feat: send email notifications on user mentions (#372)

* feat: add notifications schema

* chore: gen migration

* feat: add mention email template

* feat: add sendMentionEmail func

* feat: add repo funcs

* feat: update card router to send emails on mention

* fix: update the editor suggestion to show all members

* feat: skip pending members in sendMentionEmails

* feat: update comments to use tiptap editor

packages/api/src/routers/card.ts

@@ -10,6 +10,7 @@ import * as workspaceRepo from "@kan/db/repository/workspace.repo";
 
 import { createTRPCRouter, protectedProcedure, publicProcedure } from "../trpc";
 import { mergeActivities } from "../utils/activities";
+import { sendMentionEmails } from "../utils/notifications";
 import { assertCanDelete, assertCanEdit, assertPermission } from "../utils/permissions";
 import { generateAttachmentUrl, generateAvatarUrl } from "@kan/shared/utils";
 
@@ -153,6 +154,17 @@ export const cardRouter = createTRPCRouter({
         await cardActivityRepo.bulkCreate(ctx.db, cardActivitesInsert);
       }
 
+      if (input.description) {
+        sendMentionEmails({
+          db: ctx.db,
+          cardPublicId: newCard.publicId,
+          commentHtml: input.description,
+          commenterUserId: userId,
+        }).catch((error) => {
+          console.error("Failed to send mention emails:", error);
+        });
+      }
+
       return newCard;
     }),
   addComment: protectedProcedure
@@ -215,6 +227,16 @@ export const cardRouter = createTRPCRouter({
         createdBy: userId,
       });
 
+      sendMentionEmails({
+        db: ctx.db,
+        cardPublicId: input.cardPublicId,
+        commentHtml: input.comment,
+        commenterUserId: userId,
+        commentId: newComment.id,
+      }).catch((error) => {
+        console.error("Failed to send mention emails:", error);
+      });
+
       return newComment;
     }),
   updateComment: protectedProcedure
@@ -295,6 +317,16 @@ export const cardRouter = createTRPCRouter({
         createdBy: userId,
       });
 
+      sendMentionEmails({
+        db: ctx.db,
+        cardPublicId: input.cardPublicId,
+        commentHtml: input.comment,
+        commenterUserId: userId,
+        commentId: updatedComment.id,
+      }).catch((error) => {
+        console.error("Failed to send mention emails:", error);
+      });
+
       return updatedComment;
     }),
   deleteComment: protectedProcedure
@@ -924,6 +956,15 @@ export const cardRouter = createTRPCRouter({
           fromDescription: existingCard.description ?? undefined,
           toDescription: input.description,
         });
+
+        sendMentionEmails({
+          db: ctx.db,
+          cardPublicId: input.cardPublicId,
+          commentHtml: input.description,
+          commenterUserId: userId,
+        }).catch((error) => {
+          console.error("Failed to send mention emails:", error);
+        });
       }
 
       if (

packages/api/src/utils/notifications.ts

@@ -0,0 +1,133 @@
+import { env } from "next-runtime-env";
+
+import type { dbClient } from "@kan/db/client";
+import * as cardRepo from "@kan/db/repository/card.repo";
+import * as memberRepo from "@kan/db/repository/member.repo";
+import * as notificationRepo from "@kan/db/repository/notification.repo";
+import * as userRepo from "@kan/db/repository/user.repo";
+import * as workspaceRepo from "@kan/db/repository/workspace.repo";
+import { sendEmail } from "@kan/email";
+import { parseMentionsFromHTML } from "@kan/shared/utils";
+
+/**
+ * Sends mention notification emails to mentioned members
+ * Only sends emails for new mentions (checks notification table to avoid duplicates)
+ */
+export async function sendMentionEmails({
+  db,
+  cardPublicId,
+  commentHtml,
+  commenterUserId,
+  commentId,
+}: {
+  db: dbClient;
+  cardPublicId: string;
+  commentHtml: string;
+  commenterUserId: string;
+  commentId?: number;
+}) {
+  try {
+    // Parse mentions from HTML
+    const mentionPublicIds = parseMentionsFromHTML(commentHtml);
+    if (mentionPublicIds.length === 0) return;
+
+    // Get card with board information
+    const card = await cardRepo.getWithListAndMembersByPublicId(db, cardPublicId);
+    if (!card?.list.board) return;
+
+    const board = card.list.board;
+    const boardName = board.name;
+    const cardTitle = card.title;
+    const cardId = card.id;
+
+    // Get workspace ID from workspace publicId
+    const workspace = await workspaceRepo.getByPublicId(
+      db,
+      board.workspace.publicId,
+    );
+    if (!workspace?.id) return;
+
+    const workspaceId = workspace.id;
+
+    // Get commenter information
+    const commenter = await userRepo.getById(db, commenterUserId);
+    if (!commenter) return;
+
+    const commenterName = commenter.name ?? commenter.email;
+
+    // Get mentioned members with full details (filtered by workspace)
+    const membersWithDetails = await memberRepo.getByPublicIdsWithUsers(
+      db,
+      mentionPublicIds,
+      workspaceId,
+    );
+
+    // Filter out the commenter
+    const membersToNotify = membersWithDetails.filter(
+      (member) => member.user?.id !== commenterUserId,
+    );
+
+    if (membersToNotify.length === 0) return;
+
+    const baseUrl = env("NEXT_PUBLIC_BASE_URL");
+    const cardUrl = `${baseUrl}/cards/${cardPublicId}`;
+
+    // Send emails to all mentioned members (only if notification doesn't exist)
+    await Promise.all(
+      membersToNotify.map(async (member) => {
+        const userId = member.user?.id;
+        const email = member.user?.email ?? member.email;
+
+        // Skip pending members (no userId) - they can be mentioned but won't receive emails
+        if (!userId || !email) return;
+
+        try {
+          // Check if notification already exists for this mention
+          const notificationExists = await notificationRepo.exists(db, {
+            userId,
+            cardId,
+            type: "mention",
+          });
+
+          // If notification already exists, skip sending email
+          if (notificationExists) {
+            return;
+          }
+
+          // Create notification record
+          await notificationRepo.create(db, {
+            type: "mention",
+            userId,
+            cardId,
+            commentId,
+          });
+
+          // Send email
+          await sendEmail(
+            email,
+            `${commenterName} mentioned you in a comment on ${cardTitle}`,
+            "MENTION",
+            {
+              commenterName,
+              boardName,
+              cardTitle,
+              cardUrl,
+            },
+          );
+        } catch (error) {
+          console.error("Failed to send mention email:", {
+            email,
+            cardPublicId,
+            error: error instanceof Error ? error.message : String(error),
+          });
+        }
+      }),
+    );
+  } catch (error) {
+    console.error("Error sending mention emails:", {
+      cardPublicId,
+      error: error instanceof Error ? error.message : String(error),
+    });
+  }
+}
+