Add lessons Phase 3: enrollments with capacity and time conflict checks

Links members to schedule slots via enrollments. Enforces max_students
capacity on slots and prevents members from double-booking the same
day/time. Supports status transitions and filtering. 11 new tests
(51 total lessons tests).

packages/backend/src/db/migrations/0030_enrollments.sql

@@ -0,0 +1,19 @@
+-- Phase 3: Enrollments — member enrollment in a schedule slot
+
+CREATE TYPE "enrollment_status" AS ENUM ('active', 'paused', 'cancelled', 'completed');
+
+CREATE TABLE "enrollment" (
+  "id" uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  "member_id" uuid NOT NULL REFERENCES "member"("id"),
+  "account_id" uuid NOT NULL REFERENCES "account"("id"),
+  "schedule_slot_id" uuid NOT NULL REFERENCES "schedule_slot"("id"),
+  "instructor_id" uuid NOT NULL REFERENCES "instructor"("id"),
+  "status" enrollment_status NOT NULL DEFAULT 'active',
+  "start_date" date NOT NULL,
+  "end_date" date,
+  "monthly_rate" numeric(10,2),
+  "makeup_credits" integer NOT NULL DEFAULT 0,
+  "notes" text,
+  "created_at" timestamptz NOT NULL DEFAULT now(),
+  "updated_at" timestamptz NOT NULL DEFAULT now()
+);

packages/backend/src/db/migrations/meta/_journal.json

@@ -211,6 +211,13 @@
       "when": 1774890000000,
       "tag": "0029_schedule_slots",
       "breakpoints": true
+    },
+    {
+      "idx": 30,
+      "version": "7",
+      "when": 1774900000000,
+      "tag": "0030_enrollments",
+      "breakpoints": true
     }
   ]
 }

packages/backend/src/db/schema/lessons.ts

@@ -4,12 +4,15 @@ import {
   varchar,
   text,
   time,
+  date,
+  numeric,
   timestamp,
   boolean,
   integer,
   pgEnum,
 } from 'drizzle-orm/pg-core'
 import { users } from './users.js'
+import { accounts, members } from './accounts.js'
 
 // --- Enums ---
 
@@ -57,6 +60,37 @@ export const scheduleSlots = pgTable('schedule_slot', {
   updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
 })
 
+export const enrollmentStatusEnum = pgEnum('enrollment_status', [
+  'active',
+  'paused',
+  'cancelled',
+  'completed',
+])
+
+export const enrollments = pgTable('enrollment', {
+  id: uuid('id').primaryKey().defaultRandom(),
+  memberId: uuid('member_id')
+    .notNull()
+    .references(() => members.id),
+  accountId: uuid('account_id')
+    .notNull()
+    .references(() => accounts.id),
+  scheduleSlotId: uuid('schedule_slot_id')
+    .notNull()
+    .references(() => scheduleSlots.id),
+  instructorId: uuid('instructor_id')
+    .notNull()
+    .references(() => instructors.id),
+  status: enrollmentStatusEnum('status').notNull().default('active'),
+  startDate: date('start_date').notNull(),
+  endDate: date('end_date'),
+  monthlyRate: numeric('monthly_rate', { precision: 10, scale: 2 }),
+  makeupCredits: integer('makeup_credits').notNull().default(0),
+  notes: text('notes'),
+  createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+  updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
+})
+
 // --- Type exports ---
 
 export type Instructor = typeof instructors.$inferSelect
@@ -65,3 +99,5 @@ export type LessonType = typeof lessonTypes.$inferSelect
 export type LessonTypeInsert = typeof lessonTypes.$inferInsert
 export type ScheduleSlot = typeof scheduleSlots.$inferSelect
 export type ScheduleSlotInsert = typeof scheduleSlots.$inferInsert
+export type Enrollment = typeof enrollments.$inferSelect
+export type EnrollmentInsert = typeof enrollments.$inferInsert

packages/backend/src/routes/v1/lessons.ts

@@ -7,8 +7,11 @@ import {
   LessonTypeUpdateSchema,
   ScheduleSlotCreateSchema,
   ScheduleSlotUpdateSchema,
+  EnrollmentCreateSchema,
+  EnrollmentUpdateSchema,
+  EnrollmentStatusUpdateSchema,
 } from '@lunarfront/shared/schemas'
-import { InstructorService, LessonTypeService, ScheduleSlotService } from '../../services/lesson.service.js'
+import { InstructorService, LessonTypeService, ScheduleSlotService, EnrollmentService } from '../../services/lesson.service.js'
 
 export const lessonRoutes: FastifyPluginAsync = async (app) => {
   // --- Instructors ---
@@ -147,4 +150,60 @@ export const lessonRoutes: FastifyPluginAsync = async (app) => {
     if (!slot) return reply.status(404).send({ error: { message: 'Schedule slot not found', statusCode: 404 } })
     return reply.send(slot)
   })
+
+  // --- Enrollments ---
+
+  app.post('/enrollments', { preHandler: [app.authenticate, app.requirePermission('lessons.edit')] }, async (request, reply) => {
+    const parsed = EnrollmentCreateSchema.safeParse(request.body)
+    if (!parsed.success) {
+      return reply.status(400).send({ error: { message: 'Validation failed', details: parsed.error.flatten(), statusCode: 400 } })
+    }
+    const result = await EnrollmentService.create(app.db, parsed.data)
+    if ('error' in result) {
+      return reply.status(409).send({ error: { message: result.error, statusCode: 409 } })
+    }
+    return reply.status(201).send(result)
+  })
+
+  app.get('/enrollments', { preHandler: [app.authenticate, app.requirePermission('lessons.view')] }, async (request, reply) => {
+    const query = request.query as Record<string, string | undefined>
+    const params = PaginationSchema.parse(query)
+    const filters = {
+      memberId: query.memberId,
+      accountId: query.accountId,
+      instructorId: query.instructorId,
+      status: query.status?.split(',').filter(Boolean),
+    }
+    const result = await EnrollmentService.list(app.db, params, filters)
+    return reply.send(result)
+  })
+
+  app.get('/enrollments/:id', { preHandler: [app.authenticate, app.requirePermission('lessons.view')] }, async (request, reply) => {
+    const { id } = request.params as { id: string }
+    const enrollment = await EnrollmentService.getById(app.db, id)
+    if (!enrollment) return reply.status(404).send({ error: { message: 'Enrollment not found', statusCode: 404 } })
+    return reply.send(enrollment)
+  })
+
+  app.patch('/enrollments/:id', { preHandler: [app.authenticate, app.requirePermission('lessons.edit')] }, async (request, reply) => {
+    const { id } = request.params as { id: string }
+    const parsed = EnrollmentUpdateSchema.safeParse(request.body)
+    if (!parsed.success) {
+      return reply.status(400).send({ error: { message: 'Validation failed', details: parsed.error.flatten(), statusCode: 400 } })
+    }
+    const enrollment = await EnrollmentService.update(app.db, id, parsed.data)
+    if (!enrollment) return reply.status(404).send({ error: { message: 'Enrollment not found', statusCode: 404 } })
+    return reply.send(enrollment)
+  })
+
+  app.post('/enrollments/:id/status', { preHandler: [app.authenticate, app.requirePermission('lessons.edit')] }, async (request, reply) => {
+    const { id } = request.params as { id: string }
+    const parsed = EnrollmentStatusUpdateSchema.safeParse(request.body)
+    if (!parsed.success) {
+      return reply.status(400).send({ error: { message: 'Validation failed', details: parsed.error.flatten(), statusCode: 400 } })
+    }
+    const enrollment = await EnrollmentService.updateStatus(app.db, id, parsed.data.status)
+    if (!enrollment) return reply.status(404).send({ error: { message: 'Enrollment not found', statusCode: 404 } })
+    return reply.send(enrollment)
+  })
 }

packages/backend/src/services/lesson.service.ts

@@ -1,6 +1,6 @@
-import { eq, and, count, type Column, type SQL } from 'drizzle-orm'
+import { eq, and, ne, count, type Column, type SQL } from 'drizzle-orm'
 import type { PostgresJsDatabase } from 'drizzle-orm/postgres-js'
-import { instructors, lessonTypes, scheduleSlots } from '../db/schema/lessons.js'
+import { instructors, lessonTypes, scheduleSlots, enrollments } from '../db/schema/lessons.js'
 import type {
   InstructorCreateInput,
   InstructorUpdateInput,
@@ -8,6 +8,8 @@ import type {
   LessonTypeUpdateInput,
   ScheduleSlotCreateInput,
   ScheduleSlotUpdateInput,
+  EnrollmentCreateInput,
+  EnrollmentUpdateInput,
   PaginationInput,
 } from '@lunarfront/shared/schemas'
 import {
@@ -279,3 +281,127 @@ export const ScheduleSlotService = {
     return slot ?? null
   },
 }
+
+export const EnrollmentService = {
+  async create(db: PostgresJsDatabase<any>, input: EnrollmentCreateInput) {
+    // Check slot capacity for group lessons
+    const slot = await ScheduleSlotService.getById(db, input.scheduleSlotId)
+    if (!slot) return { error: 'Schedule slot not found' }
+
+    const [{ activeCount }] = await db
+      .select({ activeCount: count() })
+      .from(enrollments)
+      .where(
+        and(
+          eq(enrollments.scheduleSlotId, input.scheduleSlotId),
+          eq(enrollments.status, 'active'),
+        ),
+      )
+    if (activeCount >= slot.maxStudents) {
+      return { error: 'Schedule slot is at capacity' }
+    }
+
+    // Check member not already enrolled in a slot at same day/time
+    const memberSlots = await db
+      .select({
+        dayOfWeek: scheduleSlots.dayOfWeek,
+        startTime: scheduleSlots.startTime,
+      })
+      .from(enrollments)
+      .innerJoin(scheduleSlots, eq(enrollments.scheduleSlotId, scheduleSlots.id))
+      .where(
+        and(
+          eq(enrollments.memberId, input.memberId),
+          eq(enrollments.status, 'active'),
+        ),
+      )
+    const hasConflict = memberSlots.some(
+      (s) => s.dayOfWeek === slot.dayOfWeek && s.startTime === slot.startTime,
+    )
+    if (hasConflict) {
+      return { error: 'Member already has a lesson at this day and time' }
+    }
+
+    const [enrollment] = await db
+      .insert(enrollments)
+      .values({
+        memberId: input.memberId,
+        accountId: input.accountId,
+        scheduleSlotId: input.scheduleSlotId,
+        instructorId: input.instructorId,
+        status: 'active',
+        startDate: input.startDate,
+        endDate: input.endDate,
+        monthlyRate: input.monthlyRate?.toString(),
+        notes: input.notes,
+      })
+      .returning()
+    return enrollment
+  },
+
+  async getById(db: PostgresJsDatabase<any>, id: string) {
+    const [enrollment] = await db
+      .select()
+      .from(enrollments)
+      .where(eq(enrollments.id, id))
+      .limit(1)
+    return enrollment ?? null
+  },
+
+  async list(db: PostgresJsDatabase<any>, params: PaginationInput, filters?: {
+    memberId?: string
+    accountId?: string
+    instructorId?: string
+    status?: string[]
+  }) {
+    const conditions: SQL[] = []
+
+    if (filters?.memberId) conditions.push(eq(enrollments.memberId, filters.memberId))
+    if (filters?.accountId) conditions.push(eq(enrollments.accountId, filters.accountId))
+    if (filters?.instructorId) conditions.push(eq(enrollments.instructorId, filters.instructorId))
+    if (filters?.status?.length) {
+      const { inArray } = await import('drizzle-orm')
+      conditions.push(inArray(enrollments.status, filters.status as any))
+    }
+
+    const where = conditions.length > 0 ? and(...conditions) : undefined
+
+    const sortableColumns: Record<string, Column> = {
+      start_date: enrollments.startDate,
+      status: enrollments.status,
+      created_at: enrollments.createdAt,
+    }
+
+    let query = db.select().from(enrollments).where(where).$dynamic()
+    query = withSort(query, params.sort, params.order, sortableColumns, enrollments.createdAt)
+    query = withPagination(query, params.page, params.limit)
+
+    const [data, [{ total }]] = await Promise.all([
+      query,
+      db.select({ total: count() }).from(enrollments).where(where),
+    ])
+
+    return paginatedResponse(data, total, params.page, params.limit)
+  },
+
+  async update(db: PostgresJsDatabase<any>, id: string, input: EnrollmentUpdateInput) {
+    const values: Record<string, unknown> = { ...input, updatedAt: new Date() }
+    if (input.monthlyRate !== undefined) values.monthlyRate = input.monthlyRate.toString()
+
+    const [enrollment] = await db
+      .update(enrollments)
+      .set(values)
+      .where(eq(enrollments.id, id))
+      .returning()
+    return enrollment ?? null
+  },
+
+  async updateStatus(db: PostgresJsDatabase<any>, id: string, status: string) {
+    const [enrollment] = await db
+      .update(enrollments)
+      .set({ status: status as any, updatedAt: new Date() })
+      .where(eq(enrollments.id, id))
+      .returning()
+    return enrollment ?? null
+  },
+}