Build a Sudoku Mobile & Web App

// React Native Sudoku Engine
class MobileSudokuEngine {
  constructor() {
    this.grid = Array(9).fill().map(() => Array(9).fill(0));
    this.solution = null;
    this.initialGrid = null;
    this.difficulty = 'medium';
  }

  // Generate new puzzle
  async generatePuzzle(difficulty = 'medium') {
    return new Promise((resolve) => {
      // Use web worker or async processing
      setTimeout(() => {
        const result = this.createPuzzle(difficulty);
        this.grid = result.puzzle;
        this.solution = result.solution;
        this.initialGrid = result.puzzle.map(row => [...row]);
        resolve(result);
      }, 0);
    });
  }

  // Validate user input
  validateMove(row, col, value) {
    // Don't allow changes to initial numbers
    if (this.initialGrid[row][col] !== 0) {
      return false;
    }

    const tempGrid = this.grid.map(row => [...row]);
    tempGrid[row][col] = value;
    
    return this.isValidGrid(tempGrid, row, col, value);
  }

  // Check if puzzle is complete
  isComplete() {
    for (let row = 0; row < 9; row++) {
      for (let col = 0; col < 9; col++) {
        if (this.grid[row][col] === 0) {
          return false;
        }
      }
    }
    return this.isValidSolution();
  }

  // Get hint for current state
  getHint() {
    const emptyCells = [];
    for (let row = 0; row < 9; row++) {
      for (let col = 0; col < 9; col++) {
        if (this.grid[row][col] === 0) {
          emptyCells.push({row, col, value: this.solution[row][col]});
        }
      }
    }
    
    if (emptyCells.length > 0) {
      return emptyCells[Math.floor(Math.random() * emptyCells.length)];
    }
    return null;
  }
}

import React, { useState, useEffect } from 'react';
import { View, Text, TouchableOpacity, StyleSheet } from 'react-native';

const SudokuGrid = ({ onCellPress, grid, selectedCell, initialGrid }) => {
  return (
    <View style={styles.gridContainer}>
      {grid.map((row, rowIndex) =>
        row.map((cell, colIndex) => (
          <TouchableOpacity
            key={`${rowIndex}-${colIndex}`}
            style={[
              styles.cell,
              initialGrid[rowIndex][colIndex] !== 0 && styles.initialCell,
              selectedCell?.row === rowIndex && 
              selectedCell?.col === colIndex && styles.selectedCell
            ]}
            onPress={() => onCellPress(rowIndex, colIndex)}
          >
            <Text style={[
              styles.cellText,
              initialGrid[rowIndex][colIndex] !== 0 && styles.initialCellText
            ]}>
              {cell !== 0 ? cell : ''}
            </Text>
          </TouchableOpacity>
        ))
      )}
    </View>
  );
};

const NumberPad = ({ onNumberPress, selectedNumber }) => {
  return (
    <View style={styles.numberPad}>
      {[1,2,3,4,5,6,7,8,9].map(number => (
        <TouchableOpacity
          key={number}
          style={[
            styles.numberButton,
            selectedNumber === number && styles.selectedNumber
          ]}
          onPress={() => onNumberPress(number)}
        >
          <Text style={styles.numberText}>{number}</Text>
        </TouchableOpacity>
      ))}
    </View>
  );
};

const SudokuGame = () => {
  const [engine] = useState(new MobileSudokuEngine());
  const [grid, setGrid] = useState(Array(9).fill().map(() => Array(9).fill(0)));
  const [selectedCell, setSelectedCell] = useState(null);
  const [selectedNumber, setSelectedNumber] = useState(null);
  
  useEffect(() => {
    generateNewPuzzle();
  }, []);

  const generateNewPuzzle = async () => {
    await engine.generatePuzzle('medium');
    setGrid([...engine.grid]);
  };

  const handleCellPress = (row, col) => {
    setSelectedCell({ row, col });
  };

  const handleNumberPress = (number) => {
    if (selectedCell && engine.validateMove(selectedCell.row, selectedCell.col, number)) {
      engine.grid[selectedCell.row][selectedCell.col] = number;
      setGrid([...engine.grid]);
      
      if (engine.isComplete()) {
        // Handle puzzle completion
        alert('Congratulations! Puzzle completed!');
      }
    }
  };

  return (
    <View style={styles.container}>
      <SudokuGrid 
        grid={grid}
        selectedCell={selectedCell}
        initialGrid={engine.initialGrid}
        onCellPress={handleCellPress}
      />
      <NumberPad 
        selectedNumber={selectedNumber}
        onNumberPress={handleNumberPress}
      />
    </View>
  );
};

// Redux store for state management
import { createSlice } from '@reduxjs/toolkit';

const gameSlice = createSlice({
  name: 'game',
  initialState: {
    currentPuzzle: null,
    difficulty: 'medium',
    timer: 0,
    hints: 3,
    score: 0,
    statistics: {
      puzzlesCompleted: 0,
      totalTime: 0,
      hintsUsed: 0
    }
  },
  reducers: {
    setPuzzle: (state, action) => {
      state.currentPuzzle = action.payload;
    },
    updateTimer: (state, action) => {
      state.timer = action.payload;
    },
    useHint: (state) => {
      if (state.hints > 0) {
        state.hints -= 1;
        state.statistics.hintsUsed += 1;
      }
    },
    completePuzzle: (state, action) => {
      state.statistics.puzzlesCompleted += 1;
      state.statistics.totalTime += state.timer;
      state.score += action.payload.score;
    }
  }
});

// Async storage for persistence
import AsyncStorage from '@react-native-async-storage/async-storage';

class GamePersistence {
  static async saveGame(gameState) {
    try {
      await AsyncStorage.setItem('currentGame', JSON.stringify(gameState));
    } catch (error) {
      console.error('Failed to save game:', error);
    }
  }

  static async loadGame() {
    try {
      const gameData = await AsyncStorage.getItem('currentGame');
      return gameData ? JSON.parse(gameData) : null;
    } catch (error) {
      console.error('Failed to load game:', error);
      return null;
    }
  }

  static async saveStatistics(stats) {
    try {
      await AsyncStorage.setItem('statistics', JSON.stringify(stats));
    } catch (error) {
      console.error('Failed to save statistics:', error);
    }
  }
}

import { Animated, Easing } from 'react-native';

class GameAnimations {
  static cellSelection(animatedValue) {
    return Animated.sequence([
      Animated.timing(animatedValue, {
        toValue: 1.1,
        duration: 100,
        easing: Easing.out(Easing.quad),
        useNativeDriver: true,
      }),
      Animated.timing(animatedValue, {
        toValue: 1,
        duration: 100,
        easing: Easing.out(Easing.quad),
        useNativeDriver: true,
      })
    ]);
  }

  static puzzleComplete(animatedValue) {
    return Animated.sequence([
      Animated.timing(animatedValue, {
        toValue: 1.2,
        duration: 200,
        useNativeDriver: true,
      }),
      Animated.spring(animatedValue, {
        toValue: 1,
        friction: 3,
        useNativeDriver: true,
      })
    ]);
  }

  static invalidMove(animatedValue) {
    return Animated.sequence([
      Animated.timing(animatedValue, { toValue: 10, duration: 50, useNativeDriver: true }),
      Animated.timing(animatedValue, { toValue: -10, duration: 50, useNativeDriver: true }),
      Animated.timing(animatedValue, { toValue: 10, duration: 50, useNativeDriver: true }),
      Animated.timing(animatedValue, { toValue: 0, duration: 50, useNativeDriver: true })
    ]);
  }
}

import analytics from '@react-native-firebase/analytics';

class GameAnalytics {
  static trackPuzzleStart(difficulty) {
    analytics().logEvent('puzzle_started', {
      difficulty: difficulty,
      timestamp: Date.now()
    });
  }

  static trackPuzzleComplete(difficulty, time, hintsUsed) {
    analytics().logEvent('puzzle_completed', {
      difficulty: difficulty,
      completion_time: time,
      hints_used: hintsUsed,
      timestamp: Date.now()
    });
  }

  static trackHintUsed(hintType) {
    analytics().logEvent('hint_used', {
      hint_type: hintType,
      timestamp: Date.now()
    });
  }

  static trackUserRetention(daysSinceInstall) {
    analytics().logEvent('user_retention', {
      days_since_install: daysSinceInstall
    });
  }
}