fix(tester): extend ListProblems endpoint

internal/models/problem.go

@@ -16,3 +16,12 @@ type Problem struct {
 	CreatedAt    time.Time `db:"created_at"`
 	UpdatedAt    time.Time `db:"updated_at"`
 }
+
+type ProblemListItem struct {
+	Id          int32     `db:"id"`
+	Title       string    `db:"title"`
+	MemoryLimit int32     `db:"memory_limit"`
+	TimeLimit   int32     `db:"time_limit"`
+	CreatedAt   time.Time `db:"created_at"`
+	UpdatedAt   time.Time `db:"updated_at"`
+}

internal/tester/delivery.go

@@ -14,7 +14,7 @@ type Handlers interface {
 	AddParticipant(c *fiber.Ctx, id int32, params testerv1.AddParticipantParams) error
 	DeleteTask(c *fiber.Ctx, id int32, params testerv1.DeleteTaskParams) error
 	AddTask(c *fiber.Ctx, id int32, params testerv1.AddTaskParams) error
-	ListProblems(c *fiber.Ctx) error
+	ListProblems(c *fiber.Ctx, params testerv1.ListProblemsParams) error
 	CreateProblem(c *fiber.Ctx) error
 	DeleteProblem(c *fiber.Ctx, id int32) error
 	GetProblem(c *fiber.Ctx, id int32) error

internal/tester/delivery/rest/handlers.go

@@ -23,8 +23,35 @@ func (h *TesterHandlers) ListContests(c *fiber.Ctx) error {
 	return c.SendStatus(fiber.StatusNotImplemented)
 }
 
-func (h *TesterHandlers) ListProblems(c *fiber.Ctx) error {
+func (h *TesterHandlers) ListProblems(c *fiber.Ctx, params testerv1.ListProblemsParams) error {
-	return c.SendStatus(fiber.StatusNotImplemented)
+	problems, count, err := h.problemsUC.ListProblems(c.Context(), params.Page, params.PageSize)
+	if err != nil {
+		return c.SendStatus(pkg.ToREST(err))
+	}
+
+	resp := testerv1.ListProblemsResponse{
+		Problems: make([]testerv1.ProblemListItem, len(problems)),
+		Page:     params.Page,
+		MaxPage: func() int32 {
+			if count%params.PageSize == 0 {
+				return count / params.PageSize
+			}
+			return count/params.PageSize + 1
+		}(),
+	}
+
+	for i, problem := range problems {
+		resp.Problems[i] = testerv1.ProblemListItem{
+			Id:          problem.Id,
+			Title:       problem.Title,
+			MemoryLimit: problem.MemoryLimit,
+			TimeLimit:   problem.TimeLimit,
+			CreatedAt:   problem.CreatedAt,
+			UpdatedAt:   problem.UpdatedAt,
+		}
+	}
+
+	return c.JSON(resp)
 }
 
 func (h *TesterHandlers) CreateContest(c *fiber.Ctx) error {

internal/tester/pg_repository.go

@@ -9,6 +9,7 @@ type ProblemPostgresRepository interface {
 	CreateProblem(ctx context.Context, title string) (int32, error)
 	ReadProblemById(ctx context.Context, id int32) (*models.Problem, error)
 	DeleteProblem(ctx context.Context, id int32) error
+	ListProblems(ctx context.Context, page int32, pageSize int32) ([]*models.ProblemListItem, int32, error)
 }
 
 type ContestRepository interface {

internal/tester/repository/pg_problems_repository.go

@@ -67,3 +67,33 @@ func (r *ProblemRepository) DeleteProblem(ctx context.Context, id int32) error {
 
 	return nil
 }
+
+const (
+	ListProblemsQuery = `SELECT id, title, time_limit, memory_limit, created_at, updated_at
+FROM problems
+LIMIT ? OFFSET ?`
+	CountProblemsQuery = "SELECT COUNT(*) FROM problems"
+)
+
+func (r *ProblemRepository) ListProblems(ctx context.Context, page int32, pageSize int32) ([]*models.ProblemListItem, int32, error) {
+	const op = "ContestRepository.ListProblems"
+
+	if pageSize > 20 || pageSize < 1 {
+		pageSize = 1
+	}
+
+	var problems []*models.ProblemListItem
+	query := r.db.Rebind(ListProblemsQuery)
+	err := r.db.SelectContext(ctx, &problems, query, pageSize, (page-1)*pageSize)
+	if err != nil {
+		return nil, 0, handlePgErr(err, op)
+	}
+
+	var count int32
+	err = r.db.GetContext(ctx, &count, CountProblemsQuery)
+	if err != nil {
+		return nil, 0, handlePgErr(err, op)
+	}
+
+	return problems, count, nil
+}

internal/tester/usecase.go

@@ -9,6 +9,7 @@ type ProblemUseCase interface {
 	CreateProblem(ctx context.Context, title string) (int32, error)
 	ReadProblemById(ctx context.Context, id int32) (*models.Problem, error)
 	DeleteProblem(ctx context.Context, id int32) error
+	ListProblems(ctx context.Context, page int32, pageSize int32) ([]*models.ProblemListItem, int32, error)
 }
 
 type ContestUseCase interface {

internal/tester/usecase/problems_usecase.go

@@ -32,3 +32,7 @@ func (u *ProblemUseCase) ReadProblemById(ctx context.Context, id int32) (*models
 func (u *ProblemUseCase) DeleteProblem(ctx context.Context, id int32) error {
 	return u.problemRepo.DeleteProblem(ctx, id)
 }
+
+func (u *ProblemUseCase) ListProblems(ctx context.Context, page int32, pageSize int32) ([]*models.ProblemListItem, int32, error) {
+	return u.problemRepo.ListProblems(ctx, page, pageSize)
+}