Added Holidays abstraction with GoogleCalendarRegionalHolidays implem…

…entation

composer.json

@@ -30,6 +30,7 @@
         }
     },
     "require": {
+        "ext-json": "*",
         "webmozart/assert": "^1.8"
     },
     "scripts": {

src/Ocelot/Calendar/Exception/Exception.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Ocelot\Ocelot\Calendar\Exception;
+
+class Exception extends \Exception
+{
+}

src/Ocelot/Calendar/Exception/HolidayException.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Ocelot\Ocelot\Calendar\Exception;
+
+class HolidayException extends Exception
+{
+
+}

src/Ocelot/Calendar/Exception/HolidayYearException.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Ocelot\Ocelot\Calendar\Exception;
+
+final class HolidayYearException extends HolidayException
+{
+}

src/Ocelot/Calendar/Gregorian/Day.php

@@ -52,6 +52,7 @@ public static function fromDateTime(\DateTimeImmutable $dateTime) : self
 
     /**
      * @throws \Exception
+     * @psalm-pure
      */
     public static function fromString(string $date) : self
     {
@@ -88,6 +89,11 @@ public function month() : Month
         return $this->month;
     }
 
+    public function year() : Year
+    {
+        return $this->month()->year();
+    }
+
     public function number() : int
     {
         return $this->number;
@@ -127,8 +133,30 @@ public function dayOfYear() : int
         return ((int) $this->toDateTimeImmutable()->format('z')) + 1;
     }
 
+    public function isWeekend() : bool
+    {
+        return \in_array($this->dayOfWeek(), [6, 7]);
+    }
+
     public function toDateTimeImmutable() : \DateTimeImmutable
     {
         return (new \DateTimeImmutable('now'))->setDate($this->month()->year()->number(), $this->month()->number(), $this->number());
     }
+
+    public function format(string $format) : string
+    {
+        return $this->toDateTimeImmutable()->format($format);
+    }
+
+    public function equals(Day $day) : bool
+    {
+        return $this->year()->number() === $day->year()->number()
+            && $this->month()->number() === $day->month()->number()
+            && $this->number() === $day->number();
+    }
+
+    public function equalsString(string $date) : bool
+    {
+        return $this->equals(self::fromString($date));
+    }
 }

src/Ocelot/Calendar/Holidays.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Ocelot\Ocelot\Calendar;
+
+use Ocelot\Ocelot\Calendar\Gregorian\Day;
+use Ocelot\Ocelot\Calendar\Holidays\Holiday;
+
+interface Holidays
+{
+    public function isHoliday(Day $day) : bool;
+
+    /**
+     * @return array<Holiday>
+     */
+    public function holidaysAt(Day $day) : array;
+}