chore: establish learning module baseline

OpenMAIC/app/api/learn/courses/[courseId]/route.ts

@@ -0,0 +1,70 @@
+// Large-course mode API — learner-facing course manifest (L2, public read).
+//
+//   GET /api/learn/courses/:courseId
+//
+// Static data: the published course framework + per-module courseware ids.
+// Zero LLM — the learner course page uses this to render the module list and
+// link each module into the existing /learn/:coursewareId player.
+
+import { type NextRequest } from 'next/server';
+import { apiError, apiSuccess, API_ERROR_CODES } from '@/lib/server/api-response';
+import { createLogger } from '@/lib/logger';
+import { courseManifestRepo } from '@/lib/course-manifest-repo/store';
+import { isValidCourseManifestId } from '@/lib/course-manifest-repo/store';
+import { isPinnedCourseManifestModule } from '@/lib/course-manifest-repo/types';
+
+const log = createLogger('Learner Course API');
+
+export async function GET(
+  request: NextRequest,
+  { params }: { params: Promise<{ courseId: string }> },
+) {
+  try {
+    const { courseId } = await params;
+    if (!isValidCourseManifestId(courseId)) {
+      return apiError(API_ERROR_CODES.INVALID_REQUEST, 400, `Invalid course id: ${courseId}`);
+    }
+    const versionParam = new URL(request.url).searchParams.get('version');
+    let record;
+    if (versionParam !== null) {
+      const version = Number(versionParam);
+      if (!Number.isInteger(version) || version < 1) {
+        return apiError(API_ERROR_CODES.INVALID_REQUEST, 400, 'Invalid course manifest version');
+      }
+      record = await courseManifestRepo.getRecord(courseId, version);
+    } else {
+      record = await courseManifestRepo.getLatestRecord(courseId);
+    }
+    if (!record) {
+      return apiError(API_ERROR_CODES.INVALID_REQUEST, 404, `Course not found: ${courseId}`);
+    }
+    if (record.schemaVersion !== 2 || !record.modules.every(isPinnedCourseManifestModule)) {
+      return apiError(
+        API_ERROR_CODES.INVALID_REQUEST,
+        409,
+        'This legacy course manifest must be republished before learners can open it',
+      );
+    }
+    return apiSuccess({
+      course: {
+        courseId: record.courseId,
+        version: record.version,
+        title: record.title,
+        summary: record.summary,
+        language: record.language,
+        publishedAt: record.publishedAt,
+        modules: record.modules.map((m) => ({
+          index: m.index,
+          title: m.title,
+          description: m.description,
+          coursewareId: m.coursewareId,
+          coursewareVersion: m.coursewareVersion,
+          contentHash: m.contentHash,
+        })),
+      },
+    });
+  } catch (error) {
+    log.error('Learner course manifest failed:', error);
+    return apiError(API_ERROR_CODES.INTERNAL_ERROR, 500, 'Failed to load course');
+  }
+}