feat: add book search by title, author and topic

app/app.go

@@ -355,3 +355,12 @@ func IsUniqueViolation(err error) (column string, ok bool) {
 
 	return pgErr.ColumnName, true
 }
+
+// Value dereferences a pointer and returns the value, or zero value if nil.
+func Value[T any](p *T) (v T) {
+	if p == nil {
+		return
+	}
+
+	return *p
+}

app/ds/book.go

@@ -117,6 +117,8 @@ func BookFromContext(ctx context.Context) *Book {
 // BooksFilter is used to filter and paginate user queries.
 type BooksFilter struct {
 	EntitiesFilter
+
+	Author string
 }
 
 // BookAuthor represents an author of a book.

app/ds/ds.go

@@ -72,11 +72,12 @@ func DtBetween(from, to time.Time) *FilterDT {
 
 // FilterString defines options for filtering string-type data.
 type FilterString struct {
-	NotNull     *bool
-	NotEmpty    *bool
-	ExactMatch  *string
-	Contains    *string
-	NotContains *string
-	StartsWith  *string
-	EndsWith    *string
+	Null          *bool
+	Empty         *bool
+	Equal         *string
+	Contains      *string
+	StartsWith    *string
+	EndsWith      *string
+	Not           bool
+	CaseSensitive bool
 }

app/ds/topic.go

@@ -28,6 +28,7 @@ type TopicsFilter struct {
 	Page           int
 	PerPage        int
 	Type           EntityType
+	Name           *FilterString
 	PublicIDs      []string
 	WithCount      bool
 	OrderBy        string

app/repo/book_repo.go

@@ -128,6 +128,11 @@ func (r *Repo) FilterBooks(ctx context.Context, f ds.BooksFilter) (books []ds.Bo
 		)`
 	}
 
+	var whereAuthor string
+	if f.Author != "" {
+		whereAuthor = `EXISTS (SELECT 1 FROM jsonb_to_recordset(b.authors) AS a(name text) WHERE a.name = ?)`
+	}
+
 	count, err = r.filter("entities e", "e").
 		columns(`
 		  e.id AS id,
@@ -152,6 +157,8 @@ func (r *Repo) FilterBooks(ctx context.Context, f ds.BooksFilter) (books []ds.Bo
 		join("LEFT JOIN users u ON e.owner_id = u.id").
 		where("e.type", ds.EntityTypeBook).
 		whereRaw(whereTopics, f.Topics).
+		whereRaw(whereAuthor, f.Author).
+		filterString("e.title", f.Title).
 		paginate(f.Page, f.PerPage).
 		createdAt(f.CreatedAt).
 		deletedAt(f.DeletedAt).
@@ -164,6 +171,11 @@ func (r *Repo) FilterBooks(ctx context.Context, f ds.BooksFilter) (books []ds.Bo
 		withCount(f.WithCount).
 		scan(ctx, &books)
 
+	if err != nil {
+		err = fmt.Errorf("filter books: %w", err)
+		return
+	}
+
 	// topics
 	if len(books) > 0 {
 		ids := make([]ds.ID, len(books))
@@ -196,3 +208,30 @@ func (r *Repo) FilterBooks(ctx context.Context, f ds.BooksFilter) (books []ds.Bo
 
 	return
 }
+
+// SearchBookAuthors searches book authors by name.
+func (r *Repo) SearchBookAuthors(ctx context.Context, query string) ([]ds.BookAuthor, error) {
+	_, span := r.tracer.Start(ctx, "SearchBookAuthors")
+	defer span.End()
+
+	sql := `
+		SELECT DISTINCT a.name
+		FROM entities e
+		JOIN books b ON b.id = e.id
+		JOIN LATERAL jsonb_to_recordset(b.authors) AS a(name text) ON true
+		WHERE e.type = 'book'
+		  AND e.status = 'approved'
+		  AND e.visibility = 'public'
+		  AND e.deleted_at IS NULL
+		  AND a.name ILIKE $1
+		LIMIT 25
+	`
+
+	var rows []ds.BookAuthor
+	err := pgxscan.Select(ctx, r.db, &rows, sql, "%"+query+"%")
+	if err != nil {
+		return nil, fmt.Errorf("search book authors: %w", err)
+	}
+
+	return rows, nil
+}

app/repo/repo.go

@@ -343,6 +343,61 @@ func (b *filterBuilder) withCount(ok bool) *filterBuilder {
 	return b
 }
 
+func (b *filterBuilder) filterString(col string, f *ds.FilterString) *filterBuilder {
+	if f == nil {
+		return b
+	}
+
+	if app.Value(f.Null) {
+		if f.Not {
+			b.qb = b.qb.Where(col + " IS NOT NULL")
+		} else {
+			b.qb = b.qb.Where(col + " IS NULL")
+		}
+	}
+
+	if app.Value(f.Empty) {
+		if f.Not {
+			b.qb = b.qb.Where(col + " != ''")
+		} else {
+			b.qb = b.qb.Where(col + " = ''")
+		}
+	}
+
+	if v := app.Value(f.Equal); v != "" {
+		if f.Not {
+			b.qb = b.qb.Where(col+" != ?", v)
+		} else {
+			b.qb = b.qb.Where(col+" = ?", v)
+		}
+	}
+
+	likeOP := "ILIKE"
+	if f.CaseSensitive {
+		likeOP = "LIKE"
+	}
+	if f.Not {
+		likeOP = "NOT " + likeOP
+	}
+
+	if v := app.Value(f.Contains); v != "" {
+		v = "%" + v + "%"
+		b.qb = b.qb.Where(col+" "+likeOP+" ?", v)
+	}
+
+	if v := app.Value(f.StartsWith); v != "" {
+		v += "%"
+		b.qb = b.qb.Where(col+" "+likeOP+" ?", v)
+	}
+
+	if v := app.Value(f.EndsWith); v != "" {
+		v = "%" + v
+		b.qb = b.qb.Where(col+" "+likeOP+" ?", v)
+	}
+
+	return b
+}
+
 func (b *filterBuilder) sql() (sql string, args []any, err error) {
 	lb := *b
 	if !lb.columnsSet {

app/repo/topic_repo.go

@@ -2,6 +2,7 @@ package repo
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/georgysavva/scany/v2/pgxscan"
 	"github.com/gopl-dev/server/app"
@@ -20,17 +21,21 @@ func (r *Repo) FilterTopics(ctx context.Context, f ds.TopicsFilter) (data []ds.T
 
 	if f.OrderBy == "" {
 		f.OrderBy = "name"
-		f.OrderDirection = "asc"
+		f.OrderDirection = "ASC"
 	}
 
 	count, err = r.filter("topics").
 		columns(`*`).
 		where("type", f.Type).
+		filterString("name", f.Name).
 		paginate(f.Page, f.PerPage).
 		order(f.OrderBy, f.OrderDirection).
 		withCount(f.WithCount).
 		apply(whereIn("public_id", f.PublicIDs)).
 		scan(ctx, &data)
+	if err != nil {
+		err = fmt.Errorf("filter topics: %w", err)
+	}
 
 	return
 }

app/service/book_service.go

@@ -12,6 +12,7 @@ import (
 	"github.com/gopl-dev/server/app/ds/prop"
 	"github.com/gopl-dev/server/app/repo"
 	"github.com/gopl-dev/server/email"
+	"golang.org/x/sync/errgroup"
 )
 
 var (
@@ -588,3 +589,98 @@ func (s *Service) GetBookByRef(ctx context.Context, ref any) (*ds.Book, error) {
 
 	return nil, ErrInvalidRefID
 }
+
+// SearchBookType represents the type of a search result.
+type SearchBookType string
+
+const (
+	// SearchBookTypeBook is a book result.
+	SearchBookTypeBook SearchBookType = "book"
+	// SearchBookTypeAuthor is an author result.
+	SearchBookTypeAuthor SearchBookType = "author"
+	// SearchBookTypeTopic is a topic result.
+	SearchBookTypeTopic SearchBookType = "topic"
+)
+
+// SearchBooksResult represents a single search result item.
+type SearchBooksResult struct {
+	Type SearchBookType `json:"type"`
+	Name string         `json:"name"`
+	URL  string         `json:"url"`
+}
+
+// SearchBooks searches books, books authors and books topics by query string.
+func (s *Service) SearchBooks(ctx context.Context, query string) ([]SearchBooksResult, error) {
+	ctx, span := s.tracer.Start(ctx, "SearchBooks")
+	defer span.End()
+
+	if query == "" {
+		return []SearchBooksResult{}, nil
+	}
+
+	var (
+		books   []ds.Book
+		authors []ds.BookAuthor
+		topics  []ds.Topic
+	)
+
+	g, ctx := errgroup.WithContext(ctx)
+
+	g.Go(func() (err error) {
+		books, _, err = s.db.FilterBooks(ctx, ds.BooksFilter{EntitiesFilter: ds.EntitiesFilter{
+			PerPage:    25, //nolint:mnd
+			WithCount:  false,
+			Title:      &ds.FilterString{Contains: &query},
+			Visibility: []ds.EntityVisibility{ds.EntityVisibilityPublic},
+			Status:     []ds.EntityStatus{ds.EntityStatusApproved},
+		}})
+		return
+	})
+
+	g.Go(func() (err error) {
+		authors, err = s.db.SearchBookAuthors(ctx, query)
+		return
+	})
+
+	g.Go(func() (err error) {
+		topics, _, err = s.db.FilterTopics(ctx, ds.TopicsFilter{
+			PerPage: 25, //nolint:mnd
+			Type:    ds.EntityTypeBook,
+			Name:    &ds.FilterString{Contains: &query},
+		})
+		return
+	})
+
+	err := g.Wait()
+	if err != nil {
+		return nil, err
+	}
+
+	results := make([]SearchBooksResult, 0, len(books)+len(authors)+len(topics))
+
+	for _, r := range books {
+		results = append(results, SearchBooksResult{
+			Type: SearchBookTypeBook,
+			Name: r.Title,
+			URL:  "/books/" + r.PublicID + "/",
+		})
+	}
+
+	for _, r := range authors {
+		results = append(results, SearchBooksResult{
+			Type: SearchBookTypeAuthor,
+			Name: r.Name,
+			URL:  "/books/?author=" + r.Name,
+		})
+	}
+
+	for _, r := range topics {
+		results = append(results, SearchBooksResult{
+			Type: SearchBookTypeTopic,
+			Name: r.Name,
+			URL:  "/books/?topics=" + r.PublicID,
+		})
+	}
+
+	return results, nil
+}