Update pagination (#346)

src/server/utils.js

@@ -1,5 +1,6 @@
 module.exports = {
-  toNative: toNative
+  toNative: toNative,
+  getPage: getPage
 }
 
 // Turns string to native.
@@ -22,3 +23,30 @@ function toNative (value) {
   }
   return value
 }
+
+function getPage (array, page, perPage) {
+  var obj = {}
+  var start = (page - 1) * perPage
+  var end = page * perPage
+
+  obj.items = array.slice(start, end)
+  if (obj.items.length === 0) {
+    return obj
+  }
+
+  if (page > 1) {
+    obj.prev = page - 1
+  }
+
+  if (end < array.length) {
+    obj.next = page + 1
+  }
+
+  if (obj.items.length !== array.length) {
+    obj.current = page
+    obj.first = 1
+    obj.last = Math.ceil(array.length / perPage)
+  }
+
+  return obj
+}