#!/usr/bin/env python3
"""Lists the package-history ledger at /var/lib/dnf_package_store/history.db
(see `pkg-apply`, which writes it as root on every install/uninstall this
app performs). The chain starts at a "baseline" node (zero mods, stock OS)
and each later node names the action, package and user that applied it.

Read-only, no root needed — the db directory/file are world-readable, same
convention as /var/lib/rpm-ostree.
"""

import sqlite3
import sys

DB_PATH = "/var/lib/dnf_package_store/history.db"


def main():
    try:
        conn = sqlite3.connect(f"file:{DB_PATH}?mode=ro", uri=True)
        rows = conn.execute(
            "SELECT id, parent_id, action, package, applied_by, applied_at FROM revisions ORDER BY id"
        ).fetchall()
        conn.close()
    except sqlite3.OperationalError:
        print("No history recorded yet — nothing has been installed or removed through "
              "DNF Package Store.")
        sys.exit(0)

    if not rows:
        print("No history recorded yet.")
        return

    current_id = rows[-1][0]
    for id_, parent_id, action, package, applied_by, applied_at in rows:
        marker = "* current" if id_ == current_id else "  "
        if action == "baseline":
            desc = "stock OS, zero mods"
        else:
            desc = f"{action} {package}"
        print(f"{marker} #{id_}  {desc}")
        print(f"       by: {applied_by}  at: {applied_at}")
        if id_ != current_id:
            print()


if __name__ == "__main__":
    main()