CREATE TABLE IF NOT EXISTS rag_ocr_jobs (
  job_id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  version_id uuid NOT NULL,
  document_id text NOT NULL,
  remote_job_id text NULL,
  remote_idempotency_key text NOT NULL,
  state text NOT NULL CHECK (state IN ('queued', 'running', 'succeeded', 'failed')),
  requested_pages integer[] NOT NULL,
  completed_pages integer NOT NULL DEFAULT 0 CHECK (completed_pages >= 0),
  config_version text NOT NULL,
  attempt_count integer NOT NULL DEFAULT 0 CHECK (attempt_count >= 0),
  heartbeat_at timestamptz NULL,
  lease_expires_at timestamptz NULL,
  next_attempt_at timestamptz NULL,
  error_code text NULL,
  error_detail text NULL,
  created_at timestamptz NOT NULL DEFAULT now(),
  started_at timestamptz NULL,
  completed_at timestamptz NULL,
  UNIQUE (version_id, document_id),
  FOREIGN KEY (version_id, document_id)
    REFERENCES rag_version_documents(version_id, document_id) ON DELETE RESTRICT
);

CREATE TABLE IF NOT EXISTS rag_document_pages (
  version_id uuid NOT NULL,
  document_id text NOT NULL,
  page_number integer NOT NULL CHECK (page_number > 0),
  extraction_method text NOT NULL CHECK (extraction_method IN ('native', 'ocr', 'blank')),
  native_text_hash char(64) NULL,
  ocr_text_hash char(64) NULL,
  candidate_text_hash char(64) NULL,
  reviewed_text_hash char(64) NULL,
  metrics jsonb NOT NULL DEFAULT '{}',
  risk_tokens jsonb NOT NULL DEFAULT '[]',
  blocked_reason text NULL,
  created_at timestamptz NOT NULL DEFAULT now(),
  PRIMARY KEY (version_id, document_id, page_number),
  FOREIGN KEY (version_id, document_id)
    REFERENCES rag_version_documents(version_id, document_id) ON DELETE RESTRICT
);

CREATE TABLE IF NOT EXISTS rag_review_corrections (
  correction_id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  version_id uuid NOT NULL,
  document_id text NOT NULL,
  page_number integer NOT NULL,
  line_id text NOT NULL,
  expected_line_hash char(64) NOT NULL,
  replacement_text text NOT NULL,
  reviewed_by text NOT NULL,
  created_at timestamptz NOT NULL DEFAULT now(),
  FOREIGN KEY (version_id, document_id, page_number)
    REFERENCES rag_document_pages(version_id, document_id, page_number) ON DELETE RESTRICT,
  UNIQUE (version_id, document_id, page_number, line_id)
);

CREATE UNIQUE INDEX IF NOT EXISTS rag_one_pending_ocr_identity
  ON rag_source_versions(source_id, original_manifest_hash, processing_fingerprint, metadata_hash)
  WHERE source_content_hash IS NULL
    AND state IN ('pending', 'indexing', 'review_required');