"""Disposable real infrastructure for integration and e2e tests (ADR-0016).

Registered as a plugin from the root `tests/conftest.py` rather than living in
a per-boundary conftest, because `tests/e2e/` needs the same Postgres, MinIO,
and Qdrant containers that `tests/integration/*/` does, and `pytest_plugins`
is only honoured in the root conftest.

Nothing here is autouse: the container fixtures are session-scoped but lazy,
so `pytest -m unit` still runs without Docker.
"""

import uuid
from collections.abc import AsyncIterator, Iterator

import pytest
import pytest_asyncio
from alembic.command import upgrade
from alembic.config import Config
from qdrant_client import AsyncQdrantClient
from sqlalchemy.ext.asyncio import AsyncEngine, AsyncSession, async_sessionmaker
from testcontainers.community.minio import MinioContainer
from testcontainers.community.postgres import PostgresContainer
from testcontainers.community.qdrant import QdrantContainer

from src.config import MinioSettings, PostgresSettings, QdrantSettings
from src.infrastructure.minio.client import create_client as create_minio_client
from src.infrastructure.postgres.database import create_engine
from src.infrastructure.qdrant.client import create_client as create_qdrant_client

_MINIO_BUCKET = "test-source-files"

# Pinned to match the `qdrant-client` major/minor in pyproject.toml. The
# testcontainers default image trails it far enough that the client emits an
# incompatibility warning, and testing against a version we do not deploy is
# the wrong signal anyway.
_QDRANT_IMAGE = "qdrant/qdrant:v1.19.0"


# --- Postgres ---------------------------------------------------------------


def _alembic_config(database_url: str) -> Config:
    config = Config("alembic.ini")
    config.set_main_option("sqlalchemy.url", database_url)
    return config


def _postgres_settings_from_url(url: str) -> PostgresSettings:
    # testcontainers returns postgresql+asyncpg://user:pass@host:port/db ;
    # PostgresSettings builds its own dsn from parts, so parse the parts back out.
    without_scheme = url.split("://", 1)[1]
    creds, hostpart = without_scheme.split("@", 1)
    user, password = creds.split(":", 1)
    hostport, db = hostpart.split("/", 1)
    host, port = hostport.split(":", 1)
    return PostgresSettings(host=host, port=int(port), user=user, password=password, db=db)


@pytest.fixture(scope="session")
def postgres_container() -> Iterator[PostgresContainer]:
    with PostgresContainer("postgres:17", driver="asyncpg") as container:
        yield container


@pytest.fixture(scope="session")
def postgres_url(postgres_container: PostgresContainer) -> str:
    """The container's URL, pinned to IPv4.

    Testcontainers reports the host as `localhost`, which resolves to `::1`
    before `127.0.0.1`. Docker publishes the mapped port on IPv4 only, and the
    IPv6 SYN is dropped rather than refused, so asyncpg blocks on the first
    address until its connect timeout instead of falling back to the second --
    the connection does not fail, it hangs.
    """
    return postgres_container.get_connection_url().replace("@localhost:", "@127.0.0.1:")


@pytest.fixture(scope="session")
def migrated_postgres_url(postgres_url: str) -> str:
    """The container's URL, after Alembic has created the schema on it once."""
    upgrade(_alembic_config(postgres_url), "head")
    return postgres_url


@pytest.fixture(scope="session")
def postgres_settings(migrated_postgres_url: str) -> PostgresSettings:
    """Settings an application component can be constructed from directly."""
    return _postgres_settings_from_url(migrated_postgres_url)


@pytest_asyncio.fixture(scope="session", loop_scope="session")
async def postgres_engine(postgres_settings: PostgresSettings) -> AsyncIterator[AsyncEngine]:
    engine = create_engine(postgres_settings)
    try:
        yield engine
    finally:
        await engine.dispose()


@pytest_asyncio.fixture(loop_scope="session")
async def db_sessionmaker(
    postgres_engine: AsyncEngine,
) -> AsyncIterator[async_sessionmaker[AsyncSession]]:
    """A session *factory* per test, bound to a rolled-back outer transaction.

    Every session it produces shares one connection/outer transaction, so
    writes `commit()`ed by one session are visible to the next -- needed for
    code under test that opens more than one session per operation (auth
    resolution, the ADR-0017 two-phase upload) -- while the whole test's
    writes still roll back together at teardown (ADR-0016: isolate data per
    test).
    """
    async with postgres_engine.connect() as connection:
        outer_transaction = await connection.begin()
        sessionmaker = async_sessionmaker(
            bind=connection, expire_on_commit=False, join_transaction_mode="create_savepoint"
        )
        yield sessionmaker
        await outer_transaction.rollback()


@pytest_asyncio.fixture(loop_scope="session")
async def db_session(
    db_sessionmaker: async_sessionmaker[AsyncSession],
) -> AsyncIterator[AsyncSession]:
    """One session per test, bound to a rolled-back outer transaction.

    Isolates each test's writes (ADR-0016: isolate data per test) without
    needing a fresh container or unique keys per test.
    """
    async with db_sessionmaker() as session:
        yield session


# --- MinIO ------------------------------------------------------------------


@pytest.fixture(scope="session")
def minio_container() -> Iterator[MinioContainer]:
    with MinioContainer() as container:
        yield container


@pytest.fixture(scope="session")
def minio_settings(minio_container: MinioContainer) -> MinioSettings:
    """Settings for the container, with the bucket already created.

    Bucket creation belongs here rather than in a separate autouse fixture:
    autouse in a *globally registered* plugin would pull a MinIO container
    into every unit test run.
    """
    config = minio_container.get_config()
    # Pinned to IPv4 for the same reason as postgres_url above: `localhost`
    # resolves to `::1` first, but Docker only publishes the mapped port on
    # IPv4, so the connection hangs instead of failing.
    endpoint = config["endpoint"].replace("localhost:", "127.0.0.1:")
    settings = MinioSettings(
        endpoint=endpoint,
        access_key=config["access_key"],
        secret_key=config["secret_key"],
        secure=False,
        bucket=_MINIO_BUCKET,
    )
    client = create_minio_client(settings)
    if not client.bucket_exists(settings.bucket):
        client.make_bucket(settings.bucket)
    return settings


# --- Qdrant -----------------------------------------------------------------


@pytest.fixture(scope="session")
def qdrant_container() -> Iterator[QdrantContainer]:
    with QdrantContainer(image=_QDRANT_IMAGE) as container:
        yield container


@pytest.fixture(scope="session")
def qdrant_url(qdrant_container: QdrantContainer) -> str:
    """The container's REST URL, pinned to IPv4.

    Same gotcha as postgres_url/minio_settings above: testcontainers reports
    the host as `localhost`, which resolves to `::1` first, but Docker
    publishes the mapped port on IPv4 only. The IPv6 SYN is dropped rather
    than refused, so the client hangs until its timeout instead of falling
    back to the second address -- the connection does not fail, it hangs.
    """
    host = qdrant_container.get_container_host_ip().replace("localhost", "127.0.0.1")
    return f"http://{host}:{qdrant_container.get_exposed_port(6333)}"


@pytest.fixture
def qdrant_settings(qdrant_url: str) -> QdrantSettings:
    """Settings naming a collection unique to this test (ADR-0016 isolation)."""
    return QdrantSettings(url=qdrant_url, collection=f"chunks_{uuid.uuid4().hex}")


@pytest_asyncio.fixture(loop_scope="session")
async def qdrant_client(qdrant_settings: QdrantSettings) -> AsyncIterator[AsyncQdrantClient]:
    client = create_qdrant_client(qdrant_settings)
    try:
        yield client
    finally:
        await client.close()