2 files changed, 192 insertions, 0 deletions
diff --git a/lib/models/Courseware/CustomFiles.php b/lib/models/Courseware/CustomFiles.php
new file mode 100644
index 0000000..21a0ea6
--- /dev/null
+++ b/lib/models/Courseware/CustomFiles.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Courseware;
+
+use Courseware\Filesystem\CustomFile;
+
+/**
+ * This interface enables a courseware-block to have a user defined representation
+ * of files. This enables a block to have its own internal representation for
+ * arbitrary content as well allowing the import and export of said content in
+ * a defined and coherent way.
+ */
+interface CustomFiles
+{
+    /**
+     * Returns an array of CustomFile objects belongig to this block
+     *
+     * @return array<int, CustomFile>
+     */
+    public function getCustomFiles() : array;
+
+    /**
+     * create a new custom file, the contents have to be set by updateCustomFilesContent afterwards
+     *
+     * @param  array     $metadata   any additional metadata needed, like id
+     * @param  string    $content    the files contets
+     *
+     * @return CustomFile            the newly created custom file
+     */
+    public function createCustomFile(CustomFile $custom_file) : CustomFile;
+
+    /**
+     * returns the contents for the custom file with the passed id
+     *
+     * @param  string   $id         the id for the custom file
+     *
+     * @return string
+     */
+    public function readCustomFile($id) : string;
+
+    /**
+     * update the attributes of the custom file for the passed id
+     *
+     * @param  string     $id
+     * @param  array      $metadata
+     *
+     * @return CustomFile
+     */
+    public function updateCustomFileMetadata($id, CustomFile $custom_file) : CustomFile;
+
+    /**
+     * update the contents of the customf ile for the passed id
+     *
+     * @param  string     $id
+     * @param  string     $content
+     *
+     * @return CustomFile
+     */
+    public function updateCustomFileContent($id, $content) : CustomFile;
+
+    /**
+     * delete the custom file for the passed id
+     *
+     * @param  string     $id
+     *
+     * @return bool
+     */
+    public function deleteCustomFile($id) : bool;
+}
diff --git a/lib/models/Courseware/Filesystem/CustomFile.php b/lib/models/Courseware/Filesystem/CustomFile.php
new file mode 100644
index 0000000..7a6d4b8
--- /dev/null
+++ b/lib/models/Courseware/Filesystem/CustomFile.php
@@ -0,0 +1,123 @@
+<?php
+
+namespace Courseware\Filesystem;
+
+/**
+ * This class represents the metdata for a custom file in a courseware block
+ */
+class CustomFile
+{
+    /**
+     * The payload for this custom file, containt id, block_id and arbitrary attributes
+     * @var [type]
+     */
+    protected
+        $payload;
+
+    /**
+     * create a new custom file object, containing a self assigned id (make it unique!),
+     * the blocks id this custom file is referenced to and some attributes of
+     * your choice
+     *
+     * @param string $id          an unique id for this custom file
+     * @param int    $block_id    the id of the related block
+     * @param array  $attributes  [description]
+     */
+    public function __construct($id = null, $block_id, $attributes = [])
+    {
+        $this->payload = [
+            'id'         => $id,
+            'block_id'   => $block_id,
+            'attributes' => $attributes
+        ];
+    }
+
+    /**
+     * returns the payload: [
+     *     'id'         => ...,
+     *     'block_id'   => ...,
+     *     'attributes' => [ ... ]
+     * ]
+     *
+     * @return array the payload
+     */
+    public function getPayload()
+    {
+        return $this->payload;
+    }
+
+    /**
+     * get id for this custom file
+     *
+     * @return string custom file id
+     */
+    public function getId()
+    {
+        return $this->payload['id'];
+    }
+
+    /**
+     * get id of related block
+     *
+     * @return int  related block id
+     */
+    public function getBlockId()
+    {
+        return $this->payload['block_id'];
+    }
+
+    /**
+     * Overwrite the complete payload for this block. The payload MUST have the
+     * following structure: [
+     *     'id'         => ...,
+     *     'block_id'   => ...,
+     *     'attributes' => [ ... ]
+     * ]
+     *
+     * @param array $payload  the payload of appropriate structure
+     */
+    public function setPayload($payload): void
+    {
+        if (!$payload['id']) {
+            throw new InvalidArgumentException();
+        }
+
+        if (!$payload['block_id']) {
+            throw new InvalidArgumentException();
+        }
+
+        $this->payload = $payload;
+    }
+
+    /**
+     * Set the unique id for this custom file
+     *
+     * @param string $id
+     */
+    public function setId($id): void
+    {
+        $this->payload['id'] = $id;
+    }
+
+    /**
+     * Set the id for the related block
+     *
+     * @param int $block_id
+     */
+    public function setBlockId($block_id): void
+    {
+        $this->payload['block_id'] = $block_id;
+    }
+
+    /**
+     * Get the download url for this custom file
+     *
+     * @return string the download url
+     */
+    public function getDownloadUrl() : string
+    {
+        return rtrim(\URLHelper::getUrl('jsonapi.php/v1'), '/')
+            . '/courseware-blocks/' . $this->payload['block_id']
+            . '/custom-files/'. $this->payload['id'];
+    }
+}