checkout.py
python
| 1 | """muse checkout — switch branches or restore working tree from a commit. |
| 2 | |
| 3 | Usage:: |
| 4 | |
| 5 | muse checkout <branch> — switch to existing branch |
| 6 | muse checkout -b <branch> — create and switch to new branch |
| 7 | muse checkout <commit-id> — detach HEAD at a specific commit |
| 8 | """ |
| 9 | |
| 10 | from __future__ import annotations |
| 11 | |
| 12 | import json |
| 13 | import logging |
| 14 | import pathlib |
| 15 | |
| 16 | import typer |
| 17 | |
| 18 | from muse.core.errors import ExitCode |
| 19 | from muse.core.object_store import restore_object |
| 20 | from muse.core.repo import require_repo |
| 21 | from muse.core.store import ( |
| 22 | get_head_commit_id, |
| 23 | get_head_snapshot_id, |
| 24 | read_snapshot, |
| 25 | resolve_commit_ref, |
| 26 | ) |
| 27 | from muse.domain import SnapshotManifest |
| 28 | from muse.plugins.registry import read_domain, resolve_plugin |
| 29 | |
| 30 | logger = logging.getLogger(__name__) |
| 31 | |
| 32 | app = typer.Typer() |
| 33 | |
| 34 | |
| 35 | def _read_current_branch(root: pathlib.Path) -> str: |
| 36 | head_ref = (root / ".muse" / "HEAD").read_text().strip() |
| 37 | return head_ref.removeprefix("refs/heads/").strip() |
| 38 | |
| 39 | |
| 40 | def _read_repo_id(root: pathlib.Path) -> str: |
| 41 | return str(json.loads((root / ".muse" / "repo.json").read_text())["repo_id"]) |
| 42 | |
| 43 | |
| 44 | def _checkout_snapshot( |
| 45 | root: pathlib.Path, |
| 46 | target_snapshot_id: str, |
| 47 | current_snapshot_id: str | None, |
| 48 | ) -> None: |
| 49 | """Incrementally update muse-work/ from current to target snapshot. |
| 50 | |
| 51 | Uses the domain plugin to compute the delta between the two snapshots and |
| 52 | only touches files that actually changed — removing deleted paths and |
| 53 | restoring added/modified ones from the object store. Calls |
| 54 | ``plugin.apply()`` as the domain-level post-checkout hook. |
| 55 | """ |
| 56 | plugin = resolve_plugin(root) |
| 57 | domain = read_domain(root) |
| 58 | |
| 59 | target_snap_rec = read_snapshot(root, target_snapshot_id) |
| 60 | if target_snap_rec is None: |
| 61 | typer.echo(f"❌ Snapshot {target_snapshot_id[:8]} not found in object store.") |
| 62 | raise typer.Exit(code=ExitCode.INTERNAL_ERROR) |
| 63 | |
| 64 | target_snap = SnapshotManifest(files=target_snap_rec.manifest, domain=domain) |
| 65 | |
| 66 | if current_snapshot_id is not None: |
| 67 | cur_rec = read_snapshot(root, current_snapshot_id) |
| 68 | current_snap = ( |
| 69 | SnapshotManifest(files=cur_rec.manifest, domain=domain) |
| 70 | if cur_rec else SnapshotManifest(files={}, domain=domain) |
| 71 | ) |
| 72 | else: |
| 73 | current_snap = SnapshotManifest(files={}, domain=domain) |
| 74 | |
| 75 | delta = plugin.diff(current_snap, target_snap) |
| 76 | |
| 77 | workdir = root / "muse-work" |
| 78 | workdir.mkdir(exist_ok=True) |
| 79 | |
| 80 | # Remove files that no longer exist in the target snapshot. |
| 81 | removed = [op["address"] for op in delta["ops"] if op["op"] == "delete"] |
| 82 | for rel_path in removed: |
| 83 | fp = workdir / rel_path |
| 84 | if fp.exists(): |
| 85 | fp.unlink() |
| 86 | |
| 87 | # Restore added and modified files from the content-addressed store. |
| 88 | # InsertOp, ReplaceOp, and PatchOp all mean the file's content changed; |
| 89 | # the authoritative hash for each is in the target snapshot manifest. |
| 90 | to_restore = [ |
| 91 | op["address"] for op in delta["ops"] |
| 92 | if op["op"] in ("insert", "replace", "patch") |
| 93 | ] |
| 94 | for rel_path in to_restore: |
| 95 | object_id = target_snap_rec.manifest[rel_path] |
| 96 | if not restore_object(root, object_id, workdir / rel_path): |
| 97 | typer.echo(f"⚠️ Object {object_id[:8]} for '{rel_path}' not in local store — skipped.") |
| 98 | |
| 99 | # Domain-level post-checkout hook: rescan the workdir to confirm state. |
| 100 | plugin.apply(delta, workdir) |
| 101 | |
| 102 | |
| 103 | @app.callback(invoke_without_command=True) |
| 104 | def checkout( |
| 105 | ctx: typer.Context, |
| 106 | target: str = typer.Argument(..., help="Branch name or commit ID to check out."), |
| 107 | create: bool = typer.Option(False, "-b", "--create", help="Create a new branch."), |
| 108 | force: bool = typer.Option(False, "--force", "-f", help="Discard uncommitted changes."), |
| 109 | ) -> None: |
| 110 | """Switch branches or restore working tree from a commit.""" |
| 111 | root = require_repo() |
| 112 | repo_id = _read_repo_id(root) |
| 113 | current_branch = _read_current_branch(root) |
| 114 | muse_dir = root / ".muse" |
| 115 | |
| 116 | current_snapshot_id = get_head_snapshot_id(root, repo_id, current_branch) |
| 117 | |
| 118 | if create: |
| 119 | ref_file = muse_dir / "refs" / "heads" / target |
| 120 | if ref_file.exists(): |
| 121 | typer.echo(f"❌ Branch '{target}' already exists. Use 'muse checkout {target}' to switch to it.") |
| 122 | raise typer.Exit(code=ExitCode.USER_ERROR) |
| 123 | current_commit = get_head_commit_id(root, current_branch) or "" |
| 124 | ref_file.parent.mkdir(parents=True, exist_ok=True) |
| 125 | ref_file.write_text(current_commit) |
| 126 | (muse_dir / "HEAD").write_text(f"refs/heads/{target}\n") |
| 127 | typer.echo(f"Switched to a new branch '{target}'") |
| 128 | return |
| 129 | |
| 130 | # Check if target is a known branch |
| 131 | ref_file = muse_dir / "refs" / "heads" / target |
| 132 | if ref_file.exists(): |
| 133 | if target == current_branch: |
| 134 | typer.echo(f"Already on '{target}'") |
| 135 | return |
| 136 | |
| 137 | target_snapshot_id = get_head_snapshot_id(root, repo_id, target) |
| 138 | if target_snapshot_id: |
| 139 | _checkout_snapshot(root, target_snapshot_id, current_snapshot_id) |
| 140 | |
| 141 | (muse_dir / "HEAD").write_text(f"refs/heads/{target}\n") |
| 142 | typer.echo(f"Switched to branch '{target}'") |
| 143 | return |
| 144 | |
| 145 | # Try as a commit ID (detached HEAD) |
| 146 | commit = resolve_commit_ref(root, repo_id, current_branch, target) |
| 147 | if commit is None: |
| 148 | typer.echo(f"❌ '{target}' is not a branch or commit ID.") |
| 149 | raise typer.Exit(code=ExitCode.USER_ERROR) |
| 150 | |
| 151 | _checkout_snapshot(root, commit.snapshot_id, current_snapshot_id) |
| 152 | (muse_dir / "HEAD").write_text(commit.commit_id + "\n") |
| 153 | typer.echo(f"HEAD is now at {commit.commit_id[:8]} {commit.message}") |