Tic Tac Toe

#!/bin/bash
# Colorful 2-player Tic Tac Toe with replay, player choice, and winner starts next round

# Define colors
RED='\033[0;31m'
BLUE='\033[0;34m'
RESET='\033[0m'

# Global variables for player symbols
player1=""
player2=""
starter=""

play_game() {
  # Initialize board
  board=(1 2 3 4 5 6 7 8 9)
  player="$starter"  # The player who starts this round
  winner=""

  print_board() {
    echo ""
    for i in {0..8}; do
      symbol="${board[$i]}"
      # Colorize X and O
      if [[ "$symbol" == "X" ]]; then
        symbol="${RED}X${RESET}"
      elif [[ "$symbol" == "O" ]]; then
        symbol="${BLUE}O${RESET}"
      fi

      # Print rows
      printf " %b " "$symbol"
      if (( (i + 1) % 3 == 0 )); then
        echo ""
        if (( i < 6 )); then
          echo "-----------"
        fi
      else
        printf "|"
      fi
    done
    echo ""
  }

  check_winner() {
    local wins=(
      "0 1 2" "3 4 5" "6 7 8"
      "0 3 6" "1 4 7" "2 5 8"
      "0 4 8" "2 4 6"
    )

    for combo in "${wins[@]}"; do
      set -- $combo
      if [[ "${board[$1]}" == "$player" && "${board[$2]}" == "$player" && "${board[$3]}" == "$player" ]]; then
        return 0
      fi
    done
    return 1
  }

  is_full() {
    for i in "${board[@]}"; do
      if [[ "$i" =~ ^[1-9]$ ]]; then
        return 1
      fi
    done
    return 0
  }

  # --- Game loop ---
  while true; do
    clear
    print_board
    echo "Player $player, choose a position (1-9):"
    read -r move

    # Validate input
    if ! [[ "$move" =~ ^[1-9]$ ]]; then
      echo "Invalid input! Choose 1–9."
      sleep 1
      continue
    fi

    idx=$((move - 1))
    if [[ "${board[$idx]}" == "X" || "${board[$idx]}" == "O" ]]; then
      echo "Cell already taken!"
      sleep 1
      continue
    fi

    # Make the move
    board[$idx]=$player

    # Check for a win
    if check_winner; then
      clear
      print_board
      if [[ "$player" == "X" ]]; then
        echo -e "🎉 Player ${RED}$player${RESET} wins!"
      else
        echo -e "🎉 Player ${BLUE}$player${RESET} wins!"
      fi
      winner="$player"
      break
    fi

    # Check for a draw
    if is_full; then
      clear
      print_board
      echo "🤝 It's a draw!"
      winner="draw"
      break
    fi

    # Switch player
    if [[ "$player" == "X" ]]; then
      player="O"
    else
      player="X"
    fi
  done
}

# ---- Game Start ----
while true; do
  clear
  echo "🎾 Welcome to Tic Tac Toe!"
  echo ""
  echo "Player 1, choose your symbol (X or O):"
  read -r choice
  choice=$(echo "$choice" | tr '[:lower:]' '[:upper:]')

  if [[ "$choice" == "X" ]]; then
    player1="X"
    player2="O"
    starter="$player1"
    break
  elif [[ "$choice" == "O" || "$choice" == "0" ]]; then
    player1="O"
    player2="X"
    starter="$player1"
    break
  else
    echo "Invalid choice! Please type X or O."
    sleep 1
  fi
done

# ---- Main Replay Loop ----
while true; do
  play_game

  echo ""
  echo "Play again? (y/n)"
  read -r again

  if [[ "$again" =~ ^[Yy]$ ]]; then
    # Determine who starts next
    if [[ "$winner" == "X" || "$winner" == "O" ]]; then
      starter="$winner"
    else
      # Alternate starter if draw
      [[ "$starter" == "X" ]] && starter="O" || starter="X"
    fi
  else
    echo "👋 Thanks for playing!"
    break
  fi
done