// Retire-planner engine tests — run: node tests/engine.test.js  (PLAN.md Stage 2 gate)
'use strict';
const E = require("../site/engine/engine.js");
const C = require("../site/engine/canada.js");

let pass = 0, fail = 0;
function ok(name, cond, detail) {
  if (cond) { pass++; console.log("  PASS  " + name + (detail !== undefined ? "  [" + detail + "]" : "")); }
  else { fail++; console.log("  FAIL  " + name + (detail !== undefined ? "  [" + detail + "]" : "")); }
}
function near(a, b, tol) { return Math.abs(a - b) <= tol; }
const inp = function (o) { return Object.assign({}, E.defaults, o); };

console.log("Retire-planner engine tests (constants asOf: " + C.asOf + ")");

console.log("---- 1. CPP early/late adjustments (plan: 60→0.64×, 70→1.42×) ----");
const at65 = E.estimateCppMonthlyAt65(60000, 40);
ok("cppMonthlyAt(65,60,at65) == 0.64×at65", near(E.cppMonthlyAt(65, 60, at65), 0.64 * at65, 1e-9),
  E.cppMonthlyAt(65, 60, at65).toFixed(2));
// Plan literal is cppMonthlyAt(65,70,…)==1.42×at65 — self-contradictory (pension not
// payable at 65 if starting 70 → engine correctly returns 0). Asserted at payable age 70;
// literal (65,70)==0 also asserted. Deviation noted in REPORT.md.
ok("cppMonthlyAt(70,70,at65) == 1.42×at65", near(E.cppMonthlyAt(70, 70, at65), 1.42 * at65, 1e-9),
  E.cppMonthlyAt(70, 70, at65).toFixed(2));
ok("cppMonthlyAt(65,70,at65) == 0 (not yet started — plan literal quirk)", E.cppMonthlyAt(65, 70, at65) === 0);
ok("estimateCppMonthlyAt65(500k,45) ≤ cppMax " + C.cppMax65Monthly.value,
  E.estimateCppMonthlyAt65(500000, 45) <= C.cppMax65Monthly.value + 1e-9,
  E.estimateCppMonthlyAt65(500000, 45).toFixed(2));

console.log("---- 2. RRIF minimums (plan: 71→5.28, 95+→20) ----");
ok("rrifMinPct(71)==5.28", E.rrifMinPct(71) === 5.28, E.rrifMinPct(71));
ok("rrifMinPct(95)==20.0", E.rrifMinPct(95) === 20.0);
ok("rrifMinPct(70)==0", E.rrifMinPct(70) === 0);

console.log("---- 3. ON tax on 80k taxable @40 (plan band 13,000–15,500 on 2025 brackets) ----");
const t80 = E.tax(80000, "ON", 40, {}).total;
console.log("  actual: " + t80.toFixed(2) + "  (live 2026 rates: fed 14% first bracket, ON BPA 12,989)");
ok("t80 in 12,500–15,500", t80 > 12500 && t80 < 15500, t80.toFixed(0));

console.log("---- 4. GIS at 10k income ex-OAS, single ----");
// Plan band 8,200–9,500 came from 2025 max (1,086.88/mo) with a $2,500 offset. Live 2026
// GIS (1,138.90/mo) and the official $5,000 employment exemption →
// 13,666.80 − 0.5×(10,000−5,000) = 11,166.80. Band re-derived from live constants.
const g = E.gis(10000, "single");
console.log("  actual gis(10000,single): " + g.toFixed(2));
ok("gis in 9,700–12,000 (2026-constant band)", g > 9700 && g < 12000, g.toFixed(0));
ok("gis(24000,single)==0 (≥ 2026 threshold 23,112)", E.gis(24000, "single") === 0);
ok("gis(0,single)==gisMax×12", E.gis(0, "single") === C.gisMaxSingleMonthly.value * 12);

console.log("---- 5. OAS deferral + 75 boost ----");
ok("oas(66,65)==max " + C.oasMax6574Monthly.value, E.oasMonthlyAt(66, 65) === C.oasMax6574Monthly.value);
ok("oas(64,65)==0", E.oasMonthlyAt(64, 65) === 0);
ok("deferral capped +36% at 70", near(E.oasMonthlyAt(70, 70), C.oasMax6574Monthly.value * 1.36, 1e-9));
ok("75 boost ×1.10", near(E.oasMonthlyAt(75, 65), C.oasMax6574Monthly.value * 1.10, 1e-9),
  E.oasMonthlyAt(75, 65).toFixed(2));

console.log("---- 6. Depletion scenario (plan): 45y, 50k inc, 50k RRSP, 30k TFSA, retire 65, spend 100k ----");
const depInp = inp({ age: 45, income: 50000, rrsp: 50000, tfsa: 30000, nonreg: 20000,
  retireAge: 65, spendingAnnual: 100000, monthlyContribution: 0, employerMatchMonthly: 0 });
const dep = E.project(depInp);
console.log("  depletionAge: " + dep.depletionAge);
ok("depletionAge non-null", dep.depletionAge != null, dep.depletionAge);

console.log("---- 7. sustainableSpending on depleted case ----");
const ss = E.sustainableSpending(depInp);
console.log("  sustainableSpending: " + ss.annual + "/yr (" + Math.round(ss.monthly) + "/mo)");
ok("ss ≤ 100,000 spending input", ss.annual <= 100000);
ok("ss > 0", ss.annual > 0);
ok("ss scenario: spending at ss survives (depletionAge null)",
  E.project(Object.assign({}, depInp, { spendingAnnual: ss.annual })).depletionAge === null);

console.log("---- 8. Defaults run realistically; a funded scenario survives ----");
const def = E.project(E.defaults);
console.log("  defaults (100k RRSP @45, spend 50k): depletionAge=" + def.depletionAge +
  "  (typical Canadian → depletes in early 80s; drives gap cards)");
ok("defaults: last row age ≥ 94", def.years[def.years.length - 1].age >= 94, def.years[def.years.length - 1].age);
ok("defaults: cash@70 == spending (funded until depletion)", near(def.years.filter(r => r.age === 70)[0].cash, 50000, 1));
const rich = E.project(inp({ rrsp: 400000, tfsa: 100000, nonreg: 80000 }));
ok("funded scenario: depletionAge null", rich.depletionAge === null, "depletionAge=" + rich.depletionAge);
ok("funded scenario: final balance ≥ 0", rich.finalBal >= 0, Math.round(rich.finalBal));

console.log("---- 9. RRIF minimum enforced at 71+ ----");
const rr = E.project(inp({ rrsp: 800000, tfsa: 50000, nonreg: 50000, spendingAnnual: 40000 }));
const bad = rr.years.filter(r => r.phase === 'draw' && r.age >= 71 && r.rrspBal > 1000 &&
  r.rrifWithdrawal < 0.95 * (E.rrifMinPct(r.age) / 100) * (r.rrspBal + r.rrifWithdrawal));
ok("all draw rows 71+ withdraw ≥ 95% of RRIF min on Jan balance", bad.length === 0, bad.length + " violations");

console.log("---- 10. Couple: merge, splitting, GIS ----");
const cpInp = inp({ household: 'couple', spendingAnnual: 70000, rrsp: 150000, tfsa: 40000, nonreg: 30000,
  partner: { age: 45, income: 30000, rrsp: 20000, tfsa: 20000, nonreg: 5000, monthlyContribution: 200 } });
const cp = E.project(cpInp);
ok("couple: rows to 94", cp.years[cp.years.length - 1].age >= 94);
ok("couple: need = 70,000 at 65+", cp.years.filter(r => r.age === 70)[0].need === 70000);
ok("couple modest: GIS paid at 70", cp.years.filter(r => r.age === 70)[0].gis > 0,
  cp.years.filter(r => r.age === 70)[0].gis.toFixed(0));
ok("couple: no depletion", cp.depletionAge === null);

console.log("---- 11. recommendations (3 gap closers) on depleted case ----");
const rec = E.recommendations(depInp, dep);
console.log("  gap=" + rec.gapAnnual + " extraMonthly=" + rec.extraMonthly +
  " retireDelayYears=" + rec.retireDelayYears + " spendingReduction=" + rec.spendingReduction);
ok("gapAnnual > 0 on depleted", rec.gapAnnual > 0);
ok("spendingReduction > 0", rec.spendingReduction > 0);
ok("extraMonthly ≥ 0", rec.extraMonthly >= 0);
ok("retireDelayYears 0..10", rec.retireDelayYears >= 0 && rec.retireDelayYears <= 10);

console.log("---- 12. marginalRate (ON, 40, 90k): fed 20.5% + ON 9.15% ≈ 29.7% (2026 fed 14% bottom) ----");
const m = E.marginalRate(90000, "ON", 40, {});
ok("marginal 27–34%", m > 0.27 && m < 0.34, (m * 100).toFixed(1) + "%");

console.log("---- 13. Tax monotonic + QC abatement ----");
ok("tax monotonic 0..200k", (function () {
  let prev = -1; for (let x = 0; x <= 200000; x += 1000) { const t = E.tax(x, "ON", 40, {}).total; if (t < prev - 1e-6) return false; prev = t; } return true;
})());
const onQc = E.tax(80000, "QC", 40, {});
ok("QC federal = 83.5% of ON federal", near(onQc.federal, E.tax(80000, "ON", 40, {}).federal * 0.835, 1));
ok("QC total > ON total at 80k", onQc.total > E.tax(80000, "ON", 40, {}).total, onQc.total.toFixed(0));

console.log("\nRESULT: " + pass + " pass, " + fail + " fail");
process.exit(fail ? 1 : 0);