azuyalabs · stelgenhof · Sep 5, 2021 · Jul 6, 2021 · Jul 6, 2021 · Jul 6, 2021
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -12,14 +12,17 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/) and this
   Canada [\#257](https://github.com/azuyalabs/yasumi/pull/257) ([Owen V. Gray](https://github.com/adrx))
 - New Juneteenth National Independence Day to
   USA [\#253](https://github.com/azuyalabs/yasumi/pull/253) ([Mark Heintz](https://github.com/mheintz))
+- The Korea Tourism Organization's holiday guide link was added to the source of SouthKorea Provider. [\#255](https://github.com/azuyalabs/yasumi/pull/253) ([barami](https://github.com/barami)) 
 - All providers now include a method that returns a list of external sources (i.e. references to websites, books,
   scientific papers, etc.) that are used for determining the calculation logic of the providers' holidays.
 
 ### Changed
 
 - Provider tests must implement the `ProviderTestCase` interface to ensure all required test methods are defined.
-- `YasumiTestCaseInterface` was renamed to `HolidayTestCase` to better match the newly added `ProviderTestCase`
-  interface.
+- `YasumiTestCaseInterface` was renamed to `HolidayTestCase` to better match the newly added `ProviderTestCase` interface.
+- Revised rules to calculate substitution holidays of SouthKorea to apply the newly enacted law on June 2021. [\#255](https://github.com/azuyalabs/yasumi/pull/253) ([barami](https://github.com/barami))
+- Seperate `calculateSubstituteHolidays` method of SouthKorea Provider to `calculateSubstituteHolidays` and `calculateOldSubstituteHolidays`. [\#255](https://github.com/azuyalabs/yasumi/pull/253) ([barami](https://github.com/barami))
+- Refactored the tests of SouthKorea provider to testing substitution holidays. [\#255](https://github.com/azuyalabs/yasumi/pull/253) ([barami](https://github.com/barami))
 
 ### Fixed
 

diff --git a/src/Yasumi/Provider/SouthKorea.php b/src/Yasumi/Provider/SouthKorea.php
@@ -157,6 +157,7 @@ public function getSources(): array
         return [
             'https://en.wikipedia.org/wiki/Public_holidays_in_South_Korea',
             'https://ko.wikipedia.org/wiki/%EB%8C%80%ED%95%9C%EB%AF%BC%EA%B5%AD%EC%9D%98_%EA%B3%B5%ED%9C%B4%EC%9D%BC',
+            'https://english.visitkorea.or.kr/enu/TRV/TV_ENG_1_1.jsp',
         ];
     }
 
@@ -468,68 +469,152 @@ private function calculateHangulDay(): void
     }
 
     /**
-     * Substitute Holidays.
+     * Substitute Holidays up to 2021.
      * Related statutes: Article 3 Alternative Statutory Holidays of the Regulations on Holidays of Government Offices.
      *
      * Since 2014, it has been applied only on Seollal, Chuseok and Children's Day.
      * Due to the lunar calendar, public holidays can overlap even if it's not a Sunday.
      * When public holidays fall on each other, the first non-public holiday after the holiday becomes a public holiday.
      * As an exception, Children's Day also applies on Saturday.
      *
+     * Since new legislation about public holiday was enacted in June 2021,
+     * this function is used to calculate the holidays up to 2021.
+     *
+     * @throws \Exception
+     */
+    private function calculateOldSubstituteHolidays(): void
+    {
+        if ($this->year < 2014) {
+            return;
+        }
+
+        // Add substitute holidays by fixed entries.
+        switch ($this->year) {
+            case 2014:
+                $this->addSubstituteHoliday($this->getHoliday('dayBeforeChuseok'), "$this->year-9-10");
+                break;
+            case 2015:
+                $this->addSubstituteHoliday($this->getHoliday('chuseok'), "$this->year-9-29");
+                break;
+            case 2016:
+                $this->addSubstituteHoliday($this->getHoliday('dayBeforeSeollal'), "$this->year-2-10");
+                break;
+            case 2017:
+                $this->addSubstituteHoliday($this->getHoliday('dayAfterSeollal'), "$this->year-1-30");
+                $this->addSubstituteHoliday($this->getHoliday('dayBeforeChuseok'), "$this->year-10-6");
+                break;
+            case 2018:
+                $this->addSubstituteHoliday($this->getHoliday('childrensDay'), "$this->year-5-7");
+                $this->addSubstituteHoliday($this->getHoliday('dayBeforeChuseok'), "$this->year-9-26");
+                break;
+            case 2019:
+                $this->addSubstituteHoliday($this->getHoliday('childrensDay'), "$this->year-5-6");
+                break;
+            case 2020:
+                $this->addSubstituteHoliday($this->getHoliday('dayAfterSeollal'), "$this->year-1-27");
+                break;
+            case 2021:
+                $this->addSubstituteHoliday($this->getHoliday('liberationDay'), "$this->year-8-16");
+                $this->addSubstituteHoliday($this->getHoliday('nationalFoundationDay'), "$this->year-10-4");
+                $this->addSubstituteHoliday($this->getHoliday('hangulDay'), "$this->year-10-11");
+                break;
+        }
+    }
+
+    /**
+     * Substitute Holidays.
+     *
+     * Since 2022, it has been applied for all public holidays.
+     * When public holidays overlap on each other or weekend,
+     * the first working day after the holiday becomes a substitute holiday.
+     *
      * @throws \Exception
      */
     private function calculateSubstituteHolidays(): void
     {
-        if ($this->year <= 2013) {
+        if ($this->year < 2022) {
+            $this->calculateOldSubstituteHolidays();
+
             return;
         }
 
-        // Initialize holidays variable
-        $holidays = $this->getHolidays();
-        $acceptedHolidays = [
+        // Holiday list to allowed to substitute.
+        $accptedHolidays = [];
+
+        // When deciding on alternative holidays, place lunar holidays first for consistent rules.
+        // These holidays will substitute for the sunday only.
+        $accptedHolidays += array_fill_keys([
             'dayBeforeSeollal', 'seollal', 'dayAfterSeollal',
             'dayBeforeChuseok', 'chuseok', 'dayAfterChuseok',
-            'childrensDay',
-        ];
-
-        // Loop through all holidays
-        foreach ($holidays as $key => $holiday) {
-            // Get list of holiday dates except this
-            $holidayDates = array_map(static function ($holiday) use ($key) {
-                return $holiday->getKey() === $key ? false : $holiday;
-            }, $holidays);
-
-            // Only process accepted holidays and conditions
-            if (\in_array($key, $acceptedHolidays, true)
-                && (
-                    0 === (int) $holiday->format('w')
-                    || \in_array($holiday, $holidayDates, false)
-                    || (6 === (int) $holiday->format('w') && 'childrensDay' === $key)
-                )
-            ) {
-                $date = clone $holiday;
-
-                // Find next week day (not being another holiday)
-                while (0 === (int) $date->format('w')
-                    || (6 === (int) $date->format('w') && 'childrensDay' === $key)
-                    || \in_array($date, $holidayDates, false)) {
-                    $date->add(new DateInterval('P1D'));
-                }
-
-                // Add a new holiday that is substituting the original holiday
-                $substitute = new SubstituteHoliday(
-                    $holiday,
-                    [],
-                    $date,
-                    $this->locale
-                );
+        ], [0]);
+
+        // These holidays will substitute for any weekend days (Sunday and Saturday).
+        $accptedHolidays += array_fill_keys([
+            'childrensDay', 'independenceMovementDay', 'liberationDay',
+            'nationalFoundationDay', 'hangulDay',
+        ], [0, 6]);
+
+        // Step 1. Build a temporary table that aggregates holidays by date.
+        $dates = [];
+        foreach ($this->getHolidayDates() as $name => $day) {
+            $holiday = $this->getHoliday($name);
+            $dates[$day][] = $name;
+
+            if (!isset($accptedHolidays[$name])) {
+                continue;
+            }
 
-                // Add a new holiday that is substituting the original holiday
-                $this->addHoliday($substitute);
+            $dayOfWeek = (int) $holiday->format('w');
+            if (in_array($dayOfWeek, $accptedHolidays[$name], true)) {
+                $dates[$day]['weekend:'.$day] = $name;
+            }
+        }
 
-                // Add substitute holiday to the list
-                $holidays[] = $substitute;
+        // Step 2. Add substitute holidays by referring to the temporary table.
+        $tz = DateTimeZoneFactory::getDateTimeZone($this->timezone);
+        foreach ($dates as $day => $names) {
+            $count = count($names);
+            if ($count < 2) {
+                continue;
+            } else {
+                // In a temporary table, public holidays are keyed by numeric number.
+                // And weekends are keyed by string start with 'weekend:'.
+                // For the substitute, we will use first item in queue.
+                $origin = $this->getHoliday($names[0]);
+                $workDay = $this->nextWorkingDay(DateTime::createFromFormat('Y-m-d', $day, $tz));
+                $this->addSubstituteHoliday($origin, $workDay->format('Y-m-d'));
             }
         }
     }
+
+    /**
+     * Helper method to find a first working day after specific date.
+     */
+    private function nextWorkingDay(DateTime $date): DateTime
+    {
+        $interval = new DateInterval('P1D');
+        $next = clone $date;
+        do {
+            $next->add($interval);
+        } while (!$this->isWorkingDay($next));
+
+        return $next;
+    }
+
+    /**
+     * Helper method to add substitute holiday.
+     *
+     * Add a substitute holiday from origin holiday to different date.
+     *
+     * @throws \Exception
+     */
+    private function addSubstituteHoliday(Holiday $origin, string $date_str): void
+    {
+        $this->addHoliday(new SubstituteHoliday(
+            $origin,
+            [],
+            new DateTime($date_str, DateTimeZoneFactory::getDateTimeZone($this->timezone)),
+            $this->locale
+        ));
+    }
 }
diff --git a/tests/SouthKorea/ChildrensDayTest.php b/tests/SouthKorea/ChildrensDayTest.php
@@ -43,7 +43,7 @@ class ChildrensDayTest extends SouthKoreaBaseTestCase implements HolidayTestCase
      * @throws Exception
      * @throws ReflectionException
      */
-    public function testMainHoliday(): void
+    public function testHoliday(): void
     {
         $year = $this->generateRandomYear(self::ESTABLISHMENT_YEAR);
         $this->assertHoliday(
@@ -62,47 +62,57 @@ public function testMainHoliday(): void
      */
     public function testSubstituteHolidayByBuddhasBirthday(): void
     {
+        $tz = new DateTimeZone(self::TIMEZONE);
+
         foreach ([2025, 2044] as $year) {
             $this->assertHoliday(
                 self::REGION,
-                'substituteHoliday:childrensDay',
+                'buddhasBirthday',
+                $year,
+                new DateTime("$year-5-5", $tz)
+            );
+            $this->assertSubstituteHoliday(
+                self::REGION,
+                self::HOLIDAY,
                 $year,
-                new DateTime("$year-5-6", new DateTimeZone(self::TIMEZONE))
+                new DateTime("$year-5-6", $tz)
             );
         }
     }
 
     /**
-     * Tests the substitute holiday defined in this test (conflict with Saturday).
+     * Tests the substitute holiday defined in this test.
      *
      * @throws Exception
      * @throws ReflectionException
      */
-    public function testSubstituteHolidayBySaturday(): void
+    public function testSubstituteHoliday(): void
     {
-        $year = 2029;
-        $this->assertHoliday(
+        $tz = new DateTimeZone(self::TIMEZONE);
+
+        // Before 2022
+        $this->assertNotSubstituteHoliday(self::REGION, self::HOLIDAY, 2013);
+        $this->assertSubstituteHoliday(
             self::REGION,
-            'substituteHoliday:childrensDay',
-            $year,
-            new DateTime("$year-5-7", new DateTimeZone(self::TIMEZONE))
+            self::HOLIDAY,
+            2019,
+            new DateTime('2019-5-6', $tz)
         );
-    }
 
-    /**
-     * Tests the substitute holiday defined in this test (conflict with Sunday).
-     *
-     * @throws Exception
-     * @throws ReflectionException
-     */
-    public function testSubstituteHolidayBySunday(): void
-    {
-        $year = 2019;
-        $this->assertHoliday(
+        // By saturday
+        $this->assertSubstituteHoliday(
             self::REGION,
-            'substituteHoliday:childrensDay',
-            $year,
-            new DateTime("$year-5-6", new DateTimeZone(self::TIMEZONE))
+            self::HOLIDAY,
+            2029,
+            new DateTime('2029-5-7', $tz)
+        );
+
+        // By sunday
+        $this->assertSubstituteHoliday(
+            self::REGION,
+            self::HOLIDAY,
+            2024,
+            new DateTime('2024-5-6', $tz)
         );
     }