revert.py
python
| 1 | """muse revert — create a new commit that undoes a prior commit.""" |
| 2 | from __future__ import annotations |
| 3 | |
| 4 | import datetime |
| 5 | import json |
| 6 | import logging |
| 7 | import pathlib |
| 8 | import shutil |
| 9 | |
| 10 | import typer |
| 11 | |
| 12 | from muse.core.errors import ExitCode |
| 13 | from muse.core.object_store import restore_object |
| 14 | from muse.core.repo import require_repo |
| 15 | from muse.core.snapshot import compute_commit_id |
| 16 | from muse.core.store import ( |
| 17 | CommitRecord, |
| 18 | get_head_commit_id, |
| 19 | read_commit, |
| 20 | read_snapshot, |
| 21 | resolve_commit_ref, |
| 22 | write_commit, |
| 23 | ) |
| 24 | |
| 25 | logger = logging.getLogger(__name__) |
| 26 | |
| 27 | app = typer.Typer() |
| 28 | |
| 29 | |
| 30 | def _read_branch(root: pathlib.Path) -> str: |
| 31 | head_ref = (root / ".muse" / "HEAD").read_text().strip() |
| 32 | return head_ref.removeprefix("refs/heads/").strip() |
| 33 | |
| 34 | |
| 35 | def _read_repo_id(root: pathlib.Path) -> str: |
| 36 | return str(json.loads((root / ".muse" / "repo.json").read_text())["repo_id"]) |
| 37 | |
| 38 | |
| 39 | @app.callback(invoke_without_command=True) |
| 40 | def revert( |
| 41 | ctx: typer.Context, |
| 42 | ref: str = typer.Argument(..., help="Commit to revert."), |
| 43 | message: str | None = typer.Option(None, "-m", "--message", help="Override revert commit message."), |
| 44 | no_commit: bool = typer.Option(False, "--no-commit", "-n", help="Apply changes but do not commit."), |
| 45 | ) -> None: |
| 46 | """Create a new commit that undoes a prior commit.""" |
| 47 | root = require_repo() |
| 48 | repo_id = _read_repo_id(root) |
| 49 | branch = _read_branch(root) |
| 50 | |
| 51 | target = resolve_commit_ref(root, repo_id, branch, ref) |
| 52 | if target is None: |
| 53 | typer.echo(f"❌ Commit '{ref}' not found.") |
| 54 | raise typer.Exit(code=ExitCode.USER_ERROR) |
| 55 | |
| 56 | # The revert of a commit restores its parent snapshot |
| 57 | if target.parent_commit_id is None: |
| 58 | typer.echo("❌ Cannot revert the root commit (no parent to restore).") |
| 59 | raise typer.Exit(code=ExitCode.USER_ERROR) |
| 60 | |
| 61 | parent_commit = read_commit(root, target.parent_commit_id) |
| 62 | if parent_commit is None: |
| 63 | typer.echo(f"❌ Parent commit {target.parent_commit_id[:8]} not found.") |
| 64 | raise typer.Exit(code=ExitCode.INTERNAL_ERROR) |
| 65 | |
| 66 | target_snapshot = read_snapshot(root, parent_commit.snapshot_id) |
| 67 | if target_snapshot is None: |
| 68 | typer.echo(f"❌ Snapshot {parent_commit.snapshot_id[:8]} not found.") |
| 69 | raise typer.Exit(code=ExitCode.INTERNAL_ERROR) |
| 70 | |
| 71 | # Restore parent snapshot to muse-work/ |
| 72 | workdir = root / "muse-work" |
| 73 | if workdir.exists(): |
| 74 | shutil.rmtree(workdir) |
| 75 | workdir.mkdir() |
| 76 | for rel_path, object_id in target_snapshot.manifest.items(): |
| 77 | restore_object(root, object_id, workdir / rel_path) |
| 78 | |
| 79 | if no_commit: |
| 80 | typer.echo(f"Reverted changes from {target.commit_id[:8]} applied to muse-work/. Run 'muse commit' to record.") |
| 81 | return |
| 82 | |
| 83 | revert_message = message or f"Revert \"{target.message}\"" |
| 84 | head_commit_id = get_head_commit_id(root, branch) |
| 85 | |
| 86 | # The parent snapshot is already content-addressed in the object store — |
| 87 | # reuse its snapshot_id directly rather than re-scanning the workdir. |
| 88 | snapshot_id = parent_commit.snapshot_id |
| 89 | committed_at = datetime.datetime.now(datetime.timezone.utc) |
| 90 | commit_id = compute_commit_id( |
| 91 | parent_ids=[head_commit_id] if head_commit_id else [], |
| 92 | snapshot_id=snapshot_id, |
| 93 | message=revert_message, |
| 94 | committed_at_iso=committed_at.isoformat(), |
| 95 | ) |
| 96 | |
| 97 | write_commit(root, CommitRecord( |
| 98 | commit_id=commit_id, |
| 99 | repo_id=repo_id, |
| 100 | branch=branch, |
| 101 | snapshot_id=snapshot_id, |
| 102 | message=revert_message, |
| 103 | committed_at=committed_at, |
| 104 | parent_commit_id=head_commit_id, |
| 105 | )) |
| 106 | (root / ".muse" / "refs" / "heads" / branch).write_text(commit_id) |
| 107 | |
| 108 | typer.echo(f"[{branch} {commit_id[:8]}] {revert_message}") |