/**
 * Health contract for rectification schema. gitCommit proves the web image;
 * latestMigration proves the business database actually applied the SQL.
 */
export const RECTIFICATION_CONTRACT_VERSION = "v4";

export const REQUIRED_RECTIFICATION_MIGRATIONS = [
  "20260826010000_rectification_inference_round_audit.sql",
  "20260826020000_rectification_choice_focus_identity.sql",
  "20260826030000_rectification_migration_ledger_health.sql",
] as const;

export type DatabaseHealth = Readonly<{
  latestMigration: string | null;
  rectificationContractVersion: typeof RECTIFICATION_CONTRACT_VERSION;
  requiredMigrationsPresent: boolean;
  missingMigrations: readonly string[];
}>;

export function databaseHealthFromFilenames(
  filenames: readonly string[],
): DatabaseHealth {
  const present = new Set(filenames);
  const missing = REQUIRED_RECTIFICATION_MIGRATIONS.filter((name) => !present.has(name));
  const latest = [...filenames].sort().at(-1) ?? null;
  return {
    latestMigration: latest,
    rectificationContractVersion: RECTIFICATION_CONTRACT_VERSION,
    requiredMigrationsPresent: missing.length === 0,
    missingMigrations: missing,
  };
}