import subprocess
import os
import logging
from datetime import datetime

# ---------------- CONFIG ----------------
GITHUB_USER = ""
GITHUB_EMAIL = ""
GITHUB_TOKEN = ""  # <-- Put your GitHub PAT here

# Folder where working LFS-migrated repos exist
PROJECTS_DIR = "./git_repo_project_files"

# ---------------- Logging Setup ----------------
log_filename = f"lfs_heatmap_update_{datetime.now().strftime('%Y%m%d_%H%M%S')}.log"
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s",
    handlers=[
        logging.FileHandler(log_filename),
        logging.StreamHandler()
    ]
)

# ---------------- FUNCTIONS ----------------
def list_local_repos():
    """Return a list of folder names in PROJECTS_DIR"""
    repos = []
    for entry in os.listdir(PROJECTS_DIR):
        full_path = os.path.join(PROJECTS_DIR, entry)
        if os.path.isdir(full_path) and os.path.exists(os.path.join(full_path, ".git")):
            repos.append(entry)
    return repos

def process_repo(repo_name):
    local_path = os.path.join(PROJECTS_DIR, repo_name)
    github_url = f"https://{GITHUB_TOKEN}@github.com/{GITHUB_USER}/{repo_name}.git"

    try:
        logging.info(f"Fetching latest commits for {repo_name}...")
        subprocess.run(["git", "-C", local_path, "fetch", "--all"], check=True)

        # Rewrite commits to GitHub email (preserve dates)
        logging.info(f"Rewriting commits in {repo_name} to GitHub email...")
        subprocess.run([
            "git", "-C", local_path, "filter-repo",
            "--email-callback", f'return b"{GITHUB_EMAIL}"',
            "--force"
        ], check=True)

        # Ensure 'github' remote exists
        remotes = subprocess.run(
            ["git", "-C", local_path, "remote"],
            capture_output=True, text=True
        ).stdout.splitlines()
        if "github" not in remotes:
            logging.info(f"Adding 'github' remote for {repo_name}...")
            subprocess.run(["git", "-C", local_path, "remote", "add", "github", github_url], check=True)
        else:
            logging.info(f"Updating 'github' remote URL for {repo_name}...")
            subprocess.run(["git", "-C", local_path, "remote", "set-url", "github", github_url], check=True)

        # Push all refs to GitHub
        logging.info(f"Pushing all branches and tags of {repo_name} to GitHub...")
        subprocess.run(["git", "-C", local_path, "push", "--mirror", "github"], check=True)

        logging.info(f"✅ Finished processing {repo_name}")

    except subprocess.CalledProcessError as e:
        logging.error(f"❌ Error processing {repo_name}: {e}")

# ---------------- MAIN ----------------
def main():
    logging.info(f"Starting LFS heatmap update for GitHub user: {GITHUB_USER}")

    existing_repos = list_local_repos()
    if not existing_repos:
        logging.info(f"No repos found in {PROJECTS_DIR}. Nothing to process.")
        return

    for repo_name in existing_repos:
        logging.info(f"Processing repo: {repo_name}")
        process_repo(repo_name)

    logging.info(f"All done! Log saved to {log_filename}")

if __name__ == "__main__":
    main()