ace: prometheus completion improvements

public/app/core/components/code_editor/code_editor.ts

@@ -128,22 +128,6 @@ function link(scope, elem, attrs) {
     }
   });
 
-  let extCompleter = {
-    identifierRegexps: [/[\[\]a-zA-Z_0-9=]/],
-    getCompletions: function (editor, session, pos, prefix, callback) {
-      console.log(pos);
-      scope.getCompletions({$query: prefix}).then(results => {
-        callback(null, results.map(hit => {
-          return {
-            caption: hit.word,
-            value: hit.word,
-            meta: hit.type
-          };
-        }));
-      });
-    },
-  };
-
   function setLangMode(lang) {
     let aceModeName = `ace/mode/${lang}`;
     setModuleUrl("mode", lang);
@@ -161,6 +145,8 @@ function link(scope, elem, attrs) {
         codeEditor.completers.push(scope.getCompleter());
       }
     });
+
+    codeEditor.setBehavioursEnabled(true);
   }
 
   function setThemeMode(theme) {

public/app/plugins/datasource/prometheus/completer.ts

@@ -9,12 +9,30 @@ export class PromCompleter {
   }
 
   getCompletions(editor, session, pos, prefix, callback) {
+    if (prefix === '[') {
+      var vectors = [];
+      for (let unit of ['s', 'm', 'h']) {
+        for (let value of [1,5,10,30]) {
+         vectors.push({caption: value+unit, value: '['+value+unit, meta: 'range vector'});
+        }
+      }
+      callback(null, vectors);
+      return;
+    }
+
     var query = prefix;
+    var line = editor.session.getLine(pos.row);
+
     return this.datasource.performSuggestQuery(query).then(metricNames => {
       callback(null, metricNames.map(name => {
+        let value = name;
+        if (prefix === '(') {
+          value = '(' + name;
+        }
+
         return {
           caption: name,
-          value: name,
+          value: value,
           meta: 'metric',
         };
       }));