Upload 47 files

package.json

@@ -1,3 +1,4 @@
+
 {
   "name": "smart-school-system",
   "version": "1.0.0",
@@ -19,6 +20,7 @@
     "recharts": "^2.10.3",
     "compression": "^1.7.4",
     "xlsx": "^0.18.5",
+    "openai": "^4.28.0",
     "@google/genai": "*"
   },
   "devDependencies": {
@@ -32,4 +34,4 @@
     "typescript": "^5.2.2",
     "vite": "^5.0.8"
   }
-}
+}

pages/AIAssistant.tsx

@@ -177,6 +177,8 @@ export const AIAssistant: React.FC = () => {
             console.error("Chat error:", error);
             if (error.message.includes('MAINTENANCE')) {
                 setMessages(prev => [...prev, { id: Date.now().toString(), role: 'model', text: '⚠️ 系统维护中：管理员已暂停 AI 功能。', timestamp: Date.now() }]);
+            } else if (error.message === 'QUOTA_EXCEEDED' || error.message.includes('429')) {
+                setMessages(prev => [...prev, { id: Date.now().toString(), role: 'model', text: '⚠️ 系统繁忙：AI 请求量已达上限，请休息一会再试。', timestamp: Date.now() }]);
             } else {
                 setMessages(prev => [...prev, { id: Date.now().toString(), role: 'model', text: '抱歉，遇到错误，请重试。', timestamp: Date.now() }]);
             }
@@ -194,6 +196,7 @@ export const AIAssistant: React.FC = () => {
         } catch (error: any) {
             console.error("Eval error:", error);
             if (error.message.includes('MAINTENANCE')) alert("系统维护中，AI 功能暂时不可用");
+            else if (error.message === 'QUOTA_EXCEEDED' || error.message.includes('429')) alert("请求过于频繁，请稍后再试");
             else alert("评分失败，请重试");
         } finally { setIsProcessing(false); setSelectedImage(null); }
     };

server.js

@@ -6,6 +6,26 @@ const {
     WishModel, FeedbackModel
 } = require('./models');
 
+// Initialize OpenAI (OpenRouter) Client
+// We use lazy initialization inside the function to avoid crashes if API Key is missing initially
+const OpenAI = require('openai');
+let openAIClient = null;
+
+function getOpenRouter() {
+    if (openAIClient) return openAIClient;
+    if (!process.env.OPENROUTER_API_KEY) return null;
+    
+    openAIClient = new OpenAI({
+        baseURL: "https://openrouter.ai/api/v1",
+        apiKey: process.env.OPENROUTER_API_KEY,
+        defaultHeaders: {
+            "HTTP-Referer": "https://smart-school-ai.com", // Placeholder
+            "X-Title": "Smart School System", 
+        },
+    });
+    return openAIClient;
+}
+
 // Initialize Gemini via Dynamic Import (Helper)
 // @google/genai is an ESM-only package, so we cannot use require() in this CommonJS file.
 let genAIContext = null;
@@ -103,32 +123,160 @@ const generateStudentNo = async () => {
     return `${year}${random}`;
 };
 
-// --- Helper: Retry Logic for AI Calls (Fix 503 Errors) ---
+// --- Helper: Basic Retry Logic (Network blips) ---
 const wait = (ms) => new Promise(resolve => setTimeout(resolve, ms));
 
-async function callAIWithRetry(aiModel, params, retries = 3) {
+async function callAIWithRetry(aiModel, params, retries = 1) {
     for (let i = 0; i < retries; i++) {
         try {
             return await aiModel.generateContent(params);
         } catch (e) {
-            // Check for 503 Service Unavailable or "overloaded" message
-            const isOverloaded = e.message?.includes('503') || 
-                                 e.status === 503 || 
-                                 e.message?.includes('overloaded');
+            // If it's a critical auth error or bad request, don't retry locally
+            if (e.status === 400 || e.status === 401 || e.status === 403) throw e;
+            if (i < retries - 1) {
+                await wait(1000 * Math.pow(2, i));
+                continue;
+            }
+            throw e;
+        }
+    }
+}
+
+// --- Adapter: Google Gemini Params -> OpenAI Messages ---
+function convertGeminiToOpenAI(baseParams) {
+    const messages = [];
+    
+    // 1. System Instruction
+    if (baseParams.config?.systemInstruction) {
+        messages.push({ role: 'system', content: baseParams.config.systemInstruction });
+    }
+
+    // 2. Chat History & User Input
+    if (baseParams.contents && Array.isArray(baseParams.contents)) {
+        baseParams.contents.forEach(content => {
+            let role = 'user';
+            if (content.role === 'model') role = 'assistant';
+            
+            // Extract text from parts
+            let textParts = [];
+            if (content.parts && Array.isArray(content.parts)) {
+                content.parts.forEach(p => {
+                    if (p.text) textParts.push(p.text);
+                    // OpenRouter free models usually don't support image parts well via standard OpenAI format,
+                    // so we largely ignore non-text parts here or add a placeholder.
+                });
+            }
+            
+            if (textParts.length > 0) {
+                messages.push({ role: role, content: textParts.join('\n') });
+            }
+        });
+    }
+    
+    return messages;
+}
+
+// --- NEW Helper: Smart Model Fallback Strategy (Multi-Tier) ---
+async function generateContentWithSmartFallback(aiModelObj, baseParams) {
+    // Check if request has media (image/audio)
+    const hasMedia = baseParams.contents && Array.isArray(baseParams.contents) && 
+                     baseParams.contents.some(c => c.parts && c.parts.some(p => p.inlineData));
+
+    // --- Tier 1: Google Gemini (Best quality, Multi-modal) ---
+    const primaryModels = [
+        'gemini-2.5-flash',       // Standard (20 RPD) - Try first
+        'gemini-2.5-flash-lite'   // Lite (20 RPD) - Separate quota bucket
+    ];
+
+    for (const modelName of primaryModels) {
+        try {
+            const currentParams = { ...baseParams, model: modelName };
+            return await callAIWithRetry(aiModelObj, currentParams, 1);
+        } catch (e) {
+            const isQuotaOrServerIssue = e.status === 429 || e.status === 503 || 
+                                         e.message?.includes('Quota') || 
+                                         e.message?.includes('overloaded') ||
+                                         e.message?.includes('RESOURCE_EXHAUSTED');
             
-            if (isOverloaded) {
-                if (i < retries - 1) {
-                    const delay = 1000 * Math.pow(2, i); // Exponential backoff: 1s, 2s, 4s...
-                    console.warn(`⚠️ AI Model Overloaded. Retrying in ${delay}ms... (Attempt ${i + 1}/${retries})`);
-                    await wait(delay);
-                    continue;
-                } else {
-                    console.error("❌ AI Model Overloaded: Max retries reached.");
+            if (isQuotaOrServerIssue) {
+                console.warn(`⚠️ Gemini Model ${modelName} exhausted/busy. Trying next...`);
+                continue; 
+            } else {
+                throw e; // Non-quota errors should fail immediately
+            }
+        }
+    }
+
+    // --- Tier 2: OpenRouter (Text Only, Free Models) ---
+    // Only attempt if NO media, as free OR models are mostly text-based or tricky with images via standard API
+    const openRouter = getOpenRouter();
+    
+    if (!hasMedia && openRouter) {
+        const openRouterModels = [
+            'qwen/qwen3-coder:free',
+            'openai/gpt-oss-120b:free', // Supports reasoning
+            'qwen/qwen3-235b-a22b:free',
+            'tngtech/deepseek-r1t-chimera:free'
+        ];
+
+        const openAIMessages = convertGeminiToOpenAI(baseParams);
+
+        for (const modelName of openRouterModels) {
+            try {
+                console.log(`🛡️ Switching to OpenRouter Model: ${modelName}`);
+                
+                // Specific config for reasoning models
+                const extraBody = {};
+                if (modelName === 'openai/gpt-oss-120b:free') {
+                    // extraBody.reasoning = { enabled: true }; // Optional: Enable if supported by library/endpoint
                 }
+
+                const completion = await openRouter.chat.completions.create({
+                    model: modelName,
+                    messages: openAIMessages,
+                    // ...extraBody 
+                });
+
+                // Normalize response to look like Gemini's { text: "..." }
+                const content = completion.choices[0]?.message?.content || "";
+                return { text: content };
+
+            } catch (e) {
+                console.warn(`⚠️ OpenRouter Model ${modelName} failed.`, e.message);
+                // Continue to next OpenRouter model
+            }
+        }
+    }
+
+    // --- Tier 3: Google Gemma 3 (Final Resort, Text Only) ---
+    // Note: 'gemma-3-27b-it' consumes the 14,400 RPD quota.
+    const fallbackModels = [
+        'gemma-3-27b-it',
+        'gemma-3-12b-it',
+        'gemma-3-4b-it'
+    ];
+    
+    if (!hasMedia) {
+        // Strip system instruction for Gemma compatibility
+        const gemmaConfig = { ...baseParams.config };
+        if (gemmaConfig.systemInstruction) delete gemmaConfig.systemInstruction;
+        
+        for (const modelName of fallbackModels) {
+            try {
+                console.log(`🛡️ Switching to Final Backup (Gemma 3): ${modelName}`);
+                const currentParams = { 
+                    ...baseParams, 
+                    model: modelName,
+                    config: gemmaConfig 
+                };
+                return await callAIWithRetry(aiModelObj, currentParams, 1);
+            } catch (e) {
+                console.warn(`⚠️ Backup Model ${modelName} failed.`, e.message);
             }
-            throw e; // Re-throw other errors or if retries exhausted
         }
     }
+
+    throw new Error('All AI models (Gemini, OpenRouter, Gemma) are currently unavailable.');
 }
 
 // --- Middleware: Check AI Access ---
@@ -192,16 +340,12 @@ app.post('/api/ai/chat', checkAIAccess, async (req, res) => {
         if (currentParts.length === 0) return res.status(400).json({ error: 'No input provided' });
 
         // 2. Build Full Context (History + Current)
-        // Gemini API `contents` is an array of messages
         const fullContents = [];
         
         // Add previous history if exists
         if (history && Array.isArray(history)) {
             history.forEach(msg => {
-                // Ensure valid role mapping
                 const role = msg.role === 'user' ? 'user' : 'model';
-                // Only text history is robustly supported in stateless mode for now to save bandwidth/complexity
-                // (Passing back audio bytes in history is heavy)
                 if (msg.text) {
                     fullContents.push({
                         role: role,
@@ -217,10 +361,9 @@ app.post('/api/ai/chat', checkAIAccess, async (req, res) => {
             parts: currentParts
         });
 
-        // Step 1: Thinking (Gemini Flash Lite for low latency)
-        const thinkingResponse = await callAIWithRetry(ai.models, {
-            model: 'gemini-2.5-flash-lite',
-            contents: fullContents, // Send full history
+        // Step 1: Thinking (Using Multi-Stage Smart Fallback)
+        const thinkingResponse = await generateContentWithSmartFallback(ai.models, {
+            contents: fullContents, 
             config: {
                 systemInstruction: "你是一位友善、耐心且知识渊博的中小学AI助教。请用简洁、鼓励性的语言回答学生的问题。如果学生使用语音，你也应当在回答中体现出自然的口语风格。",
             }
@@ -228,21 +371,28 @@ app.post('/api/ai/chat', checkAIAccess, async (req, res) => {
         
         const answerText = thinkingResponse.text || "抱歉，我没有听清，请再说一遍。";
 
-        // Step 2: Speaking (Gemini TTS)
-        const ttsResponse = await callAIWithRetry(ai.models, {
-            model: "gemini-2.5-flash-preview-tts",
-            contents: [{ parts: [{ text: answerText }] }],
-            config: {
-                responseModalities: [Modality.AUDIO],
-                speechConfig: {
-                    voiceConfig: {
-                        prebuiltVoiceConfig: { voiceName: 'Kore' },
+        // Step 2: Speaking (Gemini TTS) 
+        // CRITICAL FIX: Wrap TTS in try-catch to allow graceful degradation.
+        // If TTS fails (quota exceeded), we simply return text without audio.
+        let audioBytes = null;
+        try {
+            const ttsResponse = await ai.models.generateContent({
+                model: "gemini-2.5-flash-preview-tts", // No fallback for TTS currently as it's specialized
+                contents: [{ parts: [{ text: answerText }] }],
+                config: {
+                    responseModalities: [Modality.AUDIO],
+                    speechConfig: {
+                        voiceConfig: {
+                            prebuiltVoiceConfig: { voiceName: 'Kore' },
+                        },
                     },
                 },
-            },
-        });
-
-        const audioBytes = ttsResponse.candidates?.[0]?.content?.parts?.[0]?.inlineData?.data;
+            });
+            audioBytes = ttsResponse.candidates?.[0]?.content?.parts?.[0]?.inlineData?.data;
+        } catch (ttsError) {
+            // Log but do not fail the request
+            console.warn("⚠️ TTS Generation skipped (Quota or Error). Returning text only.");
+        }
 
         // Increment Counter
         await ConfigModel.findOneAndUpdate({ key: 'main' }, { $inc: { aiTotalCalls: 1 } }, { upsert: true });
@@ -254,6 +404,9 @@ app.post('/api/ai/chat', checkAIAccess, async (req, res) => {
 
     } catch (e) {
         console.error("AI Chat Error:", e);
+        if (e.status === 429 || e.message?.includes('QUOTA_EXCEEDED') || e.message?.includes('RESOURCE_EXHAUSTED')) {
+             return res.status(429).json({ error: 'QUOTA_EXCEEDED', message: '所有AI模型（包括备用线路）的免费额度均已耗尽，请明天再试。' });
+        }
         res.status(500).json({ error: e.message || 'AI Service Unavailable' });
     }
 });
@@ -280,9 +433,11 @@ app.post('/api/ai/evaluate', checkAIAccess, async (req, res) => {
 
         evalParts.push({ text: `请分析：1. 内容准确性 2. 表达/书写规范。返回 JSON: {score(0-100), feedback(简短评语), transcription(识别内容)}` });
 
-        // 1. Analyze
-        const response = await callAIWithRetry(ai.models, {
-            model: 'gemini-2.5-flash-lite',
+        // 1. Analyze (Using Multi-Stage Smart Fallback)
+        // Note: Evaluation usually outputs JSON. Gemma might struggle with strict JSON schemas without system instruction.
+        // We hope Primary Tier handles this. If falling back to Gemma, it might return raw text.
+        // For stability, Evaluation heavily relies on Gemini.
+        const response = await generateContentWithSmartFallback(ai.models, {
             contents: { parts: evalParts },
             config: {
                 responseMimeType: "application/json",
@@ -298,13 +453,31 @@ app.post('/api/ai/evaluate', checkAIAccess, async (req, res) => {
             }
         });
 
-        const resultJson = JSON.parse(response.text);
+        let resultJson;
+        // Attempt to parse JSON. OpenRouter models might wrap JSON in Markdown code blocks (```json ... ```).
+        let rawText = response.text || "{}";
+        if (rawText.includes('```json')) {
+            rawText = rawText.replace(/```json/g, '').replace(/```/g, '').trim();
+        } else if (rawText.includes('```')) {
+            rawText = rawText.replace(/```/g, '').trim();
+        }
 
-        // 2. Generate Audio for the Feedback (TTS)
+        try {
+            resultJson = JSON.parse(rawText);
+        } catch (jsonErr) {
+            // Fallback for models that return unstructured text
+            resultJson = {
+                score: 0,
+                feedback: rawText,
+                transcription: "（解析 JSON 失败，显示原始回复）"
+            };
+        }
+
+        // 2. Generate Audio for the Feedback (TTS) - Graceful Degradation
         let feedbackAudio = null;
         if (resultJson.feedback) {
             try {
-                const ttsResponse = await callAIWithRetry(ai.models, {
+                const ttsResponse = await ai.models.generateContent({
                     model: "gemini-2.5-flash-preview-tts",
                     contents: [{ parts: [{ text: resultJson.feedback }] }],
                     config: {
@@ -318,7 +491,7 @@ app.post('/api/ai/evaluate', checkAIAccess, async (req, res) => {
                 });
                 feedbackAudio = ttsResponse.candidates?.[0]?.content?.parts?.[0]?.inlineData?.data;
             } catch (ttsErr) {
-                console.warn("TTS Generation failed:", ttsErr);
+                console.warn("⚠️ TTS Generation failed:", ttsErr.message);
             }
         }
 
@@ -332,6 +505,9 @@ app.post('/api/ai/evaluate', checkAIAccess, async (req, res) => {
 
     } catch (e) {
         console.error("AI Eval Error:", e);
+        if (e.status === 429 || e.message?.includes('QUOTA_EXCEEDED') || e.message?.includes('RESOURCE_EXHAUSTED')) {
+             return res.status(429).json({ error: 'QUOTA_EXCEEDED', message: '所有AI模型的免费额度均已耗尽，请明天再试。' });
+        }
         res.status(500).json({ error: e.message || 'AI Service Unavailable' });
     }
 });