import os
import socket
import sys

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

from api.routers import auth_router, health_router, todo_router, user_router
from db.database import create_tables

app = FastAPI(
    title="SimpleTodoApp API",
    description="API for a simple todo application with authentication",
    version="0.1.0",
)

# CORS settings
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # For development, in production specify your frontend domain
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(auth_router.router, prefix="/api/auth", tags=["auth"])
app.include_router(user_router.router, prefix="/api/users", tags=["users"])
app.include_router(todo_router.router, prefix="/api/todos", tags=["todos"])
app.include_router(health_router.router, prefix="/api", tags=["health"])

# Create database tables on startup
@app.on_event("startup")
async def startup():
    create_tables()

def is_port_in_use(port, host='0.0.0.0'):
    """Check if a port is in use."""
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        try:
            s.bind((host, port))
            return False
        except OSError:
            return True

if __name__ == "__main__":
    # Get port from environment variable or use default of 8000
    port = int(os.environ.get("PORT", 8000))
    host = os.environ.get("HOST", "0.0.0.0")

    # If the preferred port is in use, try to find an available port
    if is_port_in_use(port, host):
        print(f"Port {port} is already in use. Trying alternative ports...")
        for alt_port in [8001, 8002, 8003, 8004, 8005]:
            if not is_port_in_use(alt_port, host):
                port = alt_port
                print(f"Found available port: {port}")
                break
        else:
            print("No available ports found between 8000-8005. Exiting.")
            sys.exit(1)

    print(f"Starting server on {host}:{port}")
    uvicorn.run("main:app", host=host, port=port, reload=True)