#!/usr/bin/env python3
"""Quick JSON schema validator: validates a JSON file against a schema file.

Usage: python validate_json_schema.py <data.json> <schema.json>
Exit 0 if valid, 1 if invalid, 2 on error.

Example:
    echo '{"type":"object","properties":{"name":{"type":"string"}}}' > schema.json
    echo '{"name":"test"}' > data.json
    python validate_json_schema.py data.json schema.json  # exits 0
"""
import json
import sys
from jsonschema import validate, ValidationError, SchemaError

def main():
    if len(sys.argv) < 3:
        print("Usage: validate_json_schema.py <data.json> <schema.json>", file=sys.stderr)
        sys.exit(2)
    
    try:
        with open(sys.argv[1], 'r') as f:
            data = json.load(f)
        with open(sys.argv[2], 'r') as f:
            schema = json.load(f)
    except FileNotFoundError as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(2)
    except json.JSONDecodeError as e:
        print(f"Error: Invalid JSON - {e}", file=sys.stderr)
        sys.exit(2)
    
    try:
        validate(instance=data, schema=schema)
        print("Valid: JSON conforms to schema")
        sys.exit(0)
    except ValidationError as e:
        print(f"Invalid: {e.message}", file=sys.stderr)
        sys.exit(1)
    except SchemaError as e:
        print(f"Invalid schema: {e.message}", file=sys.stderr)
        sys.exit(2)

if __name__ == "__main__":
    main()