import pytest
from httpx import ASGITransport, AsyncClient
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
from sqlalchemy.orm import sessionmaker

from app.db import get_db
from app.main import app
from app.models import Base, PMUser, Project, Task
from app.security import create_token, hash_password


@pytest.fixture
def anyio_backend():
    return "asyncio"


@pytest.mark.asyncio
async def test_gantt_and_relations_api():
    engine = create_async_engine("sqlite+aiosqlite:///:memory:", echo=False)
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)

    async_session = sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)

    async with async_session() as session:
        admin = PMUser(
            username="admin",
            password_hash=hash_password("admin123"),
            display_name="مدیر ارشد",
            role="project_manager",
        )
        session.add(admin)
        await session.flush()

        project = Project(name="پروژه تست گانت", description="تست")
        session.add(project)
        await session.flush()

        task1 = Task(project_id=project.id, title="فونداسیون", duration=5)
        task2 = Task(project_id=project.id, title="اسکلت بتنی", duration=10)
        session.add_all([task1, task2])
        await session.commit()

        admin_id = admin.id
        p_id = str(project.id)
        t1_id = str(task1.id)
        t2_id = str(task2.id)

    token = create_token(admin_id)
    headers = {"Authorization": f"Bearer {token}"}

    async def override_get_db():
        async with async_session() as session:
            yield session

    app.dependency_overrides[get_db] = override_get_db

    try:
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://test", headers=headers) as client:
            # 1. Add relation: task1 -> task2 (FS + 2 days lag)
            rel_res = await client.post(
                f"/api/v1/projects/{p_id}/relations",
                json={"from_task_id": t1_id, "to_task_id": t2_id, "relation_type": "FS", "lag_days": 2},
            )
            assert rel_res.status_code == 200
            rel_data = rel_res.json()["data"]
            assert rel_data["relation_type"] == "FS"
            assert rel_data["lag_days"] == 2
            rel_id = rel_data["id"]

            # 2. Add reverse relation: task2 -> task1 (should detect cycle and reject with 400)
            cycle_res = await client.post(
                f"/api/v1/projects/{p_id}/relations",
                json={"from_task_id": t2_id, "to_task_id": t1_id, "relation_type": "FS"},
            )
            assert cycle_res.status_code == 400
            assert "چرخه" in cycle_res.json()["error"]["message"]

            # 3. Query Gantt dataset
            gantt_res = await client.get(f"/api/v1/projects/{p_id}/gantt")
            assert gantt_res.status_code == 200
            gantt_data = gantt_res.json()["data"]
            assert len(gantt_data["tasks"]) == 2
            assert len(gantt_data["relations"]) == 1
            assert len(gantt_data["critical_path"]) >= 1

            # 4. Delete relation
            del_rel = await client.delete(f"/api/v1/projects/{p_id}/relations/{rel_id}")
            assert del_rel.status_code == 200
            assert del_rel.json()["data"]["deleted"] is True
    finally:
        app.dependency_overrides.clear()
        await engine.dispose()