-- 006: publishing pipeline (drafts -> approval -> scheduling -> publication)
CREATE TABLE drafts (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  workspace_id uuid NOT NULL REFERENCES workspaces(id) ON DELETE CASCADE,
  author_user_id uuid NOT NULL REFERENCES users(id),
  post jsonb NOT NULL,
  state text NOT NULL DEFAULT 'editing'
    CHECK (state IN ('editing', 'in_review', 'approved', 'rejected', 'scheduled', 'published')),
  reviewer_user_id uuid REFERENCES users(id),
  created_at timestamptz NOT NULL DEFAULT now(),
  updated_at timestamptz NOT NULL DEFAULT now()
);

CREATE TABLE scheduled_publications (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  workspace_id uuid NOT NULL REFERENCES workspaces(id) ON DELETE CASCADE,
  draft_id uuid NOT NULL REFERENCES drafts(id) ON DELETE CASCADE,
  connection_id uuid NOT NULL REFERENCES connections(id),
  publish_at timestamptz NOT NULL,
  idempotency_key text NOT NULL UNIQUE,
  state text NOT NULL DEFAULT 'pending'
    CHECK (state IN ('pending', 'in_flight', 'done', 'failed')),
  error text,
  UNIQUE (draft_id)
);

CREATE TABLE publications (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  workspace_id uuid NOT NULL REFERENCES workspaces(id) ON DELETE CASCADE,
  draft_id uuid NOT NULL REFERENCES drafts(id) ON DELETE CASCADE,
  connection_id uuid NOT NULL REFERENCES connections(id),
  idempotency_key text NOT NULL UNIQUE,
  remote_id text NOT NULL,
  remote_url text,
  published_at timestamptz NOT NULL,
  provider_metadata jsonb NOT NULL DEFAULT '{}'
);

CREATE INDEX drafts_workspace_state ON drafts (workspace_id, state);
CREATE INDEX scheduled_publications_due ON scheduled_publications (publish_at)
  WHERE state = 'pending';
CREATE INDEX publications_draft ON publications (draft_id);

CREATE TRIGGER trg_draft_ws_immutable BEFORE UPDATE ON drafts
  FOR EACH ROW EXECUTE FUNCTION reject_workspace_change();
CREATE TRIGGER trg_scheduled_pub_ws_immutable BEFORE UPDATE ON scheduled_publications
  FOR EACH ROW EXECUTE FUNCTION reject_workspace_change();
CREATE TRIGGER trg_publication_ws_immutable BEFORE UPDATE ON publications
  FOR EACH ROW EXECUTE FUNCTION reject_workspace_change();

ALTER TABLE drafts ENABLE ROW LEVEL SECURITY;
ALTER TABLE scheduled_publications ENABLE ROW LEVEL SECURITY;
ALTER TABLE publications ENABLE ROW LEVEL SECURITY;
ALTER TABLE drafts FORCE ROW LEVEL SECURITY;
ALTER TABLE scheduled_publications FORCE ROW LEVEL SECURITY;
ALTER TABLE publications FORCE ROW LEVEL SECURITY;

CREATE POLICY tenant_isolation ON drafts
  USING (workspace_id = NULLIF(current_setting('app.workspace_id', true), '')::uuid)
  WITH CHECK (workspace_id = NULLIF(current_setting('app.workspace_id', true), '')::uuid);
CREATE POLICY tenant_isolation ON scheduled_publications
  USING (workspace_id = NULLIF(current_setting('app.workspace_id', true), '')::uuid)
  WITH CHECK (workspace_id = NULLIF(current_setting('app.workspace_id', true), '')::uuid);
CREATE POLICY tenant_isolation ON publications
  USING (workspace_id = NULLIF(current_setting('app.workspace_id', true), '')::uuid)
  WITH CHECK (workspace_id = NULLIF(current_setting('app.workspace_id', true), '')::uuid);

GRANT SELECT, INSERT, UPDATE, DELETE ON drafts, scheduled_publications, publications TO sp_app;

-- Narrow SECURITY DEFINER lookups let the scheduler discover tenant context
-- without weakening FORCE RLS for ordinary table access.
CREATE FUNCTION publishing_schedule_workspace(p_idempotency_key text) RETURNS uuid
LANGUAGE sql STABLE SECURITY DEFINER SET search_path = public AS $$
  SELECT workspace_id
  FROM scheduled_publications
  WHERE idempotency_key = p_idempotency_key
$$;

CREATE FUNCTION publishing_due_schedules() RETURNS TABLE(idempotency_key text, publish_at timestamptz)
LANGUAGE sql STABLE SECURITY DEFINER SET search_path = public AS $$
  SELECT sp.idempotency_key, sp.publish_at
  FROM scheduled_publications sp
  WHERE sp.state = 'pending' AND sp.publish_at <= now()
  ORDER BY sp.publish_at
$$;

REVOKE ALL ON FUNCTION publishing_schedule_workspace(text) FROM PUBLIC;
REVOKE ALL ON FUNCTION publishing_due_schedules() FROM PUBLIC;
GRANT EXECUTE ON FUNCTION publishing_schedule_workspace(text), publishing_due_schedules() TO sp_app;