feat: add flashcard entities and migration

Author: uouake

backend/src/infrastructure/db/flashcard.entities.ts

@@ -0,0 +1,54 @@
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  PrimaryGeneratedColumn,
+} from 'typeorm';
+
+@Entity({ name: 'flashcards' })
+export class FlashcardEntity {
+  @PrimaryGeneratedColumn('uuid')
+  id!: string;
+
+  @Column({ type: 'text', unique: true })
+  conceptKey!: string;
+
+  @Column({ type: 'text' })
+  front!: string;
+
+  @Column({ type: 'text' })
+  back!: string;
+
+  @Column({ type: 'text' })
+  category!: string;
+
+  @Column({ type: 'int', default: 1 })
+  difficulty!: number;
+
+  @CreateDateColumn({ type: 'timestamptz' })
+  createdAt!: Date;
+}
+
+@Entity({ name: 'flashcard_progress' })
+export class FlashcardProgressEntity {
+  @PrimaryGeneratedColumn('uuid')
+  id!: string;
+
+  @Column({ type: 'uuid' })
+  userId!: string;
+
+  @Column({ type: 'uuid' })
+  flashcardId!: string;
+
+  @Column({ type: 'boolean', default: false })
+  known!: boolean;
+
+  @Column({ type: 'int', default: 0 })
+  reviewCount!: number;
+
+  @CreateDateColumn({ type: 'timestamptz' })
+  createdAt!: Date;
+
+  @Column({ type: 'timestamptz', nullable: true })
+  lastReviewedAt!: Date | null;
+}

backend/src/infrastructure/db/migrations/003-add-flashcards-tables.sql

@@ -0,0 +1,33 @@
+-- Migration: Create flashcards tables
+-- Created: 2024-02-11
+
+-- Flashcards table: stores AWS concept flashcards
+CREATE TABLE IF NOT EXISTS flashcards (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    concept_key TEXT NOT NULL UNIQUE,
+    front TEXT NOT NULL,
+    back TEXT NOT NULL,
+    category TEXT NOT NULL,
+    difficulty INTEGER DEFAULT 1,
+    created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Index for concept key lookups
+CREATE INDEX IF NOT EXISTS idx_flashcards_concept_key ON flashcards(concept_key);
+CREATE INDEX IF NOT EXISTS idx_flashcards_category ON flashcards(category);
+
+-- Flashcard progress table: tracks user learning progress
+CREATE TABLE IF NOT EXISTS flashcard_progress (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    flashcard_id UUID NOT NULL REFERENCES flashcards(id) ON DELETE CASCADE,
+    known BOOLEAN DEFAULT FALSE,
+    review_count INTEGER DEFAULT 0,
+    created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+    last_reviewed_at TIMESTAMPTZ,
+    UNIQUE(user_id, flashcard_id)
+);
+
+-- Indexes for performance
+CREATE INDEX IF NOT EXISTS idx_flashcard_progress_user_id ON flashcard_progress(user_id);
+CREATE INDEX IF NOT EXISTS idx_flashcard_progress_flashcard_id ON flashcard_progress(flashcard_id);

backend/src/infrastructure/db/typeorm.config.ts

@@ -1,6 +1,6 @@
 import { DataSourceOptions } from 'typeorm';
 import { requireEnv, envInt, env } from '../../config/env';
-import { QuestionEntity, UserEntity, AttemptEntity, ChapterEntity, UserChapterProgressEntity } from './typeorm.entities';
+import { QuestionEntity, UserEntity, AttemptEntity, ChapterEntity, UserChapterProgressEntity, FlashcardEntity, FlashcardProgressEntity } from './typeorm.entities';
 
 // Parse DATABASE_URL if provided (Render style), otherwise use individual vars
 function parseDatabaseUrl(): { host: string; port: number; username: string; password: string; database: string } | null {
@@ -45,7 +45,7 @@ export function makeTypeOrmOptions(): DataSourceOptions {
 
     // Entities are the TypeORM representations of our DB tables.
     // They are NOT the same thing as Domain entities.
-    entities: [QuestionEntity, UserEntity, AttemptEntity, ChapterEntity, UserChapterProgressEntity],
+    entities: [QuestionEntity, UserEntity, AttemptEntity, ChapterEntity, UserChapterProgressEntity, FlashcardEntity, FlashcardProgressEntity],
 
     // Migrations are generated as TypeScript during development.
     // When we build (`nest build`), they will be compiled to JS under dist/.

backend/src/infrastructure/db/typeorm.entities.ts

@@ -12,6 +12,7 @@ import {
 export { UserEntity } from './user.entity';
 export { AttemptEntity } from './attempt.entity';
 export { ChapterEntity, UserChapterProgressEntity } from './chapter.entities';
+export { FlashcardEntity, FlashcardProgressEntity } from './flashcard.entities';
 
 // Database entity for a question.
 //

backend/src/scripts/seed-flashcards.ts

@@ -1,5 +1,5 @@
-import { DataSource } from 'typeorm';
 import { AppDataSource } from '../infrastructure/db/data-source';
+import { FlashcardEntity } from '../infrastructure/db/flashcard.entities';
 
 const flashcards = [
   {
@@ -221,7 +221,7 @@ async function seedFlashcards() {
     await AppDataSource.initialize();
     console.log('📊 Database connected');
 
-    const flashcardRepository = AppDataSource.getRepository('Flashcard');
+    const flashcardRepository = AppDataSource.getRepository(FlashcardEntity);
 
     // Check if flashcards already exist
     const count = await flashcardRepository.count();