1 files changed, 137 insertions, 0 deletions
diff --git a/src/Metabox.php b/src/Metabox.php
new file mode 100644
index 0000000..0f4c5d7
--- /dev/null
+++ b/src/Metabox.php
@@ -0,0 +1,137 @@
+<?php
+
+namespace PostTypes;
+
+/**
+ * A Metabox in ACF is called a "Field Group" or just "Group".
+ * So all instances of "Metabox" or "Box" can be understood as an "ACF Field Group"
+ *
+ * @see https://github.com/AdvancedCustomFields/acf
+ */
+class Metabox
+{
+    /**
+     * The Box's key
+     */
+    public string $key;
+
+    /**
+     * The Box's title
+     * they $key is derived from that
+     */
+    public string $title;
+
+    /**
+     * The PostType/s to add the Metabox to
+     */
+    public array $posttypes = [];
+
+    /**
+     * The Box's fields to add
+     *
+     * @var MetaboxField[]
+     */
+    public array $fields = [];
+
+    /**
+     * The "ACF Group Settings"
+     * @see https://www.advancedcustomfields.com/resources/register-fields-via-php/#group-settings
+     */
+    public array $options = [];
+
+    /**
+     * Metabox constructor.
+     *
+     * @param string $title
+     * @param array  $options
+     */
+    public function __construct(string $title, array $options = [])
+    {
+        // @see https://github.com/AdvancedCustomFields/acf/blob/5.9.3/includes/local-fields.php#L163
+        $this->key = 'group_' . str_replace(['_', '-', '/', ' '], '_', strtolower($title));
+        $this->title = $title;
+
+        $this->options($options);
+    }
+
+    /**
+     * Assign a PostType to add the Metabox to
+     *
+     * @param  string|array $posttypes
+     *
+     * @return $this
+     */
+    public function posttype($posttypes)
+    {
+        $posttypes = (array)$posttypes;
+
+        foreach ($posttypes as $posttype) {
+            $this->posttypes[$posttype] = $posttype;
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param MetaboxField|array $fields
+     *
+     * @return $this
+     */
+    public function field($fields)
+    {
+        if ($fields instanceof MetaboxField) {
+            $fields = [$fields];
+        }
+
+        foreach ($fields as $field) {
+            // set the field's parent
+            $field->parent($this->key);
+
+            $this->fields[$field->key] = &$field;
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param array $options
+     *
+     * @return $this
+     */
+    public function options(array $options)
+    {
+        $this->options = $options;
+
+        return $this;
+    }
+
+    /**
+     * Add the acf local field group
+     */
+    public function add()
+    {
+        // build the rule groups for the location
+        $postTypeRuleGroups = array_map(function ($posttype) {
+            return [[
+                'param' => 'post_type',
+                'operator' => '==',
+                'value' => $posttype,
+            ]];
+        }, $this->posttypes);
+
+        // merge with extra options
+        $fieldGroup = array_merge_recursive([
+            'key' => $this->key,
+            'title' => $this->title,
+            'location' => $postTypeRuleGroups,
+        ], $this->options);
+
+        // add field group
+        acf_add_local_field_group($fieldGroup);
+
+        // add fields
+        foreach ($this->fields as $field) {
+            $field->add();
+        }
+    }
+}