350 lines
11 KiB
JavaScript
350 lines
11 KiB
JavaScript
const axios = require('axios');
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class ArkChatService {
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constructor() {
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this.baseUrl = 'https://ark.cn-beijing.volces.com/api/v3';
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}
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_getAuth() {
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return process.env.VOLC_ARK_API_KEY || process.env.VOLC_ACCESS_KEY_ID;
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}
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isMockMode() {
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const ep = process.env.VOLC_ARK_ENDPOINT_ID;
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return !ep || ep === 'your_ark_endpoint_id';
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}
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_isMockMode() {
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return this.isMockMode();
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}
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/**
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* 获取方舟知识库配置（如果已配置）
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* @returns {object|null} 知识库 metadata 配置
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*/
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_getKnowledgeBaseConfig(kbIdsOverride = null) {
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const kbIds = kbIdsOverride || process.env.VOLC_ARK_KNOWLEDGE_BASE_IDS;
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if (!kbIds || kbIds === 'your_knowledge_base_dataset_id') return null;
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const datasetIds = kbIds.split(',').map(id => id.trim()).filter(Boolean);
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if (datasetIds.length === 0) return null;
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const topK = parseInt(process.env.VOLC_ARK_KNOWLEDGE_TOP_K) || 3;
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const threshold = parseFloat(process.env.VOLC_ARK_KNOWLEDGE_THRESHOLD) || 0.5;
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return {
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dataset_ids: datasetIds,
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top_k: topK,
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threshold: threshold,
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};
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}
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async summarizeContextForHandoff(messages, maxRounds = 3) {
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const normalizedMessages = (Array.isArray(messages) ? messages : [])
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.filter((item) => item && (item.role === 'user' || item.role === 'assistant') && String(item.content || '').trim());
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let startIndex = 0;
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let userRounds = 0;
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for (let index = normalizedMessages.length - 1; index >= 0; index -= 1) {
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if (normalizedMessages[index].role === 'user') {
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userRounds += 1;
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startIndex = index;
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if (userRounds >= Math.max(1, maxRounds)) {
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break;
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}
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}
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}
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const recentMessages = normalizedMessages.slice(startIndex);
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if (!recentMessages.length) {
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return '';
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}
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const transcript = recentMessages
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.map((item, index) => `${index + 1}. ${item.role === 'user' ? '用户' : '助手'}：${String(item.content || '').trim()}`)
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.join('\n');
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if (this._isMockMode()) {
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const lastUserMessage = [...recentMessages].reverse().find((item) => item.role === 'user');
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return lastUserMessage ? `用户当前主要在追问：${lastUserMessage.content}` : '';
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}
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const result = await this.chat([
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{
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role: 'system',
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content: '你是对话交接摘要助手。请基于最近几轮对话生成一段简洁中文摘要，供另一个模型无缝接管会话。摘要必须同时包含：用户当前主要问题、已经确认的信息、仍待解决的问题。不要使用标题、项目符号或编号，不要虚构事实，控制在120字以内。',
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},
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{
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role: 'user',
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content: `请总结以下最近${Math.ceil(recentMessages.length / 2)}轮对话：\n${transcript}`,
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},
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], []);
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return String(result.content || '').trim();
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}
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/**
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* 非流式调用方舟 LLM
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*/
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async chat(messages, tools = [], options = {}) {
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if (this._isMockMode()) {
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console.warn('[ArkChat] EndPointId not configured, returning mock response');
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return this._mockChat(messages);
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}
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const { useKnowledgeBase = false, knowledgeBaseIds = null } = options || {};
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const body = {
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model: process.env.VOLC_ARK_ENDPOINT_ID,
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messages,
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stream: false,
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};
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if (tools.length > 0) body.tools = tools;
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const kbConfig = useKnowledgeBase ? this._getKnowledgeBaseConfig(knowledgeBaseIds) : null;
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if (kbConfig) {
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body.metadata = { knowledge_base: kbConfig };
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console.log('[ArkChat] Knowledge base enabled:', kbConfig.dataset_ids);
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}
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try {
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const response = await axios.post(`${this.baseUrl}/chat/completions`, body, {
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headers: {
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'Content-Type': 'application/json',
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'Authorization': `Bearer ${this._getAuth()}`,
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},
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timeout: 30000,
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});
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const choice = response.data.choices?.[0];
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if (!choice) throw new Error('No response from Ark LLM');
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const msg = choice.message;
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return {
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content: msg.content || '',
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toolCalls: msg.tool_calls || null,
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finishReason: choice.finish_reason,
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usage: response.data.usage,
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};
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} catch (error) {
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if (error.response) {
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console.error('[ArkChat] API error:', error.response.status, error.response.data);
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}
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throw error;
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}
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}
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/**
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* SSE 流式调用方舟 LLM，通过回调逐块输出
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* @param {Array} messages
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* @param {Array} tools
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* @param {function} onChunk - (text: string) => void
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* @param {function} onToolCall - (toolCalls: Array) => void
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* @param {function} onDone - (fullContent: string) => void
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*/
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async chatStream(messages, tools = [], { onChunk, onToolCall, onDone, useKnowledgeBase = false, knowledgeBaseIds = null } = {}) {
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if (this._isMockMode()) {
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return this._mockChatStream(messages, { onChunk, onDone });
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}
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const body = {
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model: process.env.VOLC_ARK_ENDPOINT_ID,
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messages,
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stream: true,
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};
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if (tools.length > 0) body.tools = tools;
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const kbConfig = useKnowledgeBase ? this._getKnowledgeBaseConfig(knowledgeBaseIds) : null;
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if (kbConfig) {
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body.metadata = { knowledge_base: kbConfig };
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}
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const response = await axios.post(`${this.baseUrl}/chat/completions`, body, {
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headers: {
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'Content-Type': 'application/json',
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'Authorization': `Bearer ${this._getAuth()}`,
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},
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timeout: 60000,
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responseType: 'stream',
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});
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return new Promise((resolve, reject) => {
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let fullContent = '';
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let toolCalls = [];
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let buffer = '';
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response.data.on('data', (chunk) => {
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buffer += chunk.toString();
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const lines = buffer.split('\n');
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buffer = lines.pop() || '';
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for (const line of lines) {
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const trimmed = line.trim();
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if (!trimmed || !trimmed.startsWith('data: ')) continue;
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const data = trimmed.slice(6);
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if (data === '[DONE]') continue;
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try {
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const parsed = JSON.parse(data);
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const delta = parsed.choices?.[0]?.delta;
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if (!delta) continue;
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if (delta.content) {
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fullContent += delta.content;
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onChunk?.(delta.content);
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}
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if (delta.tool_calls) {
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for (const tc of delta.tool_calls) {
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if (!toolCalls[tc.index]) {
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toolCalls[tc.index] = { id: tc.id, type: tc.type, function: { name: '', arguments: '' } };
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}
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if (tc.function?.name) toolCalls[tc.index].function.name += tc.function.name;
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if (tc.function?.arguments) toolCalls[tc.index].function.arguments += tc.function.arguments;
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}
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}
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} catch (e) {
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// skip malformed lines
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}
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}
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});
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response.data.on('end', () => {
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if (toolCalls.length > 0) {
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onToolCall?.(toolCalls);
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}
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onDone?.(fullContent);
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resolve({ content: fullContent, toolCalls: toolCalls.length > 0 ? toolCalls : null });
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});
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response.data.on('error', reject);
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});
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}
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/**
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* 处理包含工具调用的完整对话循环（非流式）
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*/
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async chatWithTools(messages, tools, toolExecutor) {
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const result = await this.chat(messages, tools);
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if (!result.toolCalls || result.toolCalls.length === 0) {
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return result;
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}
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const updatedMessages = [
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...messages,
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{ role: 'assistant', content: result.content, tool_calls: result.toolCalls },
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];
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for (const tc of result.toolCalls) {
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const args = typeof tc.function.arguments === 'string'
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? JSON.parse(tc.function.arguments)
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: tc.function.arguments;
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const toolResult = await toolExecutor.execute(tc.function.name, args, messages);
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updatedMessages.push({
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role: 'tool',
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tool_call_id: tc.id,
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content: JSON.stringify(toolResult),
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});
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}
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const finalResult = await this.chat(updatedMessages, tools);
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return {
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...finalResult,
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messages: updatedMessages,
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};
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}
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/**
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* 流式版工具调用循环：先流式输出，如遇工具调用则执行后再流式输出最终结果
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*/
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async chatStreamWithTools(messages, tools, toolExecutor, { onChunk, onToolCall, onDone }) {
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const result = await this.chatStream(messages, tools, {
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onChunk,
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onToolCall,
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onDone: () => {}, // don't fire onDone yet
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});
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if (!result.toolCalls || result.toolCalls.length === 0) {
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onDone?.(result.content);
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return result;
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}
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// 通知前端正在调用工具
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onToolCall?.(result.toolCalls);
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const updatedMessages = [
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...messages,
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{ role: 'assistant', content: result.content, tool_calls: result.toolCalls },
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];
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for (const tc of result.toolCalls) {
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const args = typeof tc.function.arguments === 'string'
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? JSON.parse(tc.function.arguments)
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: tc.function.arguments;
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const toolResult = await toolExecutor.execute(tc.function.name, args, messages);
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updatedMessages.push({
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role: 'tool',
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tool_call_id: tc.id,
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content: JSON.stringify(toolResult),
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});
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}
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// 工具执行完后，流式输出最终回答
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const finalResult = await this.chatStream(updatedMessages, tools, { onChunk, onToolCall: null, onDone });
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return {
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...finalResult,
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messages: updatedMessages,
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};
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}
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_mockChat(messages) {
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const lastMsg = messages[messages.length - 1];
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const userText = lastMsg?.content || '';
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console.log(`[ArkChat][MOCK] User: ${userText}`);
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return {
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content: this._getMockReply(userText),
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toolCalls: null,
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finishReason: 'stop',
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usage: { prompt_tokens: 0, completion_tokens: 0 },
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};
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}
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async _mockChatStream(messages, { onChunk, onDone }) {
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const lastMsg = messages[messages.length - 1];
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const userText = lastMsg?.content || '';
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console.log(`[ArkChat][MOCK-STREAM] User: ${userText}`);
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const reply = this._getMockReply(userText);
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// 模拟逐字输出
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for (let i = 0; i < reply.length; i++) {
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onChunk?.(reply[i]);
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await new Promise((r) => setTimeout(r, 30));
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}
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onDone?.(reply);
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return { content: reply, toolCalls: null };
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}
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_getMockReply(userText) {
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if (userText.includes('天气')) {
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return '根据 query_weather 工具查询，北京今天晴，气温 22°C，湿度 45%，北风3级。适合外出活动！';
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}
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if (userText.includes('订单')) {
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return '通过 query_order 工具查询，您的订单（ID: 12345）当前状态为：已发货，预计明天送达。快递单号：SF1234567890。';
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}
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if (userText.includes('你好') || userText.includes('嗨') || userText.includes('hi')) {
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return '你好！我是小智，很高兴为你服务。有什么我可以帮你的吗？';
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}
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if (userText.includes('知识') || userText.includes('退货') || userText.includes('政策')) {
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return '根据知识库查询，我们的退货政策如下：自签收之日起7天内可无理由退货，15天内可换货。请保持商品及包装完好。如需退货，请在"我的订单"中提交退货申请。';
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}
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return `收到你的消息："${userText}"。当前为模拟模式，配置方舟 LLM 凭证后将接入真实 AI 模型。你可以试试问我天气、订单、退货政策等问题。`;
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}
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}
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module.exports = new ArkChatService();
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