add smart random

src/modules/decks/decks.controller.ts

@@ -22,13 +22,15 @@ import {
   GetAllDecksCommand,
   GetDeckByIdCommand,
   UpdateDeckCommand,
+  CreateCardCommand,
 } from './use-cases'
 import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard'
 import { GetAllDecksDto } from './dto/get-all-decks.dto'
 import { GetAllCardsInDeckDto } from '../cards/dto/get-all-cards.dto'
-import { CreateCardCommand } from './use-cases'
 import { CreateCardDto } from '../cards/dto/create-card.dto'
 import { Pagination } from '../../infrastructure/common/pagination/pagination.service'
+import { GetRandomCardInDeckCommand } from './use-cases/get-random-card-in-deck-use-case'
+import { SaveGradeCommand } from './use-cases/save-grade-use-case'
 
 @Controller('decks')
 export class DecksController {
@@ -57,9 +59,21 @@ export class DecksController {
   @UseGuards(JwtAuthGuard)
   @Get(':id/cards')
   findCardsInDeck(@Param('id') id: string, @Req() req, @Query() query: GetAllCardsInDeckDto) {
-    return this.commandBus.execute(new GetAllCardsInDeckCommand(req.user.id, id, query))
+    const finalQuery = Pagination.getPaginationData(query)
+    return this.commandBus.execute(new GetAllCardsInDeckCommand(req.user.id, id, finalQuery))
+  }
+  @UseGuards(JwtAuthGuard)
+  @Get(':id/learn')
+  findRandomCardInDeck(@Param('id') id: string, @Req() req) {
+    return this.commandBus.execute(new GetRandomCardInDeckCommand(req.user.id, id))
+  }
+  @UseGuards(JwtAuthGuard)
+  @Post(':id/learn')
+  saveGrade(@Param('id') id: string, @Req() req, @Body() body: any) {
+    return this.commandBus.execute(
+      new SaveGradeCommand(req.user.id, { cardId: body.cardId, grade: body.grade })
+    )
   }
-
   @UseGuards(JwtAuthGuard)
   @Post(':id/cards')
   createCardInDeck(@Param('id') id: string, @Req() req, @Body() card: CreateCardDto) {

src/modules/decks/decks.module.ts

@@ -13,21 +13,26 @@ import {
 } from './use-cases'
 import { DecksRepository } from './infrastructure/decks.repository'
 import { CardsRepository } from '../cards/infrastructure/cards.repository'
+import { GetRandomCardInDeckHandler } from './use-cases/get-random-card-in-deck-use-case'
+import { GradesRepository } from './infrastructure/grades.repository'
+import { SaveGradeHandler } from './use-cases/save-grade-use-case'
 
 const commandHandlers = [
   CreateDeckHandler,
   GetAllDecksHandler,
   GetDeckByIdHandler,
+  GetRandomCardInDeckHandler,
   DeleteDeckByIdHandler,
   UpdateDeckHandler,
   GetAllCardsInDeckHandler,
   CreateCardHandler,
+  SaveGradeHandler,
 ]
 
 @Module({
   imports: [CqrsModule],
   controllers: [DecksController],
-  providers: [DecksService, DecksRepository, CardsRepository, ...commandHandlers],
+  providers: [DecksService, DecksRepository, CardsRepository, GradesRepository, ...commandHandlers],
   exports: [CqrsModule],
 })
 export class DecksModule {}

src/modules/decks/dto/create-grade.dto.ts

@@ -0,0 +1,10 @@
+import { IsUUID, Max, Min } from 'class-validator'
+
+export class CreateDeckDto {
+  @Min(1)
+  @Max(5)
+  grade: number
+
+  @IsUUID()
+  cardId: string
+}

src/modules/decks/dto/get-all-decks.dto.ts

@@ -1,6 +1,7 @@
 import { IsUUID } from 'class-validator'
 import { IsOptionalOrEmptyString } from '../../../infrastructure/decorators/is-optional-or-empty-string'
 import { PaginationDto } from '../../../infrastructure/common/pagination/pagination.dto'
+import { IsOrderBy } from '../../../infrastructure/decorators/is-order-by-constraint'
 
 export class GetAllDecksDto extends PaginationDto {
   @IsOptionalOrEmptyString()
@@ -17,4 +18,7 @@ export class GetAllDecksDto extends PaginationDto {
   authorId?: string
 
   userId: string
+
+  @IsOrderBy()
+  orderBy?: string | null
 }

src/modules/decks/infrastructure/decks.repository.ts

@@ -2,6 +2,7 @@ import { Injectable, InternalServerErrorException, Logger } from '@nestjs/common
 import { PrismaService } from '../../../prisma.service'
 import { GetAllDecksDto } from '../dto/get-all-decks.dto'
 import { Pagination } from '../../../infrastructure/common/pagination/pagination.service'
+import { createPrismaOrderBy } from '../../../infrastructure/common/helpers/get-order-by-object'
 
 @Injectable()
 export class DecksRepository {
@@ -48,13 +49,15 @@ export class DecksRepository {
     itemsPerPage,
     minCardsCount,
     maxCardsCount,
+    orderBy,
   }: GetAllDecksDto) {
-    console.log({ name, authorId, userId, currentPage, itemsPerPage, minCardsCount, maxCardsCount })
+    console.log(minCardsCount)
+    console.log(Number(minCardsCount))
     try {
       const where = {
         cardsCount: {
-          gte: Number(minCardsCount) ?? undefined,
-          lte: Number(maxCardsCount) ?? undefined,
+          gte: minCardsCount ? Number(minCardsCount) : undefined,
+          lte: maxCardsCount ? Number(maxCardsCount) : undefined,
         },
         name: {
           contains: name,
@@ -85,9 +88,7 @@ export class DecksRepository {
         }),
         this.prisma.deck.findMany({
           where,
-          orderBy: {
-            created: 'desc',
-          },
+          orderBy: createPrismaOrderBy(orderBy),
           include: {
             author: {
               select: {
@@ -124,6 +125,24 @@ export class DecksRepository {
       throw new InternalServerErrorException(e?.message)
     }
   }
+  public async findDeckByCardId(cardId: string) {
+    try {
+      const card = await this.prisma.card.findUnique({
+        where: {
+          id: cardId,
+        },
+      })
+
+      return await this.prisma.deck.findUnique({
+        where: {
+          id: card.deckId,
+        },
+      })
+    } catch (e) {
+      this.logger.error(e?.message)
+      throw new InternalServerErrorException(e?.message)
+    }
+  }
 
   public async deleteDeckById(id: string) {
     try {

src/modules/decks/infrastructure/grades.repository.ts

@@ -0,0 +1,59 @@
+import { Injectable, InternalServerErrorException, Logger } from '@nestjs/common'
+import { PrismaService } from '../../../prisma.service'
+
+@Injectable()
+export class GradesRepository {
+  constructor(private prisma: PrismaService) {}
+
+  private readonly logger = new Logger(GradesRepository.name)
+
+  async createGrade({
+    cardId,
+    userId,
+    deckId,
+    grade,
+  }: {
+    cardId: string
+    userId: string
+    deckId: string
+    grade: number
+  }) {
+    try {
+      return await this.prisma.grade.upsert({
+        where: {
+          userId,
+          cardId,
+          deckId,
+        },
+        update: {
+          grade,
+          shots: {
+            increment: 1,
+          },
+        },
+        create: {
+          grade,
+          shots: 1,
+          user: {
+            connect: {
+              id: userId,
+            },
+          },
+          card: {
+            connect: {
+              id: cardId,
+            },
+          },
+          deck: {
+            connect: {
+              id: deckId,
+            },
+          },
+        },
+      })
+    } catch (e) {
+      this.logger.error(e?.message)
+      throw new InternalServerErrorException(e?.message)
+    }
+  }
+}

src/modules/decks/use-cases/get-all-cards-in-deck-use-case.ts

@@ -2,6 +2,7 @@ import { CommandHandler, ICommandHandler } from '@nestjs/cqrs'
 import { CardsRepository } from '../../cards/infrastructure/cards.repository'
 import { GetAllCardsInDeckDto } from '../../cards/dto/get-all-cards.dto'
 import { ForbiddenException, NotFoundException } from '@nestjs/common'
+import { DecksRepository } from '../infrastructure/decks.repository'
 
 export class GetAllCardsInDeckCommand {
   constructor(
@@ -13,10 +14,13 @@ export class GetAllCardsInDeckCommand {
 
 @CommandHandler(GetAllCardsInDeckCommand)
 export class GetAllCardsInDeckHandler implements ICommandHandler<GetAllCardsInDeckCommand> {
-  constructor(private readonly cardsRepository: CardsRepository) {}
+  constructor(
+    private readonly cardsRepository: CardsRepository,
+    private readonly decksRepository: DecksRepository
+  ) {}
 
   async execute(command: GetAllCardsInDeckCommand) {
-    const deck = await this.cardsRepository.findDeckById(command.deckId)
+    const deck = await this.decksRepository.findDeckById(command.deckId)
     if (!deck) throw new NotFoundException(`Deck with id ${command.deckId} not found`)
 
     if (deck.userId !== command.userId && deck.isPrivate) {

src/modules/decks/use-cases/get-random-card-in-deck-use-case.ts

@@ -0,0 +1,53 @@
+import { CommandHandler, ICommandHandler } from '@nestjs/cqrs'
+import { CardsRepository } from '../../cards/infrastructure/cards.repository'
+import { ForbiddenException, NotFoundException } from '@nestjs/common'
+import { DecksRepository } from '../infrastructure/decks.repository'
+import { Prisma } from '@prisma/client'
+import { pick } from 'remeda'
+
+export class GetRandomCardInDeckCommand {
+  constructor(public readonly userId: string, public readonly deckId: string) {}
+}
+type CardWithGrade = Prisma.cardGetPayload<{ include: { grades: true } }>
+@CommandHandler(GetRandomCardInDeckCommand)
+export class GetRandomCardInDeckHandler implements ICommandHandler<GetRandomCardInDeckCommand> {
+  constructor(
+    private readonly cardsRepository: CardsRepository,
+    private readonly decksRepository: DecksRepository
+  ) {}
+  private async getSmartRandomCard(cards: Array<CardWithGrade>) {
+    const selectionPool: Array<CardWithGrade> = []
+    cards.forEach(card => {
+      // Calculate the average grade for the card
+      const averageGrade =
+        card.grades.length === 0
+          ? 0
+          : card.grades.reduce((acc, grade) => acc + grade.grade, 0) / card.grades.length
+      // Calculate weight for the card, higher weight for lower grade card
+      const weight = 6 - averageGrade
+
+      // Add the card to the selection pool `weight` times
+      for (let i = 0; i < weight; i++) {
+        selectionPool.push(card)
+      }
+    })
+
+    return selectionPool[Math.floor(Math.random() * selectionPool.length)]
+  }
+
+  async execute(command: GetRandomCardInDeckCommand) {
+    const deck = await this.decksRepository.findDeckById(command.deckId)
+    if (!deck) throw new NotFoundException(`Deck with id ${command.deckId} not found`)
+
+    if (deck.userId !== command.userId && deck.isPrivate) {
+      throw new ForbiddenException(`You can't get a private deck that you don't own`)
+    }
+
+    const cards = await this.cardsRepository.findCardsByDeckIdWithGrade(
+      command.userId,
+      command.deckId
+    )
+    const smartRandomCard = await this.getSmartRandomCard(cards)
+    return pick(smartRandomCard, ['id', 'question', 'answer', 'deckId'])
+  }
+}

src/modules/decks/use-cases/save-grade-use-case.ts

@@ -0,0 +1,41 @@
+import { CommandHandler, ICommandHandler } from '@nestjs/cqrs'
+import { CardsRepository } from '../../cards/infrastructure/cards.repository'
+import { ForbiddenException, NotFoundException } from '@nestjs/common'
+import { DecksRepository } from '../infrastructure/decks.repository'
+import { GradesRepository } from '../infrastructure/grades.repository'
+
+export class SaveGradeCommand {
+  constructor(
+    public readonly userId: string,
+    public readonly args: {
+      cardId: string
+      grade: number
+    }
+  ) {}
+}
+
+@CommandHandler(SaveGradeCommand)
+export class SaveGradeHandler implements ICommandHandler<SaveGradeCommand> {
+  constructor(
+    private readonly cardsRepository: CardsRepository,
+    private readonly decksRepository: DecksRepository,
+    private readonly gradesRepository: GradesRepository
+  ) {}
+
+  async execute(command: SaveGradeCommand) {
+    const deck = await this.decksRepository.findDeckByCardId(command.args.cardId)
+    if (!deck)
+      throw new NotFoundException(`Deck containing card with id ${command.args.cardId} not found`)
+
+    if (deck.userId !== command.userId && deck.isPrivate) {
+      throw new ForbiddenException(`You can't save cards to  a private deck that you don't own`)
+    }
+
+    return await this.gradesRepository.createGrade({
+      userId: command.userId,
+      grade: command.args.grade,
+      cardId: command.args.cardId,
+      deckId: deck.id,
+    })
+  }
+}