Create initial structure and classes

src/Reason.php

@@ -0,0 +1,119 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Anwinged\Reason;
+
+class Reason
+{
+    /**
+     * @var ReasonStatusInterface
+     */
+    private $status;
+
+    /**
+     * @var string[]
+     */
+    private $messages;
+
+    /**
+     * @param ReasonStatusInterface $status
+     * @param string[]              $messages
+     */
+    public function __construct(ReasonStatusInterface $status, array $messages)
+    {
+        $this->status = $status;
+        $this->messages = $messages;
+    }
+
+    /**
+     * Clones the reason.
+     */
+    public function __clone()
+    {
+        $this->status = clone $this->status;
+    }
+
+    /**
+     * @return ReasonStatusInterface
+     */
+    public function getStatus(): ReasonStatusInterface
+    {
+        return clone $this->status;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getMessages(): array
+    {
+        return $this->messages;
+    }
+
+    /**
+     * Appends reason to current and returns new reason.
+     *
+     * Reason with highest weighs wins.
+     *
+     * If other reason has highest weight, then it will be returned without changes.
+     * If weights are equal, then messages will be merged. Otherwise,
+     * returns current reason.
+     *
+     * Don't change original objects.
+     *
+     * @param Reason $other
+     *
+     * @return self
+     */
+    public function andX(Reason $other): self
+    {
+        if ($other->getStatus()->getWeight() > $this->status->getWeight()) {
+            return clone $other;
+        }
+
+        if ($other->getStatus()->getWeight() === $this->status->getWeight()) {
+            return $this->withMessages($other->getMessages());
+        }
+
+        return clone $this;
+    }
+
+    /**
+     * Join reason to current and return new reason.
+     *
+     * Reason with lowest weight wins.
+     *
+     * If other reason has lowest weight, then it will be returned without changes.
+     * If weights are equal, then messages will be merged. Otherwise,
+     * returns current reason.
+     *
+     * @param Reason $other
+     *
+     * @return self
+     */
+    public function orX(Reason $other): self
+    {
+        if ($other->getStatus()->getWeight() < $this->status->getWeight()) {
+            return clone $other;
+        }
+
+        if ($other->getStatus()->getWeight() === $this->status->getWeight()) {
+            return $this->withMessages($other->getMessages());
+        }
+
+        return clone $this;
+    }
+
+    /**
+     * @param string[] $messages
+     *
+     * @return self
+     */
+    private function withMessages(array $messages): self
+    {
+        $reason = clone $this;
+        $reason->messages = array_merge($reason->messages, $messages);
+
+        return $reason;
+    }
+}

src/ReasonStatusInterface.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Anwinged\Reason;
+
+interface ReasonStatusInterface
+{
+    /**
+     * @return bool
+     */
+    public function isSuccess(): bool;
+
+    /**
+     * @return bool
+     */
+    public function isFail(): bool;
+
+    /**
+     * @return int
+     */
+    public function getWeight(): int;
+}

src/Status/BooleanStatus.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Anwinged\Reason\Status;
+
+use Anwinged\Reason\ReasonStatusInterface;
+
+class BooleanStatus implements ReasonStatusInterface
+{
+    /**
+     * @var bool
+     */
+    private $value;
+
+    /**
+     * @param bool $value
+     */
+    public function __construct(bool $value)
+    {
+        $this->value = $value;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isSuccess(): bool
+    {
+        return $this->value;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isFail(): bool
+    {
+        return !$this->value;
+    }
+
+    /**
+     * @return int
+     */
+    public function getWeight(): int
+    {
+        return $this->value ? 0 : 1;
+    }
+}