#!/usr/bin/env python3
"""Simple JSON validator CLI - validates JSON files and reports errors."""

import json
import sys
from pathlib import Path


def validate_json_file(filepath: str) -> tuple[bool, str]:
    """Validate a JSON file.
    
    Returns:
        (True, "") if valid
        (False, error_message) if invalid
    """
    try:
        with open(filepath, 'r') as f:
            json.load(f)
        return True, ""
    except FileNotFoundError:
        return False, f"Error: File not found: {filepath}"
    except json.JSONDecodeError as e:
        return False, f"Error: Invalid JSON at line {e.lineno}, column {e.colno}: {e.msg}"
    except Exception as e:
        return False, f"Error reading file: {e}"


def main():
    if len(sys.argv) < 2:
        print("Usage: json_validator.py <file1.json> [file2.json] ...", file=sys.stderr)
        sys.exit(1)
    
    files = sys.argv[1:]
    all_valid = True
    results = []
    
    for filepath in files:
        valid, error = validate_json_file(filepath)
        if valid:
            results.append(f"✓ VALID: {filepath}")
        else:
            results.append(f"✗ INVALID: {filepath} - {error}")
            all_valid = False
    
    for r in results:
        print(r)
    
    sys.exit(0 if all_valid else 1)


if __name__ == "__main__":
    main()