from contextlib import asynccontextmanager

from fastapi import FastAPI, WebSocket, WebSocketDisconnect
from fastapi.middleware.cors import CORSMiddleware
from sqlalchemy import text
from sqlalchemy.exc import OperationalError

from app.config import get_settings
from app.database import engine
from app.models import Base
from app.routers import auth, users, children, subjects, schedules, sessions, logs, dashboard
from app.routers import morning_routine, break_activity
from app.websocket.manager import manager

settings = get_settings()


async def _add_column_if_missing(conn, table: str, column: str, definition: str):
    """Add a column to a table, silently ignoring if it already exists (MySQL 1060)."""
    try:
        await conn.execute(text(f"ALTER TABLE {table} ADD COLUMN {column} {definition}"))
    except OperationalError as e:
        if e.orig.args[0] != 1060:  # 1060 = Duplicate column name
            raise


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Create tables on startup (Alembic handles migrations in prod, this is a safety net)
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)
        # Idempotent column additions for schema migrations
        await _add_column_if_missing(conn, "schedule_blocks", "duration_minutes", "INT NULL")
        await _add_column_if_missing(conn, "schedule_blocks", "break_time_enabled", "TINYINT(1) NOT NULL DEFAULT 0")
        await _add_column_if_missing(conn, "schedule_blocks", "break_time_minutes", "INT NULL")
        await _add_column_if_missing(conn, "children", "strikes", "INT NOT NULL DEFAULT 0")
        await _add_column_if_missing(conn, "users", "timezone", "VARCHAR(64) NOT NULL DEFAULT 'UTC'")
    yield


app = FastAPI(
    title="Homeschool API",
    version="1.0.0",
    docs_url="/api/docs",
    redoc_url="/api/redoc",
    openapi_url="/api/openapi.json",
    lifespan=lifespan,
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.cors_origins_list,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Routers
app.include_router(auth.router)
app.include_router(users.router)
app.include_router(children.router)
app.include_router(subjects.router)
app.include_router(schedules.router)
app.include_router(sessions.router)
app.include_router(logs.router)
app.include_router(morning_routine.router)
app.include_router(break_activity.router)
app.include_router(dashboard.router)


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


@app.websocket("/ws/{child_id}")
async def websocket_endpoint(websocket: WebSocket, child_id: int):
    await manager.connect(websocket, child_id)
    try:
        while True:
            # Keep connection alive; TV clients are receive-only
            await websocket.receive_text()
    except WebSocketDisconnect:
        manager.disconnect(websocket, child_id)