"""
FastAPI application with integrated FileWatcher for document processing.

This module provides the main FastAPI application with:
- JWT authentication
- User management APIs
- Real-time file monitoring via FileWatcher
- Document processing via Celery tasks
"""

import logging
from contextlib import asynccontextmanager
from typing import AsyncGenerator

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

from app.api.routes.auth import router as auth_router
from app.api.routes.users import router as users_router
from app.config import settings
from app.database.connection import get_database
from app.file_watcher import create_file_watcher, FileWatcher
from app.services.document_service import DocumentService
from app.services.init_service import InitializationService
from app.services.job_service import JobService
from app.services.user_service import UserService

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# Global file watcher instance
file_watcher: FileWatcher = None


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
  """
  FastAPI lifespan context manager.
  
  Handles application startup and shutdown events including:
  - Database connection
  - Default admin user creation
  - FileWatcher startup/shutdown
  """
  global file_watcher
  
  # Startup
  logger.info("Starting MyDocManager application...")
  
  try:
    # Initialize database connection
    database = get_database()
    logger.info("Database connection established")
    
    document_service = DocumentService(database=database, objects_folder=settings.get_objects_folder())
    job_service = JobService(database=database)
    user_service = UserService(database=database)
    logger.info("Service created")
    
    # Create default admin user
    init_service = InitializationService(user_service)
    init_service.initialize_application()
    logger.info("Default admin user initialization completed")
    
    # Create and start file watcher
    file_watcher = create_file_watcher(
      watch_directory=settings.get_watch_folder(),
      document_service=document_service,
      job_service=job_service
    )
    file_watcher.start()
    logger.info(f"FileWatcher started for directory: {settings.get_watch_folder()}")
    
    logger.info("Application startup completed successfully")
    
    yield
  
  except Exception as e:
    logger.error(f"Application startup failed: {str(e)}")
    raise
  
  finally:
    # Shutdown
    logger.info("Shutting down MyDocManager application...")
    
    if file_watcher and file_watcher.is_running():
      file_watcher.stop()
      logger.info("FileWatcher stopped")
    
    logger.info("Application shutdown completed")


# Create FastAPI application
app = FastAPI(
  title="MyDocManager",
  description="Real-time document processing application with authentication",
  version="0.1.0",
  lifespan=lifespan
)

# Configure CORS
app.add_middleware(
  CORSMiddleware,
  allow_origins=["http://localhost:5173", "http://localhost:5174"],  # React frontend
  allow_credentials=True,
  allow_methods=["*"],
  allow_headers=["*"],
)

# Include routers
app.include_router(auth_router, prefix="/auth", tags=["Authentication"])
app.include_router(users_router, prefix="/users", tags=["User Management"])
# app.include_router(documents_router, prefix="/documents", tags=["Documents"])
# app.include_router(jobs_router, prefix="/jobs", tags=["Processing Jobs"])


@app.get("/health")
async def health_check():
  """
  Health check endpoint.
  
  Returns:
      Dictionary containing application health status
  """
  return {
      "status": "healthy",
      "service": "MyDocManager",
      "version": "1.0.0",
      "file_watcher_running": file_watcher.is_running() if file_watcher else False
  }


@app.get("/")
async def root():
  """
  Root endpoint with basic application information.
  
  Returns:
      Dictionary containing welcome message and available endpoints
  """
  return {
      "message": "Welcome to MyDocManager",
      "description": "Real-time document processing application",
      "docs": "/docs",
      "health": "/health"
  }


@app.get("/watcher/status")
async def watcher_status():
  """
  Get file watcher status.
  
  Returns:
      Dictionary containing file watcher status information
  """
  if not file_watcher:
    return {
        "status": "not_initialized",
        "running": False
    }
  
  return {
      "status": "initialized",
      "running": file_watcher.is_running(),
      "watch_directory": str(file_watcher.watch_directory),
      "recursive": file_watcher.recursive
  }