/** * CheckpointStore - Repository interface for filesystem-backed workspace checkpoints. * * Owns hidden Git-ref checkpoint capture/restore and diff computation for a * workspace thread timeline. It does not store user-facing checkpoint metadata * and does not coordinate provider conversation rollback. * * The live adapter resolves the active VCS driver once per checkpoint operation * and delegates to the driver's optional checkpoint capability. * * Uses Effect `Context.Service` for dependency injection and exposes typed * domain errors for checkpoint storage operations. * * @module CheckpointStore */import { VcsUnsupportedOperationError, type CheckpointRef } from "@t3tools/contracts";import * as Context from "effect/Context";import * as Effect from "effect/Effect";import * as Layer from "effect/Layer"; import type { CheckpointStoreError } from "./Errors.ts";import type { VcsCheckpointOps } from "../vcs/VcsDriver.ts";import * as VcsDriverRegistry from "../vcs/VcsDriverRegistry.ts"; export interface CaptureCheckpointInput {  readonly cwd: string;  readonly checkpointRef: CheckpointRef;} export interface RestoreCheckpointInput {  readonly cwd: string;  readonly checkpointRef: CheckpointRef;  readonly fallbackToHead?: boolean;} export interface DiffCheckpointsInput {  readonly cwd: string;  readonly fromCheckpointRef: CheckpointRef;  readonly toCheckpointRef: CheckpointRef;  readonly fallbackFromToHead?: boolean;  readonly ignoreWhitespace: boolean;  readonly format?: "patch" | "numstat";} export interface DeleteCheckpointRefsInput {  readonly cwd: string;  readonly checkpointRefs: ReadonlyArray<CheckpointRef>;} /** Service tag for checkpoint persistence and restore operations. */export class CheckpointStore extends Context.Service<  CheckpointStore,  {    /** Check whether cwd is inside a Git worktree. */    readonly isGitRepository: (cwd: string) => Effect.Effect<boolean, CheckpointStoreError>;     /**     * Capture a checkpoint commit and store it at the provided checkpoint ref.     *     * Uses an isolated temporary Git index and writes a hidden ref.     */    readonly captureCheckpoint: (      input: CaptureCheckpointInput,    ) => Effect.Effect<void, CheckpointStoreError>;     /** Check whether a checkpoint ref exists. */    readonly hasCheckpointRef: (      input: Omit<RestoreCheckpointInput, "fallbackToHead">,    ) => Effect.Effect<boolean, CheckpointStoreError>;     /**     * Restore workspace and staging state to a checkpoint.     *     * Optionally falls back to current `HEAD` when the checkpoint ref is missing.     */    readonly restoreCheckpoint: (      input: RestoreCheckpointInput,    ) => Effect.Effect<boolean, CheckpointStoreError>;     /**     * Compute a diff between two checkpoint refs. Defaults to a full patch.     *     * Numstat output has NUL-delimited paths for file summaries.     * Can optionally treat a missing "from" ref as `HEAD`.     */    readonly diffCheckpoints: (      input: DiffCheckpointsInput,    ) => Effect.Effect<string, CheckpointStoreError>;     /**     * Delete the provided checkpoint refs.     *     * Best-effort delete: missing refs are tolerated.     */    readonly deleteCheckpointRefs: (      input: DeleteCheckpointRefsInput,    ) => Effect.Effect<void, CheckpointStoreError>;  }>()("t3/checkpointing/CheckpointStore") {} /** @public Service construction is part of the canonical Effect module API. */export const make = Effect.gen(function* () {  const vcsRegistry = yield* VcsDriverRegistry.VcsDriverRegistry;   const resolveCheckpoints = Effect.fn("CheckpointStore.resolveCheckpoints")(function* (    operation: string,    cwd: string,  ) {    const handle = yield* vcsRegistry.resolve({ cwd });    if (!handle.driver.checkpoints) {      return yield* new VcsUnsupportedOperationError({        operation,        kind: handle.kind,        detail: `${handle.kind} driver does not implement checkpoint operations.`,      });    }    return handle.driver.checkpoints satisfies VcsCheckpointOps;  });   const isGitRepository: CheckpointStore["Service"]["isGitRepository"] = (cwd) =>    vcsRegistry      .detect({ cwd, requestedKind: "git" })      .pipe(Effect.map((repository) => repository !== null));   const captureCheckpoint: CheckpointStore["Service"]["captureCheckpoint"] = Effect.fn(    "captureCheckpoint",  )(function* (input) {    const checkpoints = yield* resolveCheckpoints("CheckpointStore.captureCheckpoint", input.cwd);    return yield* checkpoints.captureCheckpoint(input);  });   const hasCheckpointRef: CheckpointStore["Service"]["hasCheckpointRef"] = Effect.fn(    "hasCheckpointRef",  )(function* (input) {    const checkpoints = yield* resolveCheckpoints("CheckpointStore.hasCheckpointRef", input.cwd);    return yield* checkpoints.hasCheckpointRef(input);  });   const restoreCheckpoint: CheckpointStore["Service"]["restoreCheckpoint"] = Effect.fn(    "restoreCheckpoint",  )(function* (input) {    const checkpoints = yield* resolveCheckpoints("CheckpointStore.restoreCheckpoint", input.cwd);    return yield* checkpoints.restoreCheckpoint(input);  });   const diffCheckpoints: CheckpointStore["Service"]["diffCheckpoints"] = Effect.fn(    "diffCheckpoints",  )(function* (input) {    const checkpoints = yield* resolveCheckpoints("CheckpointStore.diffCheckpoints", input.cwd);    return yield* checkpoints.diffCheckpoints(input);  });   const deleteCheckpointRefs: CheckpointStore["Service"]["deleteCheckpointRefs"] = Effect.fn(    "deleteCheckpointRefs",  )(function* (input) {    const checkpoints = yield* resolveCheckpoints(      "CheckpointStore.deleteCheckpointRefs",      input.cwd,    );    return yield* checkpoints.deleteCheckpointRefs(input);  });   return CheckpointStore.of({    isGitRepository,    captureCheckpoint,    hasCheckpointRef,    restoreCheckpoint,    diffCheckpoints,    deleteCheckpointRefs,  });}); export const layer = Layer.effect(CheckpointStore, make);