"""Shared fixtures for Chrysopedia integration tests.

Provides:
- Async SQLAlchemy engine/session against a real PostgreSQL test database
- Sync SQLAlchemy engine/session for pipeline stage tests (Celery stages are sync)
- httpx.AsyncClient wired to the FastAPI app with dependency overrides
- Pre-ingest fixture for pipeline tests
- Sample transcript fixture path and temporary storage directory

Key design choice: function-scoped engine with NullPool avoids asyncpg
"another operation in progress" errors caused by session-scoped connection
reuse between the ASGI test client and verification queries.
"""

import json
import os
import pathlib
import uuid

import pytest
import pytest_asyncio
from httpx import ASGITransport, AsyncClient
from sqlalchemy import create_engine
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
from sqlalchemy.orm import Session, sessionmaker
from sqlalchemy.pool import NullPool

# Ensure backend/ is on sys.path so "from models import ..." works
import sys
sys.path.insert(0, str(pathlib.Path(__file__).resolve().parent.parent))

from database import Base, get_session  # noqa: E402
from main import app  # noqa: E402
from models import (  # noqa: E402
    ContentType,
    Creator,
    InviteCode,
    ProcessingStatus,
    SourceVideo,
    TranscriptSegment,
    User,
    UserRole,
)

TEST_DATABASE_URL = os.getenv(
    "TEST_DATABASE_URL",
    "postgresql+asyncpg://chrysopedia:changeme@localhost:5433/chrysopedia_test",
)

TEST_DATABASE_URL_SYNC = TEST_DATABASE_URL.replace(
    "postgresql+asyncpg://", "postgresql+psycopg2://"
)


@pytest_asyncio.fixture()
async def db_engine():
    """Create a per-test async engine (NullPool) and create/drop all tables."""
    engine = create_async_engine(TEST_DATABASE_URL, echo=False, poolclass=NullPool)

    # Create all tables fresh for each test
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
        await conn.run_sync(Base.metadata.create_all)

    yield engine

    # Drop all tables after test
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)

    await engine.dispose()


@pytest_asyncio.fixture()
async def client(db_engine, tmp_path):
    """Async HTTP test client wired to FastAPI with dependency overrides."""
    session_factory = async_sessionmaker(
        db_engine, class_=AsyncSession, expire_on_commit=False
    )

    async def _override_get_session():
        async with session_factory() as session:
            yield session

    # Override DB session dependency
    app.dependency_overrides[get_session] = _override_get_session

    # Override transcript_storage_path via environment variable
    os.environ["TRANSCRIPT_STORAGE_PATH"] = str(tmp_path)
    # Clear the lru_cache so Settings picks up the new env var
    from config import get_settings
    get_settings.cache_clear()

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

    # Teardown: clean overrides and restore settings cache
    app.dependency_overrides.clear()
    os.environ.pop("TRANSCRIPT_STORAGE_PATH", None)
    get_settings.cache_clear()


@pytest.fixture()
def sample_transcript_path() -> pathlib.Path:
    """Path to the sample 5-segment transcript JSON fixture."""
    return pathlib.Path(__file__).parent / "fixtures" / "sample_transcript.json"


@pytest.fixture()
def tmp_transcript_dir(tmp_path) -> pathlib.Path:
    """Temporary directory for transcript storage during tests."""
    return tmp_path


# ── Sync engine/session for pipeline stages ──────────────────────────────────


@pytest.fixture()
def sync_engine(db_engine):
    """Create a sync SQLAlchemy engine pointing at the test database.

    Tables are already created/dropped by the async ``db_engine`` fixture,
    so this fixture just wraps a sync engine around the same DB URL.
    """
    engine = create_engine(TEST_DATABASE_URL_SYNC, echo=False, poolclass=NullPool)
    yield engine
    engine.dispose()


@pytest.fixture()
def sync_session(sync_engine) -> Session:
    """Create a sync SQLAlchemy session for pipeline stage tests."""
    factory = sessionmaker(bind=sync_engine)
    session = factory()
    yield session
    session.close()


# ── Pre-ingest fixture for pipeline tests ────────────────────────────────────


@pytest.fixture()
def pre_ingested_video(sync_engine):
    """Ingest the sample transcript directly into the test DB via sync ORM.

    Returns a dict with ``video_id``, ``creator_id``, and ``segment_count``.
    """
    factory = sessionmaker(bind=sync_engine)
    session = factory()
    try:
        # Create creator
        creator = Creator(
            name="Skope",
            slug="skope",
            folder_name="Skope",
        )
        session.add(creator)
        session.flush()

        # Create video
        video = SourceVideo(
            creator_id=creator.id,
            filename="mixing-basics-ep1.mp4",
            file_path="Skope/mixing-basics-ep1.mp4",
            duration_seconds=1234,
            content_type=ContentType.tutorial,
            processing_status=ProcessingStatus.transcribed,
        )
        session.add(video)
        session.flush()

        # Create transcript segments
        sample = pathlib.Path(__file__).parent / "fixtures" / "sample_transcript.json"
        data = json.loads(sample.read_text())
        for idx, seg in enumerate(data["segments"]):
            session.add(TranscriptSegment(
                source_video_id=video.id,
                start_time=float(seg["start"]),
                end_time=float(seg["end"]),
                text=str(seg["text"]),
                segment_index=idx,
            ))

        session.commit()

        result = {
            "video_id": str(video.id),
            "creator_id": str(creator.id),
            "segment_count": len(data["segments"]),
        }
    finally:
        session.close()

    return result


# ── Auth fixtures ────────────────────────────────────────────────────────────

_TEST_INVITE_CODE = "TEST-INVITE-2026"
_TEST_EMAIL = "testuser@chrysopedia.com"
_TEST_PASSWORD = "securepass123"


@pytest_asyncio.fixture()
async def invite_code(db_engine):
    """Create a test invite code in the DB and return the code string."""
    factory = async_sessionmaker(db_engine, class_=AsyncSession, expire_on_commit=False)
    async with factory() as session:
        code = InviteCode(code=_TEST_INVITE_CODE, uses_remaining=10)
        session.add(code)
        await session.commit()
    return _TEST_INVITE_CODE


@pytest_asyncio.fixture()
async def registered_user(client, invite_code):
    """Register a user via the API and return the response dict."""
    resp = await client.post("/api/v1/auth/register", json={
        "email": _TEST_EMAIL,
        "password": _TEST_PASSWORD,
        "display_name": "Test User",
        "invite_code": invite_code,
    })
    assert resp.status_code == 201
    return resp.json()


@pytest_asyncio.fixture()
async def auth_headers(client, registered_user):
    """Log in and return Authorization headers dict."""
    resp = await client.post("/api/v1/auth/login", json={
        "email": _TEST_EMAIL,
        "password": _TEST_PASSWORD,
    })
    assert resp.status_code == 200
    token = resp.json()["access_token"]
    return {"Authorization": f"Bearer {token}"}