Python Script for Converting Gameplay Tags from INI to Native CPP

convert_ue_gameplay_tags_to_native.py

#!/usr/bin/env python3
##
# Copyright 2024, Guy Elsmore-Paddock. All Rights Reserved.
#
# This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not
# distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.
#
# This script can be used to convert Unreal Engine gameplay tags in INI format into native tags. See the following
# article for an overview of native gameplay tags:
# https://unrealdirective.com/tips/declare-define-native-gameplay-tags
#
#
# Consider the following gameplay tag INI file (`sample.ini`):
# ```
# ; Some comment
# [/Script/GameplayTags.GameplayTagsList]
# GameplayTagList=(Tag="Sample.Tag",DevComment="Comment about this tag.")
#
# ; Another comment
# GameplayTagList=(Tag="Sample.Tag2")
# ```
#
# Now, consider invoking this script using the following command:
# ```
# python3 convert_tags.py sample.ini \
#   --tag-prefix=TagExample \
#   --declaration-linkage=SAMPLE_PROJECT_API \
#   --comment-prefix='[Prefix] ' \
#   --comment-suffix=' [Suffix]'
# ```
#
# The generated header would be:
# ```
# #pragma once
#
# #include <NativeGameplayTags.h>
#
# // Some comment
# SAMPLE_PROJECT_API UE_DECLARE_GAMEPLAY_TAG_EXTERN(TagExampleSampleTag)
# // Another comment
# SAMPLE_PROJECT_API UE_DECLARE_GAMEPLAY_TAG_EXTERN(TagExampleSampleTag2)
# ```
# And the generated C++ file would be:
# ```
# #include "sample.h"
#
# // Some comment
# UE_DEFINE_GAMEPLAY_TAG_COMMENT(
# 	TagExampleSampleTag,
# 	"Sample.Tag",
# 	"[Prefix] Comment about this tag. [Suffix]"
# )
#
# // Another comment
# UE_DEFINE_GAMEPLAY_TAG(
# 	TagExampleSampleTag2,
# 	"Sample.Tag2"
# )
# ```
#
# Implementation by ChatGPT :)
#
import os
import sys
import argparse

def process_ini_file(input_file, tag_prefix, declaration_linkage, comment_prefix="", comment_suffix=""):
    base_name = os.path.splitext(os.path.basename(input_file))[0]
    header_file = f'{base_name}.h'
    cpp_file = f'{base_name}.cpp'

    with open(input_file, 'rb') as f:
        content = f.read()

    # Remove BOM if present
    if content.startswith(b'\xef\xbb\xbf'):
        content = content[3:]

    lines = content.decode('utf-8').splitlines()

    header_content = []
    cpp_content = []

    for line in lines:
        line = line.strip()
        if line.startswith(';'):
            comment_line = '// ' + line[1:].strip()
            header_content.append(comment_line)
            cpp_content.append(comment_line)
        elif line.startswith('['):
            # Ignore section headers
            continue
        elif line.startswith('GameplayTagList'):
            tag_name = line.split('Tag="')[1].split('"')[0]
            if 'DevComment="' in line:
                comment = line.split('DevComment="')[1].split('"')[0]
                tag_identifier = tag_prefix + tag_name.replace('.', '')
                full_comment = f'{comment_prefix}{comment}{comment_suffix}'
                if declaration_linkage:
                    header_content.append(f'{declaration_linkage} UE_DECLARE_GAMEPLAY_TAG_EXTERN({tag_identifier})')
                else:
                    header_content.append(f'UE_DECLARE_GAMEPLAY_TAG_EXTERN({tag_identifier})')
                cpp_content.append(f'UE_DEFINE_GAMEPLAY_TAG_COMMENT(')
                cpp_content.append(f'\t{tag_identifier},')
                cpp_content.append(f'\t"{tag_name}",')
                cpp_content.append(f'\t"{full_comment}"')
                cpp_content.append(f')\n')
            else:
                tag_identifier = tag_prefix + tag_name.replace('.', '')
                if declaration_linkage:
                    header_content.append(f'{declaration_linkage} UE_DECLARE_GAMEPLAY_TAG_EXTERN({tag_identifier})')
                else:
                    header_content.append(f'UE_DECLARE_GAMEPLAY_TAG_EXTERN({tag_identifier})')
                cpp_content.append(f'UE_DEFINE_GAMEPLAY_TAG(')
                cpp_content.append(f'\t{tag_identifier},')
                cpp_content.append(f'\t"{tag_name}"')
                cpp_content.append(f')\n')
        else:
            continue

    with open(header_file, 'w') as f:
        f.write('#pragma once\n')
        f.write('\n')
        f.write('#include <NativeGameplayTags.h>\n')
        f.write('\n')
        f.write('\n'.join(header_content))
        f.write('\n')

    with open(cpp_file, 'w') as f:
        f.write(f'#include "{header_file}"\n')
        f.write('\n')
        f.write('\n'.join(cpp_content))
        f.write('\n')

    print(f'Generated header file: {header_file}')
    print(f'Generated CPP file: {cpp_file}')

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Generate header and cpp files from INI file.")
    parser.add_argument("input_file", help="The input INI file.")
    parser.add_argument("--tag-prefix", help="Prefix for the tag identifiers.", default="Tag")
    parser.add_argument("--declaration-linkage", help="String for the declaration linkage.", default="")
    parser.add_argument("--comment-prefix", help="String to prepend to generated tag dev comments.", default="")
    parser.add_argument("--comment-suffix", help="String to append to generated tag dev comments.", default="")

    args = parser.parse_args()

    process_ini_file(args.input_file, args.tag_prefix, args.declaration_linkage, args.comment_prefix, args.comment_suffix)