// Connect 4

#include <stdio.h>
#define NUM_ROWS 6
#define NUM_COLS 7

enum cell_state { EMPTY, RED, YELLOW };

void print_gameboard(enum cell_state gameboard[NUM_ROWS][NUM_COLS]) {
  // clears the terminal
  printf("\e[1;1H\e[2J");

  int i = 0;
  while (i < NUM_ROWS) {
    int j = 0;
    while (j < NUM_COLS) {
      printf("%d  ", gameboard[i][j]);
      j++;
    }
    printf("\n");
    i++;
  }
}

int read_player_input() {
  int input;
  printf("\nWhich column do you want to place your piece?\n");
  printf("Enter the column (1-7): ");
  scanf("%d", &input);
  input--;

  while (input < 0 || input >= NUM_COLS) {
    printf("Invalid column. Enter the column (1-7): ");
    scanf("%d", &input);
    input--;
  }

  return input;
}

int check_horizontal(enum cell_state gameboard[NUM_ROWS][NUM_COLS]) {
  for (int row = 0; row < NUM_ROWS; row++) {
    for (int col = 0; col < NUM_COLS - 3; col++) {
      if (gameboard[row][col] == RED && 
          gameboard[row][col + 1] == RED &&
          gameboard[row][col + 2] == RED && 
          gameboard[row][col + 3] == RED) {
        return 1;
      }
    }
  }
  return 0;
}

int check_diagonal_from_bottom_left(
    enum cell_state gameboard[NUM_ROWS][NUM_COLS]) {
  for (int row = 3; row < NUM_ROWS; row++) {
    for (int col = 0; col < NUM_COLS - 3; col++) {
      if (gameboard[row][col] == RED && 
          gameboard[row - 1][col + 1] == RED &&
          gameboard[row - 2][col + 2] == RED &&
          gameboard[row - 3][col + 3] == RED) {
        return 1;
      }
    }
  }
  return 0;
}

int check_diagonal_from_top_left(
    enum cell_state gameboard[NUM_ROWS][NUM_COLS]) {
  for (int row = 0; row < NUM_ROWS - 3; row++) {
    for (int col = 0; col < NUM_COLS - 3; col++) {
      if (gameboard[row][col] == RED && 
          gameboard[row + 1][col + 1] == RED &&
          gameboard[row + 2][col + 2] == RED &&
          gameboard[row + 3][col + 3] == RED) {
        return 1;
      }
    }
  }
  return 0;
}

int check_vertical(enum cell_state gameboard[NUM_ROWS][NUM_COLS]) {
  for (int col = 0; col < NUM_COLS; col++) {
    for (int row = 0; row < NUM_ROWS - 3; row++) {
      if (gameboard[row][col] == RED     && 
          gameboard[row + 1][col] == RED &&
          gameboard[row + 2][col] == RED && 
          gameboard[row + 3][col] == RED) {
        return 1;
      }
    }
  }
  return 0;
}

int check_for_win(enum cell_state gameboard[NUM_ROWS][NUM_COLS]) {
  return  check_horizontal(gameboard)             || 
          check_vertical(gameboard)               ||
          check_diagonal_from_top_left(gameboard) ||
          check_diagonal_from_bottom_left(gameboard);
}

int main(void) {
  enum cell_state gameboard[NUM_ROWS][NUM_COLS] = {};

  int p_1_pos;

  while (1) {
    p_1_pos = read_player_input();

    // check if piece can go into column
    int row_to_check = NUM_ROWS - 1;

    while (row_to_check >= 0 && gameboard[row_to_check][p_1_pos] != EMPTY) {
      row_to_check--;
    }
    if (row_to_check < 0) {
      // here, we have no position to
      printf("That's an invalid placement\n");
    } else {
      // placing the piece
      gameboard[row_to_check][p_1_pos] = RED;
    }

    print_gameboard(gameboard);

    // checking for a win...
    if (check_for_win(gameboard)) {
      printf("Win detected!\n");
    } else {
      printf("Still no win\n");
    }
  }

  return 0;
}