import sys
import subprocess
import importlib.metadata
import os

def check_dependencies():
    """Checks if dependencies in requirements.txt are installed."""
    requirements_file = "requirements.txt"
    if not os.path.exists(requirements_file):
        print(f"Warning: {requirements_file} not found. Skipping dependency check.")
        return

    print("Checking dependencies...")
    missing_packages = []
    
    with open(requirements_file, "r") as f:
        for line in f:
            line = line.strip()
            if not line or line.startswith("#"):
                continue
            
            # Simple parsing for package name. 
            # This handles 'package>=version', 'package==version', 'package'
            # It does NOT handle complex markers perfectly, but suffices for basic checking.
            package_name = line.split("=")[0].split(">")[0].split("<")[0].strip()
            
            try:
                importlib.metadata.version(package_name)
            except importlib.metadata.PackageNotFoundError:
                missing_packages.append(line)

    if missing_packages:
        print(f"Missing dependencies: {', '.join(missing_packages)}")
        print("Installing missing dependencies...")
        try:
            subprocess.check_call([sys.executable, "-m", "pip", "install", "-r", requirements_file])
            print("Dependencies installed successfully.")
        except subprocess.CalledProcessError as e:
            print(f"Error installing dependencies: {e}")
            sys.exit(1)
    else:
        print("All dependencies checked.")

def main():
    check_dependencies()
    
    print("Starting application...")
    try:
        # Run the main application
        # Using sys.executable ensures we use the same python interpreter
        subprocess.run([sys.executable, "main.py"], check=True)
    except subprocess.CalledProcessError as e:
        print(f"Application exited with error: {e}")
        sys.exit(e.returncode)
    except KeyboardInterrupt:
        print("\nApplication stopped by user.")
    except Exception as e:
        print(f"An unexpected error occurred: {e}")
        sys.exit(1)

if __name__ == "__main__":
    main()