#!/usr/bin/env python3
"""
git-claim-authorship.py

Rewrites git history so that all commits list you as the author.

Usage:
    python git-claim-authorship.py --name "Your Name" --email "you@example.com"

Run from inside the repository you want to rewrite.
WARNING: This rewrites history. Force-push required afterwards.
"""

import subprocess
import argparse
import sys


def run(cmd, capture=True, check=True):
    result = subprocess.run(
        cmd, shell=True, capture_output=capture, text=True, check=check
    )
    return result.stdout.strip() if capture else None


def get_all_commits():
    output = run("git log --format='%H' --all")
    return output.splitlines() if output else []
def main():
    parser = argparse.ArgumentParser(
        description="Rewrite history so all commits use the provided author."
    )
    parser.add_argument("--name", required=True, help="Your full name (as in git)")
    parser.add_argument("--email", required=True, help="Your email (as in git)")
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="Show what would change without modifying anything",
    )
    args = parser.parse_args()

    # Make sure we're in a git repo
    try:
        run("git rev-parse --is-inside-work-tree")
    except subprocess.CalledProcessError:
        print("Error: not inside a git repository.", file=sys.stderr)
        sys.exit(1)

    print(f"Scanning commits to rewrite author to: {args.name} <{args.email}>")
    commits = get_all_commits()
    print(f"Total commits found: {len(commits)}")

    if not commits:
        print("No commits found. Nothing to do.")
        return

    print(f"\nFound {len(commits)} commit(s) to rewrite.\n")

    if args.dry_run:
        print("\n[Dry run] No changes made.")
        return

    confirm = input(
        "\n⚠️  This will rewrite history. Proceed? (yes/no): "
    ).strip().lower()
    if confirm != "yes":
        print("Aborted.")
        return

    # Build a filter-branch env filter script
    env_filter = f"""
export GIT_AUTHOR_NAME='{args.name}'
export GIT_AUTHOR_EMAIL='{args.email}'
"""

    print("\nRewriting history with git filter-branch...")
    try:
        result = subprocess.run(
            [
                "git", "filter-branch", "-f",
                "--env-filter", env_filter,
                "--tag-name-filter", "cat",
                "--", "--all"
            ],
            capture_output=False,
            text=True,
        )
        if result.returncode != 0:
            print("filter-branch failed.", file=sys.stderr)
            sys.exit(1)
    except Exception as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(1)

    print("\n✅ Done! History rewritten.")
    print("\nTo publish the changes, force-push all branches:")
    print("  git push --force --all")
    print("  git push --force --tags")
    print("\nNote: Anyone else with a clone of this repo will need to re-clone or rebase.")


if __name__ == "__main__":
    main()