feat(completion): add support for built-in agent completion #101

This commit introduces a new completion provider for built-in agents in the DevInLanguage. It extends the completion type to include psi elements for agent identifiers and provides a list of built-in agents along with their descriptions. The completion provider also adds a custom insert handler to insert a colon after the agent name is selected, allowing for the specification of agent parameters.

Author: phodal

exts/devin-lang/src/main/kotlin/cc/unitmesh/devti/language/completion/BuiltinAgentProvider.kt

@@ -0,0 +1,43 @@
+package cc.unitmesh.devti.language.completion
+
+import cc.unitmesh.devti.language.DevInIcons
+import com.intellij.codeInsight.completion.*
+import com.intellij.codeInsight.lookup.LookupElement
+import com.intellij.codeInsight.lookup.LookupElementBuilder
+import com.intellij.util.ProcessingContext
+
+enum class BuiltinAgent(val agentName: String, val description: String) {
+    FILE("file", "Read the content of a file"),
+    REV("rev", "Read git revision of a file"),
+    SYMBOL("symbol", "Read content by Java/Kotlin canonicalName"),
+
+    ;
+
+    companion object {
+        fun all(): List<BuiltinAgent> {
+            return values().toList()
+        }
+    }
+}
+
+class BuiltinAgentProvider : CompletionProvider<CompletionParameters>() {
+    override fun addCompletions(
+        parameters: CompletionParameters,
+        context: ProcessingContext,
+        result: CompletionResultSet,
+    ) {
+        val builtinAgents = BuiltinAgent.all()
+        builtinAgents.forEach {
+            val withTypeText = LookupElementBuilder.create(it.agentName)
+                .withIcon(DevInIcons.DEFAULT)
+                .withTypeText(it.description, true)
+                .withInsertHandler { context, _ ->
+                    context.document.insertString(context.tailOffset, ":")
+                    context.editor.caretModel.moveCaretRelatively(0, 1, false, false, false)
+                }
+
+            result.addElement(withTypeText)
+        }
+    }
+}
+

exts/devin-lang/src/main/kotlin/cc/unitmesh/devti/language/completion/DevInCompletionContributor.kt

@@ -13,6 +13,7 @@ class DevInCompletionContributor : CompletionContributor() {
     init {
         extend(CompletionType.BASIC, psiElement(DevInTypes.LANGUAGE_ID), CodeFenceLanguageProvider())
         extend(CompletionType.BASIC, psiElement(DevInTypes.VARIABLE_ID), CustomVariableProvider())
+        extend(CompletionType.BASIC, psiElement(DevInTypes.AGENT_ID), BuiltinAgentProvider())
     }
 
     override fun beforeCompletion(context: CompletionInitializationContext) {