const INVALID_SUDOKU_GRID = [
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 5, 6, 7, 8, 9]
];

const VALID_SUDOKU_GRID = [
  [5, 4, 6, 8, 9, 3, 2, 1, 7],
  [3, 9, 2, 1, 7, 4, 6, 8, 5],
  [8, 1, 7, 5, 2, 6, 9, 3, 4],
  [7, 6, 9, 3, 4, 1, 8, 5, 2],
  [2, 3, 4, 7, 8, 5, 1, 9, 6],
  [1, 8, 5, 2, 6, 9, 7, 4, 3],
  [4, 5, 8, 6, 1, 2, 3, 7, 9],
  [9, 2, 1, 4, 3, 7, 5, 6, 8],
  [6, 7, 3, 9, 5, 8, 4, 2, 1]
];

// main driver function
const main = sudokuGrid => {
  // rows_grid --> rows as rows
  // columns_grid --> columns as rows
  // blocks_grid --> 3 x 3 blocks as rows

  let rows_grid = [...sudokuGrid];

  let columns_grid = [];
  for (let i = 0; i < 9; i++) {
    columns_grid[i] = [];
    for (let j = 0; j < 9; j++) {
      columns_grid[i][j] = sudokuGrid[j][i];
    }
  }

  let blocks_grid = [];
  for (let i = 0; i < 3; i++) {
    for (let j = 0; j < 3; j++) {
      blocks_grid[3 * i + j] = [];
      for (let k = 0; k < 3; k++) {
        for (let l = 0; l < 3; l++) {
          // console.log(3 * i + k, 3 * j + l);
          // console.log(3 * i + j, 3 * k + l);
          blocks_grid[3 * i + j][3 * k + l] = sudokuGrid[3 * i + k][3 * j + l];
        }
      }
    }
  }

  rows_grid = sortSudokuGridRows(rows_grid);
  rows_grid_flag = checkSudokuGridRows(rows_grid);
  if (rows_grid_flag) {
    columns_grid = sortSudokuGridRows(columns_grid);
    columns_grid_flag = checkSudokuGridRows(columns_grid);
    if (columns_grid_flag) {
      blocks_grid = sortSudokuGridRows(blocks_grid);
      blocks_grid_flag = checkSudokuGridRows(blocks_grid);
      if (blocks_grid_flag) {
        return true;
      } else {
        return false;
      }
    } else {
      return false;
    }
  } else {
    return false;
  }

  // console.log(rows_grid);
  // console.log(columns_grid);
  // console.log(blocks_grid);
};

// sorts every row
const sortSudokuGridRows = sudokuGrid => {
  for (let i = 0; i < 9; i++) {
    sudokuGrid[i] = sudokuGrid[i].sort();
  }
  return sudokuGrid;
};

// checks if every row has numbers from 1 to 9
const checkSudokuGridRows = sudokuGrid => {
  for (let i = 0; i < 9; i++) {
    for (let j = 0; j < 9; j++) {
      if (sudokuGrid[i][j] !== j + 1) {
        return false;
      }
    }
  }
  return true;
};

/*

** Rows Grid
[ [ 5, 4, 6, 8, 9, 3, 2, 1, 7 ],
  [ 3, 9, 2, 1, 7, 4, 6, 8, 5 ],
  [ 8, 1, 7, 5, 2, 6, 9, 3, 4 ],
  [ 7, 6, 9, 3, 4, 1, 8, 5, 2 ],
  [ 2, 3, 4, 7, 8, 5, 1, 9, 6 ],
  [ 1, 8, 5, 2, 6, 9, 7, 4, 3 ],
  [ 4, 5, 8, 6, 1, 2, 3, 7, 9 ],
  [ 9, 2, 1, 4, 3, 7, 5, 6, 8 ],
  [ 6, 7, 3, 9, 5, 8, 4, 2, 1 ] ]

** Columns Grid
[ [ 5, 3, 8, 7, 2, 1, 4, 9, 6 ],
  [ 4, 9, 1, 6, 3, 8, 5, 2, 7 ],
  [ 6, 2, 7, 9, 4, 5, 8, 1, 3 ],
  [ 8, 1, 5, 3, 7, 2, 6, 4, 9 ],
  [ 9, 7, 2, 4, 8, 6, 1, 3, 5 ],
  [ 3, 4, 6, 1, 5, 9, 2, 7, 8 ],
  [ 2, 6, 9, 8, 1, 7, 3, 5, 4 ],
  [ 1, 8, 3, 5, 9, 4, 7, 6, 2 ],
  [ 7, 5, 4, 2, 6, 3, 9, 8, 1 ] ]

** Blocks Grid
[ [ 5, 4, 6, 3, 9, 2, 8, 1, 7 ],
  [ 8, 9, 3, 1, 7, 4, 5, 2, 6 ],
  [ 2, 1, 7, 6, 8, 5, 9, 3, 4 ],
  [ 7, 6, 9, 2, 3, 4, 1, 8, 5 ],
  [ 3, 4, 1, 7, 8, 5, 2, 6, 9 ],
  [ 8, 5, 2, 1, 9, 6, 7, 4, 3 ],
  [ 4, 5, 8, 9, 2, 1, 6, 7, 3 ],
  [ 6, 1, 2, 4, 3, 7, 9, 5, 8 ],
  [ 3, 7, 9, 5, 6, 8, 4, 2, 1 ] ]

  */

// call the main function and print the output
main(VALID_SUDOKU_GRID) ? console.log("Valid") : console.log("Invalid");
// VALID
main(INVALID_SUDOKU_GRID) ? console.log("Valid") : console.log("Invalid");
// INVALID