-- Knowledge Platform schema migration
-- Migration id: 0036_page_index_findability
-- Dialect: postgres
-- Persists generation-scoped PageIndex navigation quality and a bounded summary-repair request.

CREATE TABLE IF NOT EXISTS "page_index_findability_evaluations" (
  "id" UUID PRIMARY KEY NOT NULL,
  "tenant_id" VARCHAR(255) NOT NULL,
  "knowledge_space_id" UUID NOT NULL,
  "document_asset_id" UUID NOT NULL,
  "document_version" BIGINT NOT NULL,
  "outline_id" UUID NOT NULL,
  "publication_generation_id" UUID NOT NULL,
  "publication_fingerprint" VARCHAR(96) NOT NULL,
  "compilation_attempt_id" UUID NOT NULL,
  "evaluator_version" VARCHAR(128) NOT NULL,
  "status" VARCHAR(32) NOT NULL,
  "recommended_route" VARCHAR(16) NOT NULL,
  "evaluation" JSONB NOT NULL,
  "summary_repair_state" VARCHAR(24) NOT NULL,
  "summary_repair_attempts" INTEGER NOT NULL DEFAULT 0,
  "summary_repair_error" VARCHAR(2000),
  "available_at" TIMESTAMPTZ,
  "lock_token" UUID,
  "locked_by" VARCHAR(255),
  "lease_expires_at" TIMESTAMPTZ,
  "evaluated_at" TIMESTAMPTZ NOT NULL,
  "updated_at" TIMESTAMPTZ NOT NULL,
  CONSTRAINT "page_index_findability_scope_fk"
    FOREIGN KEY ("tenant_id", "knowledge_space_id")
    REFERENCES "knowledge_spaces" ("tenant_id", "id") ON DELETE CASCADE,
  CONSTRAINT "page_index_findability_status_ck"
    CHECK ("status" IN ('failed', 'not-evaluated', 'passed')),
  CONSTRAINT "page_index_findability_route_ck"
    CHECK ("recommended_route" IN ('hybrid', 'layered', 'unchanged')),
  CONSTRAINT "page_index_findability_repair_ck"
    CHECK (
      "summary_repair_state" IN ('not-requested', 'queued', 'leased', 'dispatched', 'failed')
      AND "summary_repair_attempts" >= 0
      AND (
        ("summary_repair_state" = 'leased'
          AND "lock_token" IS NOT NULL
          AND "locked_by" IS NOT NULL
          AND "lease_expires_at" IS NOT NULL)
        OR
        ("summary_repair_state" <> 'leased'
          AND "lock_token" IS NULL
          AND "locked_by" IS NULL
          AND "lease_expires_at" IS NULL)
      )
    ),
  CONSTRAINT "page_index_findability_evaluation_ck"
    CHECK (jsonb_typeof("evaluation") = 'object'),
  CONSTRAINT "page_index_findability_document_version_ck"
    CHECK ("document_version" >= 1)
);

CREATE UNIQUE INDEX IF NOT EXISTS "page_index_findability_generation_evaluator_uq"
  ON "page_index_findability_evaluations" (
    "tenant_id", "knowledge_space_id", "publication_generation_id", "evaluator_version"
  );
CREATE INDEX IF NOT EXISTS "page_index_findability_route_idx"
  ON "page_index_findability_evaluations" (
    "tenant_id", "knowledge_space_id", "document_asset_id", "publication_generation_id"
  );
CREATE INDEX IF NOT EXISTS "page_index_findability_repair_queue_idx"
  ON "page_index_findability_evaluations" (
    "summary_repair_state", "available_at", "lease_expires_at", "updated_at", "id"
  );