#!/usr/bin/env python3
"""Quick Python environment validator.
Checks pip, site-packages accessibility, and common import paths.
"""

import sys
import os
import importlib.util

def check_pip():
    """Verify pip is accessible."""
    try:
        import pip
        return True, "pip available"
    except ImportError:
        try:
            import ensurepip
            return True, "pip can be bootstrapped via ensurepip"
        except ImportError:
            return False, "pip not available and cannot bootstrap"

def check_site_packages():
    """Check site-packages directory exists and is writable."""
    import site
    paths = site.getsitepackages()
    for p in paths:
        if os.path.isdir(p):
            writable = os.access(p, os.W_OK)
            return True, f"site-packages found at {p}, writable={writable}"
    return False, "no site-packages directory found"

def check_stdlib_imports():
    """Test critical stdlib modules."""
    modules = ['os', 'sys', 'json', 'urllib.request', 'pathlib', 'typing']
    failed = []
    for mod in modules:
        try:
            importlib.import_module(mod)
        except ImportError as e:
            failed.append((mod, str(e)))
    return len(failed) == 0, failed if failed else "all stdlib modules importable"

def main():
    print(f"Python environment check (py{sys.version_info.major}.{sys.version_info.minor})")
    print(f"Executable: {sys.executable}")
    print(f"Site-packages: {next((p for p in __import__('site').getsitepackages() if os.path.isdir(p)), 'none')}\n")
    
    checks = [
        ("pip", check_pip),
        ("site-packages", check_site_packages),
        ("stdlib imports", check_stdlib_imports),
    ]
    
    results = []
    for name, func in checks:
        passed, msg = func()
        results.append((name, passed, msg))
    
    all_passed = all(p for _, p, _ in results)
    
    for name, passed, msg in results:
        status = "PASS" if passed else "FAIL"
        print(f"[{status}] {name}: {msg}")
    
    print(f"\n{'All checks passed!' if all_passed else 'Some checks failed.'}")
    return 0 if all_passed else 1

if __name__ == '__main__':
    sys.exit(main())