Convert Protobuf to JSON and Dict in Python

from google.protobuf.json_format import MessageToJson, Parse
import json


class DataConverter:
    """Helper class to convert between protobuf messages and common formats."""

    @staticmethod
    def to_json(message, indent=2):
        """Convert a protobuf message to JSON string."""
        return MessageToJson(message, indent=indent)

    @staticmethod
    def from_json(json_str, message_type):
        """Parse JSON string back into a protobuf message."""
        return Parse(json_str, message_type())

    @staticmethod
    def to_dict(message):
        """Convert a protobuf message to a Python dictionary (lowercase keys)."""
        return json.loads(MessageToJson(message))

    @staticmethod
    def from_dict(data_dict, message_type):
        """Build a protobuf message from a Python dictionary."""
        return Parse(json.dumps(data_dict), message_type())


if __name__ == "__main__":
    # Example usage with a simple test message (using google.protobuf)
    from google.protobuf import descriptor_pb2
    
    # Create a FileDescriptorProto as sample message
    msg = descriptor_pb2.FileDescriptorProto()
    msg.name = "sample.proto"
    msg.package = "example"
    
    # Convert to JSON and back
    json_output = DataConverter.to_json(msg)
    print("JSON output:")
    print(json_output)
    
    # Parse back
    restored = DataConverter.from_json(json_output, descriptor_pb2.FileDescriptorProto)
    print("\nRestored name:", restored.name)
    
    # Convert to dict and back
    data_dict = DataConverter.to_dict(msg)
    print("\nDict output:", data_dict)
    
    restored_dict = DataConverter.from_dict(data_dict, descriptor_pb2.FileDescriptorProto)
    print("Restored from dict:", restored_dict.name)