From 59ab9790e2f03046ca7fef31a6db883e1ec31075 Mon Sep 17 00:00:00 2001
From: Christian Cleberg <hello@cleberg.net>
Date: Sat, 21 Feb 2026 23:46:01 -0600
Subject: modernize site and migrate to TypeScript

---
 assets/ts/app.ts | 152 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 assets/ts/app.ts

(limited to 'assets/ts')

diff --git a/assets/ts/app.ts b/assets/ts/app.ts
new file mode 100644
index 0000000..9b29604
--- /dev/null
+++ b/assets/ts/app.ts
@@ -0,0 +1,152 @@
+declare const Plotly: {
+  newPlot(
+    el: string | HTMLElement,
+    data: object[],
+    layout: object,
+    config?: object
+  ): void;
+};
+
+interface GraphColors {
+  bgColor: string;
+  fgColor: string;
+  gridColor: string;
+  lineColor: string;
+}
+
+function formatMoney(num: number): string {
+  return num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, "$&,");
+}
+
+function getInputValue(id: string): number {
+  const el = document.getElementById(id) as HTMLInputElement | null;
+  return el ? parseFloat(el.value) : NaN;
+}
+
+function getThemeColors(): GraphColors {
+  const dark = window.matchMedia("(prefers-color-scheme: dark)").matches;
+  return dark
+    ? { bgColor: "#1a1d27", fgColor: "#e8eaf0", gridColor: "#2d3141", lineColor: "#3d4258" }
+    : { bgColor: "#ffffff", fgColor: "#1a1d23", gridColor: "#e2e6ea", lineColor: "#c8cdd5" };
+}
+
+function buildAxisLayout(title: string, colors: GraphColors): object {
+  const { bgColor, fgColor, gridColor, lineColor } = colors;
+  return {
+    title: { text: title, font: { color: fgColor, size: 13 } },
+    paper_bgcolor: bgColor,
+    plot_bgcolor: bgColor,
+    font: { color: fgColor, family: "-apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif" },
+    margin: { t: 40, r: 16, b: 48, l: 60 },
+    yaxis: { gridcolor: gridColor, zerolinecolor: gridColor, linecolor: lineColor },
+    xaxis: { title: { text: "Months", font: { size: 11 } }, gridcolor: gridColor, zerolinecolor: gridColor, linecolor: lineColor },
+  };
+}
+
+class Data {
+  balance: number;
+  contribution: number;
+  returnRate: number;
+  inflationRate: number;
+
+  constructor(balance: number, contribution: number, returnRate: number, inflationRate: number) {
+    this.balance = balance;
+    this.contribution = contribution;
+    this.returnRate = returnRate;
+    this.inflationRate = inflationRate;
+  }
+
+  summaryRow(): string {
+    return `<tr>
+      <td>$${formatMoney(this.balance)}</td>
+      <td>$${formatMoney(this.contribution)}</td>
+      <td>${this.returnRate.toFixed(2)}%</td>
+      <td>${this.inflationRate.toFixed(2)}%</td>
+    </tr>`;
+  }
+
+  adjustedRate(): number {
+    return (1 + this.returnRate / 100) / (1 + this.inflationRate / 100) - 1;
+  }
+}
+
+function showResults(data: Data, monthsArr: number[], balanceArr: number[], interestArr: number[]): void {
+  const infoTbody = document.querySelector("#infoTable tbody") as HTMLTableSectionElement;
+  infoTbody.innerHTML = data.summaryRow();
+
+  document.querySelectorAll<HTMLElement>(".table-section").forEach((el) => (el.style.display = "block"));
+
+  const graphCard = document.getElementById("graphCard") as HTMLElement;
+  graphCard.style.display = "block";
+
+  const colors = getThemeColors();
+  const balanceTrace = { x: monthsArr, y: balanceArr, type: "scatter", line: { color: "#4f6ef7", width: 2 } };
+  const interestTrace = { x: monthsArr, y: interestArr, type: "scatter", line: { color: "#22c55e", width: 2 } };
+
+  Plotly.newPlot("balChartContainer", [balanceTrace], buildAxisLayout("Total Balance", colors), { responsive: true });
+  Plotly.newPlot("intChartContainer", [interestTrace], buildAxisLayout("Accrued Interest", colors), { responsive: true });
+}
+
+function runCalculation(data: Data, stopCondition: (balance: number, month: number) => boolean): void {
+  document.querySelectorAll("tbody").forEach((el) => (el.innerHTML = ""));
+
+  const resultsTbody = document.querySelector(".resultsTable tbody") as HTMLTableSectionElement;
+  const adjustedRate = data.adjustedRate();
+  const monthlyContr = data.contribution;
+
+  const monthsArr: number[] = [];
+  const balanceArr: number[] = [];
+  const interestArr: number[] = [];
+
+  let pVal = data.balance;
+  let i = 0;
+
+  while (!stopCondition(pVal, i)) {
+    const month = i + 1;
+    const interest = pVal * (adjustedRate / 12);
+    const newBalance = pVal + interest + monthlyContr;
+
+    const row = document.createElement("tr");
+    row.innerHTML = `<td>${month}</td><td>$${formatMoney(interest)}</td><td>$${formatMoney(monthlyContr)}</td><td>$${formatMoney(newBalance)}</td>`;
+    resultsTbody.appendChild(row);
+
+    if (month === 1 || month % 12 === 0) {
+      interestArr.push(Math.round(interest * 100) / 100);
+      balanceArr.push(Math.round(newBalance * 100) / 100);
+      monthsArr.push(month);
+    }
+
+    pVal = newBalance;
+    i++;
+  }
+
+  showResults(data, monthsArr, balanceArr, interestArr);
+}
+
+function retirementYears(): void {
+  const data = new Data(
+    getInputValue("begBalance"),
+    getInputValue("monthlyContr"),
+    getInputValue("returnRate"),
+    getInputValue("inflationRate")
+  );
+  const years = getInputValue("years");
+  const totalMonths = years * 12;
+  runCalculation(data, (_bal, i) => i >= totalMonths);
+  document.getElementById("graphCard")?.scrollIntoView({ behavior: "smooth" });
+}
+
+function retirementMoney(): void {
+  const data = new Data(
+    getInputValue("begBalance"),
+    getInputValue("monthlyContr"),
+    getInputValue("returnRate"),
+    getInputValue("inflationRate")
+  );
+  const target = getInputValue("money");
+  runCalculation(data, (bal) => bal >= target);
+  document.getElementById("graphCard")?.scrollIntoView({ behavior: "smooth" });
+}
+
+(window as Window & typeof globalThis & { retirementYears: () => void; retirementMoney: () => void }).retirementYears = retirementYears;
+(window as Window & typeof globalThis & { retirementYears: () => void; retirementMoney: () => void }).retirementMoney = retirementMoney;
-- 
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