from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager
from sqlalchemy import text
import asyncio

from app.core.database import engine, AsyncSessionLocal, Base
from app.core.config import settings
from app.api import auth, activities, routes, health, records, upload


async def init_db():
    """Create tables then seed admin, with retries for slow DB startup."""
    for attempt in range(10):
        try:
            # Step 1: create all tables (separate connection so it commits cleanly)
            async with engine.begin() as conn:
                await conn.run_sync(Base.metadata.create_all)
            break
        except Exception as e:
            if attempt == 9:
                raise
            print(f"DB not ready yet (attempt {attempt + 1}/10): {e}")
            await asyncio.sleep(3)

    # Step 2: try to enable TimescaleDB hypertable (separate connection,
    # failure here is non-fatal - falls back to plain Postgres)
    try:
        async with engine.begin() as conn:
            await conn.execute(text(
                "SELECT create_hypertable('activity_data_points', 'timestamp', "
                "if_not_exists => TRUE, migrate_data => TRUE)"
            ))
    except Exception as e:
        print(f"TimescaleDB hypertable skipped: {e}")

    # Step 3: seed admin user
    from sqlalchemy import select
    from app.models.user import User
    from app.core.security import hash_password

    async with AsyncSessionLocal() as db:
        result = await db.execute(
            select(User).where(User.username == settings.admin_username)
        )
        if not result.scalar_one_or_none():
            admin = User(
                username=settings.admin_username,
                hashed_password=hash_password(settings.admin_password),
                is_admin=True,
            )
            db.add(admin)
            await db.commit()
            print(f"Admin user '{settings.admin_username}' created")


@asynccontextmanager
async def lifespan(app: FastAPI):
    await init_db()
    yield


app = FastAPI(
    title="MileVault",
    version="1.0.0",
    lifespan=lifespan,
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"] if settings.environment == "development" else [],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

app.include_router(auth.router, prefix="/api/auth", tags=["auth"])
app.include_router(activities.router, prefix="/api/activities", tags=["activities"])
app.include_router(routes.router, prefix="/api/routes", tags=["routes"])
app.include_router(health.router, prefix="/api/health-metrics", tags=["health"])
app.include_router(records.router, prefix="/api/records", tags=["records"])
app.include_router(upload.router, prefix="/api/upload", tags=["upload"])


@app.get("/health")
async def healthcheck():
    return {"status": "ok"}