Implemented mailing abstraction

Closes #434

2 files changed, 147 insertions, 0 deletions

diff --git a/src/Mail/Transport/LogTransport.php b/src/Mail/Transport/LogTransport.php
new file mode 100644
index 00000000..6e351302
--- /dev/null
+++ b/src/Mail/Transport/LogTransport.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace Engelsystem\Mail\Transport;
+
+use Psr\Log\LoggerInterface;
+use Swift_Mime_SimpleMessage as SimpleMessage;
+
+class LogTransport extends Transport
+{
+    /** @var LoggerInterface */
+    protected $logger;
+
+    public function __construct(LoggerInterface $logger)
+    {
+        $this->logger = $logger;
+    }
+
+    /**
+     * Send the given Message.
+     *
+     * Recipient/sender data will be retrieved from the Message API.
+     * The return value is the number of recipients
+     *
+     * @param SimpleMessage $message
+     * @param string[]      $failedRecipients An array of failures by-reference
+     *
+     * @return int
+     */
+    public function send(
+        SimpleMessage $message,
+        &$failedRecipients = null
+    ): int {
+        $this->logger->debug(
+            'Mail: Send mail "{title}" to "{recipients}":' . PHP_EOL . '{content}',
+            [
+                'title'      => $message->getSubject(),
+                'recipients' => $this->getTo($message),
+                'content'    => (string)$message->getHeaders() . PHP_EOL . PHP_EOL . $message->toString(),
+            ]
+        );
+
+        return count($this->allRecipients($message));
+    }
+}
diff --git a/src/Mail/Transport/Transport.php b/src/Mail/Transport/Transport.php
new file mode 100644
index 00000000..691faf60
--- /dev/null
+++ b/src/Mail/Transport/Transport.php
@@ -0,0 +1,103 @@
+<?php
+
+namespace Engelsystem\Mail\Transport;
+
+use Swift_Events_EventListener;
+use Swift_Mime_SimpleMessage as SimpleMessage;
+use Swift_Transport as SwiftTransport;
+
+abstract class Transport implements SwiftTransport
+{
+    /**
+     * Test if this Transport mechanism has started.
+     *
+     * @return bool
+     */
+    public function isStarted(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Start this Transport mechanism.
+     */
+    public function start() { }
+
+    /**
+     * Stop this Transport mechanism.
+     */
+    public function stop() { }
+
+    /**
+     * Check if this Transport mechanism is alive.
+     *
+     * If a Transport mechanism session is no longer functional, the method
+     * returns FALSE. It is the responsibility of the developer to handle this
+     * case and restart the Transport mechanism manually.
+     *
+     * @example
+     *
+     *   if (!$transport->ping()) {
+     *      $transport->stop();
+     *      $transport->start();
+     *   }
+     *
+     * The Transport mechanism will be started, if it is not already.
+     *
+     * It is undefined if the Transport mechanism attempts to restart as long as
+     * the return value reflects whether the mechanism is now functional.
+     *
+     * @return bool TRUE if the transport is alive
+     */
+    public function ping(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Register a plugin in the Transport.
+     *
+     * @param Swift_Events_EventListener $plugin
+     */
+    public function registerPlugin(Swift_Events_EventListener $plugin) { }
+
+    /**
+     * Returns a unified list of all recipients
+     *
+     * @param SimpleMessage $message
+     * @return array
+     */
+    protected function allRecipients(SimpleMessage $message): array
+    {
+        return array_merge(
+            (array)$message->getTo(),
+            (array)$message->getCc(),
+            (array)$message->getBcc()
+        );
+    }
+
+    /**
+     * Returns a concatenated list of mail recipients
+     *
+     * @param  SimpleMessage $message
+     * @return string
+     */
+    protected function getTo(SimpleMessage $message): string
+    {
+        return $this->formatTo($this->allRecipients($message));
+    }
+
+    /**
+     * @param array $recipients
+     * @return string
+     */
+    protected function formatTo(array $recipients)
+    {
+        $list = [];
+        foreach ($recipients as $address => $name) {
+            $list[] = $name ? sprintf('%s <%s>', $name, $address) : $address;
+        }
+
+        return implode(',', $list);
+    }
+}