'use strict';

/**
 * MODEL VERSION — ONE source, because two were not the same.
 *
 * ── WHAT WENT WRONG ──────────────────────────────────────────────────────
 * `ledgerService` and `retentionService` both read `process.env.MODEL_VERSION`,
 * and both carried a HARDCODED DEFAULT — but different ones:
 *
 *     ledgerService.js:57     … || 'engine1@2026-07-20'
 *     retentionService.js:59  … || 'engine1@2026-08-07-fullwindow'
 *
 * Production does not set the env var, so the two tables took different
 * defaults. The 2026-08-07 champion repair bumped one and left the other behind.
 * Result: `model_snapshots` carried the repaired marker on 34,128 rows while
 * `ledger_entries` carried the OLD marker on all 15,739 — including rows graded
 * by the repaired champion.
 *
 * That is not a cosmetic mismatch. `reAuditEligibility.isEligible` requires
 * `model_version === REPAIRED_CHAMPION_VERSION`, so applied to the ledger it
 * returned ZERO eligible rows and ZERO eligible dates, permanently, for all four
 * pending measurements. The accrual clock read "blocked" when the real state was
 * "mis-stamped".
 *
 * ── THE RULE ─────────────────────────────────────────────────────────────
 * There is exactly one place a model version may be declared. Anything that
 * stamps a row imports it from here. A default that lives next to its consumer
 * will drift from the other consumer, and the drift is invisible because both
 * sides look locally correct.
 *
 * ── WHAT THIS DOES NOT DO ────────────────────────────────────────────────
 * It does not re-stamp history. Rows already written keep the marker they were
 * written with — rewriting them would destroy the one record of which forecast
 * actually produced them, which is the thing the marker exists to preserve. Old
 * rows stay honestly old; a backfill is a separate, explicit decision.
 */

/** The version every NEW row is stamped with. Override with MODEL_VERSION. */
const MODEL_VERSION = process.env.MODEL_VERSION || 'engine1@2026-08-07-fullwindow';

/**
 * Rows at or after this marker were produced by the repaired champion and are
 * eligible for forward re-audit.
 *
 * Deliberately NOT `MODEL_VERSION`: the eligibility bar is a fixed historical
 * fact about a specific repair, and tying it to "whatever we stamp today" would
 * make every future version silently re-qualify itself.
 */
const REPAIRED_CHAMPION_VERSION = 'engine1@2026-08-07-fullwindow';

/** The marker that preceded the repair — kept so old rows are nameable. */
const PRE_REPAIR_VERSION = 'engine1@2026-07-20';

module.exports = { MODEL_VERSION, REPAIRED_CHAMPION_VERSION, PRE_REPAIR_VERSION };