allow to switch the clock timezone

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+## Added
+
+- `Innmind\TimeContinuum\Clock::switch()`
+
 ### Changed
 
 - `Innmind\TimeContinuum\Format` is now a `final class`

src/Clock.php

@@ -20,12 +20,12 @@ private function __construct(
 
     public static function live(): self
     {
-        return new self(new Live);
+        return new self(new Live(Offset::utc()));
     }
 
     public static function frozen(PointInTime $point): self
     {
-        return new self(new Frozen($point));
+        return new self(new Frozen($point, new Live(Offset::utc())));
     }
 
     public static function logger(self $clock, LoggerInterface $logger): self
@@ -38,6 +38,14 @@ public function now(): PointInTime
         return $this->implementation->now();
     }
 
+    /**
+     * @param callable(Timezones): Timezone $changeTimezone
+     */
+    public function switch(callable $changeTimezone): self
+    {
+        return new self($this->implementation->switch($changeTimezone));
+    }
+
     /**
      * @psalm-pure
      *

src/Clock/Frozen.php

@@ -6,6 +6,8 @@
 use Innmind\TimeContinuum\{
     PointInTime,
     Format,
+    Timezones,
+    Timezone,
 };
 use Innmind\Immutable\Maybe;
 
@@ -17,10 +19,21 @@ final class Frozen
     private PointInTime $now;
     private Live $concrete;
 
-    public function __construct(PointInTime $now)
+    public function __construct(PointInTime $now, Live $concrete)
     {
         $this->now = $now;
-        $this->concrete = new Live;
+        $this->concrete = $concrete;
+    }
+
+    /**
+     * @param callable(Timezones): Timezone $changeTimezone
+     */
+    public function switch(callable $changeTimezone): self
+    {
+        return new self(
+            $this->now,
+            $this->concrete->switch($changeTimezone),
+        );
     }
 
     public function now(): PointInTime

src/Clock/Live.php

@@ -7,6 +7,8 @@
     Offset,
     PointInTime,
     Format,
+    Timezones,
+    Timezone,
 };
 use Innmind\Immutable\Maybe;
 
@@ -17,9 +19,30 @@ final class Live
 {
     private Offset $offset;
 
-    public function __construct()
+    public function __construct(Offset $offset)
     {
-        $this->offset = Offset::utc();
+        $this->offset = $offset;
+    }
+
+    /**
+     * @param callable(Timezones): Timezone $changeTimezone
+     */
+    public function switch(callable $changeTimezone): self
+    {
+        /** @var callable(non-empty-string): Timezone */
+        $of = static function(string $zone): Timezone {
+            /** @var non-empty-string $zone */
+            $now = (new \DateTimeImmutable('now'))->setTimezone(new \DateTimeZone($zone));
+
+            return Timezone::of(
+                Offset::from($now->format('P')),
+                (bool) (int) $now->format('I'),
+            );
+        };
+
+        return new self(
+            $changeTimezone(Timezones::new($of))->offset(),
+        );
     }
 
     public function now(): PointInTime

src/Clock/Logger.php

@@ -7,6 +7,8 @@
     Clock,
     PointInTime,
     Format,
+    Timezones,
+    Timezone,
 };
 use Innmind\Immutable\Maybe;
 use Psr\Log\LoggerInterface;
@@ -25,6 +27,17 @@ public function __construct(Clock $clock, LoggerInterface $logger)
         $this->logger = $logger;
     }
 
+    /**
+     * @param callable(Timezones): Timezone $changeTimezone
+     */
+    public function switch(callable $changeTimezone): self
+    {
+        return new self(
+            $this->clock->switch($changeTimezone),
+            $this->logger,
+        );
+    }
+
     public function now(): PointInTime
     {
         $now = $this->clock->now();

src/Timezone.php

@@ -0,0 +1,31 @@
+<?php
+declare(strict_types = 1);
+
+namespace Innmind\TimeContinuum;
+
+final class Timezone
+{
+    private function __construct(
+        private Offset $offset,
+        private bool $dst,
+    ) {
+    }
+
+    /**
+     * @internal
+     */
+    public static function of(Offset $offset, bool $daylightSavingTime): self
+    {
+        return new self($offset, $daylightSavingTime);
+    }
+
+    public function offset(): Offset
+    {
+        return $this->offset;
+    }
+
+    public function daylightSavingTimeApplied(): bool
+    {
+        return $this->dst;
+    }
+}