update_project_and_app_references.py

"""
Purpose:
- Renames all project and app references from foo_project and foo_app to the desired project and app names.

Usage:
$ python ./update_project_and_app_references.py --target_dir "/path/to/foo_project/" --new_project_name "bar_project" --new_app_name "bar_app"

Note:
- This script will delete the git-cloned `.git` directory in the target directory, so you can start a new git repository.
"""

import argparse
import shutil
from pathlib import Path, PosixPath


## constants --------------------------------------------------------
REPO_PROJECT_NAME = 'django_template_42_project'  # raw git-clone name
OLD_PROJECT_NAME = 'foo_project'  # all the internal code project-references
OLD_APP_NAME = 'foo_app'


## helper functions -------------------------------------------------


def rename_top_level_directory(target_directory: Path, new_project_name: str) -> Path:
    """
    Renames the top-level project directory if needed.
    Called by run_updater().
    """
    if REPO_PROJECT_NAME in target_directory.name:
        new_directory: Path = target_directory.with_name(
            target_directory.name.replace(REPO_PROJECT_NAME, new_project_name)
        )
        target_directory.rename(new_directory)
        return_dir: Path = new_directory
    else:
        return_dir: Path = target_directory
    return return_dir


def rename_files_and_directories(
    target_directory: Path, new_project_name: str, new_app_name: str
) -> None:
    """
    Renames any files and directories in the target directory.
    Called by run_updater.
    """
    for item in target_directory.rglob('*'):
        assert type(item) is PosixPath
        if item.is_dir():
            if OLD_PROJECT_NAME in item.name:
                new_dir_name: str = item.name.replace(OLD_PROJECT_NAME, new_project_name)
                item.rename(item.with_name(new_dir_name))
            elif OLD_APP_NAME in item.name:
                new_dir_name: str = item.name.replace(OLD_APP_NAME, new_app_name)
                item.rename(item.with_name(new_dir_name))
        elif item.is_file():
            if OLD_PROJECT_NAME in item.name:
                new_file_name: str = item.name.replace(OLD_PROJECT_NAME, new_project_name)
                item.rename(item.with_name(new_file_name))
            elif OLD_APP_NAME in item.name:
                new_file_name: str = item.name.replace(OLD_APP_NAME, new_app_name)
                item.rename(item.with_name(new_file_name))


def update_file_contents(target_directory: Path, new_project_name: str, new_app_name: str) -> None:
    for item in target_directory.rglob('*'):
        assert type(item) is PosixPath
        if item.is_file():
            if item.name == 'update_project_and_app_references.py':
                continue
            replace_in_file(item, OLD_PROJECT_NAME, new_project_name)
            replace_in_file(item, OLD_APP_NAME, new_app_name)
    return


def replace_in_file(file_path: Path, old_text: str, new_text: str) -> None:
    """
    Replaces old_text with new_text in the file at file_path.
    Called by update_file_contents.
    """
    try:
        content = file_path.read_text(encoding='utf-8')
        content = content.replace(old_text, new_text)
        file_path.write_text(content, encoding='utf-8')
    except UnicodeDecodeError:
        pass  # skip files that can't be read as UTF-8
    return


def delete_git_directory(target_directory: Path) -> None:
    """
    Deletes the .git directory in the target directory if it exists.
    Called by run_updater.
    """
    git_dir: Path = target_directory / '.git'
    if git_dir.exists():
        if git_dir.is_dir():
            shutil.rmtree(git_dir)
            print(f'Deleted .git directory in ``{target_directory}``.')
    else:
        print(f'No .git directory found at ``{git_dir}``.')
    return


## manager functions ------------------------------------------------


def parse_args() -> None:
    """
    Parses args and passes them to the main manager function.
    Called by dundermain.
    """
    ## configure argument parser
    parser = argparse.ArgumentParser(
        description='Update project and app references in a directory.'
    )
    parser.add_argument('--target_dir', type=str, required=True, help='The directory to update.')
    parser.add_argument('--new_project_name', type=str, required=True, help='The new project name.')
    parser.add_argument('--new_app_name', type=str, required=True, help='The new app name.')
    args = parser.parse_args()
    ## get the values
    target_directory: Path = Path(args.target_dir)
    new_project_name: str = args.new_project_name
    new_app_name: str = args.new_app_name
    ## confirm target_directory exists
    if not target_directory.exists():
        raise FileNotFoundError(f'Target directory ``{target_directory}`` does not exist.')
    ## run updater
    run_updater(target_directory, new_project_name, new_app_name)
    return


def run_updater(target_directory: Path, new_project_name: str, new_app_name: str) -> None:
    """
    Performs the update operations on the target directory.
    Called by parse_args.
    """
    ## rename top-level directory if needed
    target_directory = rename_top_level_directory(target_directory, new_project_name)
    ## first pass: rename files and directories
    rename_files_and_directories(target_directory, new_project_name, new_app_name)
    ## second pass: update file contents
    update_file_contents(target_directory, new_project_name, new_app_name)
    ## delete .git directory
    delete_git_directory(target_directory)
    print(
        f'Updated project and app references in ``{target_directory}`` to ``{new_project_name}`` and ``{new_app_name}``.'
    )
    return


## dundermain -------------------------------------------------------
if __name__ == '__main__':
    parse_args()