fix(submissions): resolve Mongoose populate error for hybrid BlogPost model

- BlogPost uses native MongoDB (not Mongoose), causing MissingSchemaError
- Removed all .populate('blogPostId') calls that tried to reference non-existent Mongoose model
- Manually fetch blog post data in controllers when needed
- Updated getSubmissions, getSubmissionById, getSubmissionByBlogPost, exportSubmission
- Updated SubmissionTracking static methods: getByStatus, getByPublication
- Standalone submissions (like Le Monde) now display without errors

src/controllers/submissions.controller.js

@@ -81,24 +81,44 @@ async function getSubmissions(req, res) {
     if (status) query.status = status;
     if (publicationId) query.publicationId = publicationId;
 
+    // NOTE: BlogPost is a native MongoDB class, not a Mongoose model,
+    // so we can't use .populate() for blogPostId. Fetch blog post data separately if needed.
     const submissions = await SubmissionTracking.find(query)
-      .populate({
-        path: 'blogPostId',
-        select: 'title slug',
-        options: { strictPopulate: false } // Allow null blogPostId
-      })
       .populate('createdBy', 'email')
       .sort({ submittedAt: -1, createdAt: -1 })
       .limit(parseInt(limit, 10))
       .skip(parseInt(offset, 10));
 
+    // Manually fetch blog post titles for submissions that have blogPostId
+    const submissionsWithBlogData = await Promise.all(
+      submissions.map(async (submission) => {
+        const submissionObj = submission.toObject();
+
+        if (submissionObj.blogPostId) {
+          try {
+            const blogPost = await BlogPost.findById(submissionObj.blogPostId);
+            if (blogPost) {
+              submissionObj.blogPost = {
+                title: blogPost.title,
+                slug: blogPost.slug
+              };
+            }
+          } catch (err) {
+            console.error(`[Submissions] Error fetching blog post ${submissionObj.blogPostId}:`, err.message);
+          }
+        }
+
+        return submissionObj;
+      })
+    );
+
     const total = await SubmissionTracking.countDocuments(query);
 
     res.json({
       success: true,
-      count: submissions.length,
+      count: submissionsWithBlogData.length,
       total,
-      data: submissions
+      data: submissionsWithBlogData
     });
   } catch (error) {
     console.error('[Submissions] Get submissions error:', error);
@@ -118,7 +138,6 @@ async function getSubmissionById(req, res) {
     const { id } = req.params;
 
     const submission = await SubmissionTracking.findById(id)
-      .populate('blogPostId', 'title slug content')
       .populate('createdBy', 'email')
       .populate('lastUpdatedBy', 'email')
       .populate('notes.author', 'email');
@@ -130,9 +149,27 @@ async function getSubmissionById(req, res) {
       });
     }
 
+    const submissionObj = submission.toObject();
+
+    // Manually fetch blog post data if blogPostId exists
+    if (submissionObj.blogPostId) {
+      try {
+        const blogPost = await BlogPost.findById(submissionObj.blogPostId);
+        if (blogPost) {
+          submissionObj.blogPost = {
+            title: blogPost.title,
+            slug: blogPost.slug,
+            content: blogPost.content
+          };
+        }
+      } catch (err) {
+        console.error(`[Submissions] Error fetching blog post:`, err.message);
+      }
+    }
+
     res.json({
       success: true,
-      data: submission
+      data: submissionObj
     });
   } catch (error) {
     console.error('[Submissions] Get submission by ID error:', error);
@@ -282,7 +319,6 @@ async function getSubmissionByBlogPost(req, res) {
     const { blogPostId } = req.params;
 
     const submission = await SubmissionTracking.findOne({ blogPostId })
-      .populate('blogPostId', 'title slug content')
       .populate('createdBy', 'email')
       .populate('lastUpdatedBy', 'email');
 
@@ -293,9 +329,25 @@ async function getSubmissionByBlogPost(req, res) {
       });
     }
 
+    const submissionObj = submission.toObject();
+
+    // Manually fetch blog post data
+    try {
+      const blogPost = await BlogPost.findById(blogPostId);
+      if (blogPost) {
+        submissionObj.blogPost = {
+          title: blogPost.title,
+          slug: blogPost.slug,
+          content: blogPost.content
+        };
+      }
+    } catch (err) {
+      console.error(`[Submissions] Error fetching blog post:`, err.message);
+    }
+
     res.json({
       success: true,
-      data: submission
+      data: submissionObj
     });
   } catch (error) {
     console.error('[Submissions] Get by blog post error:', error);
@@ -370,8 +422,7 @@ async function exportSubmission(req, res) {
     const { id } = req.params;
     const { format = 'json' } = req.query;
 
-    const submission = await SubmissionTracking.findById(id)
-      .populate('blogPostId', 'title content');
+    const submission = await SubmissionTracking.findById(id);
 
     if (!submission) {
       return res.status(404).json({
@@ -383,6 +434,21 @@ async function exportSubmission(req, res) {
     const language = req.query.language || 'en';
     const packageData = submission.exportPackage(language);
 
+    // Add blog post data if blogPostId exists
+    if (submission.blogPostId) {
+      try {
+        const blogPost = await BlogPost.findById(submission.blogPostId);
+        if (blogPost) {
+          packageData.blogPost = {
+            title: blogPost.title,
+            content: blogPost.content
+          };
+        }
+      } catch (err) {
+        console.error(`[Submissions] Error fetching blog post:`, err.message);
+      }
+    }
+
     if (format === 'json') {
       res.json({
         success: true,

src/models/SubmissionTracking.model.js

@@ -218,20 +218,20 @@ SubmissionTrackingSchema.virtual('submissionDurationDays').get(function() {
 
 /**
  * Get submissions by status
+ * NOTE: BlogPost is a native MongoDB class, not Mongoose model, so we can't populate it
  */
 SubmissionTrackingSchema.statics.getByStatus = async function(status) {
   return await this.find({ status })
-    .populate('blogPostId', 'title slug')
     .populate('createdBy', 'email')
     .sort({ submittedAt: -1 });
 };
 
 /**
  * Get submissions for a specific publication
+ * NOTE: BlogPost is a native MongoDB class, not Mongoose model, so we can't populate it
  */
 SubmissionTrackingSchema.statics.getByPublication = async function(publicationId) {
   return await this.find({ publicationId })
-    .populate('blogPostId', 'title slug')
     .sort({ submittedAt: -1 });
 };