"""
Pytest configuration and fixtures for integration tests.

Provides test database setup, client fixtures, and authentication helpers.
"""

import os
import asyncio
from typing import AsyncGenerator
import pytest
import sqlalchemy as sa
from httpx import AsyncClient, ASGITransport
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
from sqlalchemy.pool import NullPool

from app.main import app
from app.core.database import Base, get_db
from app.core.admin_database import get_admin_db
from app.core.config import settings
# Import every model module so all tables are registered with Base.metadata
# before the test_db fixture calls create_all. app.main imports models lazily
# (inside scheduler functions and route modules), which is fine at runtime
# but leaves the metadata incomplete at fixture-setup time — surfacing as
# "relation X does not exist" errors for any model whose route/scheduler
# hasn't been loaded yet. The `from app import models` form avoids
# shadowing the `app` FastAPI instance imported just above.
from app import models as _models  # noqa: F401

# Disable invite code requirement for tests
settings.REQUIRE_INVITE_CODE = False

# Test database URL — NEVER reuse DATABASE_URL. The test_db fixture does
# `DROP SCHEMA public CASCADE` on every test; if DATABASE_URL (which normally
# points at the dev/prod DB) leaked into this value, running `pytest tests/`
# would silently nuke the dev database. Only DATABASE_TEST_URL is honored,
# and the safety assertion below refuses to run against a DB whose name
# doesn't contain "test".
_BASE_TEST_DATABASE_URL = os.environ.get(
    "DATABASE_TEST_URL",
    "postgresql+asyncpg://postgres:postgres@localhost:5432/resolutionflow_test",
)


def _worker_db_url(base_url: str) -> str:
    """Per-worker DB URL for pytest-xdist parallelization.

    pytest-xdist sets PYTEST_XDIST_WORKER to 'gw0', 'gw1', ... per worker
    process. Each worker needs its own database so the per-test
    `DROP SCHEMA public CASCADE` doesn't race across workers. Master/serial
    runs (no xdist) keep the base DB. The base DB is created by the postgres
    service container; per-worker DBs are CREATE DATABASE-d on first import
    by `_ensure_worker_db_exists` below.
    """
    worker = os.environ.get("PYTEST_XDIST_WORKER")
    if not worker or worker == "master":
        return base_url
    head, tail = base_url.rsplit("/", 1)
    db_name, _, query = tail.partition("?")
    suffix = f"?{query}" if query else ""
    return f"{head}/{db_name}_{worker}{suffix}"


def _ensure_worker_db_exists(worker_url: str, base_url: str) -> None:
    """Create the per-worker DB if it doesn't exist. Runs synchronously at
    conftest import time (before any async test machinery), using psycopg2
    against the postgres maintenance DB. No-op when not running under xdist.
    """
    if worker_url == base_url:
        return
    head, tail = worker_url.rsplit("/", 1)
    worker_db = tail.partition("?")[0]
    # Strip the +asyncpg dialect for sync psycopg2 + connect to 'postgres'.
    sync_head = head.replace("+asyncpg", "")
    admin_url = f"{sync_head}/postgres"
    # Lazy import — psycopg2 is a transitive backend dep; not imported at
    # module top to keep the conftest light when xdist isn't in use.
    from sqlalchemy import create_engine
    engine = create_engine(admin_url, isolation_level="AUTOCOMMIT")
    try:
        with engine.begin() as conn:
            exists = conn.execute(
                sa.text("SELECT 1 FROM pg_database WHERE datname = :n"),
                {"n": worker_db},
            ).scalar()
            if not exists:
                # Identifier interpolation is safe — worker_db is built from
                # the trusted base URL + 'gw\d+' worker suffix.
                conn.execute(sa.text(f'CREATE DATABASE "{worker_db}"'))
    finally:
        engine.dispose()


TEST_DATABASE_URL = _worker_db_url(_BASE_TEST_DATABASE_URL)
_ensure_worker_db_exists(TEST_DATABASE_URL, _BASE_TEST_DATABASE_URL)

# Belt-and-suspenders: refuse to run tests against a DB whose name doesn't
# contain "test". Parses the last path segment of the URL (everything after
# the final '/', with query string stripped) so credentials / hosts that
# happen to contain "test" can't bypass the check.
_test_db_name = TEST_DATABASE_URL.rsplit("/", 1)[-1].split("?", 1)[0].lower()
assert "test" in _test_db_name, (
    f"Refusing to run tests against database {_test_db_name!r} — "
    f"the DB name must contain 'test'. Set DATABASE_TEST_URL to a dedicated "
    f"test database (e.g. resolutionflow_test)."
)

_RUN_RLS_TESTS = os.environ.get("RUN_RLS_TESTS") == "1"
_RLS_ISOLATION_FILE = "test_rls_isolation.py"


def pytest_collection_modifyitems(config, items):
    """Keep migration-managed RLS checks out of the default create_all suite."""
    if _RUN_RLS_TESTS:
        return

    selected = []
    deselected = []
    for item in items:
        item_path = getattr(item, "path", None) or getattr(item, "fspath", None)
        if item_path and str(item_path).endswith(_RLS_ISOLATION_FILE):
            deselected.append(item)
        else:
            selected.append(item)

    if deselected:
        config.hook.pytest_deselected(items=deselected)
        items[:] = selected


@pytest.hookimpl(trylast=True, hookwrapper=True)
def pytest_runtest_teardown(item, nextitem):
    """Close pytest-asyncio's post-test clean loop before warnings collect it."""
    yield
    policy = asyncio.get_event_loop_policy()
    try:
        loop = policy.get_event_loop()
    except RuntimeError:
        return
    if not loop.is_running() and not loop.is_closed():
        loop.close()
        policy.set_event_loop(None)


@pytest.fixture
async def test_db() -> AsyncGenerator[AsyncSession, None]:
    """
    Create a fresh database for each test function.

    This fixture:
    1. Creates a test database engine
    2. Drops all existing tables (CASCADE to handle circular FKs)
    3. Creates all tables
    4. Yields a session for the test
    5. Drops all tables after the test
    """
    # Create async engine for tests (with NullPool to avoid connection reuse issues)
    engine = create_async_engine(
        TEST_DATABASE_URL,
        poolclass=NullPool,
        echo=False
    )

    # Drop and recreate all tables (use raw SQL CASCADE to handle circular FKs
    # between users <-> invite_codes)
    async with engine.begin() as conn:
        await conn.execute(sa.text("DROP SCHEMA public CASCADE"))
        await conn.execute(sa.text("CREATE SCHEMA public"))
        await conn.run_sync(Base.metadata.create_all)

        # Seed plan_limits for subscription checks
        await conn.execute(sa.text("""
            INSERT INTO plan_limits (plan, max_trees, max_sessions_per_month, max_users, custom_branding, priority_support, export_formats)
            VALUES
                ('free', 3, 20, 1, false, false, '["markdown", "text"]'),
                ('starter', 10, 75, 1, false, false, '["markdown", "text", "html"]'),
                ('pro', 25, 200, 5, true, false, '["markdown", "text", "html"]'),
                ('enterprise', NULL, NULL, NULL, true, true, '["markdown", "text", "html"]')
        """))

        # Seed the platform/system account (PLATFORM_ACCOUNT_ID) needed by
        # global categories, gallery items, and other platform-owned content.
        await conn.execute(sa.text("""
            INSERT INTO accounts (id, name, display_code, created_at, updated_at)
            VALUES (
                '00000000-0000-0000-0000-000000000001',
                'ResolutionFlow System',
                'RF-SYS-1',
                NOW(), NOW()
            )
            ON CONFLICT (id) DO NOTHING
        """))

    # Create async session maker
    async_session_maker = async_sessionmaker(
        engine,
        class_=AsyncSession,
        expire_on_commit=False
    )

    # Provide session to test
    async with async_session_maker() as session:
        yield session
        # Ensure session is fully closed before teardown
        await session.close()

    # Dispose engine first so all pooled connections are released,
    # then reconnect to perform the schema teardown cleanly.
    await engine.dispose()
    await asyncio.sleep(0.01)

    # Drop all tables after test (CASCADE for circular FKs)
    teardown_engine = create_async_engine(
        TEST_DATABASE_URL,
        poolclass=NullPool,
        echo=False,
    )
    try:
        async with teardown_engine.begin() as conn:
            await conn.execute(sa.text("DROP SCHEMA public CASCADE"))
            await conn.execute(sa.text("CREATE SCHEMA public"))
    finally:
        await teardown_engine.dispose()
        await asyncio.sleep(0.01)


@pytest.fixture
async def client(test_db: AsyncSession):
    """
    Create an async HTTP client for testing API endpoints.

    Overrides the database dependency to use the test database.
    """

    async def override_get_db():
        yield test_db

    app.dependency_overrides[get_db] = override_get_db
    # Endpoints that use get_admin_db (register, admin routes, service accounts)
    # must also hit the test DB; otherwise they leak into the real admin DB.
    # RLS is not enabled in the test schema (create_all, not alembic), so sharing
    # the same session is safe.
    app.dependency_overrides[get_admin_db] = override_get_db

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

    app.dependency_overrides.clear()


@pytest.fixture
async def test_user(client, test_db):
    """
    Create a test user and return their credentials.

    Also seeds a default active Pro Subscription so Pro-guarded routes work
    in tests. Phase 1 Task 11 added require_active_subscription; without
    this seed every existing test that hits a Pro router would 402. The
    register endpoint creates a default `free`/`active` Subscription, so
    we delete-then-insert to avoid the unique account_id constraint.

    Returns:
        dict with email, password, and user_data
    """
    import uuid
    from sqlalchemy import delete
    from app.models.subscription import Subscription

    user_data = {
        "email": "test@example.com",
        "password": "TestPassword123!",
        "name": "Test User"
    }

    response = await client.post("/api/v1/auth/register", json=user_data)
    assert response.status_code == 200 or response.status_code == 201

    account_id = uuid.UUID(response.json()["account_id"])
    await test_db.execute(
        delete(Subscription).where(Subscription.account_id == account_id)
    )
    test_db.add(Subscription(account_id=account_id, plan="pro", status="active"))
    await test_db.commit()

    return {
        "email": user_data["email"],
        "password": user_data["password"],
        "user_data": response.json()
    }


@pytest.fixture
async def auth_headers(client, test_user):
    """
    Get authentication headers for an authenticated test user.

    Returns:
        dict with Authorization header
    """
    login_data = {
        "email": test_user["email"],
        "password": test_user["password"]
    }

    response = await client.post("/api/v1/auth/login/json", json=login_data)
    assert response.status_code == 200

    token_data = response.json()
    return {"Authorization": f"Bearer {token_data['access_token']}"}


@pytest.fixture
async def test_tree(client, auth_headers):
    """
    Create a test decision tree.

    Returns:
        dict with tree data
    """
    tree_data = {
        "name": "Test Troubleshooting Tree",
        "description": "A test tree for integration tests",
        "category": "Testing",
        "tree_structure": {
            "id": "root",
            "type": "decision",
            "question": "Is this a test?",
            "options": [
                {"id": "yes", "label": "Yes", "next_node_id": "solution1"},
                {"id": "no", "label": "No", "next_node_id": "solution2"}
            ],
            "children": [
                {
                    "id": "solution1",
                    "type": "solution",
                    "title": "Test Confirmed",
                    "description": "This is a test tree",
                    "solution": "Test confirmed - this is a test tree"
                },
                {
                    "id": "solution2",
                    "type": "solution",
                    "title": "Not a Test",
                    "description": "This should not happen",
                    "solution": "Not a test - this should not happen"
                }
            ]
        }
    }

    response = await client.post(
        "/api/v1/trees",
        json=tree_data,
        headers=auth_headers
    )
    assert response.status_code == 201

    return response.json()


@pytest.fixture
async def test_admin(client, test_db):
    """
    Create a test super-admin user.

    Registers as engineer (the only role available at registration),
    then promotes to super_admin directly via the DB session. Also
    seeds a default active Pro Subscription (see test_user docstring).
    """
    import uuid
    from uuid import UUID as PyUUID
    from sqlalchemy import select, delete
    from app.models.user import User
    from app.models.subscription import Subscription

    admin_data = {
        "email": "admin@example.com",
        "password": "AdminPassword123!",
        "name": "Test Admin"
    }

    response = await client.post("/api/v1/auth/register", json=admin_data)
    assert response.status_code == 200 or response.status_code == 201

    user_id = PyUUID(response.json()["id"])
    result = await test_db.execute(select(User).where(User.id == user_id))
    user = result.scalar_one()
    user.is_super_admin = True

    account_id = uuid.UUID(response.json()["account_id"])
    await test_db.execute(
        delete(Subscription).where(Subscription.account_id == account_id)
    )
    test_db.add(Subscription(account_id=account_id, plan="pro", status="active"))
    await test_db.commit()

    return {
        "email": admin_data["email"],
        "password": admin_data["password"],
        "user_data": response.json()
    }


@pytest.fixture
async def admin_auth_headers(client, test_admin):
    """
    Get authentication headers for an authenticated admin user.

    Returns:
        dict with Authorization header
    """
    login_data = {
        "email": test_admin["email"],
        "password": test_admin["password"]
    }

    response = await client.post("/api/v1/auth/login/json", json=login_data)
    assert response.status_code == 200

    token_data = response.json()
    return {"Authorization": f"Bearer {token_data['access_token']}"}