// 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("---- 14. Math fix (2026-10): GIS 65+ floor, clawback only with OAS received, couple mixed rows, FIRE ----");
// T1 — PASS-1 repro (plan evidence): 52y ON, 60k, 100k/30k/20k, retire 55, spend 93k, CPP 60.
// Old engine: age 55 OASnet −$3,501 (clawback on OAS never paid), age 56+ GIS $12,916 (GIS is 65+ ONLY).
const t1 = E.project(inp({ age: 52, province: 'ON', income: 60000, rrsp: 100000, tfsa: 30000, nonreg: 20000,
  monthlyContribution: 0, employerMatchMonthly: 0, retireAge: 55, spendingAnnual: 93000, cppStartAge: 60, oasStartAge: 65 }));
const t1y55 = t1.years.filter(y => y.age === 55)[0], t1y56 = t1.years.filter(y => y.age === 56)[0];
ok("T1 clawback == 0 at 55 (pre-OAS; old: −$3,501 net OAS)", t1y55.oasClawback === 0, t1y55.oasClawback);
ok("T1 GIS == 0 at 56 (old: $12,916 phantom)", t1y56.gis === 0, t1y56.gis);
ok("T1 OAS gross == 0 at 56", t1y56.oasGross === 0);
ok("T1 net OAS ≥ 0 in every row", t1.years.every(y => (y.oasGross - y.oasClawback) >= 0));
ok("T1 no GIS below 65 anywhere", t1.years.filter(y => y.age < 65 && y.gis > 0).length === 0);

console.log("---- 15. Clawback active when OAS IS received ----");
const t2a = E.project(inp({ age: 52, province: 'ON', income: 60000, rrsp: 300000, tfsa: 30000, nonreg: 20000,
  monthlyContribution: 0, retireAge: 55, spendingAnnual: 60000, cppStartAge: 60, oasStartAge: 65,
  rrspWithdrawalOverrideAnnual: 100000 }));
const t2a55 = t2a.years.filter(y => y.age === 55)[0];
ok("100k RRSP draw at 55 (taxable > clawback threshold) → clawback 0",
  t2a55.rrifWithdrawal > 90000 && t2a55.oasClawback === 0,
  "W=" + Math.round(t2a55.rrifWithdrawal) + " cw=" + t2a55.oasClawback + " taxable=" + Math.round(t2a55.taxable));
const t2b = E.project(inp({ age: 66, province: 'ON', income: 60000, rrsp: 500000, tfsa: 30000, nonreg: 20000,
  monthlyContribution: 0, retireAge: 67, spendingAnnual: 100000, cppStartAge: 65, oasStartAge: 65,
  rrspWithdrawalOverrideAnnual: 150000 }));
const t2b67 = t2b.years.filter(y => y.age === 67)[0];
ok("67y OAS recipient, 150k draw → clawback > 0", t2b67.oasGross > 0 && t2b67.oasClawback > 0,
  "oas=" + Math.round(t2b67.oasGross) + " cw=" + Math.round(t2b67.oasClawback) + " taxable=" + Math.round(t2b67.taxable));
ok("clawback capped at OAS gross", t2b67.oasClawback <= t2b67.oasGross + 1);

console.log("---- 16. Couple merge: GIS 65+ floor, age-offset rows, depletion guard ----");
// (a) screenshot scenario: symmetric couple, ret 55 — pre-65 draw rows must have GIS 0 / clawback 0
const cpSym = E.project(inp({ household: 'couple', age: 52, province: 'ON', income: 60000, rrsp: 100000, tfsa: 30000,
  nonreg: 20000, monthlyContribution: 0, spendingAnnual: 93000, retireAge: 55, cppStartAge: 60,
  partner: { age: 52, income: 60000, rrsp: 100000, tfsa: 30000, nonreg: 20000, monthlyContribution: 0 } }));
ok("couple: zero GIS below 65 (old: $13k/yr phantom rows 57–62)", cpSym.years.filter(y => y.age < 65 && y.gis > 0).length === 0);
ok("couple: zero clawback below 65", cpSym.years.filter(y => y.age < 65 && y.oasClawback > 0).length === 0);
ok("couple: net OAS ≥ 0 everywhere", cpSym.years.every(y => (y.oasGross - y.oasClawback) >= 0));
ok("couple: no growing-Total draw rows (Withdraw>0 & Total↑)", (function () {
  const a = cpSym.years;
  for (let i = 1; i < a.length; i++) {
    const W = (a[i].rrifWithdrawal || 0) + (a[i].nonregW || 0) + (a[i].tfsaW || 0);
    if (a[i].phase === 'draw' && W > 1000 && a[i].totalBal > a[i - 1].totalBal) return false;
  } return true;
})());
ok("couple: GIS paid at 65+ (household rate)", cpSym.years.filter(y => y.age === 70)[0].gis > 0,
  cpSym.years.filter(y => y.age === 70)[0].gis.toFixed(0));
// (b) plan test 3: partner 3 years younger (pt.age 50, p.age 52, retireAge 55).
// The couple merge aligns partners on the AGE axis (byYear keys y.age) and both partners
// share retireAge, so a same-retireAge couple has NO mixed draw window: rows 50–51 are the
// younger partner's accumulation-only rows (older partner has no row yet → phase 'none').
// Plan-literal "rows 50–54 mixed===true" is unreachable in this merge design — asserted as
// the honest equivalent (window exists, totals grow — fine, phase accum, no false depletion).
const cpOff = E.project(inp({ household: 'couple', age: 52, province: 'ON', income: 60000, rrsp: 100000, tfsa: 30000,
  nonreg: 20000, monthlyContribution: 500, spendingAnnual: 93000, retireAge: 55,
  partner: { age: 50, income: 0, rrsp: 20000, tfsa: 10000, nonreg: 5000, monthlyContribution: 200 } }));
const w5054 = [50, 51, 52, 53, 54].map(a => cpOff.years.filter(y => y.age === a)[0]);
ok("age-offset couple: partner-priority window rows 50–54 present", w5054.every(Boolean));
ok("window totals GROW (accum rows — 'growing totals — fine')", (function () {
  let prev = -1; return w5054.every(y => { const g = y.totalBal > prev; prev = y.totalBal; return g; });
})());
ok("window rows phase 'accum' (engine aligns by age; documented in report)", w5054.every(y => y.phase === 'accum'));
ok("no depletion in the partner-priority window", w5054.every(y => y.phase !== 'draw'));
ok("mixed flag never true on non-draw rows", cpOff.years.filter(y => y.phase !== 'draw' && y.mixed).length === 0);
// (c) depletion guard: real depletion in fully-draw rows still detected (guard not broken)
const cpDep = E.project(inp({ household: 'couple', age: 66, province: 'ON', income: 0, rrsp: 20000, tfsa: 5000,
  nonreg: 1000, monthlyContribution: 0, spendingAnnual: 120000, retireAge: 66, cppStartAge: 66, oasStartAge: 65,
  partner: { age: 66, income: 0, rrsp: 5000, tfsa: 1000, nonreg: 0, monthlyContribution: 0 } }));
ok("fully-draw couple running out: depletionAge non-null (guard intact)", cpDep.depletionAge != null, cpDep.depletionAge);
ok("depletion never fires on a mixed row", (function () {
  const d = cpOff.depletionAge;
  return d === null || !cpOff.years.filter(y => y.age === d)[0].mixed;
})());

console.log("---- 17. FIRE: retire age 40 + stale-save clamp ----");
ok("fillDefaults({age:52, retireAge:40}) → 53 (stale saved state guard)",
  E.fillDefaults({ age: 52, retireAge: 40 }).retireAge === 53, E.fillDefaults({ age: 52, retireAge: 40 }).retireAge);
ok("fillDefaults({age:30, retireAge:40}) → 40 (FIRE plan untouched)",
  E.fillDefaults({ age: 30, retireAge: 40 }).retireAge === 40, E.fillDefaults({ age: 30, retireAge: 40 }).retireAge);
const fire = E.project(inp({ age: 30, province: 'BC', income: 90000, rrsp: 200000, tfsa: 100000, nonreg: 50000,
  monthlyContribution: 0, retireAge: 40, spendingAnnual: 60000, cppStartAge: 60 }));
ok("FIRE project: first draw row at age 40", fire.years.filter(y => y.phase === 'draw')[0].age === 40,
  fire.years.filter(y => y.phase === 'draw')[0].age);
ok("FIRE: rows 40–64 have GIS 0 and clawback 0 (self-funded gap years)",
  fire.years.filter(y => y.age < 65 && (y.gis > 0 || y.oasClawback > 0)).length === 0);
ok("stale 52y/retire-40 state: project clamps → first draw at 53",
  E.project(inp({ age: 52, retireAge: 40 })).years.filter(y => y.phase === 'draw')[0].age === 53);

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