1 files changed, 136 insertions, 0 deletions
diff --git a/internal/store/modules.go b/internal/store/modules.go
new file mode 100644
index 0000000..c7d9760
--- /dev/null
+++ b/internal/store/modules.go
@@ -0,0 +1,136 @@
+package store
+
+import (
+	"context"
+	"time"
+)
+
+// Module is one building block of a blog's layout: a menu, an archive, a
+// block of custom HTML… placed in one of the areas of the page.
+type Module struct {
+	ID        int64
+	BlogID    int64
+	Area      string // header | left | right | above | below | footer
+	Kind      string // title | logo | menu | archive | recent | html | rss | text | sitemap
+	Title     string // optional heading (side columns and footer)
+	Body      string // custom HTML, or the footer text
+	Count     int    // recent posts to show
+	SortOrder int
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+const moduleCols = `id, blog_id, area, kind, title, body, count, sort_order, created_at, updated_at`
+
+func scanModule(row interface{ Scan(...any) error }) (*Module, error) {
+	var m Module
+	err := row.Scan(&m.ID, &m.BlogID, &m.Area, &m.Kind, &m.Title, &m.Body, &m.Count, &m.SortOrder, &m.CreatedAt, &m.UpdatedAt)
+	if err != nil {
+		return nil, wrap(err)
+	}
+	return &m, nil
+}
+
+// ListModules returns every module of a blog, grouped by area in display order.
+func (s *Store) ListModules(ctx context.Context, blogID int64) ([]Module, error) {
+	rows, err := s.db.Query(ctx, `SELECT `+moduleCols+` FROM modules WHERE blog_id=$1 ORDER BY area, sort_order, id`, blogID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []Module
+	for rows.Next() {
+		m, err := scanModule(rows)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, *m)
+	}
+	return out, rows.Err()
+}
+
+func (s *Store) ModuleByID(ctx context.Context, blogID, id int64) (*Module, error) {
+	return scanModule(s.db.QueryRow(ctx, `SELECT `+moduleCols+` FROM modules WHERE blog_id=$1 AND id=$2`, blogID, id))
+}
+
+// CreateModule appends a module to the end of its area.
+func (s *Store) CreateModule(ctx context.Context, m *Module) (*Module, error) {
+	return scanModule(s.db.QueryRow(ctx, `INSERT INTO modules (blog_id, area, kind, title, body, count, sort_order)
+		VALUES ($1,$2,$3,$4,$5,$6,(SELECT coalesce(max(sort_order),-1)+1 FROM modules WHERE blog_id=$1 AND area=$2)) RETURNING `+moduleCols,
+		m.BlogID, m.Area, m.Kind, m.Title, m.Body, m.Count))
+}
+
+// UpdateModule saves the editable settings; area and kind never change.
+func (s *Store) UpdateModule(ctx context.Context, m *Module) error {
+	_, err := s.db.Exec(ctx, `UPDATE modules SET title=$3, body=$4, count=$5, updated_at=now() WHERE blog_id=$1 AND id=$2`,
+		m.BlogID, m.ID, m.Title, m.Body, m.Count)
+	return wrap(err)
+}
+
+func (s *Store) DeleteModule(ctx context.Context, blogID, id int64) error {
+	_, err := s.db.Exec(ctx, `DELETE FROM modules WHERE blog_id=$1 AND id=$2`, blogID, id)
+	return err
+}
+
+// MoveModule swaps sort_order with the neighbouring module of the same area (dir = -1 up, +1 down).
+func (s *Store) MoveModule(ctx context.Context, blogID, id int64, dir int) error {
+	cur, err := s.ModuleByID(ctx, blogID, id)
+	if err != nil {
+		return err
+	}
+	all, err := s.ListModules(ctx, blogID)
+	if err != nil {
+		return err
+	}
+	var mods []Module
+	idx := -1
+	for _, m := range all {
+		if m.Area != cur.Area {
+			continue
+		}
+		if m.ID == id {
+			idx = len(mods)
+		}
+		mods = append(mods, m)
+	}
+	j := idx + dir
+	if idx < 0 || j < 0 || j >= len(mods) {
+		return nil
+	}
+	mods[idx], mods[j] = mods[j], mods[idx]
+	tx, err := s.db.Begin(ctx)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback(ctx)
+	for i, m := range mods { // renumber the area; keeps orders dense
+		if _, err := tx.Exec(ctx, `UPDATE modules SET sort_order=$3 WHERE blog_id=$1 AND id=$2`, blogID, m.ID, i); err != nil {
+			return err
+		}
+	}
+	return tx.Commit(ctx)
+}
+
+// ResetModules puts the layout back to what a new blog starts with.
+func (s *Store) ResetModules(ctx context.Context, blogID int64) error {
+	tx, err := s.db.Begin(ctx)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback(ctx)
+	if _, err := tx.Exec(ctx, `DELETE FROM modules WHERE blog_id=$1`, blogID); err != nil {
+		return err
+	}
+	if err := insertDefaultModules(ctx, tx, blogID); err != nil {
+		return err
+	}
+	return tx.Commit(ctx)
+}
+
+// insertDefaultModules is the starting layout: title and menu in the header,
+// an RSS link in the footer. Must match what the layout migration gave old blogs.
+func insertDefaultModules(ctx context.Context, tx querier, blogID int64) error {
+	_, err := tx.Exec(ctx, `INSERT INTO modules (blog_id, area, kind, sort_order) VALUES
+		($1,'header','title',0), ($1,'header','menu',1), ($1,'footer','rss',0)`, blogID)
+	return err
+}