feat(desktop): aggregated overview rail, commit detail page, and full breadcrumbs (#1573)

desktop/src/features/projects/useProjectCommitDiff.ts

@@ -0,0 +1,69 @@
+import { useQuery } from "@tanstack/react-query";
+
+import {
+  getProjectLocalRepoDiff,
+  getProjectRepoDiff,
+} from "@/shared/api/projectGit";
+import type { ProjectRepoDiff } from "@/shared/api/types";
+import type { Project } from "./hooks";
+
+async function fetchProjectCommitDiff(
+  project: Project,
+  commitHash: string,
+  repoSource: "remote" | "local",
+  reposDir: string | null | undefined,
+): Promise<ProjectRepoDiff> {
+  if (repoSource === "local") {
+    // Passing only the target commit (no base branch/commit) makes the
+    // backend diff the commit against its parent.
+    const local = await getProjectLocalRepoDiff({
+      reposDir,
+      projectDtag: project.dtag,
+      cloneUrl: project.cloneUrls[0] ?? null,
+      targetCommit: commitHash,
+    });
+    if (local) return local;
+  }
+
+  const cloneUrl = project.cloneUrls[0];
+  if (!cloneUrl) {
+    throw new Error("This project has no clone URL to load the commit from.");
+  }
+  return getProjectRepoDiff({
+    cloneUrl,
+    defaultBranch: project.defaultBranch,
+    targetCommit: commitHash,
+  });
+}
+
+/**
+ * Diff of a single commit against its parent, for the commit detail view.
+ * Prefers the local checkout when the repository source is "local" and falls
+ * back to a remote fetch when no checkout exists.
+ */
+export function useProjectCommitDiffQuery(
+  project: Project | null | undefined,
+  commitHash: string | null,
+  repoSource: "remote" | "local",
+  reposDir?: string | null,
+) {
+  return useQuery({
+    enabled: Boolean(project && commitHash),
+    queryKey: [
+      "project",
+      project?.id ?? "none",
+      "commit-diff",
+      repoSource,
+      commitHash ?? "none",
+    ],
+    queryFn: () => {
+      if (!project || !commitHash) {
+        return Promise.reject(new Error("No commit selected."));
+      }
+      return fetchProjectCommitDiff(project, commitHash, repoSource, reposDir);
+    },
+    // A commit's diff is immutable, so never refetch it while cached.
+    staleTime: Number.POSITIVE_INFINITY,
+    retry: 1,
+  });
+}