From 1e94a9e2a40ae1445d749ea976e10db2b30ff00a Mon Sep 17 00:00:00 2001
From: Gus Caplan <gustavcaplan@gmail.com>
Date: Wed, 1 Feb 2017 16:02:16 -0600
Subject: [PATCH] serious role position stuff (#1159)

* serious role position stuff

* kill meh

* Update Role.js

* Update Guild.js

* Update Role.js
---
 src/client/actions/GuildRoleCreate.js |  1 +
 src/structures/Guild.js               | 27 +++++++--------------------
 src/structures/Role.js                | 17 ++++++++++++++---
 src/util/MoveElementInArray.js        | 17 +++++++++++++++++
 4 files changed, 39 insertions(+), 23 deletions(-)
 create mode 100644 src/util/MoveElementInArray.js

diff --git a/src/client/actions/GuildRoleCreate.js b/src/client/actions/GuildRoleCreate.js
index 82ea19a3b..0fa07a0fd 100644
--- a/src/client/actions/GuildRoleCreate.js
+++ b/src/client/actions/GuildRoleCreate.js
@@ -12,6 +12,7 @@ class GuildRoleCreate extends Action {
       const role = new Role(guild, data.role);
       guild.roles.set(role.id, role);
       if (!already) client.emit(Constants.Events.GUILD_ROLE_CREATE, role);
+
       return {
         role,
       };
diff --git a/src/structures/Guild.js b/src/structures/Guild.js
index 2c4c93b22..e8cc450b1 100644
--- a/src/structures/Guild.js
+++ b/src/structures/Guild.js
@@ -7,6 +7,7 @@ const Constants = require('../util/Constants');
 const Collection = require('../util/Collection');
 const cloneObject = require('../util/CloneObject');
 const arraysEqual = require('../util/ArraysEqual');
+const moveElementInArray = require('../util/MoveElementInArray');
 
 /**
  * Represents a guild (or a server) on Discord.
@@ -643,9 +644,10 @@ class Guild {
    * Set the position of a role in this guild
    * @param {string|Role} role the role to edit, can be a role object or a role ID.
    * @param {number} position the new position of the role
+   * @param {boolean} [relative=false] Position moves the role relative to its current position
    * @returns {Promise<Guild>}
    */
-  setRolePosition(role, position) {
+  setRolePosition(role, position, relative = false) {
     if (typeof role === 'string') {
       role = this.roles.get(role);
       if (!role) return Promise.reject(new Error('Supplied role is not a role or string.'));
@@ -654,27 +656,12 @@ class Guild {
     position = Number(position);
     if (isNaN(position)) return Promise.reject(new Error('Supplied position is not a number.'));
 
-    const lowestAffected = Math.min(role.position, position);
-    const highestAffected = Math.max(role.position, position);
+    let updatedRoles = Object.assign([], this.roles.array()
+      .sort((r1, r2) => r1.position !== r2.position ? r1.position - r2.position : r1.id - r2.id));
 
-    const rolesToUpdate = this.roles.filter(r => r.position >= lowestAffected && r.position <= highestAffected);
-
-    // stop role positions getting stupidly inflated
-    if (position > role.position) {
-      position = rolesToUpdate.first().position;
-    } else {
-      position = rolesToUpdate.last().position;
-    }
-
-    const updatedRoles = [];
-
-    for (const uRole of rolesToUpdate.values()) {
-      updatedRoles.push({
-        id: uRole.id,
-        position: uRole.id === role.id ? position : uRole.position + (position < role.position ? 1 : -1),
-      });
-    }
+    moveElementInArray(updatedRoles, role, position, relative);
 
+    updatedRoles = updatedRoles.map((r, i) => ({ id: r.id, position: i }));
     return this.client.rest.methods.setRolePositions(this.id, updatedRoles);
   }
 
diff --git a/src/structures/Role.js b/src/structures/Role.js
index 92759b552..e0319d896 100644
--- a/src/structures/Role.js
+++ b/src/structures/Role.js
@@ -48,7 +48,7 @@ class Role {
     this.hoist = data.hoist;
 
     /**
-     * The position of the role in the role manager
+     * The position of the role from the API
      * @type {number}
      */
     this.position = data.position;
@@ -122,6 +122,16 @@ class Role {
     return clientMember.highestRole.comparePositionTo(this) > 0;
   }
 
+  /**
+   * The position of the role in the role manager
+   * @type {number}
+   */
+  get calculatedPosition() {
+    const sorted = this.guild.roles.array()
+      .sort((r1, r2) => r1.position !== r2.position ? r1.position - r2.position : r1.id - r2.id);
+    return sorted.indexOf(sorted.find(r => r.id === this.id));
+  }
+
   /**
    * Get an object mapping permission names to whether or not the role enables that permission
    * @returns {Object<string, boolean>}
@@ -246,6 +256,7 @@ class Role {
   /**
    * Set the position of the role
    * @param {number} position The position of the role
+   * @param {boolean} [relative=false] Move the position relative to its current value
    * @returns {Promise<Role>}
    * @example
    * // set the position of the role
@@ -253,8 +264,8 @@ class Role {
    *  .then(r => console.log(`Role position: ${r.position}`))
    *  .catch(console.error);
    */
-  setPosition(position) {
-    return this.guild.setRolePosition(this, position).then(() => this);
+  setPosition(position, relative) {
+    return this.guild.setRolePosition(this, position, relative).then(() => this);
   }
 
   /**
diff --git a/src/util/MoveElementInArray.js b/src/util/MoveElementInArray.js
new file mode 100644
index 000000000..24c4a59ae
--- /dev/null
+++ b/src/util/MoveElementInArray.js
@@ -0,0 +1,17 @@
+/**
+ * Moves an element in an array *in place*
+ * @param {Array} array Array to modify
+ * @param {*} element Element to move
+ * @param {number} newIndex Index or offset to move the element to
+ * @param {boolean} [offset=false] Move the element by an offset amount rather than to a set index
+ * @returns {Array}
+ */
+module.exports = function moveElementInArray(array, element, newIndex, offset = false) {
+  const index = array.indexOf(element);
+  newIndex = (offset ? index : 0) + newIndex;
+  if (newIndex > -1 && newIndex < array.length) {
+    const removedElement = array.splice(index, 1)[0];
+    array.splice(newIndex, 0, removedElement);
+  }
+  return array;
+};