"""
IRT Bank Soal - Adaptive Question Bank System

Main FastAPI application entry point.

Features:
- CTT (Classical Test Theory) scoring with exact Excel formulas
- IRT (Item Response Theory) support for adaptive testing
- Multi-website support for WordPress integration
- AI-powered question generation
"""

from contextlib import asynccontextmanager
from typing import AsyncGenerator

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from app.admin import admin as admin_app
from app.core.config import get_settings
from app.database import close_db, init_db
from app.routers import (
    admin_router,
    ai_router,
    import_export_router,
    reports_router,
    sessions_router,
    tryouts_router,
    wordpress_router,
)

settings = get_settings()


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
    """
    Application lifespan manager.
    
    Handles startup and shutdown events.
    """
    # Startup: Initialize database
    await init_db()
    
    yield
    
    # Shutdown: Close database connections
    await close_db()


# Initialize FastAPI application
app = FastAPI(
    title="IRT Bank Soal",
    description="""
## Adaptive Question Bank System with IRT/CTT Scoring

This API provides a comprehensive backend for adaptive assessment systems.

### Features
- **CTT Scoring**: Classical Test Theory with exact Excel formula compatibility
- **IRT Support**: Item Response Theory for adaptive testing (1PL Rasch model)
- **Multi-Site**: Single backend serving multiple WordPress sites
- **AI Generation**: Automatic question variant generation

### Scoring Formulas (PRD Section 13.1)
- **CTT p-value**: `p = Σ Benar / Total Peserta`
- **CTT Bobot**: `Bobot = 1 - p`
- **CTT NM**: `NM = (Total_Bobot_Siswa / Total_Bobot_Max) × 1000`
- **CTT NN**: `NN = 500 + 100 × ((NM - Rataan) / SB)`

### Authentication
Most endpoints require `X-Website-ID` header for multi-site isolation.
    """,
    version="1.0.0",
    docs_url="/docs",
    redoc_url="/redoc",
    openapi_url="/openapi.json",
    lifespan=lifespan,
)

# Configure CORS middleware
# Parse ALLOWED_ORIGINS from settings (comma-separated string)
allowed_origins = settings.ALLOWED_ORIGINS
if isinstance(allowed_origins, str):
    allowed_origins = [origin.strip() for origin in allowed_origins.split(",") if origin.strip()]

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


# Health check endpoint
@app.get(
    "/",
    summary="Health check",
    description="Returns API status and version information.",
    tags=["health"],
)
async def root():
    """
    Health check endpoint.
    
    Returns basic API information for monitoring and load balancer checks.
    """
    return {
        "status": "healthy",
        "service": "IRT Bank Soal",
        "version": "1.0.0",
        "docs": "/docs",
    }


@app.get(
    "/health",
    summary="Detailed health check",
    description="Returns detailed health status including database connectivity.",
    tags=["health"],
)
async def health_check():
    """
    Detailed health check endpoint.
    
    Includes database connectivity verification.
    """
    from app.database import engine
    from sqlalchemy import text
    
    db_status = "unknown"
    try:
        async with engine.connect() as conn:
            await conn.execute(text("SELECT 1"))
        db_status = "connected"
    except Exception as e:
        db_status = f"error: {str(e)}"
    
    return {
        "status": "healthy" if db_status == "connected" else "degraded",
        "service": "IRT Bank Soal",
        "version": "1.0.0",
        "database": db_status,
        "environment": settings.ENVIRONMENT,
    }


# Include API routers with version prefix
app.include_router(
    import_export_router,
)
app.include_router(
    sessions_router,
    prefix=f"{settings.API_V1_STR}",
)
app.include_router(
    tryouts_router,
    prefix=f"{settings.API_V1_STR}",
)
app.include_router(
    wordpress_router,
    prefix=f"{settings.API_V1_STR}",
)
app.include_router(
    ai_router,
    prefix=f"{settings.API_V1_STR}",
)
app.include_router(
    reports_router,
    prefix=f"{settings.API_V1_STR}",
)


# Mount FastAPI Admin panel
app.mount("/admin", admin_app)


# Include admin API router for custom actions
app.include_router(
    admin_router,
    prefix=f"{settings.API_V1_STR}",
)


# Placeholder routers for future implementation
# These will be implemented in subsequent phases

# app.include_router(
#     items_router,
#     prefix=f"{settings.API_V1_STR}",
#     tags=["items"],
# )


if __name__ == "__main__":
    import uvicorn
    
    uvicorn.run(
        "app.main:app",
        host="0.0.0.0",
        port=8000,
        reload=settings.ENVIRONMENT == "development",
    )