(scope="session")
def lfx_server(tmp_path_factory):
    """Real `lfx serve` subprocess on a free port; points settings at it.

    Serves an (initially seeded) flow dir; tests upload fixture flows through
    the same deploy path production uses.
    """
    import shutil
    import socket
    import subprocess
    import sys
    import time
    import urllib.request
    from pathlib import Path

    from app.settings import settings

    bindir = Path(sys.executable).parent
    lfx_bin = shutil.which("lfx", path=str(bindir)) or "lfx"

    sock = socket.socket()
    sock.bind(("127.0.0.1", 0))
    port = sock.getsockname()[1]
    sock.close()

    flow_dir = tmp_path_factory.mktemp("lfx-flows")
    seed = (
        Path(__file__).parent / "fixtures" / "flows" / "simple_rule.json"
    ).read_text()
    (flow_dir / "seed.json").write_text(seed)

    env = {
        **os.environ,
        # lfx serve refuses to start without a serve key; requests need it too.
        # get_api_key() prefers LANGFLOW_API_KEY over LFX_API_KEY, and the repo
        # .env may put a real Langflow key in the environment — clear it so the
        # test key below is the one the client sends.
        "LANGFLOW_API_KEY": "",
        "LFX_API_KEY": "test-lfx-key",
    }
    proc = subprocess.Popen(
        [
            lfx_bin,
            "serve",
            "--host",
            "127.0.0.1",
            "--port",
            str(port),
            "--flow-dir",
            str(flow_dir),
            str(flow_dir),
        ],
        stdout=subprocess.PIPE,
        stderr=subprocess.STDOUT,
        text=True,
        env=env,
    )
    url = f"http://127.0.0.1:{port}"
    deadline = time.time() + 240
    healthy = False
    while time.time() < deadline:
        if proc.poll() is not None:
            out = proc.stdout.read() if proc.stdout else ""
            raise RuntimeError(f"lfx serve exited early:\n{out[-4000:]}")
        try:
            with urllib.request.urlopen(url + "/health", timeout=3) as response:
                if response.status == 200:
                    healthy = True
                    break
        except OSError:
            time.sleep(1)
    if not healthy:
        proc.terminate()
        raise RuntimeError("lfx serve did not become healthy in time")

    old_url = settings.lfx_url
    old_key = settings.lfx_api_key
    settings.lfx_url = url
    settings.lfx_api_key = "test-lfx-key"
    yield url
    settings.lfx_url = old_url
    settings.lfx_api_key = old_key
    proc.terminate()
    try:
        proc.wait(timeout=20)
    except subprocess.TimeoutExpired:
        proc.kill()


@pytest.fixture()
def override_langflow():
    """Replace the Langflow dependency with a fake (real LFX stays untouched).

    Usage: override_langflow(export_doc) -- the fake export_flow() returns the
    doc, or raises LangflowNotFound/Unavailable for status=404/0.
    """
    from app.flows.api import get_langflow
    from app.flows.langflow_client import LangflowNotFound, LangflowUnavailable
    from app.main import app

    def _override(export_doc=None, status=200):
        class FakeLangflow:
            async def export_flow(self, flow_id):
                if status == 404:
                    raise LangflowNotFound(f"flow {flow_id} not found")
                if status == 0:
                    raise LangflowUnavailable("Langflow unreachable")
                return export_doc

            async def list_flows(self):
                return [{"id": "fake-1", "name": "fake"}]

        app.dependency_overrides[get_langflow] = lambda: FakeLangflow()

    yield _override
    app.dependency_overrides.pop(get_langflow, None)


@pytest.fixture(scope="session")
def live_server():
    """Real uvicorn server (ephemeral port) so LFX flows can call back
    into our API over HTTP, exactly like production."""
    import threading
    import time

    import uvicorn

    from app.main import app

    config = uvicorn.Config(app, host="127.0.0.1", port=0, log_level="warning")
    server = uvicorn.Server(config)
    thread = threading.Thread(target=server.run, daemon=True)
    thread.start()
    deadline = time.time() + 30
    while not server.started and time.time() < deadline:
        time.sleep(0.05)
    assert server.started, "uvicorn test server did not start"
    port = server.servers[0].sockets[0].getsockname()[1]
    yield f"http://127.0.0.1:{port}"
    server.should_exit = True
    thread.join(timeout=15)