jsonpointer

#!/usr/bin/env python3

import argparse
import json
import os
import sys

import jsonpointer

def main():
    # First handle backward compatibility for v1 command line syntax:
    # jsonpointer ptr.json file.json
    if len(sys.argv) >= 3 and not sys.argv[1].startswith('-'):
        # Check if the first argument is a file path
        if os.path.isfile(sys.argv[1]):
            # Insert -f option before the first argument
            sys.argv.insert(1, '-f')

    parser = argparse.ArgumentParser(
        description='Resolve a JSON pointer on JSON files')

    # Use mutually exclusive group for pointer specification
    pointer_group = parser.add_mutually_exclusive_group(required=True)
    pointer_group.add_argument('-e', '--expression',
                             help='A JSON pointer expression (e.g. "/foo/bar")')
    pointer_group.add_argument('-f', '--pointer-file', metavar='POINTER_FILE',
                             help='File containing a JSON pointer expression')

    parser.add_argument('FILE', type=argparse.FileType('r'), nargs='+',
                        help='Files for which the pointer should be resolved')
    parser.add_argument('--indent', type=int, default=None,
                        help='Indent output by n spaces')
    parser.add_argument('-v', '--version', action='version',
                        version='%(prog)s ' + jsonpointer.__version__)

    args = parser.parse_args()
    
    try:
        resolve_files(args)
    except KeyboardInterrupt:
        sys.exit(1)


def resolve_files(args):
    """Resolve a JSON pointer on JSON files"""
    # Get pointer from expression or file
    if args.expression:
        ptr = args.expression
    elif args.pointer_file:
        try:
            with open(args.pointer_file) as f:
                content = f.read().strip()
                # Handle JSON-encoded strings
                if content.startswith('"') and content.endswith('"'):
                    try:
                        ptr = json.loads(content)
                    except json.JSONDecodeError:
                        ptr = content
                else:
                    ptr = content
        except FileNotFoundError:
            print(f"Error: Pointer file '{args.pointer_file}' not found", file=sys.stderr)
            sys.exit(1)
    else:
        sys.exit(1)  # This should never happen because the group is required

    # Process each file
    for f in args.FILE:
        doc = json.load(f)
        try:
            result = jsonpointer.resolve_pointer(doc, ptr)
            print(json.dumps(result, indent=args.indent))
        except jsonpointer.JsonPointerException as e:
            print('Could not resolve pointer: %s' % str(e), file=sys.stderr)


if __name__ == "__main__":
    main()