Release version 2.0.0.

Author: xclud

CHANGELOG.md

@@ -1,3 +1,8 @@
+## [2.0.0]
+
+* Convert a [PersianDate] to [DateTime].
+* Added some utility methods to [PersianDate].
+
 ## [1.2.0]
 
 * Better lints, a more complete example.

analysis_options.yaml

@@ -22,13 +22,6 @@ analyzer:
     dead_code: error
     duplicate_import: error
     file_names: error
-    implicit_dynamic_function: ignore
-    implicit_dynamic_parameter: error
-    implicit_dynamic_list_literal: ignore
-    implicit_dynamic_map_literal: ignore
-    implicit_dynamic_method: ignore
-    implicit_dynamic_type: ignore
-    implicit_dynamic_variable: ignore
     invalid_assignment: error
     missing_return: error
     prefer_const_constructors: error

lib/persian.dart

@@ -3,6 +3,8 @@ library persian;
 
 import 'dart:core';
 
+import 'package:persian/src/date_utils.dart';
+
 part 'src/humanizer.dart';
 part 'src/int_extensions.dart';
 part 'src/extensions.dart';

lib/src/date.dart

@@ -1,56 +1,15 @@
-part of persian;
-
-int _getJulianDayNumber(int year, int month, int day) {
-  return (((year + ((month - 8) ~/ 6) + 100100) * 1461) ~/ 4) +
-      ((153 * ((month + 9) % 12) + 2) ~/ 5) +
-      day -
-      34840408 -
-      ((((year + 100100 + ((month - 8) ~/ 6)) ~/ 100) * 3) ~/ 4) +
-      752;
-}
+part of '../persian.dart';
 
 /// An instant in Persian calendar, such as Farvardin 11, 1365.
 class PersianDate {
   /// Creates a [PersianDate] from the Persian year, month and day.
   ///
   /// Example: PersianDate(1400, 12, 29);
-  const PersianDate(
-    this.year,
-    this.month,
-    this.day,
-  );
+  const PersianDate(this.year, this.month, this.day);
 
   /// Creates a [PersianDate] from the equivalent [DateTime].
   factory PersianDate.fromDateTime(DateTime date) {
-    final julianDayNumber =
-        _getJulianDayNumber(date.year, date.month, date.day);
-    final int year = date.year;
-    int persianYear = year - 621;
-    final r = _PersianDateCalculation.calculate(persianYear);
-    final int jdn1f = _getJulianDayNumber(year, 3, r.march);
-    int k = julianDayNumber - jdn1f;
-    // Find number of days that passed since 1 Farvardin.
-    if (k >= 0) {
-      if (k <= 185) {
-        // The first 6 months.
-        final int jm = 1 + (k ~/ 31);
-        final int jd = (k % 31) + 1;
-
-        return PersianDate(persianYear, jm, jd);
-      } else {
-        // The remaining months.
-        k -= 186;
-      }
-    } else {
-      // Previous Persian year.
-      persianYear -= 1;
-      k += 179;
-      if (r.leap == 1) k += 1;
-    }
-    final int jm = 7 + (k ~/ 30);
-    final int jd = (k % 30) + 1;
-
-    return PersianDate(persianYear, jm, jd);
+    return toPersian(date.year, date.month, date.day);
   }
 
   /// Constructs a new [PersianDate] instance
@@ -67,10 +26,8 @@ class PersianDate {
     bool isUtc = false,
   }) =>
       PersianDate.fromDateTime(
-        DateTime.fromMillisecondsSinceEpoch(
-          millisecondsSinceEpoch,
-          isUtc: isUtc,
-        ),
+        DateTime.fromMillisecondsSinceEpoch(millisecondsSinceEpoch,
+            isUtc: isUtc),
       );
 
   /// Constructs a new [PersianDate] instance
@@ -86,10 +43,8 @@ class PersianDate {
     bool isUtc = false,
   }) =>
       PersianDate.fromDateTime(
-        DateTime.fromMicrosecondsSinceEpoch(
-          microsecondsSinceEpoch,
-          isUtc: isUtc,
-        ),
+        DateTime.fromMicrosecondsSinceEpoch(microsecondsSinceEpoch,
+            isUtc: isUtc),
       );
 
   /// The Year.
@@ -101,109 +56,54 @@ class PersianDate {
   /// The Day.
   final int day;
 
-  @override
-  String toString() {
-    return '$year/${month.toString().padLeft(2, '0')}/${day.toString().padLeft(2, '0')}'
-        .withPersianNumbers();
+  /// Converts this [PersianDate] instance to a [DateTime].
+  DateTime toDateTime() {
+    return toGregorian(year, month, day);
   }
-}
-
-/// Internal class
-class _PersianDateCalculation {
-  const _PersianDateCalculation({
-    required this.leap,
-    required this.gy,
-    required this.march,
-  });
-
-  /// This determines if the Persian Year is
-  /// leap (366-day long) or is the common year (365 days), and
-  /// finds the day in March (Gregorian calendar) of the first
-  /// day of the Persian Year.
-  ///
-  /// [1. see here](http://www.astro.uni.torun.pl/~kb/Papers/EMP/PersianC-EMP.htm)
-  ///
-  /// [2. see here](http://www.fourmilab.ch/documents/calendar/)
-  factory _PersianDateCalculation.calculate(int persianYear) {
-    // Persian years starting the 33-year rule.
 
-    final int bl = breaks.length;
-    final int gy = persianYear + 621;
-    int leapJ = -14;
-    int jp = breaks[0];
-    int jump = 0;
+  /// Checks whether a Persian date is valid or not.
+  static bool isValidPersianDate(
+      int persianYear, int persianMonth, int persianDay) {
+    return persianYear >= -61 &&
+        persianYear <= 3177 &&
+        persianMonth >= 1 &&
+        persianMonth <= 12 &&
+        persianDay >= 1 &&
+        persianDay <= getDaysInPersianMonth(persianYear, persianMonth);
+  }
 
-    // should not happen
-    if (persianYear < -61 || persianYear >= 3178) {
-      throw StateError('should not happen');
+  /// Get the number of days in a Persian year.
+  static int getDaysInPersianYear(int persianYear) {
+    if (isLeapPersianYear(persianYear)) {
+      return 366;
     }
 
-    // Find the limiting years for the Persian year jy.
-    for (int i = 1; i < bl; i += 1) {
-      final int jm = breaks[i];
-      jump = jm - jp;
-      if (persianYear < jm) {
-        break;
-      }
-      leapJ = leapJ + (jump ~/ 33) * 8 + (((jump % 33)) ~/ 4);
-      jp = jm;
-    }
-    int n = persianYear - jp;
+    return 365;
+  }
 
-    // Find the number of leap years from AD 621 to the beginning
-    // of the current Persian year in the Persian calendar.
-    leapJ = leapJ + ((n) ~/ 33) * 8 + (((n % 33) + 3) ~/ 4);
-    if ((jump % 33) == 4 && jump - n == 4) {
-      leapJ += 1;
+  /// Number of days in a given month in a Persian year.
+  static int getDaysInPersianMonth(int persianYear, int persianMonth) {
+    if (persianMonth < 7) {
+      return 31;
     }
-
-    // And the same in the Gregorian calendar (until the year gy).
-    final int leapG = ((gy) ~/ 4) - (((((gy) ~/ 100) + 1) * 3) ~/ 4) - 150;
-
-    // Determine the Gregorian date of Farvardin the 1st.
-    final int march = 20 + leapJ - leapG;
-
-    // Find how many years have passed since the last leap year.
-    if (jump - n < 6) {
-      n = n - jump + ((jump + 4) ~/ 33) * 33;
+    if (persianMonth < 12) {
+      return 30;
     }
-    int leap = ((((n + 1) % 33) - 1) % 4);
-    if (leap == -1) {
-      leap = 4;
+    if (isLeapPersianYear(persianYear)) {
+      return 30;
     }
 
-    return _PersianDateCalculation(leap: leap, gy: gy, march: march);
+    return 29;
   }
 
-  /// Number of years since the last leap year (0 to 4)
-  final int leap;
-
-  /// Gregorian year of the beginning of Persian year
-  final int gy;
-
-  /// The March day of Farvardin the 1st (1st day of jy)
-  final int march;
+  /// Is this a leap year or not?
+  static bool isLeapPersianYear(int persianYear) {
+    return persianCalendar(persianYear)!.leap == 0;
+  }
 
-  static final List<int> breaks = const [
-    -61,
-    9,
-    38,
-    199,
-    426,
-    686,
-    756,
-    818,
-    1111,
-    1181,
-    1210,
-    1635,
-    2060,
-    2097,
-    2192,
-    2262,
-    2324,
-    2394,
-    2456,
-    3178,
-  ];
+  @override
+  String toString() {
+    return '$year/${month.toString().padLeft(2, '0')}/${day.toString().padLeft(2, '0')}'
+        .withPersianNumbers();
+  }
 }