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 examPrepCatalogCourseToDomain(c dbgen.ExamPrepCatalogCourse) domain.ExamPrepCatalogCourse {
	out := domain.ExamPrepCatalogCourse{
		ID:        c.ID,
		Name:      c.Name,
		Category:  c.Category,
		SortOrder: int(c.SortOrder),
	}
	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
	}
	return out
}

func (s *Store) CreateExamPrepCatalogCourse(ctx context.Context, input domain.CreateExamPrepCatalogCourseInput) (domain.ExamPrepCatalogCourse, error) {
	c, err := s.queries.ExamPrepCreateCatalogCourse(ctx, dbgen.ExamPrepCreateCatalogCourseParams{
		Name:        input.Name,
		Description: toPgText(input.Description),
		Category:    input.Category,
		Thumbnail:   toPgText(input.Thumbnail),
	})
	if err != nil {
		return domain.ExamPrepCatalogCourse{}, err
	}
	return examPrepCatalogCourseToDomain(c), nil
}

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

func (s *Store) ListExamPrepCatalogCourses(ctx context.Context, limit, offset int32) ([]domain.ExamPrepCatalogCourse, int64, error) {
	rows, err := s.queries.ExamPrepListCatalogCourses(ctx, dbgen.ExamPrepListCatalogCoursesParams{
		Limit:  limit,
		Offset: offset,
	})
	if err != nil {
		return nil, 0, err
	}
	if len(rows) == 0 {
		return []domain.ExamPrepCatalogCourse{}, 0, nil
	}
	var total int64
	out := make([]domain.ExamPrepCatalogCourse, 0, len(rows))
	for i, r := range rows {
		if i == 0 {
			total = r.TotalCount
		}
		item := examPrepCatalogCourseToDomain(dbgen.ExamPrepCatalogCourse{
			ID:          r.ID,
			Name:        r.Name,
			Description: r.Description,
			Category:    r.Category,
			Thumbnail:   r.Thumbnail,
			SortOrder:   r.SortOrder,
			CreatedAt:   r.CreatedAt,
			UpdatedAt:   r.UpdatedAt,
		})
		item.UnitsCount = &r.UnitsCount
		item.ModulesCount = &r.ModulesCount
		item.LessonsCount = &r.LessonsCount
		item.HasPractice = r.HasPractice
		out = append(out, item)
	}
	return out, total, nil
}

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

func (s *Store) UpdateExamPrepCatalogCourse(ctx context.Context, id int64, input domain.UpdateExamPrepCatalogCourseInput) (domain.ExamPrepCatalogCourse, error) {
	var nameText pgtype.Text
	if input.Name != nil {
		nameText = pgtype.Text{String: *input.Name, Valid: true}
	} else {
		nameText = pgtype.Text{Valid: false}
	}
	c, err := s.queries.ExamPrepUpdateCatalogCourse(ctx, dbgen.ExamPrepUpdateCatalogCourseParams{
		ID:          id,
		Name:        nameText,
		Description: optionalTextUpdate(input.Description),
		Category:    optionalTextUpdate(input.Category),
		Thumbnail:   optionalTextUpdate(input.Thumbnail),
		SortOrder:   optionalInt4Update(input.SortOrder),
	})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return domain.ExamPrepCatalogCourse{}, pgx.ErrNoRows
		}
		return domain.ExamPrepCatalogCourse{}, err
	}
	return examPrepCatalogCourseToDomain(c), nil
}

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