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   "source": [
    "# <center> Practical Session 2 : Partizan games - The minimax Algorithm"
   ]
  },
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   "id": "43cc2b0c-5ccb-4f7b-97b2-070d48527b0f",
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   "source": [
    "The objective of this second practical session is to implement the minimax algorithm for a quite simple (but still complicated enough to not be able to go through the whole game tree) game : Connect 4. "
   ]
  },
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    "You will find below Python functions that implement the logic of the Connect 4 games, including the following functions:\n",
    "- `__init__()`: Initializes an empty 6 × 7 board.\n",
    "- `set_piece(player, column)`: Places a player's piece in the chosen column.\n",
    "- `print_board()`: Displays the current board.\n",
    "- `is_legal_move(column)`: Checks whether a move in the column is possible.\n",
    "   `_check_line(self, player, row, col, delta_row, delta_col)`: Checks if player has four consecutive pieces from (`row`, `col`), going in the direction (`delta_row`, `delta_col`).\n",
    "- `check_winner(player)`: Checks whether the player has connected four pieces."
   ]
  },
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   "execution_count": 1,
   "id": "58c73abc-9141-49e0-8788-090e8f9813ab",
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   "source": [
    "class Logic:\n",
    "    def __init__ (self):\n",
    "        self._board = [ [ 0 for i in range(0, 7) ] for i in range(0, 6) ]\n",
    "\n",
    "    def set_piece (self, player, column):\n",
    "        for i in range(6):\n",
    "            if self._board[i][column] == 0:\n",
    "                self._board[i][column] = player\n",
    "                return\n",
    "\n",
    "    def print_board(self):\n",
    "        for row in reversed(self._board):\n",
    "            print(row)\n",
    "        \n",
    "    def is_legal_move (self, column):\n",
    "        for i in range(6):\n",
    "            if self._board[i][column] == 0:\n",
    "                return True\n",
    "        return False\n",
    "        \n",
    "    def _check_line(self, player, row, col, delta_row, delta_col):\n",
    "        count = 0\n",
    "        for i in range(4):\n",
    "            r = row + i * delta_row\n",
    "            c = col + i * delta_col\n",
    "            if 0 <= r < 6 and 0 <= c < 7 and self._board[r][c] == player:\n",
    "                count += 1\n",
    "            else:\n",
    "                break\n",
    "        return count == 4\n",
    "            \n",
    "    def check_winner(self, player):\n",
    "        for row in range(6):\n",
    "            for col in range(7):\n",
    "                if self._check_line(player, row, col, 1, 0) or \\\n",
    "                   self._check_line(player, row, col, 0, 1) or \\\n",
    "                   self._check_line(player, row, col, 1, 1) or \\\n",
    "                   self._check_line(player, row, col, 1, -1):\n",
    "                    return True\n",
    "        return False"
   ]
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   "source": [
    "## Exercicse - Let's add the player.\n",
    "\n",
    "Below you will find some classes implementing Human and Random players. You will have to add the Minimax player. To do so, you need to:\n",
    "- choose a good evaluation function of a grid. You can use the static grid of scores given by\n",
    "$$\n",
    "\\begin{pmatrix}\n",
    "3 & 4 & 5 & 7 & 5 & 4 & 3 \\\\\n",
    "4 &6 & 8 & 10 &8 &6 &4 \\\\\n",
    "5 & 8 & 11 & 13 &11 &8 &5 \\\\\n",
    "5 & 8 & 11 &13 &11 &8 &5 \\\\\n",
    "4 &6 &8 &10 &8 &6 &4\\\\\n",
    "3 &4 &5 &7 &5 &4 &3\n",
    "\\end{pmatrix} $$\n",
    "- implement the minimax function that recursively evaluates the position of a game using the minimax principle.\n",
    "- write down the function that finds the move giving this score."
   ]
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   "execution_count": 2,
   "id": "fc3ac1e0-0c35-4205-b9e9-d3eaa9915eb1",
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "pygame 2.1.2 (SDL 2.0.20, Python 3.10.12)\n",
      "Hello from the pygame community. https://www.pygame.org/contribute.html\n"
     ]
    }
   ],
   "source": [
    "import random\n",
    "import copy\n",
    "import math\n",
    "import time\n",
    "import pygame\n",
    "from pygame.locals import MOUSEBUTTONDOWN, QUIT\n",
    "\n",
    "class Player:\n",
    "    def __init__(self, player_id):\n",
    "        self.player_id = player_id\n",
    "\n",
    "class Human(Player):\n",
    "    def play_move(self, logic):\n",
    "        while True:\n",
    "            for event in pygame.event.get():\n",
    "                if event.type == MOUSEBUTTONDOWN:\n",
    "                    x, y = event.pos\n",
    "                    column = x // 100\n",
    "                    if 0 <= column < 7 and logic.is_legal_move(column):\n",
    "                        return column\n",
    "                if event.type == QUIT:\n",
    "                    pygame.quit()\n",
    "                    return None\n",
    "\n",
    "            pygame.time.wait(10)\n",
    "\n",
    "\n",
    "class Random(Player):\n",
    "    def play_move(self, logic):\n",
    "        legal_moves = [c for c in range(7) if logic.is_legal_move(c)]\n",
    "        if not legal_moves:\n",
    "            return None\n",
    "        return random.choice(legal_moves)\n",
    "\n",
    "\n",
    "class Minimax(Player):\n",
    "    def __init__(self, player_id, depth=5): #YOU CAN CHANGE THE DEPTH OF THE ALGORITHM HERE\n",
    "        super().__init__(player_id)\n",
    "        self.depth = depth\n",
    "\n",
    "    def evaluate_board(self, logic):\n",
    "        scores = [\n",
    "            [3, 4, 5, 7, 5, 4, 3],\n",
    "            [4, 6, 8, 10, 8, 6, 4],\n",
    "            [5, 8, 11, 13, 11, 8, 5],\n",
    "            [5, 8, 11, 13, 11, 8, 5],\n",
    "            [4, 6, 8, 10, 8, 6, 4],\n",
    "            [3, 4, 5, 7, 5, 4, 3]\n",
    "        ]\n",
    "        next_player = 2 if self.player_id == 1 else 1\n",
    "        \"\"\" TODO : Implement the evaluation function that uses the grid above. \"\"\"\n",
    "           \n",
    "        return 0\n",
    "\n",
    "    def minimax(self, logic, depth, player):\n",
    "        valid_moves = [col for col in range(7) if logic.is_legal_move(col)]\n",
    "        is_terminal = (logic.check_winner(1) or logic.check_winner(2) or not valid_moves)\n",
    "\n",
    "        \"\"\" TODO : Implement the minimax algorithm to compute the evaluation of the current grid. \"\"\"\n",
    "\n",
    "        return 0\n",
    "\n",
    "    def play_move(self, logic):\n",
    "        legal_moves = [col for col in range(7) if logic.is_legal_move(col)]\n",
    "\n",
    "        if not legal_moves:\n",
    "            return None\n",
    "\n",
    "        \"\"\" TODO: Implement the function that determines the best move, that is the one that gives the highest score\n",
    "        from the previous minimax function. \"\"\"\n",
    "        return 0"
   ]
  },
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   "source": [
    "### Graphic Interface \n",
    "\n",
    "In order to play the game nicely, we introduce a graphic interface using the Pygame library."
   ]
  },
  {
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   "id": "6278e90a-5705-48a7-965b-048ada7a8465",
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   "source": [
    "import pygame\n",
    "from pygame.locals import QUIT, MOUSEBUTTONDOWN\n",
    "from time import sleep\n",
    "\n",
    "BLUE = (0, 51, 153)\n",
    "YELLOW = (255, 204, 0)\n",
    "WHITE = (255, 255, 255)\n",
    "RED = (255, 0, 0)\n",
    "BLACK = (0, 0, 0)\n",
    "\n",
    "WINDOW_SIZE = 700\n",
    "\n",
    "def draw_board(screen, board):\n",
    "    screen.fill(BLUE)\n",
    "    for row in range(6):\n",
    "        for col in range(7):\n",
    "            pygame.draw.rect(screen, BLUE, (col * 100, row * 100 + 100, 100, 100))\n",
    "            pygame.draw.circle(screen, BLACK, (col * 100 + 50, row * 100 + 150), 45)\n",
    "\n",
    "    for row in range(6):\n",
    "        for col in range(7):\n",
    "            if board[row][col] == 1:\n",
    "                pygame.draw.circle(screen, YELLOW, (col * 100 + 50, (5 - row) * 100 + 150), 45)\n",
    "            elif board[row][col] == 2:\n",
    "                pygame.draw.circle(screen, RED, (col * 100 + 50, (5 - row) * 100 + 150), 45)\n",
    "\n",
    "    pygame.display.update()\n",
    "\n",
    "\n",
    "def display_message(screen, message):\n",
    "    font = pygame.font.Font(None, 75)\n",
    "    text = font.render(message, True, WHITE)\n",
    "    screen.blit(text, (100, 10))\n",
    "    pygame.display.update()\n",
    "\n",
    "def draw_menu(screen, p1_type, p2_type):\n",
    "    font = pygame.font.Font(None, 40)\n",
    "    screen.fill(BLUE)\n",
    "\n",
    "    screen.blit(font.render(\"Player 1\", True, WHITE), (50, 50))\n",
    "    screen.blit(font.render(\"Player 2\", True, WHITE), (400, 50))\n",
    "\n",
    "    player_types = [\"Human\", \"Random\", \"Minimax\"]\n",
    "\n",
    "    def draw_options(x, selected):\n",
    "        for i, name in enumerate(player_types):\n",
    "            y = 150 + i * 100\n",
    "            pygame.draw.rect(screen, BLACK, (x, y, 30, 30))\n",
    "            if selected == name:\n",
    "                pygame.draw.rect(screen, WHITE, (x + 3, y + 3, 24, 24))\n",
    "            screen.blit(font.render(name, True, WHITE), (x + 50, y - 10))\n",
    "\n",
    "    draw_options(50, p1_type)\n",
    "    draw_options(400, p2_type)\n",
    "\n",
    "    pygame.draw.rect(screen, BLACK, (250, 650, 200, 50))\n",
    "    screen.blit(font.render(\"Start\", True, WHITE), (300, 660))\n",
    "    pygame.display.update()\n",
    "\n",
    "\n",
    "def choose_players(screen):\n",
    "    p1_type = \"Human\"\n",
    "    p2_type = \"Human\"\n",
    "    selecting = True\n",
    "\n",
    "    while selecting:\n",
    "        draw_menu(screen, p1_type, p2_type)\n",
    "\n",
    "        for event in pygame.event.get():\n",
    "            if event.type == QUIT:\n",
    "                pygame.quit()\n",
    "                return None, None\n",
    "            if event.type == MOUSEBUTTONDOWN:\n",
    "                x, y = event.pos\n",
    "                if 50 <= x <= 80:\n",
    "                    if 150 <= y <= 180:\n",
    "                        p1_type = \"Human\"\n",
    "                    elif 250 <= y <= 280:\n",
    "                        p1_type = \"Random\"\n",
    "                    elif 350 <= y <= 380:\n",
    "                        p1_type = \"Minimax\"\n",
    "                if 400 <= x <= 430:\n",
    "                    if 150 <= y <= 180:\n",
    "                        p2_type = \"Human\"\n",
    "                    elif 250 <= y <= 280:\n",
    "                        p2_type = \"Random\"\n",
    "                    elif 350 <= y <= 380:\n",
    "                        p2_type = \"Minimax\"\n",
    "                if 250 <= x <= 450 and 650 <= y <= 700:\n",
    "                    selecting = False\n",
    "\n",
    "    return p1_type, p2_type\n",
    "\n",
    "\n",
    "def pygame_main(logic):\n",
    "    pygame.init()\n",
    "    screen = pygame.display.set_mode((WINDOW_SIZE, WINDOW_SIZE))\n",
    "    pygame.display.set_caption(\"Connect 4\")\n",
    "\n",
    "    while True:\n",
    "        p1_type, p2_type = choose_players(screen)\n",
    "        if p1_type is None:\n",
    "            break\n",
    "\n",
    "        if p1_type == \"Human\":\n",
    "            player1 = Human(1)\n",
    "        elif p1_type == \"Random\":\n",
    "            player1 = Random(1)\n",
    "        else: \n",
    "            player1 = Minimax(1)\n",
    "\n",
    "        if p2_type == \"Human\":\n",
    "            player2 = Human(2)\n",
    "        elif p2_type == \"Random\":\n",
    "            player2 = Random(2)\n",
    "        else:  \n",
    "            player2 = Minimax(2)\n",
    "\n",
    "        logic.__init__()\n",
    "        draw_board(screen, logic._board)\n",
    "\n",
    "        turn = 1\n",
    "        game_over = False\n",
    "\n",
    "        while not game_over:\n",
    "            current_player = player1 if turn == 1 else player2\n",
    "\n",
    "            for event in pygame.event.get():\n",
    "                if event.type == QUIT:\n",
    "                    pygame.quit()\n",
    "                    return\n",
    "\n",
    "            col = current_player.play_move(logic)\n",
    "\n",
    "            if logic.is_legal_move(col):\n",
    "                logic.set_piece(turn, col)\n",
    "                draw_board(screen, logic._board)\n",
    "\n",
    "                if logic.check_winner(turn):\n",
    "                    display_message(screen, f\"Player {turn} wins!\")\n",
    "                    pygame.time.wait(3000)\n",
    "                    game_over = True\n",
    "                    continue\n",
    "\n",
    "                turn = 1 if turn == 2 else 2\n",
    "\n",
    "        pygame.time.wait(3000)\n",
    "\n",
    "    pygame.quit()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "263f502a-5242-4c00-9978-1ed4f410db0a",
   "metadata": {},
   "source": [
    "### Let's now try !"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "af2f6d1b-e1af-44c7-b7c4-d435450bf77d",
   "metadata": {},
   "outputs": [],
   "source": [
    "import threading\n",
    "\n",
    "logic = Logic()\n",
    "threading.Thread(target=pygame_main,args=(logic,),daemon=True).start()"
   ]
  }
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