mcp-server.js

#!/usr/bin/env node
// mcp-server.js - MCP Server for Reuben OS with Passkey System

import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import {
  CallToolRequestSchema,
  ListToolsRequestSchema,
} from '@modelcontextprotocol/sdk/types.js';
import fetch from 'node-fetch';

const BASE_URL = 'https://mcp-1st-birthday-reuben-os.hf.space';
const API_ENDPOINT = `${BASE_URL}/api/mcp-handler`;

class ReubenOSMCPServer {
  constructor() {
    this.server = new Server(
      {
        name: 'reubenos-mcp-server',
        version: '3.0.0',
        description: 'MCP Server for Reuben OS with secure passkey-based file storage',
        icon: '🖥️',
      },
      {
        capabilities: {
          tools: {},
        },
      }
    );

    this.setupToolHandlers();

    // Error handling
    this.server.onerror = (error) => console.error('[MCP Error]', error);
    process.on('SIGINT', async () => {
      await this.server.close();
      process.exit(0);
    });
  }

  setupToolHandlers() {
    this.server.setRequestHandler(ListToolsRequestSchema, async () => ({
      tools: [
        {
          name: 'save_file',
          description: 'Save a file to Reuben OS. Passkey is OPTIONAL - provide for secure storage or leave empty for public folder.',
          inputSchema: {
            type: 'object',
            properties: {
              fileName: {
                type: 'string',
                description: 'File name (e.g., main.dart, document.tex, report.pdf)',
              },
              content: {
                type: 'string',
                description: 'File content to save',
              },
              passkey: {
                type: 'string',
                description: 'OPTIONAL: Your passkey for secure storage (min 4 characters). Leave empty to save to public folder.',
              },
              isPublic: {
                type: 'boolean',
                description: 'Set to true to save to public folder (accessible to everyone). Default: false',
              },
            },
            required: ['fileName', 'content'],
          },
        },
        {
          name: 'list_files',
          description: 'List all files in your secure storage or public folder. Passkey is OPTIONAL.',
          inputSchema: {
            type: 'object',
            properties: {
              passkey: {
                type: 'string',
                description: 'OPTIONAL: Your passkey to list secure files. Leave empty to list public files.',
              },
              isPublic: {
                type: 'boolean',
                description: 'Set to true to list public files. Default: false',
              },
            },
          },
        },
        {
          name: 'delete_file',
          description: 'Delete a specific file from your storage. Passkey is OPTIONAL.',
          inputSchema: {
            type: 'object',
            properties: {
              fileName: {
                type: 'string',
                description: 'Name of the file to delete',
              },
              passkey: {
                type: 'string',
                description: 'OPTIONAL: Your passkey (required for secure files). Leave empty for public files.',
              },
              isPublic: {
                type: 'boolean',
                description: 'Set to true if deleting from public folder. Default: false',
              },
            },
            required: ['fileName'],
          },
        },
        {
          name: 'deploy_quiz',
          description: 'Deploy an interactive quiz to Reuben OS Quiz App. Passkey is REQUIRED for all quizzes.',
          inputSchema: {
            type: 'object',
            properties: {
              passkey: {
                type: 'string',
                description: 'Your passkey for secure quiz storage (REQUIRED - min 4 characters)',
              },
              quizData: {
                type: 'object',
                description: 'Quiz configuration',
                properties: {
                  title: { type: 'string', description: 'Quiz title' },
                  description: { type: 'string', description: 'Quiz description' },
                  questions: {
                    type: 'array',
                    description: 'Array of questions',
                    items: {
                      type: 'object',
                      properties: {
                        id: { type: 'string' },
                        type: { type: 'string', enum: ['multiple_choice'] },
                        question: { type: 'string' },
                        options: { type: 'array', items: { type: 'string' } },
                        explanation: { type: 'string' },
                        points: { type: 'number' },
                      },
                      required: ['id', 'question', 'type'],
                    },
                  },
                  timeLimit: {
                    type: 'number',
                    description: 'Time limit in minutes for the quiz (optional)',
                  },
                },
                required: ['title', 'questions'],
              },
            },
            required: ['passkey', 'quizData'],
          },
        },
        {
          name: 'read_file',
          description: 'Read the content of a file from secure storage or public folder. Passkey is OPTIONAL. Useful for evaluating quiz answers.',
          inputSchema: {
            type: 'object',
            properties: {
              fileName: {
                type: 'string',
                description: 'Name of the file to read (e.g., quiz_answers.json)',
              },
              passkey: {
                type: 'string',
                description: 'OPTIONAL: Your passkey (required for secure files). Leave empty for public files.',
              },
              isPublic: {
                type: 'boolean',
                description: 'Set to true if reading from public folder. Default: false',
              },
            },
            required: ['fileName'],
          },
        },
        {
          name: 'generate_song_audio',
          description: 'Generate an AI song with audio using ElevenLabs Music API. NO passkey required - saves directly to Voice Studio app.',
          inputSchema: {
            type: 'object',
            properties: {
              title: {
                type: 'string',
                description: 'Title of the song',
              },
              style: {
                type: 'string',
                description: 'Musical style/genre (e.g., "pop", "rock", "jazz", "ballad")',
              },
              lyrics: {
                type: 'string',
                description: 'Song lyrics (will be used to generate music)',
              },
            },
            required: ['title', 'style', 'lyrics'],
          },
        },
        {
          name: 'generate_story_audio',
          description: 'Generate audio narration for a story using ElevenLabs Text-to-Speech API. NO passkey required - saves directly to Voice Studio app.',
          inputSchema: {
            type: 'object',
            properties: {
              title: {
                type: 'string',
                description: 'Title of the story',
              },
              content: {
                type: 'string',
                description: 'Story content/text to be narrated (max 2000 characters for best performance)',
              },
            },
            required: ['title', 'content'],
          },
        },
        {
          name: 'analyze_quiz',
          description: 'Analyze quiz answers from quiz_answers.json against the quiz.json questions and provide feedback on correctness. Passkey is REQUIRED.',
          inputSchema: {
            type: 'object',
            properties: {
              passkey: {
                type: 'string',
                description: 'Your passkey for accessing the quiz files (REQUIRED)',
              },
            },
            required: ['passkey'],
          },
        },
      ],
    }));

    this.server.setRequestHandler(CallToolRequestSchema, async (request) => {
      const { name, arguments: args } = request.params;

      try {
        switch (name) {
          case 'save_file':
            return await this.saveFile(args);
          case 'list_files':
            return await this.listFiles(args);
          case 'delete_file':
            return await this.deleteFile(args);
          case 'deploy_quiz':
            return await this.deployQuiz(args);
          case 'read_file':
            return await this.readFile(args);
          case 'generate_song_audio':
            return await this.generateSongAudio(args);
          case 'generate_story_audio':
            return await this.generateStoryAudio(args);
          case 'analyze_quiz':
            return await this.analyzeQuiz(args);
          default:
            throw new Error(`Unknown tool: ${name}`);
        }
      } catch (error) {
        return {
          content: [
            {
              type: 'text',
              text: `Error: ${error.message}`,
            },
          ],
        };
      }
    });
  }

  async readFile(args) {
    try {
      const { fileName, passkey, isPublic = false } = args;

      if (!fileName) {
        return {
          content: [{ type: 'text', text: '❌ fileName is required' }],
        };
      }

      if (!isPublic && !passkey) {
        return {
          content: [{ type: 'text', text: '❌ Passkey is required (or set isPublic=true)' }],
        };
      }

      const ext = fileName.split('.').pop().toLowerCase();
      const isDocument = ['pdf', 'docx', 'xlsx', 'xls', 'pptx'].includes(ext);

      if (isDocument) {
        // Use document processing endpoint
        const processUrl = `${BASE_URL}/api/documents/process`;
        const response = await fetch(processUrl, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({
            fileName,
            key: passkey,
            isPublic,
            operation: 'read'
          })
        });

        const data = await response.json();

        if (response.ok && data.success) {
          let textContent = '';
          if (data.content.text) {
            textContent = data.content.text;
          } else if (data.content.sheets) {
            textContent = JSON.stringify(data.content.sheets, null, 2);
          } else {
            textContent = JSON.stringify(data.content, null, 2);
          }

          return {
            content: [
              {
                type: 'text',
                text: `📄 Content of ${fileName} (${data.content.type}):\n\n${textContent}`,
              },
            ],
          };
        } else {
          return {
            content: [{ type: 'text', text: `❌ Failed to process document: ${data.error || 'Unknown error'}` }],
          };
        }
      }

      const url = new URL(API_ENDPOINT);
      if (passkey) url.searchParams.set('passkey', passkey);
      if (isPublic) url.searchParams.set('isPublic', 'true');

      const response = await fetch(url, {
        method: 'GET',
        headers: { 'Content-Type': 'application/json' },
      });

      const data = await response.json();

      if (response.ok && data.success) {
        const file = data.files.find(f => f.name === fileName);

        if (!file) {
          return {
            content: [{ type: 'text', text: `❌ File '${fileName}' not found in ${data.location}` }],
          };
        }

        return {
          content: [
            {
              type: 'text',
              text: `📄 Content of ${fileName}:\n\n${file.content || '(Empty file)'}`,
            },
          ],
        };
      } else {
        return {
          content: [{ type: 'text', text: `❌ Failed: ${data.error || 'Unknown error'}` }],
        };
      }
    } catch (error) {
      return {
        content: [{ type: 'text', text: `❌ Error: ${error.message}` }],
      };
    }
  }

  async saveFile(args) {
    try {
      const { fileName, content, passkey, isPublic = false } = args;

      if (!fileName || content === undefined) {
        return {
          content: [{ type: 'text', text: '❌ fileName and content are required' }],
        };
      }

      if (!isPublic && !passkey) {
        return {
          content: [{ type: 'text', text: '❌ Passkey is required for secure storage (or set isPublic=true)' }],
        };
      }

      // Ensure content is properly stringified if it's an object
      let fileContent = content;
      if (typeof content === 'object' && content !== null) {
        fileContent = JSON.stringify(content, null, 2);
      }

      // Handle special characters in content for code files
      const ext = fileName.split('.').pop().toLowerCase();
      const isCodeFile = ['dart', 'js', 'ts', 'jsx', 'tsx', 'py', 'java', 'cpp', 'c', 'h', 'hpp', 'cs', 'swift', 'kt', 'go', 'rs', 'rb', 'php'].includes(ext);

      // Ensure content is a string
      fileContent = String(fileContent);

      const response = await fetch(API_ENDPOINT, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          passkey,
          action: 'save_file',
          fileName,
          content: fileContent,
          isPublic,
        }),
      });

      const data = await response.json();

      if (response.ok && data.success) {
        const location = isPublic ? 'Public Folder' : `Secure Data (passkey: ${passkey})`;
        const fileType = isCodeFile ? `(${ext.toUpperCase()} code file)` : '';

        return {
          content: [
            {
              type: 'text',
              text: `✅ File saved: ${fileName} ${fileType}\n📁 Saved to: ${location}\n📊 Size: ${(new TextEncoder().encode(fileContent).length / 1024).toFixed(2)} KB`,
            },
          ],
        };
      } else {
        return {
          content: [{ type: 'text', text: `❌ Failed to save: ${data.error || 'Unknown error'}` }],
        };
      }
    } catch (error) {
      return {
        content: [{ type: 'text', text: `❌ Error: ${error.message}` }],
      };
    }
  }

  async listFiles(args) {
    try {
      const { passkey, isPublic = false } = args;

      if (!isPublic && !passkey) {
        return {
          content: [{ type: 'text', text: '❌ Passkey is required (or set isPublic=true)' }],
        };
      }

      const url = new URL(API_ENDPOINT);
      if (passkey) url.searchParams.set('passkey', passkey);
      if (isPublic) url.searchParams.set('isPublic', 'true');

      const response = await fetch(url, {
        method: 'GET',
        headers: { 'Content-Type': 'application/json' },
      });

      const data = await response.json();

      if (response.ok && data.success) {
        if (data.files.length === 0) {
          return {
            content: [{ type: 'text', text: `📁 No files found in ${data.location}` }],
          };
        }

        const fileList = data.files
          .map(f => `📄 ${f.name} (${(f.size / 1024).toFixed(2)} KB)${f.isQuiz ? ' [QUIZ]' : ''}`)
          .join('\n');

        return {
          content: [
            {
              type: 'text',
              text: `📁 Files in ${data.location}:\n\n${fileList}\n\nTotal: ${data.count} file(s)`,
            },
          ],
        };
      } else {
        return {
          content: [{ type: 'text', text: `❌ Failed: ${data.error || 'Unknown error'}` }],
        };
      }
    } catch (error) {
      return {
        content: [{ type: 'text', text: `❌ Error: ${error.message}` }],
      };
    }
  }

  async deleteFile(args) {
    try {
      const { fileName, passkey, isPublic = false } = args;

      if (!fileName) {
        return {
          content: [{ type: 'text', text: '❌ fileName is required' }],
        };
      }

      if (!isPublic && !passkey) {
        return {
          content: [{ type: 'text', text: '❌ Passkey is required (or set isPublic=true)' }],
        };
      }

      const response = await fetch(API_ENDPOINT, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          passkey,
          action: 'delete_file',
          fileName,
          isPublic,
          content: '', // Required by API but not used
        }),
      });

      const data = await response.json();

      if (response.ok && data.success) {
        return {
          content: [{ type: 'text', text: `✅ File '${fileName}' deleted successfully` }],
        };
      } else {
        return {
          content: [{ type: 'text', text: `❌ Failed: ${data.error || 'File not found'}` }],
        };
      }
    } catch (error) {
      return {
        content: [{ type: 'text', text: `❌ Error: ${error.message}` }],
      };
    }
  }

  async deployQuiz(args) {
    try {
      const { quizData, passkey } = args;

      // Passkey is REQUIRED for quizzes
      if (!passkey || passkey.length < 4) {
        return {
          content: [{ type: 'text', text: '❌ Passkey is REQUIRED for quizzes (minimum 4 characters)' }],
        };
      }

      if (!quizData || !quizData.questions || quizData.questions.length === 0) {
        return {
          content: [{ type: 'text', text: '❌ Quiz must have at least one question' }],
        };
      }

      // Strip correct answers from questions before saving quiz.json
      // This prevents users from seeing the answers in the quiz file
      const questionsWithoutAnswers = quizData.questions.map(q => {
        const { correctAnswer, correct, answer, ...questionWithoutAnswer } = q;
        return questionWithoutAnswer;
      });

      // Save quiz.json WITHOUT correct answers (for users to take)
      const quizForUsers = {
        title: quizData.title,
        description: quizData.description,
        timeLimit: quizData.timeLimit,
        questions: questionsWithoutAnswers,
        createdAt: new Date().toISOString(),
        version: '1.0',
      };

      // Save quiz_key.json WITH correct answers (for grading) - hidden file
      const quizAnswerKey = {
        title: quizData.title,
        questions: quizData.questions.map(q => ({
          id: q.id,
          correctAnswer: q.correctAnswer || q.correct || q.answer,
          explanation: q.explanation,
          points: q.points || 1,
        })),
        createdAt: new Date().toISOString(),
      };

      // Save quiz.json (without answers)
      const quizResponse = await fetch(API_ENDPOINT, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          passkey,
          action: 'deploy_quiz',
          fileName: 'quiz.json',
          content: JSON.stringify(quizForUsers, null, 2),
          isPublic: false,
        }),
      });

      const quizResult = await quizResponse.json();

      if (!quizResponse.ok || !quizResult.success) {
        return {
          content: [{ type: 'text', text: `❌ Failed to save quiz: ${quizResult.error || 'Unknown error'}` }],
        };
      }

      // Save quiz_key.json (with correct answers for grading)
      const keyResponse = await fetch(API_ENDPOINT, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          passkey,
          action: 'save_file',
          fileName: 'quiz_key.json',
          content: JSON.stringify(quizAnswerKey, null, 2),
          isPublic: false,
        }),
      });

      const keyResult = await keyResponse.json();

      if (!keyResponse.ok || !keyResult.success) {
        console.error('Failed to save quiz key:', keyResult.error);
        // Don't fail the whole operation, just log it
      }

      const totalPoints = quizData.questions.reduce((sum, q) => sum + (q.points || 1), 0);

      return {
        content: [
          {
            type: 'text',
            text: `✅ Quiz deployed: ${quizData.title}\n📊 ${quizData.questions.length} questions, ${totalPoints} points\n🔒 Secured with passkey: ${passkey}\n📝 Answer key saved separately for grading`,
          },
        ],
      };
    } catch (error) {
      return {
        content: [{ type: 'text', text: `❌ Error: ${error.message}` }],
      };
    }
  }

  async generateSongAudio(args) {
    try {
      const { title, style, lyrics } = args;
      // Use a default passkey internally - users don't need to provide it
      const passkey = 'voice_default';

      if (!title || !style || !lyrics) {
        return {
          content: [{ type: 'text', text: '❌ title, style, and lyrics are required' }],
        };
      }

      const response = await fetch(`${BASE_URL}/api/voice/generate-song`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ title, style, lyrics, passkey }),
      });

      const data = await response.json();

      if (response.ok && data.success) {
        // Save the content to server storage
        await fetch(`${BASE_URL}/api/voice/save`, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({
            passkey,
            content: data.content,
          }),
        });

        return {
          content: [
            {
              type: 'text',
              text: `🎵 Song "${title}" generated successfully!\\n🎸 Style: ${style}\\n📱 Open the Voice Studio app to listen to your song!`,
            },
          ],
        };
      } else {
        return {
          content: [{ type: 'text', text: `❌ Failed to generate song: ${data.error || 'Unknown error'}` }],
        };
      }
    } catch (error) {
      return {
        content: [{ type: 'text', text: `❌ Error: ${error.message}` }],
      };
    }
  }

  async generateStoryAudio(args) {
    try {
      const { title, content } = args;
      // Use a default passkey internally - users don't need to provide it
      const passkey = 'voice_default';

      if (!title || !content) {
        return {
          content: [{ type: 'text', text: '❌ title and content are required' }],
        };
      }

      const response = await fetch(`${BASE_URL}/api/voice/generate-story`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ title, content, passkey }),
      });

      const data = await response.json();

      if (response.ok && data.success) {
        // Save the content to server storage
        await fetch(`${BASE_URL}/api/voice/save`, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({
            passkey,
            content: data.content,
          }),
        });

        return {
          content: [
            {
              type: 'text',
              text: `📖 Story "${title}" audio generated successfully!\\n📱 Open the Voice Studio app to listen to your story!`,
            },
          ],
        };
      } else {
        return {
          content: [{ type: 'text', text: `❌ Failed to generate story audio: ${data.error || 'Unknown error'}` }],
        };
      }
    } catch (error) {
      return {
        content: [{ type: 'text', text: `❌ Error: ${error.message}` }],
      };
    }
  }

  async analyzeQuiz(args) {
    try {
      const { passkey } = args;

      // Passkey is REQUIRED for quiz analysis
      if (!passkey || passkey.length < 4) {
        return {
          content: [{ type: 'text', text: '❌ Passkey is REQUIRED to access quiz files (minimum 4 characters)' }],
        };
      }

      // Read all files from secure storage
      const quizUrl = new URL(API_ENDPOINT);
      quizUrl.searchParams.set('passkey', passkey);

      console.log('Fetching quiz files from:', quizUrl.toString());

      const quizResponse = await fetch(quizUrl, {
        method: 'GET',
        headers: { 'Content-Type': 'application/json' },
      });

      const quizData = await quizResponse.json();

      console.log('API Response:', JSON.stringify(quizData, null, 2).substring(0, 500));

      if (!quizResponse.ok || !quizData.success) {
        return {
          content: [{ type: 'text', text: `❌ Failed to read files: ${quizData.error || 'Unknown error'}` }],
        };
      }

      if (!quizData.files || quizData.files.length === 0) {
        return {
          content: [{ type: 'text', text: '❌ No files found for this passkey. Make sure the quiz has been deployed and answered.' }],
        };
      }

      // Find quiz.json (questions without answers)
      const quizFile = quizData.files.find(f => f.name === 'quiz.json');
      if (!quizFile) {
        return {
          content: [{ type: 'text', text: `❌ quiz.json not found. Available files: ${quizData.files.map(f => f.name).join(', ')}` }],
        };
      }

      if (!quizFile.content) {
        return {
          content: [{ type: 'text', text: '❌ quiz.json exists but content is empty or could not be read' }],
        };
      }

      // Find quiz_key.json (correct answers for grading)
      // For backward compatibility, if quiz_key.json doesn't exist, try to get answers from quiz.json
      const keyFile = quizData.files.find(f => f.name === 'quiz_key.json');
      const hasAnswerKey = keyFile && keyFile.content;

      // For backward compatibility: if no quiz_key.json exists, we'll need to get answers from quiz.json (old format)
      // This happens for quizzes created before the answer-key separation was implemented

      // Find quiz_answers.json (user's answers)
      const answersFile = quizData.files.find(f => f.name === 'quiz_answers.json');
      if (!answersFile) {
        return {
          content: [{ type: 'text', text: `❌ quiz_answers.json not found. The user needs to complete the quiz first. Available files: ${quizData.files.map(f => f.name).join(', ')}` }],
        };
      }

      if (!answersFile.content) {
        return {
          content: [{ type: 'text', text: '❌ quiz_answers.json exists but content is empty or could not be read' }],
        };
      }

      console.log('Quiz file content length:', quizFile.content?.length);
      console.log('Key file found:', !!keyFile, 'content length:', keyFile?.content?.length);
      console.log('Answers file content length:', answersFile.content?.length);

      // Parse the quiz, answer key, and user answers
      let quiz, answerKey, userAnswersData;
      try {
        quiz = typeof quizFile.content === 'string' ? JSON.parse(quizFile.content) : quizFile.content;
      } catch (e) {
        return {
          content: [{ type: 'text', text: `❌ Failed to parse quiz.json: ${e.message}` }],
        };
      }

      // Parse answer key (from quiz_key.json if exists, or fall back to quiz.json for backward compatibility)
      if (hasAnswerKey) {
        try {
          answerKey = typeof keyFile.content === 'string' ? JSON.parse(keyFile.content) : keyFile.content;
        } catch (e) {
          return {
            content: [{ type: 'text', text: `❌ Failed to parse quiz_key.json: ${e.message}` }],
          };
        }
      } else {
        // Backward compatibility: create answer key from quiz.json (old format had answers in quiz.json)
        console.log('No quiz_key.json found - using backward compatibility mode with quiz.json');
        answerKey = {
          title: quiz.title,
          questions: (quiz.questions || []).map(q => ({
            id: q.id,
            correctAnswer: q.correctAnswer || q.correct || q.answer,
            explanation: q.explanation,
            points: q.points || 1,
          })),
        };
      }

      try {
        userAnswersData = typeof answersFile.content === 'string' ? JSON.parse(answersFile.content) : answersFile.content;
      } catch (e) {
        return {
          content: [{ type: 'text', text: `❌ Failed to parse quiz_answers.json: ${e.message}` }],
        };
      }

      console.log('Parsed quiz:', quiz.title, 'Questions:', quiz.questions?.length);
      console.log('Parsed answer key:', answerKey.questions?.length, 'answers');
      console.log('Parsed user answers:', JSON.stringify(userAnswersData, null, 2).substring(0, 300));

      // Convert user answers array to object for easier lookup
      const userAnswers = {};
      if (userAnswersData.answers && Array.isArray(userAnswersData.answers)) {
        // QuizApp format: { answers: [{ questionId, answer }], metadata: {...} }
        userAnswersData.answers.forEach(item => {
          userAnswers[item.questionId] = item.answer;
        });
      } else if (typeof userAnswersData === 'object') {
        // Direct object format
        Object.assign(userAnswers, userAnswersData);
      }

      // Convert answer key to object for easier lookup
      const correctAnswers = {};
      const explanations = {};
      const pointsMap = {};
      if (answerKey.questions && Array.isArray(answerKey.questions)) {
        answerKey.questions.forEach(q => {
          correctAnswers[q.id] = q.correctAnswer;
          explanations[q.id] = q.explanation;
          pointsMap[q.id] = q.points || 1;
        });
      }

      console.log('Processed user answers:', userAnswers);
      console.log('Processed correct answers:', correctAnswers);

      // Analyze the answers
      let correctCount = 0;
      let totalPoints = 0;
      let maxPoints = 0;
      const feedback = [];
      const questionsArray = quiz.questions || [];

      if (questionsArray.length === 0) {
        return {
          content: [{ type: 'text', text: '❌ Quiz has no questions to analyze' }],
        };
      }

      questionsArray.forEach((question, index) => {
        const questionId = question.id || `question_${index}`;
        const userAnswer = userAnswers[questionId];
        const correctAnswer = correctAnswers[questionId];
        const explanation = explanations[questionId];
        const points = pointsMap[questionId] || 1;
        maxPoints += points;

        if (!userAnswer) {
          feedback.push(`⚠️ Q${index + 1}: "${question.question.substring(0, 50)}..." - Not answered`);
          return;
        }

        if (!correctAnswer) {
          // No correct answer in key - just show the user's answer for manual review
          feedback.push(`📝 Q${index + 1}: "${question.question.substring(0, 50)}..." \n   User answered: "${userAnswer}" \n   (No correct answer in key - manual review needed)`);
          return;
        }

        // Check if answer is correct
        let isCorrect = false;
        if (Array.isArray(correctAnswer)) {
          isCorrect = correctAnswer.some(ca =>
            String(ca).toLowerCase().trim() === String(userAnswer).toLowerCase().trim()
          );
        } else {
          isCorrect = String(correctAnswer).toLowerCase().trim() === String(userAnswer).toLowerCase().trim();
        }

        if (isCorrect) {
          correctCount++;
          totalPoints += points;
          feedback.push(`✅ Q${index + 1}: Correct! (+${points} pts)`);
        } else {
          feedback.push(`❌ Q${index + 1}: "${question.question.substring(0, 40)}..."\n   Your answer: "${userAnswer}"\n   Correct: "${correctAnswer}"${explanation ? `\n   💡 ${explanation}` : ''}`);
        }
      });

      const percentage = maxPoints > 0 ? Math.round((totalPoints / maxPoints) * 100) : 0;
      const grade = percentage >= 90 ? 'A' :
        percentage >= 80 ? 'B' :
          percentage >= 70 ? 'C' :
            percentage >= 60 ? 'D' : 'F';

      // Include metadata if available
      let metadataInfo = '';
      if (userAnswersData.metadata) {
        const meta = userAnswersData.metadata;
        metadataInfo = `\n⏱️ Time taken: ${Math.floor((meta.timeTakenSeconds || 0) / 60)}m ${(meta.timeTakenSeconds || 0) % 60}s`;
        if (meta.timeExceeded) {
          metadataInfo += ' (Time limit exceeded!)';
        }
        metadataInfo += `\n📅 Completed: ${meta.completedAt || 'Unknown'}`;
      }

      return {
        content: [
          {
            type: 'text',
            text: `📊 Quiz Analysis Results for "${quiz.title || 'Untitled Quiz'}"

📈 Score: ${totalPoints}/${maxPoints} points (${percentage}%)
✅ Correct: ${correctCount}/${questionsArray.length} questions
🎯 Grade: ${grade}${metadataInfo}

📝 Detailed Feedback:
${feedback.join('\n\n')}

${percentage >= 70 ? '🎉 Great job!' : '📚 Keep studying and try again!'}`,
          },
        ],
      };
    } catch (error) {
      console.error('analyzeQuiz error:', error);
      return {
        content: [{ type: 'text', text: `❌ Error analyzing quiz: ${error.message}\n\nStack: ${error.stack}` }],
      };
    }
  }

  async run() {
    const transport = new StdioServerTransport();
    await this.server.connect(transport);
    console.error('ReubenOS MCP Server running with passkey authentication...');
  }
}

const server = new ReubenOSMCPServer();
server.run();