From f1562a2187c0cb644d851352ddcc119aed31c86f Mon Sep 17 00:00:00 2001
From: Eugen Neufeld <eneufeld@eclipsesource.com>
Date: Tue, 25 Feb 2025 01:03:21 +0100
Subject: [PATCH] Add variable support with #{} syntax in prompttemplate

---
 .../data/prompttemplate.tmLanguage.json       | 21 +++++++++++++
 .../browser/prompttemplate-contribution.ts    | 30 +++++++++++++++++--
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/packages/ai-core/data/prompttemplate.tmLanguage.json b/packages/ai-core/data/prompttemplate.tmLanguage.json
index 30a02cb34c4b4..7ec3e4cf072d6 100644
--- a/packages/ai-core/data/prompttemplate.tmLanguage.json
+++ b/packages/ai-core/data/prompttemplate.tmLanguage.json
@@ -97,6 +97,27 @@
           "match": "[a-zA-Z_][a-zA-Z0-9_\\-]*"
         }
       ]
+    },
+    {
+      "name": "variable.parameter.prompttemplate",
+      "begin": "#{",
+      "beginCaptures": {
+        "0": {
+          "name": "punctuation.definition.variable.begin"
+        }
+      },
+      "end": "}",
+      "endCaptures": {
+        "0": {
+          "name": "punctuation.definition.variable.end"
+        }
+      },
+      "patterns": [
+        {
+          "name": "keyword.control",
+          "match": "[a-zA-Z_][a-zA-Z0-9_\\-]*"
+        }
+      ]
     }
   ],
   "repository": {},
diff --git a/packages/ai-core/src/browser/prompttemplate-contribution.ts b/packages/ai-core/src/browser/prompttemplate-contribution.ts
index 19eef9b7ac28a..74bb83a295889 100644
--- a/packages/ai-core/src/browser/prompttemplate-contribution.ts
+++ b/packages/ai-core/src/browser/prompttemplate-contribution.ts
@@ -24,6 +24,7 @@ import { codicon, Widget } from '@theia/core/lib/browser';
 import { EditorWidget, ReplaceOperation } from '@theia/editor/lib/browser';
 import { PromptCustomizationService, PromptService, ToolInvocationRegistry } from '../common';
 import { ProviderResult } from '@theia/monaco-editor-core/esm/vs/editor/common/languages';
+import { AIVariableService } from '../common/variable-service';
 
 const PROMPT_TEMPLATE_LANGUAGE_ID = 'theia-ai-prompt-template';
 const PROMPT_TEMPLATE_TEXTMATE_SCOPE = 'source.prompttemplate';
@@ -59,19 +60,25 @@ export class PromptTemplateContribution implements LanguageGrammarDefinitionCont
     @inject(ToolInvocationRegistry)
     protected readonly toolInvocationRegistry: ToolInvocationRegistry;
 
+    @inject(AIVariableService)
+    protected readonly variableService: AIVariableService;
+
     readonly config: monaco.languages.LanguageConfiguration =
         {
             'brackets': [
                 ['${', '}'],
-                ['~{', '}']
+                ['~{', '}'],
+                ['#{', '}']
             ],
             'autoClosingPairs': [
                 { 'open': '${', 'close': '}' },
                 { 'open': '~{', 'close': '}' },
+                { 'open': '#{', 'close': '}' }
             ],
             'surroundingPairs': [
                 { 'open': '${', 'close': '}' },
-                { 'open': '~{', 'close': '}' }
+                { 'open': '~{', 'close': '}' },
+                { 'open': '#{', 'close': '}' }
             ]
         };
 
@@ -95,6 +102,12 @@ export class PromptTemplateContribution implements LanguageGrammarDefinitionCont
             provideCompletionItems: (model, position, _context, _token): ProviderResult<monaco.languages.CompletionList> => this.provideFunctionCompletions(model, position),
         });
 
+        monaco.languages.registerCompletionItemProvider(PROMPT_TEMPLATE_LANGUAGE_ID, {
+            // Monaco only supports single character trigger characters
+            triggerCharacters: ['{'],
+            provideCompletionItems: (model, position, _context, _token): ProviderResult<monaco.languages.CompletionList> => this.provideVariableCompletions(model, position),
+        });
+
         const textmateGrammar = require('../../data/prompttemplate.tmLanguage.json');
         const grammarDefinitionProvider: GrammarDefinitionProvider = {
             getGrammarDefinition: function (): Promise<GrammarDefinition> {
@@ -122,6 +135,19 @@ export class PromptTemplateContribution implements LanguageGrammarDefinitionCont
         );
     }
 
+    provideVariableCompletions(model: monaco.editor.ITextModel, position: monaco.Position): ProviderResult<monaco.languages.CompletionList> {
+        return this.getSuggestions(
+            model,
+            position,
+            '#{',
+            this.variableService.getVariables(),
+            monaco.languages.CompletionItemKind.Variable,
+            variable => variable.id,
+            variable => variable.name,
+            variable => variable.description ?? ''
+        );
+    }
+
     getCompletionRange(model: monaco.editor.ITextModel, position: monaco.Position, triggerCharacters: string): monaco.Range | undefined {
         // Check if the characters before the current position are the trigger characters
         const lineContent = model.getLineContent(position.lineNumber);