feat: articles pagination

test/article_test.go

@@ -7,6 +7,11 @@ import (
 	"sort"
 	"strings"
 	"testing"
+	"unicode"
+
+	"golang.org/x/text/runes"
+	"golang.org/x/text/transform"
+	"golang.org/x/text/unicode/norm"
 )
 
 type mockArticleRepo struct {
@@ -47,6 +52,85 @@ func (m *mockArticleRepo) FindByFilters(filters article.Filters) ([]article.Arti
 	return result, nil
 }
 
+func (m *mockArticleRepo) FindPage(filters article.Filters) (article.PageResult, error) {
+	if err := m.fail.trigger("FindPage"); err != nil {
+		return article.PageResult{}, err
+	}
+	matching := make([]article.Article, 0)
+	for _, a := range m.articles {
+		if filters.IsOnline != nil && a.IsOnline != *filters.IsOnline {
+			continue
+		}
+		if filters.Status == article.StatusOnline && !a.IsOnline {
+			continue
+		}
+		if filters.Status == article.StatusDraft && a.IsOnline {
+			continue
+		}
+		if filters.Q != "" && !strings.Contains(foldArticleSearch(a.Title), foldArticleSearch(filters.Q)) {
+			continue
+		}
+		matching = append(matching, a)
+	}
+	sort.Slice(matching, func(i, j int) bool { return articleSortsBefore(matching[i], matching[j], filters.Sort) })
+	start := min((filters.Page-1)*filters.Size, len(matching))
+	end := min(start+filters.Size, len(matching))
+	return article.PageResult{Items: matching[start:end], Total: len(matching)}, nil
+}
+
+func (m *mockArticleRepo) CountByVisibility(onlineOnly bool) (article.Counts, error) {
+	if err := m.fail.trigger("CountByVisibility"); err != nil {
+		return article.Counts{}, err
+	}
+	counts := article.Counts{}
+	for _, a := range m.articles {
+		if a.IsOnline {
+			counts.Online++
+		} else if !onlineOnly {
+			counts.Draft++
+		}
+	}
+	counts.All = counts.Online + counts.Draft
+	return counts, nil
+}
+
+func articleSortsBefore(left, right article.Article, order article.Sort) bool {
+	if order.Field == "" {
+		order = article.DefaultSort()
+	}
+	var comparison int
+	switch order.Field {
+	case article.SortByTitle:
+		comparison = strings.Compare(strings.ToLower(left.Title), strings.ToLower(right.Title))
+	case article.SortByStatus:
+		if left.IsOnline != right.IsOnline {
+			comparison = 1
+			if !left.IsOnline {
+				comparison = -1
+			}
+		}
+	case article.SortByCreatedAt:
+		comparison = left.CreatedAt.Compare(right.CreatedAt)
+	default:
+		comparison = left.UpdatedAt.Compare(right.UpdatedAt)
+	}
+	if order.Direction == article.SortDesc {
+		comparison = -comparison
+	}
+	if comparison != 0 {
+		return comparison < 0
+	}
+	return left.ID > right.ID
+}
+
+func foldArticleSearch(value string) string {
+	folded, _, err := transform.String(transform.Chain(norm.NFD, runes.Remove(runes.In(unicode.Mn)), norm.NFC), value)
+	if err != nil {
+		return strings.ToLower(value)
+	}
+	return strings.ToLower(folded)
+}
+
 func (m *mockArticleRepo) Get(id uint32) (article.Article, error) {
 	if err := m.fail.trigger("Get"); err != nil {
 		return article.Article{}, err