feat(ai-code-assistant): Enhance FIM completion with dynamic tokens and context-aware stop sequences

SonyLeo · SonyLeo · commit 28942db335b8 · 2026-02-09T23:03:43.000-08:00
- Add dynamic token calculation based on cursor context (expressions, statements, functions, classes)
- Implement context-aware stop sequences builder with support for comments, objects, and functions
- Create lowcodeFormatter utility to optimize low-code metadata and reduce token consumption
- Extract code context metadata (function names, class names) and inject as comments for better completion
- Add createLowcodeInstruction, extractCodeContext, and buildCodeMetaComment helpers to FIM prompts
- Enhance QwenClient to support stop sequences parameter in API requests
- Introduce TOKEN_LIMITS, STOP_SEQUENCES, and CONTEXT_STOP_SEQUENCES configuration constants
- Improve ModelAdapter to use formatted low-code context and dynamic parameters for better completion quality
- Limit stop sequences to maximum 16 items per API requirements
diff --git a/packages/plugins/script/src/ai-code-assistant/api/ModelAdapter.ts b/packages/plugins/script/src/ai-code-assistant/api/ModelAdapter.ts
@@ -4,12 +4,73 @@
  */
 
 import { getMetaApi, META_SERVICE } from '@opentiny/tiny-engine-meta-register'
-import { FIMPromptBuilder, FIM_SYSTEM_PROMPT } from '../prompts/fim'
+import {
+  FIMPromptBuilder,
+  FIM_SYSTEM_PROMPT,
+  createLowcodeInstruction,
+  extractCodeContext,
+  buildCodeMetaComment
+} from '../prompts/fim'
 import { buildNESUserPrompt, parseNESResponse } from '../prompts/nes-builder'
 import { NES_SYSTEM_PROMPT } from '../prompts/nes-system'
 import { buildLowcodeMetadata, cleanCompletion } from '../utils/code'
+import { formatLowcodeContext } from '../utils/lowcodeFormatter'
 import { callQwenChat } from './QwenClient'
-import { QWEN_CONFIG, FIXED_MODEL_CONFIG, HTTP_CONFIG } from '../config'
+import {
+  QWEN_CONFIG,
+  FIXED_MODEL_CONFIG,
+  HTTP_CONFIG,
+  TOKEN_LIMITS,
+  STOP_SEQUENCES,
+  CONTEXT_STOP_SEQUENCES
+} from '../config'
+
+// ==================== 辅助函数 ====================
+
+/**
+ * 根据光标上下文动态计算 max_tokens
+ */
+function calculateDynamicTokens(cursorContext: any): number {
+  if (!cursorContext) return TOKEN_LIMITS.DEFAULT
+
+  if (cursorContext.needsExpression) return TOKEN_LIMITS.EXPRESSION
+  if (cursorContext.needsStatement) return TOKEN_LIMITS.STATEMENT
+  if (cursorContext.inFunction) return TOKEN_LIMITS.FUNCTION
+  if (cursorContext.inClass) return TOKEN_LIMITS.CLASS
+
+  return TOKEN_LIMITS.DEFAULT
+}
+
+/**
+ * 根据光标上下文构建 stop sequences（最多 16 个）
+ */
+function buildStopSequences(cursorContext: any): string[] {
+  const stops: string[] = [...STOP_SEQUENCES.CORE]
+
+  if (cursorContext) {
+    if (cursorContext.inBlockComment || cursorContext.inLineComment) {
+      stops.push(...CONTEXT_STOP_SEQUENCES.COMMENT)
+    } else if (cursorContext.needsExpression) {
+      stops.push(...CONTEXT_STOP_SEQUENCES.EXPRESSION)
+      stops.push(...STOP_SEQUENCES.NEW_SCOPE)
+    } else if (cursorContext.inObject) {
+      stops.push(...CONTEXT_STOP_SEQUENCES.OBJECT)
+      stops.push(...STOP_SEQUENCES.NEW_SCOPE)
+    } else if (cursorContext.inFunction) {
+      stops.push(...CONTEXT_STOP_SEQUENCES.FUNCTION)
+      stops.push(...STOP_SEQUENCES.BLOCK_END)
+    } else {
+      stops.push(...STOP_SEQUENCES.NEW_SCOPE)
+      stops.push(...STOP_SEQUENCES.BLOCK_END)
+    }
+  } else {
+    stops.push(...STOP_SEQUENCES.NEW_SCOPE)
+    stops.push(...STOP_SEQUENCES.BLOCK_END)
+  }
+
+  const unique = [...new Set(stops)]
+  return unique.length > 16 ? unique.slice(0, 16) : unique
+}
 
 /**
  * 统一的模型适配器（固定使用 Qwen）
@@ -59,29 +120,42 @@ export class ModelAdapter {
 
       const { apiKey, baseUrl } = config
       const lowcodeMetadata = buildLowcodeMetadata()
+      const language = 'javascript'
+
+      // 格式化低代码元数据（提取签名/键名/类型，减少 token 消耗）
+      const formattedContext = formatLowcodeContext(lowcodeMetadata)
 
       const fimMetadata = {
-        language: 'javascript',
+        language,
         isComment: prefix.trim().endsWith('//') || prefix.includes('/*'),
-        lowcodeContext: lowcodeMetadata
-          ? {
-              dataSource: lowcodeMetadata.dataSource || [],
-              utils: lowcodeMetadata.utils || [],
-              globalState: lowcodeMetadata.globalState || [],
-              state: lowcodeMetadata.state || {},
-              methods: lowcodeMetadata.methods || {},
-              currentSchema: lowcodeMetadata.currentSchema || null
-            }
-          : null
+        lowcodeContext: formattedContext
       }
 
-      // 构建 FIM Prompt
+      // 提取代码上下文元信息（函数名、类名等）
+      const codeContext = extractCodeContext(prefix)
+      const metaComment = buildCodeMetaComment(language, codeContext)
+
+      // 构建 FIM Prompt（在 prefix 前注入元信息注释）
       const { fimPrompt, cursorContext } = this.fimBuilder.buildOptimizedFIMPrompt(
-        `${prefix}[CURSOR]${suffix}`,
+        `${metaComment}${prefix}[CURSOR]${suffix}`,
         fimMetadata
       )
 
-      const instruction = this.fimBuilder.selectInstruction(cursorContext, fimMetadata.language || 'javascript')
+      // 选择 instruction（低代码增强 or 普通 or 注释）
+      let instruction: string
+      if (cursorContext.inBlockComment || cursorContext.inLineComment) {
+        instruction = this.fimBuilder.selectInstruction(cursorContext, language)
+      } else if (fimMetadata.lowcodeContext) {
+        instruction = createLowcodeInstruction(language, fimMetadata.lowcodeContext)
+      } else {
+        instruction = this.fimBuilder.selectInstruction(cursorContext, language)
+      }
+
+      // 动态 Token 计算
+      const maxTokens = calculateDynamicTokens(cursorContext)
+
+      // 动态 Stop Sequences
+      const stop = buildStopSequences(cursorContext)
 
       // 合并外部 signal、去重 signal 和超时 signal
       const timeoutSignal = AbortSignal.timeout(HTTP_CONFIG.FIM_TIMEOUT_MS)
@@ -97,10 +171,11 @@ export class ModelAdapter {
         ],
         {
           model: FIXED_MODEL_CONFIG.FIM.MODEL,
-          maxTokens: FIXED_MODEL_CONFIG.FIM.MAX_TOKENS,
+          maxTokens,
           temperature: FIXED_MODEL_CONFIG.FIM.TEMPERATURE,
           top_p: FIXED_MODEL_CONFIG.FIM.TOP_P,
-          presence_penalty: FIXED_MODEL_CONFIG.FIM.PRESENCE_PENALTY
+          presence_penalty: FIXED_MODEL_CONFIG.FIM.PRESENCE_PENALTY,
+          stop
         },
         apiKey,
         baseUrl,
diff --git a/packages/plugins/script/src/ai-code-assistant/api/QwenClient.ts b/packages/plugins/script/src/ai-code-assistant/api/QwenClient.ts
@@ -16,7 +16,7 @@ export async function callQwenChat(
 ): Promise<string> {
   const chatUrl = `${baseUrl}${QWEN_CONFIG.CHAT_PATH}`
 
-  const requestBody = {
+  const requestBody: any = {
     model: config.model,
     messages,
     max_tokens: config.maxTokens,
@@ -25,6 +25,11 @@ export async function callQwenChat(
     stream: HTTP_CONFIG.STREAM
   }
 
+  // 添加 stop sequences（如果提供）
+  if (config.stop && config.stop.length > 0) {
+    requestBody.stop = config.stop
+  }
+
   const response = await fetch(chatUrl, {
     method: HTTP_CONFIG.METHOD,
     headers: {
diff --git a/packages/plugins/script/src/ai-code-assistant/config.ts b/packages/plugins/script/src/ai-code-assistant/config.ts
@@ -80,6 +80,31 @@ export const ERROR_MESSAGES = {
   QWEN_API_ERROR: 'Qwen API 错误'
 }
 
+// ==================== Token 动态计算 ====================
+
+export const TOKEN_LIMITS = {
+  EXPRESSION: 64,
+  STATEMENT: 256,
+  FUNCTION: 200,
+  CLASS: 256,
+  DEFAULT: 128
+}
+
+// ==================== Stop Sequences ====================
+
+export const STOP_SEQUENCES = {
+  CORE: ['\n\n', '```'],
+  NEW_SCOPE: ['\nfunction ', '\nclass ', '\nexport ', '\nimport '],
+  BLOCK_END: ['\n}', '\n};']
+}
+
+export const CONTEXT_STOP_SEQUENCES: Record<string, string[]> = {
+  EXPRESSION: [';', ',', '\n)'],
+  COMMENT: ['\n\n', '*/'],
+  OBJECT: ['\n}', '\n};'],
+  FUNCTION: ['\n}', '\nfunction ', '\nreturn ']
+}
+
 // ==================== 提示词配置 ====================
 
 /**
diff --git a/packages/plugins/script/src/ai-code-assistant/prompts/fim.ts b/packages/plugins/script/src/ai-code-assistant/prompts/fim.ts
@@ -70,6 +70,169 @@ ${fileContent}
 Complete the code/text at the [CURSOR] position. Return ONLY the completion text.`
 }
 
+// ==================== 低代码上下文 Prompt ====================
+
+export const LOWCODE_CONTEXT_INSTRUCTION = `You are working in a low-code platform environment with specific APIs and data structures.
+
+AVAILABLE RUNTIME APIS (all accessed via 'this.'):
+1. Data Sources (this.dataSource.xxx)
+   - Predefined data models for the application
+   - Access pattern: this.dataSource.<sourceName>
+
+2. Utility Functions (this.utils.xxx)
+   - Common utility methods and npm dependencies
+   - Access pattern: this.utils.<utilityName>
+   - May include imported libraries (check utils metadata for imports)
+
+3. Global State (this.stores.xxx)
+   - Pinia-based global state management
+   - Access pattern: this.stores.<storeName>.<property>
+   - Actions: this.stores.<storeName>.<actionName>()
+
+4. Local State (this.state.xxx)
+   - Component-level reactive state
+   - Access pattern: this.state.<propertyName>
+
+5. Local Methods (this.xxx)
+   - Component-level methods
+   - Access pattern: this.<methodName>()
+
+6. Component References (this.$('refName'))
+   - Access Vue component refs
+   - Access pattern: this.$('<refName>')
+
+IMPORTANT RULES:
+- ONLY use APIs that are explicitly defined in the provided metadata
+- DO NOT reference undefined utilities, data sources, or state properties
+- Follow the JSExpression/JSFunction protocol for dynamic values
+- Use 'function' keyword for function definitions, NOT arrow functions
+- Respect the component schema structure (props, events, refs)
+
+PROTOCOL CONVENTIONS:
+- Static values: { width: '300px' }
+- Dynamic expressions: { width: { type: 'JSExpression', value: 'this.state.xxx' } }
+- Function handlers: { onClick: { type: 'JSFunction', value: 'function onClick() {}' } }`
+
+/**
+ * 构建低代码增强指令（将元数据注入 instruction）
+ */
+export function createLowcodeInstruction(language: string, lowcodeContext: any = {}): string {
+  let instruction = createCodeInstruction(language)
+
+  if (!lowcodeContext || Object.keys(lowcodeContext).length === 0) {
+    return instruction
+  }
+
+  instruction += `\n\n${LOWCODE_CONTEXT_INSTRUCTION}`
+
+  const { dataSource, utils, globalState, state, methods, currentSchema } = lowcodeContext
+
+  if (dataSource?.length > 0) {
+    instruction += `\n\nAVAILABLE DATA SOURCES:\n${JSON.stringify(dataSource, null, 2)}`
+  }
+  if (utils?.length > 0) {
+    instruction += `\n\nAVAILABLE UTILITIES:\n${JSON.stringify(utils, null, 2)}`
+  }
+  if (globalState?.length > 0) {
+    instruction += `\n\nGLOBAL STATE (Pinia Stores):\n${JSON.stringify(globalState, null, 2)}`
+  }
+  if (state && Object.keys(state).length > 0) {
+    instruction += `\n\nLOCAL STATE:\n${JSON.stringify(state, null, 2)}`
+  }
+  if (methods && Object.keys(methods).length > 0) {
+    instruction += `\n\nLOCAL METHODS:\n${JSON.stringify(methods, null, 2)}`
+  }
+  if (currentSchema) {
+    instruction += `\n\nCURRENT COMPONENT: ${currentSchema.componentName || 'Unknown'}`
+    if (currentSchema.props) {
+      instruction += `\n- Props: Use component props as defined in schema`
+      instruction += `\n- Events: Props starting with 'on' are event handlers`
+    }
+    if (currentSchema.ref) {
+      instruction += `\nRef: this.$('${currentSchema.ref}')`
+    }
+  }
+
+  return instruction
+}
+
+// ==================== 代码上下文提取 ====================
+
+const CODE_CONTEXT_PATTERNS = {
+  FUNCTION: /function\s+(\w+)|const\s+(\w+)\s*=.*=>|(\w+)\s*\([^)]*\)\s*{/,
+  CLASS: /class\s+(\w+)/,
+  INTERFACE: /interface\s+(\w+)/,
+  TYPE: /type\s+(\w+)/
+}
+
+/**
+ * 从光标前文本中提取当前代码上下文（函数名、类名等）
+ */
+export function extractCodeContext(textBeforeCursor: string): {
+  functionName: string
+  className: string
+  interfaceName: string
+  typeName: string
+} {
+  const lines = textBeforeCursor.split('\n')
+  let functionName = ''
+  let className = ''
+  let interfaceName = ''
+  let typeName = ''
+
+  const startLine = Math.max(0, lines.length - 20)
+
+  for (let i = lines.length - 1; i >= startLine; i--) {
+    const line = lines[i]
+
+    if (!functionName) {
+      const m = line.match(CODE_CONTEXT_PATTERNS.FUNCTION)
+      if (m) functionName = m[1] || m[2] || m[3]
+    }
+    if (!className) {
+      const m = line.match(CODE_CONTEXT_PATTERNS.CLASS)
+      if (m) className = m[1]
+    }
+    if (!interfaceName) {
+      const m = line.match(CODE_CONTEXT_PATTERNS.INTERFACE)
+      if (m) interfaceName = m[1]
+    }
+    if (!typeName) {
+      const m = line.match(CODE_CONTEXT_PATTERNS.TYPE)
+      if (m) typeName = m[1]
+    }
+
+    if (functionName && className && interfaceName && typeName) break
+  }
+
+  return { functionName, className, interfaceName, typeName }
+}
+
+/**
+ * 构建代码元信息注释（注入到 FIM prefix 前面）
+ */
+export function buildCodeMetaComment(language: string, codeContext: ReturnType<typeof extractCodeContext>): string {
+  let meta = `// Language: ${language}\n`
+
+  if (codeContext.className) {
+    meta += `// Current Class: ${codeContext.className}\n`
+    meta += `// IMPORTANT: Only complete code within this class\n`
+  }
+  if (codeContext.interfaceName) {
+    meta += `// Current Interface: ${codeContext.interfaceName}\n`
+  }
+  if (codeContext.typeName) {
+    meta += `// Current Type: ${codeContext.typeName}\n`
+  }
+  if (codeContext.functionName) {
+    meta += `// Current Function: ${codeContext.functionName}\n`
+    meta += `// IMPORTANT: Only complete code within this function scope\n`
+  }
+
+  meta += `// NOTE: Do not reference variables or code from other functions\n\n`
+  return meta
+}
+
 // ==================== FIM Prompt Builder ====================
 
 export class FIMPromptBuilder {
diff --git a/packages/plugins/script/src/ai-code-assistant/utils/lowcodeFormatter.ts b/packages/plugins/script/src/ai-code-assistant/utils/lowcodeFormatter.ts
