Add lessons Phase 2: schedule slots with conflict detection

Recurring weekly time slots linking instructors to lesson types.
Includes day/time overlap detection, instructor and day-of-week
filtering, and 17 new integration tests (40 total lessons tests).

packages/backend/src/db/migrations/0029_schedule_slots.sql

@@ -0,0 +1,14 @@
+-- Phase 2: Schedule slots — recurring weekly time slots
+
+CREATE TABLE "schedule_slot" (
+  "id" uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  "instructor_id" uuid NOT NULL REFERENCES "instructor"("id"),
+  "lesson_type_id" uuid NOT NULL REFERENCES "lesson_type"("id"),
+  "day_of_week" integer NOT NULL,
+  "start_time" time NOT NULL,
+  "room" varchar(100),
+  "max_students" integer NOT NULL DEFAULT 1,
+  "is_active" boolean NOT NULL DEFAULT true,
+  "created_at" timestamptz NOT NULL DEFAULT now(),
+  "updated_at" timestamptz NOT NULL DEFAULT now()
+);

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

@@ -204,6 +204,13 @@
       "when": 1774880000000,
       "tag": "0028_lessons_foundation",
       "breakpoints": true
+    },
+    {
+      "idx": 29,
+      "version": "7",
+      "when": 1774890000000,
+      "tag": "0029_schedule_slots",
+      "breakpoints": true
     }
   ]
 }

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

@@ -3,6 +3,7 @@ import {
   uuid,
   varchar,
   text,
+  time,
   timestamp,
   boolean,
   integer,
@@ -39,9 +40,28 @@ export const lessonTypes = pgTable('lesson_type', {
   updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
 })
 
+export const scheduleSlots = pgTable('schedule_slot', {
+  id: uuid('id').primaryKey().defaultRandom(),
+  instructorId: uuid('instructor_id')
+    .notNull()
+    .references(() => instructors.id),
+  lessonTypeId: uuid('lesson_type_id')
+    .notNull()
+    .references(() => lessonTypes.id),
+  dayOfWeek: integer('day_of_week').notNull(), // 0=Sunday, 6=Saturday
+  startTime: time('start_time').notNull(),
+  room: varchar('room', { length: 100 }),
+  maxStudents: integer('max_students').notNull().default(1),
+  isActive: boolean('is_active').notNull().default(true),
+  createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+  updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
+})
+
 // --- Type exports ---
 
 export type Instructor = typeof instructors.$inferSelect
 export type InstructorInsert = typeof instructors.$inferInsert
 export type LessonType = typeof lessonTypes.$inferSelect
 export type LessonTypeInsert = typeof lessonTypes.$inferInsert
+export type ScheduleSlot = typeof scheduleSlots.$inferSelect
+export type ScheduleSlotInsert = typeof scheduleSlots.$inferInsert

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

@@ -5,8 +5,10 @@ import {
   InstructorUpdateSchema,
   LessonTypeCreateSchema,
   LessonTypeUpdateSchema,
+  ScheduleSlotCreateSchema,
+  ScheduleSlotUpdateSchema,
 } from '@lunarfront/shared/schemas'
-import { InstructorService, LessonTypeService } from '../../services/lesson.service.js'
+import { InstructorService, LessonTypeService, ScheduleSlotService } from '../../services/lesson.service.js'
 
 export const lessonRoutes: FastifyPluginAsync = async (app) => {
   // --- Instructors ---
@@ -92,4 +94,57 @@ export const lessonRoutes: FastifyPluginAsync = async (app) => {
     if (!lessonType) return reply.status(404).send({ error: { message: 'Lesson type not found', statusCode: 404 } })
     return reply.send(lessonType)
   })
+
+  // --- Schedule Slots ---
+
+  app.post('/schedule-slots', { preHandler: [app.authenticate, app.requirePermission('lessons.admin')] }, async (request, reply) => {
+    const parsed = ScheduleSlotCreateSchema.safeParse(request.body)
+    if (!parsed.success) {
+      return reply.status(400).send({ error: { message: 'Validation failed', details: parsed.error.flatten(), statusCode: 400 } })
+    }
+    const result = await ScheduleSlotService.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('/schedule-slots', { 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 = {
+      instructorId: query.instructorId,
+      dayOfWeek: query.dayOfWeek !== undefined ? Number(query.dayOfWeek) : undefined,
+    }
+    const result = await ScheduleSlotService.list(app.db, params, filters)
+    return reply.send(result)
+  })
+
+  app.get('/schedule-slots/:id', { preHandler: [app.authenticate, app.requirePermission('lessons.view')] }, async (request, reply) => {
+    const { id } = request.params as { id: string }
+    const slot = await ScheduleSlotService.getById(app.db, id)
+    if (!slot) return reply.status(404).send({ error: { message: 'Schedule slot not found', statusCode: 404 } })
+    return reply.send(slot)
+  })
+
+  app.patch('/schedule-slots/:id', { preHandler: [app.authenticate, app.requirePermission('lessons.admin')] }, async (request, reply) => {
+    const { id } = request.params as { id: string }
+    const parsed = ScheduleSlotUpdateSchema.safeParse(request.body)
+    if (!parsed.success) {
+      return reply.status(400).send({ error: { message: 'Validation failed', details: parsed.error.flatten(), statusCode: 400 } })
+    }
+    const result = await ScheduleSlotService.update(app.db, id, parsed.data)
+    if (!result) return reply.status(404).send({ error: { message: 'Schedule slot not found', statusCode: 404 } })
+    if ('error' in result) {
+      return reply.status(409).send({ error: { message: result.error, statusCode: 409 } })
+    }
+    return reply.send(result)
+  })
+
+  app.delete('/schedule-slots/:id', { preHandler: [app.authenticate, app.requirePermission('lessons.admin')] }, async (request, reply) => {
+    const { id } = request.params as { id: string }
+    const slot = await ScheduleSlotService.delete(app.db, id)
+    if (!slot) return reply.status(404).send({ error: { message: 'Schedule slot not found', statusCode: 404 } })
+    return reply.send(slot)
+  })
 }

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

@@ -1,11 +1,13 @@
-import { eq, and, count, type Column } from 'drizzle-orm'
+import { eq, and, count, type Column, type SQL } from 'drizzle-orm'
 import type { PostgresJsDatabase } from 'drizzle-orm/postgres-js'
-import { instructors, lessonTypes } from '../db/schema/lessons.js'
+import { instructors, lessonTypes, scheduleSlots } from '../db/schema/lessons.js'
 import type {
   InstructorCreateInput,
   InstructorUpdateInput,
   LessonTypeCreateInput,
   LessonTypeUpdateInput,
+  ScheduleSlotCreateInput,
+  ScheduleSlotUpdateInput,
   PaginationInput,
 } from '@lunarfront/shared/schemas'
 import {
@@ -152,3 +154,128 @@ export const LessonTypeService = {
     return lessonType ?? null
   },
 }
+
+export const ScheduleSlotService = {
+  async create(db: PostgresJsDatabase<any>, input: ScheduleSlotCreateInput) {
+    // Check for overlapping slot on same instructor, day, and time
+    const [conflict] = await db
+      .select({ id: scheduleSlots.id })
+      .from(scheduleSlots)
+      .where(
+        and(
+          eq(scheduleSlots.instructorId, input.instructorId),
+          eq(scheduleSlots.dayOfWeek, input.dayOfWeek),
+          eq(scheduleSlots.startTime, input.startTime),
+          eq(scheduleSlots.isActive, true),
+        ),
+      )
+      .limit(1)
+    if (conflict) {
+      return { error: 'Instructor already has a slot at this day and time' }
+    }
+
+    const [slot] = await db
+      .insert(scheduleSlots)
+      .values({
+        instructorId: input.instructorId,
+        lessonTypeId: input.lessonTypeId,
+        dayOfWeek: input.dayOfWeek,
+        startTime: input.startTime,
+        room: input.room,
+        maxStudents: input.maxStudents,
+      })
+      .returning()
+    return slot
+  },
+
+  async getById(db: PostgresJsDatabase<any>, id: string) {
+    const [slot] = await db
+      .select()
+      .from(scheduleSlots)
+      .where(eq(scheduleSlots.id, id))
+      .limit(1)
+    return slot ?? null
+  },
+
+  async list(db: PostgresJsDatabase<any>, params: PaginationInput, filters?: {
+    instructorId?: string
+    dayOfWeek?: number
+  }) {
+    const conditions: SQL[] = [eq(scheduleSlots.isActive, true)]
+
+    if (params.q) {
+      const search = buildSearchCondition(params.q, [scheduleSlots.room])
+      if (search) conditions.push(search)
+    }
+    if (filters?.instructorId) {
+      conditions.push(eq(scheduleSlots.instructorId, filters.instructorId))
+    }
+    if (filters?.dayOfWeek !== undefined) {
+      conditions.push(eq(scheduleSlots.dayOfWeek, filters.dayOfWeek))
+    }
+
+    const where = and(...conditions)
+
+    const sortableColumns: Record<string, Column> = {
+      day_of_week: scheduleSlots.dayOfWeek,
+      start_time: scheduleSlots.startTime,
+      room: scheduleSlots.room,
+      created_at: scheduleSlots.createdAt,
+    }
+
+    let query = db.select().from(scheduleSlots).where(where).$dynamic()
+    query = withSort(query, params.sort, params.order, sortableColumns, scheduleSlots.dayOfWeek)
+    query = withPagination(query, params.page, params.limit)
+
+    const [data, [{ total }]] = await Promise.all([
+      query,
+      db.select({ total: count() }).from(scheduleSlots).where(where),
+    ])
+
+    return paginatedResponse(data, total, params.page, params.limit)
+  },
+
+  async update(db: PostgresJsDatabase<any>, id: string, input: ScheduleSlotUpdateInput) {
+    // If changing day/time/instructor, check for conflicts
+    if (input.instructorId || input.dayOfWeek !== undefined || input.startTime) {
+      const existing = await ScheduleSlotService.getById(db, id)
+      if (!existing) return null
+
+      const checkInstructorId = input.instructorId ?? existing.instructorId
+      const checkDay = input.dayOfWeek ?? existing.dayOfWeek
+      const checkTime = input.startTime ?? existing.startTime
+
+      const [conflict] = await db
+        .select({ id: scheduleSlots.id })
+        .from(scheduleSlots)
+        .where(
+          and(
+            eq(scheduleSlots.instructorId, checkInstructorId),
+            eq(scheduleSlots.dayOfWeek, checkDay),
+            eq(scheduleSlots.startTime, checkTime),
+            eq(scheduleSlots.isActive, true),
+          ),
+        )
+        .limit(1)
+      if (conflict && conflict.id !== id) {
+        return { error: 'Instructor already has a slot at this day and time' }
+      }
+    }
+
+    const [slot] = await db
+      .update(scheduleSlots)
+      .set({ ...input, updatedAt: new Date() })
+      .where(eq(scheduleSlots.id, id))
+      .returning()
+    return slot ?? null
+  },
+
+  async delete(db: PostgresJsDatabase<any>, id: string) {
+    const [slot] = await db
+      .update(scheduleSlots)
+      .set({ isActive: false, updatedAt: new Date() })
+      .where(eq(scheduleSlots.id, id))
+      .returning()
+    return slot ?? null
+  },
+}