const LessonModule = require('../base/LessonModule');
const progressQueries = require('../../../src/models/queries/progress.queries');

/**
 * Beginner-Friendly SQL Injection Shop Lesson
 * Simplified to 3 progressive challenges with helpful hints
 *
 * Activity data structure:
 * {
 *   discoveries: ['GENERIC', 'BYPASS_FILTER', 'UNION_SELECT'],
 *   timerStart: timestamp,
 *   unionHintShown: boolean
 * }
 */
class SQLInjectionShopLesson extends LessonModule {
  constructor(config) {
    super(config);
  }

  /**
   * Get activity data from database
   */
  async _getActivityData(participantId, eventLessonId) {
    try {
      const data = await progressQueries.getActivityData(participantId, eventLessonId);
      console.log(`[SQL Injection] Loading activity data for participant ${participantId}, event ${eventLessonId}:`, data);
      return {
        discoveries: data.discoveries || [],
        timerStart: data.timerStart || null,
        unionHintShown: data.unionHintShown || false
      };
    } catch (error) {
      console.error('[SQL Injection] Error loading activity data:', error);
      return {
        discoveries: [],
        timerStart: null,
        unionHintShown: false
      };
    }
  }

  /**
   * Save activity data to database
   */
  async _saveActivityData(participantId, eventLessonId, activityData) {
    try {
      console.log(`[SQL Injection] Saving activity data for participant ${participantId}, event ${eventLessonId}:`, activityData);
      await progressQueries.updateActivityData(participantId, eventLessonId, activityData);
      console.log('[SQL Injection] Activity data saved successfully');
    } catch (error) {
      console.error('[SQL Injection] Error saving activity data:', error);
      throw error; // Re-throw to see the error in the main flow
    }
  }

  /**
   * Start challenge timer
   */
  async startTimer(participantId, eventLessonId) {
    const activityData = await this._getActivityData(participantId, eventLessonId);

    if (!activityData.timerStart) {
      activityData.timerStart = Date.now();
      await this._saveActivityData(participantId, eventLessonId, activityData);
    }

    const discoveries = new Set(activityData.discoveries);
    const totalDiscoveries = 3;

    return {
      started: true,
      duration: 600, // 10 minutes in seconds
      message: 'Timer gestartet! Du hast 10 Minuten Zeit.',
      discoveries: {
        found: discoveries.size,
        total: totalDiscoveries,
        types: Array.from(discoveries)
      },
      unionHintShown: activityData.unionHintShown
    };
  }

  /**
   * Get elapsed time for participant
   */
  async _getElapsedTime(participantId, eventLessonId) {
    const activityData = await this._getActivityData(participantId, eventLessonId);
    const start = activityData.timerStart;
    if (!start) return 0;
    return Math.floor((Date.now() - start) / 1000);
  }

  // Mock database with products
  getMockDatabase() {
    return {
      products: [
        { id: 1, name: 'Laptop Pro 15', price: 1299.99, category: 'Electronics', stock: 15 },
        { id: 2, name: 'Wireless Mouse', price: 29.99, category: 'Accessories', stock: 50 },
        { id: 3, name: 'USB-C Cable', price: 12.99, category: 'Accessories', stock: 100 },
        { id: 4, name: 'Gaming Keyboard', price: 89.99, category: 'Electronics', stock: 25 },
        { id: 5, name: 'Monitor 27"', price: 349.99, category: 'Electronics', stock: 20 }
      ],
      users: [
        { id: 1, username: 'admin', password: 'hashed_admin_password', role: 'admin' },
        { id: 2, username: 'john_doe', password: 'hashed_user_password', role: 'customer' },
        { id: 3, username: 'jane_smith', password: 'hashed_user_password', role: 'customer' }
      ]
    };
  }

  // Simulate vulnerable SQL query
  async executeVulnerableQuery(searchTerm, participantId, eventLessonId) {
    const db = this.getMockDatabase();

    // Build the "vulnerable" query string for educational display
    const vulnerableQuery = `SELECT * FROM products WHERE name LIKE '%${searchTerm}%'`;

    // Detect SQL injection attempts
    const injectionDetected = this.detectInjection(searchTerm);

    let results = [];
    let injectionType = null;
    let explanation = '';
    let pointsAwarded = 0;
    let isNewDiscovery = false;
    let unionHintMessage = null;

    // Load activity data from database
    const activityData = await this._getActivityData(participantId, eventLessonId);
    const discoveries = new Set(activityData.discoveries);
    console.log(`[SQL Injection] Current discoveries:`, Array.from(discoveries));

    if (injectionDetected) {
      const injectionInfo = this.analyzeInjection(searchTerm);
      injectionType = injectionInfo.type;
      explanation = injectionInfo.explanation;
      console.log(`[SQL Injection] Injection detected: ${injectionType}`);

      // Check if this is a new discovery
      isNewDiscovery = !discoveries.has(injectionType);
      console.log(`[SQL Injection] Is new discovery: ${isNewDiscovery}`);

      // Award points only for NEW discoveries
      if (isNewDiscovery && participantId && eventLessonId) {
        console.log(`[SQL Injection] Awarding points for new discovery: ${injectionType}`);
        const pointsMap = {
          'GENERIC': 30,              // Challenge 1: Discovering injection is possible
          'BYPASS_FILTER': 40,        // Challenge 2: Showing all products
          'UNION_SELECT': 80          // Challenge 3: Extracting user data (Easter egg!)
        };

        pointsAwarded = pointsMap[injectionType] || 0;

        // Time bonus
        const elapsedTime = await this._getElapsedTime(participantId, eventLessonId);
        if (elapsedTime > 0 && elapsedTime < 600) {
          const timeBonus = Math.max(0, Math.floor((600 - elapsedTime) / 60));
          if (timeBonus > 0) {
            pointsAwarded += timeBonus;
            explanation += ` 🎯 Zeit-Bonus: +${timeBonus} Punkte!`;
          }
        }

        try {
          await this.awardPoints(participantId, eventLessonId, pointsAwarded,
            `SQL Injection discovered: ${injectionType}`);

          // Mark as discovered and save to database
          discoveries.add(injectionType);
          activityData.discoveries = Array.from(discoveries);
          await this._saveActivityData(participantId, eventLessonId, activityData);

          // Show UNION hint after completing challenge 2
          if (injectionType === 'BYPASS_FILTER' && !activityData.unionHintShown) {
            activityData.unionHintShown = true;
            await this._saveActivityData(participantId, eventLessonId, activityData);

            unionHintMessage = {
              title: '🎯 Neue Herausforderung freigeschaltet!',
              content: 'Du kannst jetzt versuchen, Daten aus anderen Tabellen zu extrahieren! Die Datenbank hat eine "users" Tabelle mit den Spalten: id, username, password, role. Verwende UNION SELECT um diese Daten zu kombinieren. Die Anzahl der Spalten muss übereinstimmen (5 Spalten).',
              hint: "Versuche: ' UNION SELECT id, username, password, role, 'X' FROM users--"
            };
          }
        } catch (error) {
          console.error('Failed to award SQL injection points:', error);
        }
      }

      // Simulate different injection results
      if (injectionInfo.type === 'BYPASS_FILTER') {
        // Return all products
        results = db.products;
      } else if (injectionInfo.type === 'UNION_SELECT') {
        // Simulate UNION attack showing user data
        results = [
          { id: 'USER', name: 'admin', price: 'hashed_admin_password', category: 'admin', stock: 'LEAKED!' },
          { id: 'USER', name: 'john_doe', price: 'hashed_user_password', category: 'customer', stock: 'LEAKED!' },
          { id: 'USER', name: 'jane_smith', price: 'hashed_user_password', category: 'customer', stock: 'LEAKED!' }
        ];
      } else if (injectionInfo.type === 'GENERIC') {
        // Generic injection - show it affects the query
        results = db.products;
      }
    } else {
      // Normal search - filter products by name
      results = db.products.filter(p =>
        p.name.toLowerCase().includes(searchTerm.toLowerCase())
      );
    }

    const totalDiscoveries = 3; // Only 3 challenges now
    const elapsedTime = await this._getElapsedTime(participantId, eventLessonId);

    return {
      query: vulnerableQuery,
      results,
      injectionDetected,
      injectionType,
      explanation,
      recordCount: results.length,
      pointsAwarded: isNewDiscovery ? pointsAwarded : 0,
      isNewDiscovery,
      unionHintMessage,
      discoveries: {
        found: discoveries.size,
        total: totalDiscoveries,
        types: Array.from(discoveries)
      },
      elapsedTime
    };
  }

  // Detect if input contains SQL injection
  detectInjection(input) {
    const injectionPatterns = [
      /'/,                          // Single quote
      /union/i,                     // UNION keyword
      /select/i,                    // SELECT keyword
      /or\s+['"]?\d+['"]?\s*=\s*['"]?\d+['"]?/i  // OR 1=1 pattern
    ];

    return injectionPatterns.some(pattern => pattern.test(input));
  }

  // Analyze the type of SQL injection
  analyzeInjection(input) {
    const lowerInput = input.toLowerCase();

    // Challenge 3: UNION SELECT (most advanced)
    // Must include UNION SELECT FROM users/user to be valid
    if (lowerInput.includes('union') && lowerInput.includes('select') &&
        lowerInput.includes('from') && (lowerInput.includes('users') || lowerInput.includes('user'))) {
      return {
        type: 'UNION_SELECT',
        explanation: '🎉 Perfekt! UNION SELECT Injection erfolgreich! Du hast Daten aus der users-Tabelle extrahiert. **Challenge 3 abgeschlossen!** ⭐'
      };
    }

    // Challenge 2: Bypass filter to show all products
    if (lowerInput.includes("'") && (lowerInput.includes('or') || lowerInput.includes('||'))) {
      if (lowerInput.match(/or\s+['"]?\d+['"]?\s*=\s*['"]?\d+['"]?/)) {
        return {
          type: 'BYPASS_FILTER',
          explanation: "✅ Super! Die Bedingung '1'='1' ist immer wahr und umgeht den Filter. Jetzt werden ALLE Produkte angezeigt. **Challenge 2 abgeschlossen!**"
        };
      }
    }

    // Challenge 1: Generic injection - just discovered manipulation is possible
    if (lowerInput.includes("'")) {
      return {
        type: 'GENERIC',
        explanation: "🔓 Gut gemacht! Das Anführungszeichen (') zeigt, dass die Abfrage manipuliert werden kann. Du hast entdeckt, dass SQL Injection möglich ist! **Challenge 1 abgeschlossen!**"
      };
    }

    return {
      type: 'NONE',
      explanation: 'Keine SQL Injection erkannt.'
    };
  }

  // Demonstrate safe parameterized query
  executeSafeQuery(searchTerm) {
    const db = this.getMockDatabase();

    const safeQuery = `SELECT * FROM products WHERE name LIKE ?`;
    const parameter = `%${searchTerm}%`;

    const results = db.products.filter(p =>
      p.name.toLowerCase().includes(searchTerm.toLowerCase())
    );

    return {
      query: safeQuery,
      parameter,
      results,
      explanation: '✅ Parameterized query verwendet! Benutzereingaben werden als Daten behandelt, nie als SQL-Code. Injection ist unmöglich.',
      recordCount: results.length
    };
  }

  // Get interactive data for the SQL shop demo
  async getInteractiveData(stepId) {
    if (stepId === 'shop-demo') {
      return {
        timerDuration: 600, // 10 minutes
        totalChallenges: 3, // Simplified to 3 challenges
        database: this.getMockDatabase(),
        challenges: [
          {
            id: 'GENERIC',
            difficulty: 'Anfänger',
            points: 30,
            title: 'SQL Injection entdecken',
            hint: "Versuche ein ' (Anführungszeichen) einzugeben"
          },
          {
            id: 'BYPASS_FILTER',
            difficulty: 'Anfänger',
            points: 40,
            title: 'Filter umgehen (alle Produkte zeigen)',
            hint: "Verwende: ' OR '1'='1"
          },
          {
            id: 'UNION_SELECT',
            difficulty: 'Fortgeschritten',
            points: 80,
            title: 'Benutzerdaten extrahieren',
            hint: 'Wird nach Challenge 2 freigeschaltet',
            isEasterEgg: true
          }
        ],
        externalResources: [
          {
            title: 'OWASP SQL Injection',
            url: 'https://owasp.org/www-community/attacks/SQL_Injection',
            type: 'documentation',
            description: 'Grundlagen zu SQL Injection-Angriffen'
          },
          {
            title: 'SQL Tutorial (W3Schools)',
            url: 'https://www.w3schools.com/sql/',
            type: 'tutorial',
            description: 'SQL Grundlagen lernen'
          },
          {
            title: 'SQL Injection Cheat Sheet',
            url: 'https://portswigger.net/web-security/sql-injection/cheat-sheet',
            type: 'reference',
            description: 'Schnellreferenz für SQL Injection'
          }
        ],
        schemaInfo: {
          tables: ['products', 'users'],
          productsColumns: ['id', 'name', 'price', 'category', 'stock'],
          usersColumns: ['id', 'username', 'password', 'role']
        },
        initialHint: {
          title: '💡 Einstiegshilfe',
          content: 'Du hast erfahren, dass dieser Shop anfällig für SQL Injection ist. Beginne mit einem einfachen Test: Gib ein Anführungszeichen (\') ein und beobachte was passiert. Dann versuche den Filter zu umgehen.',
          examples: [
            { label: "Challenge 1", payload: "'", description: "Entdecke die Schwachstelle" },
            { label: "Challenge 2", payload: "' OR '1'='1", description: "Zeige alle Produkte (Filter umgehen)" }
          ]
        }
      };
    }

    return await super.getInteractiveData(stepId);
  }
}

module.exports = SQLInjectionShopLesson;