Tidied up the project

src/helpers/date-jalali.ts

@@ -1,13 +1,9 @@
-import * as jMoment from "jalali-moment";
-
 /**
  * Converts an ISO date string or Date to Jalali (Persian) date and time.
  * @param input - ISO date string (e.g. 2026-02-08T13:51:20.747+00:00) or Date
  * @returns Tuple [dateStr, timeStr] e.g. ['1404/11/24', '13:37']
  */
-export function toJalaliDateAndTime(
-  input: string | Date,
-): [string, string] {
+export function toJalaliDateAndTime(input: string | Date): [string, string] {
   const d = new Date(input);
   const dateStr = toJalaliDate(d);
   const timeStr = toJalaliTime(d);
@@ -32,8 +28,7 @@ export function jalaliToGregorianDate(
 ): string | null {
   if (input === null || input === undefined) return null;
 
-  const raw =
-    typeof input === "number" ? String(input) : String(input).trim();
+  const raw = typeof input === "number" ? String(input) : String(input).trim();
   if (!raw) return null;
 
   let year = 0;
@@ -58,20 +53,16 @@ export function jalaliToGregorianDate(
 
   if (!year || !month || !day) return null;
 
-  // If the year already looks Gregorian (>= 1900), assume the caller already
-  // sent a Gregorian date and just normalise the formatting.
+  // If the year already looks Gregorian (>= 1900), just normalise formatting.
   if (year >= 1900) {
     const mm = String(month).padStart(2, "0");
     const dd = String(day).padStart(2, "0");
-    const m = jMoment(`${year}-${mm}-${dd}`, "YYYY-MM-DD");
-    return m.isValid() ? m.format("YYYY-MM-DD") : null;
+    const d = new Date(`${year}-${mm}-${dd}`);
+    if (isNaN(d.getTime())) return null;
+    return `${year}-${mm}-${dd}`;
   }
 
-  const mm = String(month).padStart(2, "0");
-  const dd = String(day).padStart(2, "0");
-  const jm = jMoment(`${year}-${mm}-${dd}`, "jYYYY-jMM-jDD");
-  if (!jm.isValid()) return null;
-  return jm.format("YYYY-MM-DD");
+  return jalaliPartsToGregorian(year, month, day);
 }
 
 /**
@@ -95,6 +86,92 @@ export function toJalaliTime(d: Date): string {
   return `${hours}:${minutes}`;
 }
 
+/**
+ * Converts Jalali year/month/day parts to a Gregorian `YYYY-MM-DD` string
+ * using the algorithmic conversion (no external deps).
+ * Returns `null` if the resulting Gregorian date is invalid.
+ */
+function jalaliPartsToGregorian(
+  jYear: number,
+  jMonth: number,
+  jDay: number,
+): string | null {
+  // Jalali to Julian Day Number, then to Gregorian
+  // Algorithm: https://www.fourmilab.ch/documents/calendar/
+  const jy = jYear - 979;
+  const jm = jMonth - 1;
+  const jd = jDay - 1;
+
+  let jDayNo =
+    365 * jy + Math.floor(jy / 4) - Math.floor(jy / 100) + Math.floor(jy / 400);
+
+  const jalaliMonthDays = [31, 31, 31, 31, 31, 31, 30, 30, 30, 30, 30, 29];
+  for (let i = 0; i < jm; i++) {
+    jDayNo += jalaliMonthDays[i];
+  }
+  jDayNo += jd;
+
+  // Convert to Gregorian day number (offset from 1970-01-01 in Julian days)
+  const gDayNo = jDayNo + 79;
+
+  let gy = 1979 + 400 * Math.floor(gDayNo / 146097);
+  let days = gDayNo % 146097;
+
+  let leap = true;
+  if (days >= 36525) {
+    days--;
+    gy += 100 * Math.floor(days / 36524);
+    days %= 36524;
+    if (days >= 365) days++;
+    else leap = false;
+  }
+
+  gy += 4 * Math.floor(days / 1461);
+  days %= 1461;
+
+  if (days >= 366) {
+    leap = false;
+    days--;
+    gy += Math.floor(days / 365);
+    days %= 365;
+  }
+
+  const gregorianMonthDays = [
+    31,
+    leap ? 29 : 28,
+    31,
+    30,
+    31,
+    30,
+    31,
+    31,
+    30,
+    31,
+    30,
+    31,
+  ];
+
+  let gm = 0;
+  for (let i = 0; i < 12; i++) {
+    if (days < gregorianMonthDays[i]) {
+      gm = i + 1;
+      break;
+    }
+    days -= gregorianMonthDays[i];
+  }
+  const gd = days + 1;
+
+  const mm = String(gm).padStart(2, "0");
+  const dd = String(gd).padStart(2, "0");
+  const result = `${gy}-${mm}-${dd}`;
+
+  // Sanity check
+  const check = new Date(result);
+  if (isNaN(check.getTime())) return null;
+
+  return result;
+}
+
 const PERSIAN_TO_ENGLISH: Record<string, string> = {
   "۰": "0",
   "۱": "1",