CREATE TABLE pages (
  id         uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  space_id   uuid NOT NULL REFERENCES spaces(id) ON DELETE CASCADE,
  slug       text NOT NULL,
  title      text NOT NULL,
  body_md    text NOT NULL DEFAULT '',
  body_html  text,
  parent_id  uuid,
  -- Same-space parent enforcement (mirrors tasks.project_id pattern)
  FOREIGN KEY (parent_id, space_id) REFERENCES pages(id, space_id)
    ON DELETE SET NULL (parent_id),
  embedding  vector(1024),
  created_at timestamptz NOT NULL DEFAULT now(),
  updated_at timestamptz NOT NULL DEFAULT now(),
  UNIQUE (space_id, slug),
  -- Composite key target for parent_id self-reference above + any future FK
  UNIQUE (id, space_id)
);

CREATE TABLE page_revisions (
  id         uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  page_id    uuid NOT NULL REFERENCES pages(id) ON DELETE CASCADE,
  body_md    text NOT NULL,
  edited_by  text,
  created_at timestamptz NOT NULL DEFAULT now()
);

CREATE TABLE refs (
  id          uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  space_id    uuid NOT NULL REFERENCES spaces(id) ON DELETE CASCADE,
  kind        text NOT NULL
              CHECK (kind IN ('url','video','pdf','image','file')),
  source_url  text,
  title       text,
  description text,
  summary     text,
  body_text   text,
  blob_path   text,
  thumbnail   text,
  metadata    jsonb NOT NULL DEFAULT '{}'::jsonb,
  embedding   vector(1024),
  status      text NOT NULL DEFAULT 'ingested'
              CHECK (status IN ('ingested','indexed','enriched')),
  source_kind text,
  external_id text,
  captured_at timestamptz NOT NULL DEFAULT now(),
  created_at  timestamptz NOT NULL DEFAULT now(),
  updated_at  timestamptz NOT NULL DEFAULT now()
);

CREATE INDEX idx_pages_space ON pages(space_id);
CREATE INDEX idx_pages_parent ON pages(parent_id);
CREATE INDEX idx_pages_fts ON pages
  USING GIN (to_tsvector('english', title || ' ' || body_md));
CREATE INDEX idx_pages_embed ON pages
  USING hnsw (embedding vector_cosine_ops);

CREATE INDEX idx_refs_space ON refs(space_id);
CREATE INDEX idx_refs_kind ON refs(kind);
-- Per-space uniqueness on external dedup (mirrors tenancy-first pattern of 001).
-- upsertByExternal MUST pass space_id; cross-space same-external_id creates distinct rows.
CREATE UNIQUE INDEX idx_refs_external_unique
  ON refs(space_id, source_kind, external_id)
  WHERE source_kind IS NOT NULL AND external_id IS NOT NULL;
CREATE INDEX idx_refs_fts ON refs USING GIN (
  to_tsvector('english',
    coalesce(title,'') || ' ' || coalesce(summary,'') || ' ' || coalesce(body_text,''))
);
CREATE INDEX idx_refs_embed ON refs USING hnsw (embedding vector_cosine_ops);