Order child pages (#21)

* save ordering pages

* move to another collection

* requested changes. Code improvements

* add margin

* unit tests

* fix

* requested changes

* recursive method: create menu tree

* update comments

* fix bug

* requested changes

* move const

* fix error message on catch

* add migration

* rewrite to splices

* move methods

* testing put above method

* linter fix

src/controllers/pages.js

@@ -138,7 +138,6 @@ class Pages {
     }
 
     page.data = data;
-
     return page.save();
   }
 

src/controllers/pagesOrder.js

@@ -0,0 +1,95 @@
+const Model = require('../models/pageOrder');
+
+/**
+ * @class PagesOrder
+ * @classdesc PagesOrder controller
+ *
+ * Manipulates with Pages: changes the order, deletes, updates and so on...
+ */
+class PagesOrder {
+  /**
+   * Returns Page's order
+   *
+   * @param {string} parentId - of which page we want to get children order
+   * @returns {Promise<PageOrder>}
+   */
+  static async get(parentId) {
+    const order = await Model.get(parentId);
+
+    if (!order._id) {
+      throw new Error('Page with given id does not contain order');
+    }
+
+    return order;
+  }
+
+  /**
+   * Pushes the child page to the parent's order list
+   *
+   * @param {string} parentId - parent page's id
+   * @param {string} childId - new page pushed to the order
+   */
+  static async push(parentId, childId) {
+    const order = await Model.get(parentId);
+
+    order.push(childId);
+    await order.save();
+  }
+
+  /**
+   * Move one page to another Page's order
+   *
+   * @param {string} oldParentId - old parent page's id
+   * @param {string} newParentId - new parent page's id
+   * @param {string} targetPageId - page's id which is changing the parent page
+   */
+  static async move(oldParentId, newParentId, targetPageId) {
+    const oldParentOrder = await Model.get(oldParentId);
+
+    oldParentOrder.remove(targetPageId);
+    await oldParentOrder.save();
+
+    const newParentOrder = await Model.get(newParentId);
+
+    newParentOrder.push(targetPageId);
+    await newParentOrder.save();
+  }
+
+  /**
+   * Returns new array with ordered pages
+   *
+   * @param {Page[]} pages - list of all available pages
+   * @param {string} currentPageId - page's id around which we are ordering
+   * @param {string} parentPageId - parent page's id that contains page above
+   * @param {Boolean} ignoreSelf - should we ignore current page in list or not
+   * @return {Page[]}
+   */
+  static async getOrderedChildren(pages, currentPageId, parentPageId, ignoreSelf = false) {
+    const children = await PagesOrder.get(parentPageId);
+    const result = [];
+
+    children.order.forEach(pageId => {
+      pages.forEach(page => {
+        if (page._id === pageId && (pageId !== currentPageId || !ignoreSelf)) {
+          result.push(page);
+        }
+      });
+    });
+
+    return result;
+  }
+
+  /**
+   * @param {string} currentPageId - page's id that changes the order
+   * @param {string} parentPageId - parent page's id that contains both two pages
+   * @param {string} putAbovePageId - page's id above which we put the target page
+   */
+  static async update(currentPageId, parentPageId, putAbovePageId) {
+    const pageOrder = await Model.get(parentPageId);
+
+    pageOrder.putAbove(currentPageId, putAbovePageId);
+    await pageOrder.save();
+  }
+}
+
+module.exports = PagesOrder;