from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
from contextlib import asynccontextmanager
from pathlib import Path
import sys

from .routes import classification_router, gestational_age_router, feedback_router
from .services.model import model_service

# Get assets directory - handle both development and PyInstaller frozen modes
def get_assets_dir() -> Path:
    """Get the assets directory, works in both development and frozen (PyInstaller) modes."""
    if getattr(sys, 'frozen', False):
        # Running as PyInstaller bundle - assets are in _MEIPASS/assets
        base_path = Path(sys._MEIPASS)
        assets = base_path / "assets"
        print(f"[Frozen Mode] Base path: {base_path}")
        print(f"[Frozen Mode] Assets path: {assets}")
        return assets
    else:
        # Development mode - assets are in project root
        assets = Path(__file__).parent.parent.parent / "assets"
        print(f"[Dev Mode] Assets path: {assets}")
        return assets

ASSETS_DIR = get_assets_dir()


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Load model on startup, cleanup on shutdown."""
    print("🚀 Starting FetalCLIP API...")
    model_service.load_model(ASSETS_DIR)
    yield
    print("👋 Shutting down FetalCLIP API...")


app = FastAPI(
    title="FetalCLIP API",
    description="""
    ## FetalCLIP - Foundation Model for Fetal Ultrasound Analysis
    
    This API provides two main capabilities:
    
    ### 1. Fetal View Classification
    Classify ultrasound images into 13 anatomical view categories using zero-shot learning.
    
    ### 2. Gestational Age Estimation
    Estimate gestational age from fetal brain ultrasounds with head circumference percentiles.
    
    ---
    
    Built with ❤️ using PyTorch and OpenCLIP
    """,
    version="1.0.0",
    lifespan=lifespan,
    docs_url="/docs",
    redoc_url="/redoc"
)

# CORS middleware for frontend
app.add_middleware(
    CORSMiddleware,
    allow_origins=["http://localhost:5173", "http://localhost:3000", "http://127.0.0.1:5173", "tauri://localhost"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(classification_router)
app.include_router(gestational_age_router)
app.include_router(feedback_router)


@app.get("/", tags=["Health"])
async def root():
    """API root - health check."""
    return JSONResponse(content={
        "name": "FetalCLIP API",
        "version": "1.0.0",
        "status": "healthy",
        "docs": "/docs"
    })


@app.get("/health", tags=["Health"])
async def health_check():
    """Detailed health check."""
    return JSONResponse(content={
        "status": "healthy",
        "model_loaded": model_service.model is not None,
        "device": str(model_service.device),
        "available_views": len(model_service.list_plane)
    })