Add announcements: blog-wide notices on every page and post

A blog can have any number of announcements ("sections" in the schema):
a book club's next meeting, this month's pick, a holiday closure. Each
has a placement (above or below the posts, or under the menu when the
menu is a left sidebar), a look (highlighted, warning, plain), an order,
and an on/off switch so recurring notices can be kept around while hidden.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

1 files changed, 114 insertions, 0 deletions

diff --git a/internal/store/sections.go b/internal/store/sections.go
new file mode 100644
index 0000000..f112102
--- /dev/null
+++ b/internal/store/sections.go
@@ -0,0 +1,114 @@
+package store
+
+import (
+	"context"
+	"time"
+)
+
+// Section is an announcement shown on every page and post of a blog.
+type Section struct {
+	ID        int64
+	BlogID    int64
+	Title     string
+	BodyMD    string
+	BodyHTML  string
+	Placement string // above | below | sidebar
+	Style     string // plain | note | warning
+	Enabled   bool
+	SortOrder int
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+const sectionCols = `id, blog_id, title, body_md, body_html, placement, style, enabled, sort_order, created_at, updated_at`
+
+func scanSection(row interface{ Scan(...any) error }) (*Section, error) {
+	var s Section
+	err := row.Scan(&s.ID, &s.BlogID, &s.Title, &s.BodyMD, &s.BodyHTML, &s.Placement, &s.Style, &s.Enabled, &s.SortOrder, &s.CreatedAt, &s.UpdatedAt)
+	if err != nil {
+		return nil, wrap(err)
+	}
+	return &s, nil
+}
+
+func (s *Store) collectSections(ctx context.Context, q string, args ...any) ([]Section, error) {
+	rows, err := s.db.Query(ctx, q, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []Section
+	for rows.Next() {
+		sec, err := scanSection(rows)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, *sec)
+	}
+	return out, rows.Err()
+}
+
+func (s *Store) ListSections(ctx context.Context, blogID int64) ([]Section, error) {
+	return s.collectSections(ctx, `SELECT `+sectionCols+` FROM sections WHERE blog_id=$1 ORDER BY sort_order, id`, blogID)
+}
+
+// EnabledSections is what the public blog renders.
+func (s *Store) EnabledSections(ctx context.Context, blogID int64) ([]Section, error) {
+	return s.collectSections(ctx, `SELECT `+sectionCols+` FROM sections WHERE blog_id=$1 AND enabled ORDER BY sort_order, id`, blogID)
+}
+
+func (s *Store) SectionByID(ctx context.Context, blogID, id int64) (*Section, error) {
+	return scanSection(s.db.QueryRow(ctx, `SELECT `+sectionCols+` FROM sections WHERE blog_id=$1 AND id=$2`, blogID, id))
+}
+
+func (s *Store) CreateSection(ctx context.Context, sec *Section) (*Section, error) {
+	return scanSection(s.db.QueryRow(ctx, `INSERT INTO sections (blog_id, title, body_md, body_html, placement, style, enabled, sort_order)
+		VALUES ($1,$2,$3,$4,$5,$6,$7,(SELECT coalesce(max(sort_order),-1)+1 FROM sections WHERE blog_id=$1)) RETURNING `+sectionCols,
+		sec.BlogID, sec.Title, sec.BodyMD, sec.BodyHTML, sec.Placement, sec.Style, sec.Enabled))
+}
+
+func (s *Store) UpdateSection(ctx context.Context, sec *Section) error {
+	_, err := s.db.Exec(ctx, `UPDATE sections SET title=$3, body_md=$4, body_html=$5, placement=$6, style=$7, enabled=$8, updated_at=now() WHERE blog_id=$1 AND id=$2`,
+		sec.BlogID, sec.ID, sec.Title, sec.BodyMD, sec.BodyHTML, sec.Placement, sec.Style, sec.Enabled)
+	return wrap(err)
+}
+
+func (s *Store) SetSectionEnabled(ctx context.Context, blogID, id int64, on bool) error {
+	_, err := s.db.Exec(ctx, `UPDATE sections SET enabled=$3, updated_at=now() WHERE blog_id=$1 AND id=$2`, blogID, id, on)
+	return err
+}
+
+func (s *Store) DeleteSection(ctx context.Context, blogID, id int64) error {
+	_, err := s.db.Exec(ctx, `DELETE FROM sections WHERE blog_id=$1 AND id=$2`, blogID, id)
+	return err
+}
+
+// MoveSection swaps sort_order with the neighbouring section (dir = -1 up, +1 down).
+func (s *Store) MoveSection(ctx context.Context, blogID, id int64, dir int) error {
+	secs, err := s.ListSections(ctx, blogID)
+	if err != nil {
+		return err
+	}
+	idx := -1
+	for i := range secs {
+		if secs[i].ID == id {
+			idx = i
+		}
+	}
+	j := idx + dir
+	if idx < 0 || j < 0 || j >= len(secs) {
+		return nil
+	}
+	secs[idx], secs[j] = secs[j], secs[idx]
+	tx, err := s.db.Begin(ctx)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback(ctx)
+	for i, sec := range secs { // renumber everything; keeps orders dense
+		if _, err := tx.Exec(ctx, `UPDATE sections SET sort_order=$3 WHERE blog_id=$1 AND id=$2`, blogID, sec.ID, i); err != nil {
+			return err
+		}
+	}
+	return tx.Commit(ctx)
+}