refactor(llm): convert LlmFactory to singleton object

- Changed LlmFactory from a class to a singleton object to simplify instantiation.
- Updated all references to use LlmFactory.create() instead of LlmFactory() or LlmFactory.instance.create().
- Removed unnecessary project parameter from testLLMConnection().
- Added LLMProvider2 for improved LLM session management and testing.

Author: iptton

build.gradle.kts

@@ -402,6 +402,11 @@ project(":core") {
 
         implementation("io.reactivex.rxjava3:rxjava:3.1.10")
 
+        testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.10.1")
+        testImplementation(kotlin("test"))
+        testImplementation("com.squareup.okhttp3:mockwebserver:4.12.0") {
+            excludeKotlinDeps()
+        }
         implementation("com.squareup.okhttp3:okhttp:4.12.0") {
             excludeKotlinDeps()
         }
@@ -683,6 +688,10 @@ project(":exts:devins-lang") {
     }
 }
 
+tasks.test {
+    useJUnitPlatform()
+}
+
 fun File.isPluginJar(): Boolean {
     if (!isFile) return false
     if (extension != "jar") return false

core/src/main/kotlin/cc/unitmesh/devti/custom/document/CustomLivingDocTask.kt

@@ -26,7 +26,7 @@ class CustomLivingDocTask(
         logger.info("Prompt: $prompt")
 
         val stream =
-            LlmFactory().create(project).stream(prompt, "", false)
+            LlmFactory.create(project).stream(prompt, "", false)
 
         var result = ""
 

core/src/main/kotlin/cc/unitmesh/devti/custom/tasks/FileGenerateTask.kt

@@ -34,7 +34,7 @@ class FileGenerateTask(
         val systemPrompt = messages.filter { it.role == LlmMsg.ChatRole.System }.joinToString("\n") { it.content }
 
         val stream =
-            LlmFactory().create(project).stream(requestPrompt, systemPrompt, false)
+            LlmFactory.create(project).stream(requestPrompt, systemPrompt, false)
 
         var result = ""
         runBlocking {

core/src/main/kotlin/cc/unitmesh/devti/diff/DiffStreamHandler.kt

@@ -123,7 +123,7 @@ class DiffStreamHandler(
         val lines = originContent.lines()
 
         isRunning = true
-        val flow: Flow<String> = LlmFactory.instance.create(project).stream(prompt, "", false)
+        val flow: Flow<String> = LlmFactory.create(project).stream(prompt, "", false)
         var lastLineNo = 0
         AutoDevCoroutineScope.scope(project).launch {
             val suggestion = StringBuilder()

core/src/main/kotlin/cc/unitmesh/devti/gui/chat/ChatCodingService.kt

@@ -21,7 +21,7 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.launch
 
 class ChatCodingService(var actionType: ChatActionType, val project: Project) {
-    private val llmProvider = LlmFactory().create(project)
+    private val llmProvider = LlmFactory.create(project)
     private val counitProcessor = project.service<CustomAgentChatProcessor>()
     private var currentJob: Job? = null
 

core/src/main/kotlin/cc/unitmesh/devti/inline/AutoDevInlineChatPanel.kt

@@ -40,7 +40,7 @@ class AutoDevInlineChatPanel(val editor: Editor) : JPanel(GridBagLayout()), Edit
         val project = editor.project!!
 
         val prompt = AutoDevInlineChatService.getInstance().prompting(project, input, editor)
-        val flow: Flow<String>? = LlmFactory.instance.create(project).stream(prompt, "", false)
+        val flow: Flow<String>? = LlmFactory.create(project).stream(prompt, "", false)
 
         val panelView = SketchToolWindow(project, editor)
         panelView.minimumSize = Dimension(800, 40)

core/src/main/kotlin/cc/unitmesh/devti/intentions/action/task/BaseCompletionTask.kt

@@ -41,7 +41,7 @@ abstract class BaseCompletionTask(private val request: CodeCompletionRequest) :
         val prompt = promptText()
 
         val keepHistory = keepHistory() && prompt.length < AutoDevSettingsState.maxTokenLength
-        val flow: Flow<String> = LlmFactory().create(request.project).stream(prompt, "", keepHistory)
+        val flow: Flow<String> = LlmFactory.create(request.project).stream(prompt, "", keepHistory)
         logger.info("Prompt: $prompt")
 
         DumbAwareAction.create {

core/src/main/kotlin/cc/unitmesh/devti/intentions/action/task/CodeCompletionTask.kt

@@ -27,8 +27,6 @@ import kotlin.jvm.internal.Ref
 class CodeCompletionTask(private val request: CodeCompletionRequest) :
     Task.Backgroundable(request.project, AutoDevBundle.message("intentions.chat.code.complete.name")) {
 
-    private val llmFactory = LlmFactory()
-
     private val writeActionGroupId = "code.complete.intention.write.action"
     private val codeMessage = AutoDevBundle.message("intentions.chat.code.complete.name")
 
@@ -39,7 +37,7 @@ class CodeCompletionTask(private val request: CodeCompletionRequest) :
     override fun run(indicator: ProgressIndicator) {
         val prompt = promptText()
 
-        val flow: Flow<String> = llmFactory.create(request.project).stream(prompt, "", false)
+        val flow: Flow<String> = LlmFactory.create(request.project).stream(prompt, "", false)
         logger.info("Prompt: $prompt")
 
         val editor = request.editor
@@ -92,7 +90,7 @@ class CodeCompletionTask(private val request: CodeCompletionRequest) :
         logger.warn("Prompt: $prompt")
         AutoDevCoroutineScope.scope(project).launch {
             try {
-                val flow: Flow<String> = llmFactory.createForInlayCodeComplete(project).stream(prompt, "", false)
+                val flow: Flow<String> = LlmFactory.createForInlayCodeComplete(project).stream(prompt, "", false)
                 val suggestion = StringBuilder()
                 flow.collect {
                     AutoDevStatusService.notifyApplication(AutoDevStatus.InProgress)

core/src/main/kotlin/cc/unitmesh/devti/intentions/action/task/LivingDocumentationTask.kt

@@ -35,7 +35,7 @@ class LivingDocumentationTask(
 
         logger.info("Prompt: $prompt")
 
-        val stream = LlmFactory().create(project).stream(prompt, "", false)
+        val stream = LlmFactory.create(project).stream(prompt, "", false)
 
         var result = ""
 

core/src/main/kotlin/cc/unitmesh/devti/intentions/action/task/TestCodeGenTask.kt

@@ -122,7 +122,7 @@ class TestCodeGenTask(val request: TestCodeGenRequest, displayMessage: String) :
         indicator.text = AutoDevBundle.message("intentions.request.background.process.title")
 
         val flow: Flow<String> = try {
-            LlmFactory().create(request.project).stream(prompter, "", false)
+            LlmFactory.create(request.project).stream(prompter, "", false)
         } catch (e: Exception) {
             AutoDevStatusService.notifyApplication(AutoDevStatus.Error)
             logger.error("Failed to create LLM for: $lang", e)

core/src/main/kotlin/cc/unitmesh/devti/llm2/ChatSession.kt

@@ -0,0 +1,88 @@
+package cc.unitmesh.devti.llm2
+
+import cc.unitmesh.devti.llm2.MessageStatus.*
+import cc.unitmesh.devti.llms.custom.Message
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+
+/**
+ * 后台返回消息状态：[BEGIN] 首次返回 [CONTENT] 中间内容 [END] 内容结束
+ */
+enum class MessageStatus {
+    BEGIN, CONTENT, END
+}
+
+/**
+ * 聊天会话，每个会话包含此次会话的所有消息和名称。
+ */
+data class ChatSession<T>(
+    val conversionName: String,
+    val chatHistory: List<SessionMessageItem<T>>,
+    /**
+     * 当前会话状态，为 [MessageStatus.END] 时才允许发下一个对话
+     */
+    var status: MessageStatus = END,
+) {
+    companion object {
+        /**
+         * 为方便使用，暂时以 invoke 工厂提供默认的 ChatSession 实现
+         */
+        operator fun invoke(conversionName: String, messages: List<Message> = listOf()): ChatSession<Message> =
+            ChatSession<Message>(conversionName, messages.map { SessionMessageItem(it, END) })
+    }
+}
+
+fun <T> ChatSession<T>.canSendNextMessage() = this.status == END
+
+fun <T> ChatSession<T>.appendMessage(newMessage: T, status: MessageStatus = CONTENT): ChatSession<T> =
+    this.copy(chatHistory = this.chatHistory.toMutableList().apply {
+        add(SessionMessageItem(newMessage, status))
+    })
+
+/**
+ * http 请求的 body 数据
+ */
+val ChatSession<Message>.httpContent: String
+    get() {
+        return chatHistory.filter {
+            // exception 不需要发送给 llm server
+            // TODO 对异常消息的处理需有更合理的设计
+            it.chatMessage.role != "Error"
+        }.joinToString(prefix = """{"messages":[""", postfix = "]}", separator = ",") { item ->
+            Json.encodeToString(item.chatMessage)
+        }
+    }
+
+/**
+ * 聊天消息项
+ * 后续可扩展为多模态消息，T 可为做任意内容
+ *
+ * @property chatMessage 聊天消息
+ * @property status 消息状态，标记此消息的状态是刚开始、中间还是消息已经结束。
+ */
+open class SessionMessageItem<T>(
+    val chatMessage: T,
+    val status: MessageStatus = CONTENT,
+) {
+    companion object {
+
+        /**
+         * 为方便使用，暂时以 invoke 工厂提供默认的文本实现
+         */
+        operator fun invoke(
+            chatMessage: Message,
+            status: MessageStatus = CONTENT,
+        ): SessionMessageItem<Message> =
+            DefaultSessionMessageItem(chatMessage, status)
+
+        val Null = SessionMessageItem(Message("", ""), END)
+    }
+}
+
+/**
+ * 默认的聊天消息项
+ */
+private class DefaultSessionMessageItem(
+    chatMessage: Message,
+    status: MessageStatus = CONTENT,
+) : SessionMessageItem<Message>(chatMessage, status)