feat: broadcast

migrations/0052_broadcasts.up.sql

@@ -0,0 +1,44 @@
+-- Admin broadcasts — product updates and announcements, shown once per user.
+--
+-- On "no history": these deliberately create no notification rows and never
+-- appear in the tray. But "exactly once per user" cannot be done without
+-- storing something — the app has to know whether YOU have seen it. So two
+-- tables: the announcement, and who has dismissed it. Nothing per-user is
+-- written until that person actually sees it.
+CREATE TABLE IF NOT EXISTS broadcasts (
+    id          UUID         PRIMARY KEY DEFAULT gen_random_uuid(),
+    title       VARCHAR(200) NOT NULL,
+    body        TEXT         NOT NULL DEFAULT '',
+    -- Formatting as offset/length spans, exactly like chat messages: the same
+    -- parser produces them and the same component renders them, so no HTML is
+    -- stored and nothing needs sanitising at render time.
+    entities    JSONB        NOT NULL DEFAULT '[]'::jsonb,
+    -- R2 key for the banner. Public bucket: an announcement is not private,
+    -- and a signed URL would expire while the modal sat open.
+    banner_key  TEXT,
+    cta_label   VARCHAR(60),
+    -- App-relative path or absolute http(s) URL; validated in the service.
+    cta_url     TEXT,
+    created_by  UUID         REFERENCES users(id) ON DELETE SET NULL,
+    -- NULL = draft. Nothing is delivered until this is set.
+    published_at TIMESTAMPTZ,
+    -- After this, the announcement stops being offered. This is what keeps a
+    -- months-old update from greeting someone who signs up tomorrow.
+    expires_at   TIMESTAMPTZ,
+    created_at   TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at   TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+-- "What is live right now?" — the app's pending lookup and the admin list.
+CREATE INDEX IF NOT EXISTS broadcasts_live_idx
+    ON broadcasts (published_at DESC) WHERE published_at IS NOT NULL;
+
+-- One row per person who has seen an announcement. Written on dismissal, which
+-- is what makes "at most once" true across devices — localStorage would show
+-- it again on every new browser.
+CREATE TABLE IF NOT EXISTS broadcast_views (
+    broadcast_id UUID        NOT NULL REFERENCES broadcasts(id) ON DELETE CASCADE,
+    user_id      UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    seen_at      TIMESTAMPTZ NOT NULL DEFAULT now(),
+    PRIMARY KEY (broadcast_id, user_id)
+);