feat: add group waitlist functionality

- Introduced GroupWaitlistEntry model in Prisma schema to manage waitlisted users for groups.
- Implemented API route to add users to the group waitlist with validation.
- Enhanced attendee creation logic to handle group capacity and waitlisting scenarios.
- Added new problem builders for handling waitlist-related errors.
- Updated frontend to support waitlist interactions, including modals for capacity warnings.
- Created tests for waitlist functionality, ensuring proper handling of full groups and existing waitlist entries.

apps/backend/src/modules/attendees/features/add-to-waitlist/route.ts

@@ -0,0 +1,21 @@
+import { type CreateGroupWaitlistEntry, CreateGroupWaitlistEntrySchema } from '@gruperly/shared';
+import { Hono } from 'hono';
+import { problemJson, resultJson, unauthorizedProblem } from '@/http/problem-details';
+import { validate } from '@/http/validate';
+import { AddToGroupWaitlist } from './use-case';
+
+const route = new Hono();
+
+route.post('/:groupId/waitlist', validate.json(CreateGroupWaitlistEntrySchema), async (c) => {
+  const user = c.get('user');
+  if (!user) {
+    return problemJson(c, unauthorizedProblem(c.req.path));
+  }
+  const groupId = c.req.param('groupId');
+  const body = c.req.valid('json') as CreateGroupWaitlistEntry;
+  const useCase = new AddToGroupWaitlist();
+  const result = await useCase.execute(groupId, user.id, body);
+  return resultJson(c, result, { status: 201 });
+});
+
+export default route;

apps/backend/src/modules/attendees/features/add-to-waitlist/use-case.ts

@@ -0,0 +1,112 @@
+import type { PrismaClient } from '@generated/prisma/client';
+import type { CreateGroupWaitlistEntry, GroupWaitlistEntryDto, ProblemDetails, Result } from '@gruperly/shared';
+import { err, ok } from '@gruperly/shared';
+import {
+  alreadyWaitlistedProblem,
+  conflictProblem,
+  noGroupAccessProblem,
+  notFoundResourceProblem,
+} from '@/http/problem-builders';
+import prisma from '@/lib/prisma';
+import { normalizePhone } from '../../lib/helpers';
+
+type AddToGroupWaitlistDeps = {
+  db?: Pick<PrismaClient, 'group' | 'attendee' | 'groupWaitlistEntry'>;
+};
+
+type GroupWaitlistRecord = {
+  id: string;
+  groupId: string;
+  fullName: string;
+  phone: string;
+  email: string | null;
+  notes: string | null;
+  status: GroupWaitlistEntryDto['status'];
+  createdAt: Date;
+  updatedAt: Date;
+};
+
+function toGroupWaitlistEntryDto(record: GroupWaitlistRecord): GroupWaitlistEntryDto {
+  return {
+    id: record.id,
+    groupId: record.groupId,
+    fullName: record.fullName,
+    phone: record.phone,
+    email: record.email,
+    notes: record.notes,
+    status: record.status,
+    createdAt: record.createdAt.toISOString(),
+    updatedAt: record.updatedAt.toISOString(),
+  };
+}
+
+export class AddToGroupWaitlist {
+  constructor(private readonly deps: AddToGroupWaitlistDeps = {}) {}
+
+  async execute(
+    groupId: string,
+    userId: string,
+    payload: CreateGroupWaitlistEntry,
+  ): Promise<Result<GroupWaitlistEntryDto, ProblemDetails>> {
+    const db = this.deps.db ?? prisma;
+
+    const group = await db.group.findUnique({
+      where: { id: groupId },
+      include: {
+        members: { where: { userId } },
+      },
+    });
+
+    if (!group) {
+      return err(notFoundResourceProblem('Group', groupId));
+    }
+
+    const isOwner = group.createdById === userId;
+    const isMember = group.members.length > 0;
+    if (!isOwner && !isMember) {
+      return err(noGroupAccessProblem());
+    }
+
+    const phone = normalizePhone(payload.phone);
+
+    const existingAttendee = await db.attendee.findFirst({
+      where: {
+        groupId,
+        OR: [
+          { phone },
+          { phone: payload.phone.trim() },
+        ],
+      },
+    });
+
+    if (existingAttendee) {
+      return err(
+        conflictProblem({
+          detail: 'Ya existe un alumno registrado con este número de teléfono en este grupo.',
+          code: 'attendee_already_registered',
+        }),
+      );
+    }
+
+    const existingWaitlistEntry = await db.groupWaitlistEntry.findFirst({
+      where: { groupId, phone },
+    });
+
+    if (existingWaitlistEntry) {
+      return err(alreadyWaitlistedProblem());
+    }
+
+    const fullName = `${payload.firstName.trim()} ${payload.lastName.trim()}`.trim();
+    const entry = await db.groupWaitlistEntry.create({
+      data: {
+        groupId,
+        fullName,
+        phone,
+        email: payload.email?.trim() || null,
+        notes: payload.notes?.trim() || null,
+      },
+    });
+
+    return ok(toGroupWaitlistEntryDto(entry as unknown as GroupWaitlistRecord));
+  }
+}

apps/backend/src/modules/attendees/features/create/route.ts

@@ -13,8 +13,9 @@ route.post('/:groupId/attendees', validate.json(CreateAttendeeSchema), async (c)
   }
   const groupId = c.req.param('groupId');
   const body = c.req.valid('json') as CreateAttendee;
+  const allowOverflow = c.req.query('allowOverflow') === 'true';
   const useCase = new CreateAttendeeUseCase();
-  const result = await useCase.execute(groupId, user.id, body);
+  const result = await useCase.execute(groupId, user.id, body, { allowOverflow });
   return resultJson(c, result, { status: 201 });
 });
 

apps/backend/src/modules/attendees/features/create/use-case.ts

@@ -1,12 +1,22 @@
 import type { PrismaClient } from '@generated/prisma/client';
-import type { AttendeeDto, CreateAttendee, ProblemDetails, Result } from '@gruperly/shared';
+import type { CreateAttendee, CreateAttendeeResult, ProblemDetails, Result } from '@gruperly/shared';
 import { err, ok } from '@gruperly/shared';
-import { conflictProblem, noGroupAccessProblem, notFoundResourceProblem } from '@/http/problem-builders';
+import {
+  alreadyWaitlistedProblem,
+  capacityReachedProblem,
+  conflictProblem,
+  noGroupAccessProblem,
+  notFoundResourceProblem,
+} from '@/http/problem-builders';
 import prisma from '@/lib/prisma';
 import { type AttendeeRecord, normalizePhone, toAttendeeDto } from '../../lib/helpers';
 
 type CreateAttendeeDeps = {
-  db?: Pick<PrismaClient, 'group' | 'attendee'>;
+  db?: Pick<PrismaClient, 'group' | 'attendee' | 'groupWaitlistEntry'>;
+};
+
+type CreateAttendeeOptions = {
+  allowOverflow?: boolean;
 };
 
 export class CreateAttendeeUseCase {
@@ -16,7 +26,8 @@ export class CreateAttendeeUseCase {
     groupId: string,
     userId: string,
     payload: CreateAttendee,
-  ): Promise<Result<AttendeeDto, ProblemDetails>> {
+    options: CreateAttendeeOptions = {},
+  ): Promise<Result<CreateAttendeeResult, ProblemDetails>> {
     const db = this.deps.db ?? prisma;
 
     const group = await db.group.findUnique({
@@ -57,6 +68,42 @@ export class CreateAttendeeUseCase {
     }
 
     const fullName = `${payload.firstName.trim()} ${payload.lastName.trim()}`.trim();
+
+    if (group.capacity !== null) {
+      const currentCount = await db.attendee.count({ where: { groupId } });
+
+      if (currentCount >= group.capacity) {
+        if (isOwner && !options.allowOverflow) {
+          return err(capacityReachedProblem(group.capacity));
+        }
+
+        if (!isOwner) {
+          const existingWaitlistEntry = await db.groupWaitlistEntry.findFirst({
+            where: { groupId, phone },
+          });
+
+          if (existingWaitlistEntry) {
+            return err(alreadyWaitlistedProblem());
+          }
+
+          await db.groupWaitlistEntry.create({
+            data: {
+              groupId,
+              fullName,
+              phone,
+              email: payload.email?.trim() || null,
+              notes: payload.notes?.trim() || null,
+            },
+          });
+
+          return ok({
+            outcome: 'waitlisted',
+            message: `${fullName} fue agregado a la lista de espera del grupo.`,
+          });
+        }
+      }
+    }
+
     const attendee = await db.attendee.create({
       data: {
         groupId,
@@ -67,6 +114,9 @@ export class CreateAttendeeUseCase {
       },
     });
 
-    return ok(toAttendeeDto(attendee as unknown as AttendeeRecord));
+    return ok({
+      outcome: 'created',
+      attendee: toAttendeeDto(attendee as unknown as AttendeeRecord),
+    });
   }
-}
+}