Yimaru-BackEnd/internal/repository/lms_courses.go

package repository

import (
	"context"
	"errors"

	dbgen "Yimaru-Backend/gen/db"
	"Yimaru-Backend/internal/domain"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgtype"
)

func courseToDomain(c dbgen.Course) domain.Course {
	out := domain.Course{
		ID:        c.ID,
		ProgramID: c.ProgramID,
		Name:      c.Name,
	}
	out.Description = fromPgText(c.Description)
	out.Thumbnail = fromPgText(c.Thumbnail)
	out.CreatedAt = c.CreatedAt.Time
	if c.UpdatedAt.Valid {
		t := c.UpdatedAt.Time
		out.UpdatedAt = &t
	}
	out.SortOrder = int(c.SortOrder)
	return out
}

func (s *Store) CreateCourse(ctx context.Context, programID int64, input domain.CreateCourseInput) (domain.Course, error) {
	if input.SortOrder != nil {
		q, tx, err := s.BeginTx(ctx)
		if err != nil {
			return domain.Course{}, err
		}
		defer func() { _ = tx.Rollback(ctx) }()
		target := int32(*input.SortOrder)
		if _, err := tx.Exec(ctx,
			`UPDATE courses SET sort_order = sort_order + 1 WHERE program_id = $1 AND sort_order >= $2`,
			programID, target,
		); err != nil {
			return domain.Course{}, err
		}
		c, err := q.CreateCourse(ctx, dbgen.CreateCourseParams{
			ProgramID:   programID,
			Name:        input.Name,
			Description: toPgText(input.Description),
			Thumbnail:   toPgText(input.Thumbnail),
			SortOrder:   pgtype.Int4{Int32: target, Valid: true},
		})
		if err != nil {
			return domain.Course{}, err
		}
		if err := tx.Commit(ctx); err != nil {
			return domain.Course{}, err
		}
		return courseToDomain(c), nil
	}

	c, err := s.queries.CreateCourse(ctx, dbgen.CreateCourseParams{
		ProgramID:   programID,
		Name:        input.Name,
		Description: toPgText(input.Description),
		Thumbnail:   toPgText(input.Thumbnail),
		SortOrder:   pgtype.Int4{Valid: false},
	})
	if err != nil {
		return domain.Course{}, err
	}
	return courseToDomain(c), nil
}

func (s *Store) ListCourseIDsByProgram(ctx context.Context, programID int64) ([]int64, error) {
	return s.queries.ListCourseIDsByProgram(ctx, programID)
}

func (s *Store) GetCourseByID(ctx context.Context, id int64) (domain.Course, error) {
	c, err := s.queries.GetCourseByID(ctx, id)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return domain.Course{}, pgx.ErrNoRows
		}
		return domain.Course{}, err
	}
	out := courseToDomain(dbgen.Course{
		ID:          c.ID,
		ProgramID:   c.ProgramID,
		Name:        c.Name,
		Description: c.Description,
		Thumbnail:   c.Thumbnail,
		SortOrder:   c.SortOrder,
		CreatedAt:   c.CreatedAt,
		UpdatedAt:   c.UpdatedAt,
	})
	out.HasPractice = c.HasPractice
	return out, nil
}

func (s *Store) ListCoursesByProgramID(ctx context.Context, programID int64, limit, offset int32) ([]domain.Course, int64, error) {
	rows, err := s.queries.ListCoursesByProgramID(ctx, dbgen.ListCoursesByProgramIDParams{
		ProgramID: programID,
		Limit:     limit,
		Offset:    offset,
	})
	if err != nil {
		return nil, 0, err
	}
	if len(rows) == 0 {
		return []domain.Course{}, 0, nil
	}
	var total int64
	out := make([]domain.Course, 0, len(rows))
	for i, r := range rows {
		if i == 0 {
			total = r.TotalCount
		}
		co := courseToDomain(dbgen.Course{
			ID:          r.ID,
			ProgramID:   r.ProgramID,
			Name:        r.Name,
			Description: r.Description,
			Thumbnail:   r.Thumbnail,
			CreatedAt:   r.CreatedAt,
			UpdatedAt:   r.UpdatedAt,
			SortOrder:   r.SortOrder,
		})
		co.ModuleCount = int(r.ModuleCount)
		co.LessonCount = int(r.LessonCount)
		co.PracticeCount = int(r.PracticeCount)
		co.HasPractice = r.HasPractice
		out = append(out, co)
	}
	return out, total, nil
}

func (s *Store) UpdateCourse(ctx context.Context, id int64, input domain.UpdateCourseInput) (domain.Course, error) {
	sortParam := optionalInt4Update(input.SortOrder)
	var nameText pgtype.Text
	if input.Name != nil {
		nameText = pgtype.Text{String: *input.Name, Valid: true}
	} else {
		nameText = pgtype.Text{Valid: false}
	}

	if input.SortOrder != nil {
		cur, err := s.GetCourseByID(ctx, id)
		if err != nil {
			return domain.Course{}, err
		}
		oldPos := int32(cur.SortOrder)
		newPos := int32(*input.SortOrder)
		if oldPos != newPos {
			q, tx, err := s.BeginTx(ctx)
			if err != nil {
				return domain.Course{}, err
			}
			defer func() { _ = tx.Rollback(ctx) }()
			if err := repositionCourseSortOrder(ctx, tx, cur.ProgramID, id, oldPos, newPos); err != nil {
				return domain.Course{}, err
			}
			c, err := q.UpdateCourse(ctx, dbgen.UpdateCourseParams{
				ID:          id,
				Name:        nameText,
				Description: optionalTextUpdate(input.Description),
				Thumbnail:   optionalTextUpdate(input.Thumbnail),
				SortOrder:   pgtype.Int4{Valid: false},
			})
			if err != nil {
				return domain.Course{}, err
			}
			if err := tx.Commit(ctx); err != nil {
				return domain.Course{}, err
			}
			out := courseToDomain(c)
			out.HasPractice = cur.HasPractice
			return out, nil
		}
		sortParam = pgtype.Int4{Valid: false}
	}

	c, err := s.queries.UpdateCourse(ctx, dbgen.UpdateCourseParams{
		ID:          id,
		Name:        nameText,
		Description: optionalTextUpdate(input.Description),
		Thumbnail:   optionalTextUpdate(input.Thumbnail),
		SortOrder:   sortParam,
	})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return domain.Course{}, pgx.ErrNoRows
		}
		return domain.Course{}, err
	}
	return courseToDomain(c), nil
}

func (s *Store) DeleteCourse(ctx context.Context, id int64) error {
	return s.queries.DeleteCourse(ctx, id)
}