3 files changed, 105 insertions, 3 deletions
diff --git a/src/components/post_status_form/post_status_form.js b/src/components/post_status_form/post_status_form.js
index df4c7baf..881a9d1c 100644
--- a/src/components/post_status_form/post_status_form.js
+++ b/src/components/post_status_form/post_status_form.js
@@ -1,8 +1,10 @@
 import statusPoster from '../../services/status_poster/status_poster.service.js'
 import MediaUpload from '../media_upload/media_upload.vue'
 import fileTypeService from '../../services/file_type/file_type.service.js'
+import Completion from '../../services/completion/completion.js'
+
+import { take, filter, reject, map, uniqBy } from 'lodash'
 
-import { reject, map, uniqBy } from 'lodash'
 
 const buildMentionsString = ({user, attentions}, currentUser) => {
   let allAttentions = [...attentions]
@@ -42,15 +44,38 @@ const PostStatusForm = {
       newStatus: {
         status: statusText,
         files: []
-      }
+      },
+      caret: 0
     }
   },
   computed: {
+    candidates () {
+      if (this.textAtCaret.charAt(0) === '@') {
+        const matchedUsers = filter(this.users, (user) => (user.name + user.screen_name).match(this.textAtCaret.slice(1)))
+        // eslint-disable-next-line camelcase
+        return map(take(matchedUsers, 5), ({screen_name, name}) => screen_name)
+      } else {
+        return ['nothing']
+      }
+    },
+    textAtCaret () {
+      return (this.wordAtCaret || {}).word || ''
+    },
+    wordAtCaret () {
+      const word = Completion.wordAtPosition(this.newStatus.status, this.caret - 1) || {}
+      return word
+    },
     users () {
       return this.$store.state.users.users
     }
   },
   methods: {
+    replace (replacement) {
+      this.newStatus.status = Completion.replaceWord(this.newStatus.status, this.wordAtCaret, replacement)
+    },
+    setCaret ({target: {selectionStart}}) {
+      this.caret = selectionStart
+    },
     postStatus (newStatus) {
       statusPoster.postStatus({
         status: newStatus.status,
diff --git a/src/components/post_status_form/post_status_form.vue b/src/components/post_status_form/post_status_form.vue
index 46beb506..4f6d4565 100644
--- a/src/components/post_status_form/post_status_form.vue
+++ b/src/components/post_status_form/post_status_form.vue
@@ -2,7 +2,14 @@
   <div class="post-status-form">
     <form @submit.prevent="postStatus(newStatus)">
       <div class="form-group base03-border" >
-        <textarea v-model="newStatus.status" placeholder="Just landed in L.A." rows="1" class="form-control" @keydown.meta.enter="postStatus(newStatus)" @keyup.ctrl.enter="postStatus(newStatus)" @drop="fileDrop" @dragover.prevent="fileDrag" @input="resize"></textarea>
+        <textarea @click="setCaret" @keyup="setCaret" v-model="newStatus.status" placeholder="Just landed in L.A." rows="1" class="form-control" @keydown.meta.enter="postStatus(newStatus)" @keyup.ctrl.enter="postStatus(newStatus)" @drop="fileDrop" @dragover.prevent="fileDrag" @input="resize"></textarea>
+      </div>
+      <div>
+        <h1>Word</h1>
+        <h2>{{textAtCaret}}</h2>
+        <h1>Candidates</h1>
+
+        <h3 v-for="candidate in candidates" @click="replace('@' + candidate)">{{candidate}}</h3>
       </div>
       <div class='form-bottom'>
         <media-upload @uploading="disableSubmit" @uploaded="addMediaFile" @upload-failed="enableSubmit" :drop-files="dropFiles"></media-upload>
diff --git a/src/services/completion/completion.js b/src/services/completion/completion.js
new file mode 100644
index 00000000..8788d837
--- /dev/null
+++ b/src/services/completion/completion.js
@@ -0,0 +1,70 @@
+import { reduce, find } from 'lodash'
+
+export const replaceWord = (str, toReplace, replacement) => {
+  return str.slice(0, toReplace.start) + replacement + str.slice(toReplace.end)
+}
+
+export const wordAtPosition = (str, pos) => {
+  const words = splitIntoWords(str)
+  const wordsWithPosition = addPositionToWords(words)
+
+  return find(wordsWithPosition, ({start, end}) => start <= pos && end > pos)
+}
+
+export const addPositionToWords = (words) => {
+  return reduce(words, (result, word) => {
+    const data = {
+      word,
+      start: 0,
+      end: word.length
+    }
+
+    if (result.length > 0) {
+      const previous = result.pop()
+
+      data.start += previous.end
+      data.end += previous.end
+
+      result.push(previous)
+    }
+
+    result.push(data)
+
+    return result
+  }, [])
+}
+
+export const splitIntoWords = (str) => {
+  // Split at word boundaries
+  const regex = /\b/
+  const triggers = /[@#]+$/
+
+  let split = str.split(regex)
+
+  // Add trailing @ and # to the following word.
+  const words = reduce(split, (result, word) => {
+    if (result.length > 0) {
+      let previous = result.pop()
+      const matches = previous.match(triggers)
+      if (matches) {
+        previous = previous.replace(triggers, '')
+        word = matches[0] + word
+      }
+      result.push(previous)
+    }
+    result.push(word)
+
+    return result
+  }, [])
+
+  return words
+}
+
+const completion = {
+  wordAtPosition,
+  addPositionToWords,
+  splitIntoWords,
+  replaceWord
+}
+
+export default completion