pre-commit

#!python3

import logging
import subprocess
from datetime import date
from pathlib import Path

import frontmatter
from frontmatter.default_handlers import TOMLHandler

# Set up logging
logging.basicConfig(
    filename="pre_commit.log",
    level=logging.DEBUG,
    format="%(asctime)s:%(levelname)s:%(message)s",
)


def get_commited_files() -> list:
    """Get the list of modified files. Keeps only .md files and ignore _index.md"""
    """return: list of .md file names"""
    try:
        cmd = "git diff --cached --name-only --diff-filter=M"
        # cmd = "ls --color=never ./test/index.md"
        files = subprocess.check_output(cmd.split()).decode().split()
        target_files = [
            f for f in files if f.endswith(".md") and not f.endswith("_index.md")
        ]
        logging.debug(f"Modified .md files: {target_files}")
        return target_files
    except subprocess.CalledProcessError as e:
        logging.error(f"Failed to get committed files: {e}")
        return []
    except Exception as e:
        logging.error(f"Unexpected error: {e}")
        return []


def get_last_modified_date(path: Path) -> date:
    """Get the last modified date of a file"""
    """path: Path object"""
    """return: date object"""
    try:
        last_modified_date = date.fromtimestamp(path.stat().st_mtime)
        return last_modified_date
    except FileNotFoundError:
        logging.error(f"File not found: {path}")
        return None


def get_post_content(path: Path) -> frontmatter.Post:
    """Get the content of a post"""
    """path: Path object"""
    """return: frontmatter.Post object"""
    try:
        file_content = path.read_text()
        post = frontmatter.loads(file_content, handler=TOMLHandler())
        logging.debug(f"Post content retrieved from {path}")
        return post
    except FileNotFoundError:
        logging.error(f"File not found: {path}")
        return None
    except Exception as e:
        logging.error(f"Unexpected error: {e}")
        return None


def update_post_metadata(
    post: frontmatter.Post, last_modified_date: date
) -> frontmatter.Post:
    """Update the metadata of a post"""
    """post: frontmatter.Post object"""
    """last_modified_date: date object"""
    """return: frontmatter.Post object"""
    post.metadata["updated"] = last_modified_date
    logging.debug(f"Post metadata updated with date {last_modified_date}")
    return post


def save_post_content(path: Path, post: frontmatter.Post):
    """Save the content of a post"""
    """path: Path object"""
    """post: frontmatter.Post object"""
    try:
        path.write_text(frontmatter.dumps(post))
        logging.debug(f"Post content saved to {path}")
    except FileNotFoundError as e:
        logging.error(f"Failed to save post content to {path}: {e}")
    except Exception as e:
        logging.error(f"Unexpected error: {e}")


def add_file_to_git_index(md_file: str):
    """Add a file to the Git index"""
    """md_file: file name"""
    try:
        subprocess.run(["git", "add", md_file])
        logging.debug(f"File {md_file} added to Git index")
    except subprocess.CalledProcessError as e:
        logging.error(f"Failed to add file {md_file} to Git index: {e}")
    except Exception as e:
        logging.error(f"Unexpected error: {e}")


def main():
    try:
        for file in get_commited_files():
            path = Path(file)
            last_modified_date = get_last_modified_date(path)
            if last_modified_date:
                post = get_post_content(path)
                if post:
                    post = update_post_metadata(post, last_modified_date)
                    save_post_content(path, post)
                    add_file_to_git_index(file)
    except Exception as e:
        logging.error(f"Error in main function: {e}")


if __name__ == "__main__":
    logging.info("Starting pre-commit hook")
    main()
    logging.info("Pre-commit hook finished")