/**
 **************************************************
 * @file        Inkplate6PLUS_TicTacToe.ino
 * @brief       Touchscreen Tic-Tac-Toe game with optional AI opponent and
 *              partial e-paper updates.
 *
 * @details     This example demonstrates building an interactive touchscreen UI
 *              on Inkplate 6PLUS by implementing a full Tic-Tac-Toe game.
 *              A menu screen lets you choose difficulty (Easy/Medium/Hard),
 *              decide who plays first (human/computer), and select whether the
 *              first player uses X or O. A 2-player mode is also available.
 *
 *              In single-player mode, the computer uses a minimax-based solver
 *              (ai.h) with configurable search depth per difficulty. The game
 *              view renders a 3x3 board and updates the display after touches
 *              using partialUpdate() for responsiveness.
 *
 *              The display runs in 1-bit (BW) mode (INKPLATE_1BIT). A full
 *              refresh is used when switching major screens (menu/game), while
 *              partial updates are used for most UI interactions.
 *
 * Requirements:
 * - Board:      Soldered Inkplate 6PLUS
 * - Hardware:   Inkplate 6PLUS, USB cable
 * - Extra:      none
 *
 * Configuration:
 * - Boards Manager -> Inkplate Boards -> Soldered Inkplate6PLUS
 * - Serial settings: 115200 baud (optional; touchscreen init messages)
 * - Touchscreen: must be initialized successfully for interaction
 *
 * Don't have Inkplate Boards in Arduino Boards Manager?
 * See https://docs.soldered.com/inkplate/6PLUS/quick-start-guide/
 *
 * How to use:
 * 1) Upload the sketch to Inkplate 6PLUS.
 * 2) On the menu screen, select:
 *    - Difficulty (or 2 player mode),
 *    - Who plays first (single-player only),
 *    - Whether the first player is X or O.
 * 3) Tap START to begin the game.
 * 4) Tap a board cell to place your mark. In single-player mode, the AI will
 *    respond automatically.
 * 5) Use "Go Back" to return to the menu and start a new game.
 *
 * Expected output:
 * - Display: Menu UI with selectable options, then a Tic-Tac-Toe board with
 *   current turn and game status (win/lose/tie).
 * - Touch interaction: Tap-driven moves and menu selections with fast partial
 *   redraws.
 *
 * Notes:
 * - Display mode is 1-bit (BW). Partial updates are used heavily for UI
 *   responsiveness.
 * - E-paper partial updates can accumulate ghosting; performing a full refresh
 *   occasionally (e.g., when switching screens) helps maintain contrast.
 * - This example is fully interactive and does not use WiFi or deep sleep.
 *
 * Docs:         https://docs.soldered.com/inkplate
 * Support:      https://forum.soldered.com/
 *
 * @author      Soldered
 * @date        2024-03-15
 * @license     GNU GPL V3
 **************************************************/

// Next 3 lines are a precaution, you can ignore those, and the example would also work without them
#if !defined(ARDUINO_INKPLATE6PLUS) && !defined(ARDUINO_INKPLATE6PLUSV2)
#error "Wrong board selection for this example, please select e-radionica Inkplate 6Plus or Soldered Inkplate 6Plus in the boards menu."
#endif

#include "Inkplate.h"
#include "ai.h"

#include "generatedUIMenu.h"

Inkplate display(INKPLATE_1BIT);

// How far to search for best move
int difficultyDepth[] = {6, 7, 10};

// Global game states
int difficulty = -1;
int firstHuman = -1;
int firstXO = -1;

bool menu = 1;
bool game = 0;
int move = 0;

// Global board array
char board[3][3] = {
    {'_', '_', '_'},
    {'_', '_', '_'},
    {'_', '_', '_'},
};

void setup()
{
    Serial.begin(115200);
    // Uncomment this line if you have a USB Power Only Inkplate6PLUS
    // Must be called before display.begin()!
    //display.setInkplatePowerMode(INKPLATE_USB_PWR_ONLY);
    display.begin(); // Initialize Inkplate object

    // Initialize touchscreen
    if (!display.touchscreen.init(true))
        Serial.println("Touchscreen init failed!");

    // Call main draw function defined below
    mainDrawMenu();
    display.display();
}

void loop()
{
    // Main game loop
    if (menu)
        menuEvents();
    else if (game)
        gameEvents();
    delay(15);
}

// All touchscreen events happening while in menu
void menuEvents()
{
    if (display.touchscreen.touchInArea(39, 225, 300, 55)) // Easy difficulty
    {
        difficulty = 0;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.partialUpdate();
    }

    if (display.touchscreen.touchInArea(39, 320, 300, 55)) // Medium difficulty
    {
        difficulty = 1;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.partialUpdate();
    }

    if (display.touchscreen.touchInArea(39, 420, 300, 55)) // Hard difficulty
    {
        difficulty = 2;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.partialUpdate();
    }

    if (display.touchscreen.touchInArea(39, 516, 300, 55)) // 2 player game
    {
        difficulty = 3;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.partialUpdate();
    }

    if (display.touchscreen.touchInArea(553, 246, 300, 55) && difficulty != 3) // Human plays first
    {
        firstHuman = 0;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.partialUpdate();
    }

    if (display.touchscreen.touchInArea(553, 326, 300, 55) && difficulty != 3) // Computer plays first
    {
        firstHuman = 1;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.partialUpdate();
    }

    if (display.touchscreen.touchInArea(553, 447, 300, 55)) // First player is X
    {
        firstXO = 0;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.partialUpdate();
    }

    if (display.touchscreen.touchInArea(553, 512, 300, 55)) // First player is O
    {
        firstXO = 1;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.partialUpdate();
    }

    if (display.touchscreen.touchInArea(585, 627, 301, 79)) // Start gane
    {
        // Check if all settings are legal, and if so, start the game
        if (difficulty == 3 && (firstXO == 0 || firstXO == 1))
        {
            menu = 0;
            game = 1;
            display.clearDisplay();
            mainDrawGame();
            display.display();
        }
        else if (difficulty != -1 && firstXO != -1 && firstHuman != -1)
        {
            menu = 0;
            game = 1;
            display.clearDisplay();
            mainDrawGame();
            display.display();

            // Make first move, if computer is to make a first move
            if (difficulty != 3 && firstHuman == 1)
            {
                struct best bm =
                    minimax((move + firstXO + 1) % 2 ? 'x' : 'o', (move + firstXO + 1) % 2 ? 'x' : 'o', board, 10);
                board[bm.move / 3][bm.move % 3] = (move + firstXO + 1) % 2 ? 'x' : 'o';
                ++move;

                display.clearDisplay();
                mainDrawGame();
                display.partialUpdate();
            }
        }
        else // All settings are not legal
        {
            text13_content = "Please select all options!";
            display.clearDisplay();
            mainDrawMenu();
            drawChoices();
            display.partialUpdate();
            text13_content = "";
        }
    }
}

// Draw choice radio buttons
void drawChoices()
{
    // Switch case to select correct options
    switch (difficulty)
    {
    case 0:
        display.fillCircle(circle2_center_x, circle2_center_y, 7, BLACK);
        break;
    case 1:
        display.fillCircle(circle3_center_x, circle3_center_y, 7, BLACK);
        break;
    case 2:
        display.fillCircle(circle4_center_x, circle4_center_y, 7, BLACK);
        break;
    case 3:
        display.fillCircle(circle5_center_x, circle5_center_y, 7, BLACK);
        break;
    case 4:
        display.fillCircle(circle6_center_x, circle6_center_y, 7, BLACK);
        break;
    }
    // Switch case to select correct options
    switch (firstHuman)
    {
    case 0:
        display.fillCircle(circle7_center_x, circle7_center_y, 7, BLACK);
        break;
    case 1:
        display.fillCircle(circle6_center_x, circle6_center_y, 7, BLACK);
        break;
    }
    switch (firstXO)
    {
    case 0:
        display.fillCircle(circle8_center_x, circle8_center_y, 7, BLACK);
        break;
    case 1:
        display.fillCircle(circle9_center_x, circle9_center_y, 7, BLACK);
        break;
    }
    // If 2 player mode selected, draw computer first options out
    if (difficulty == 3)
        crossOutHumanFirst();
}

// Simulate faded text by drawing white checkerboard pattern over
void crossOutHumanFirst()
{
    for (int i = rect6_a_y; i < rect6_b_y; ++i)
        for (int j = rect6_a_x + (i % 2); j < rect6_b_x; j += 2)
            display.drawPixel(j, i, WHITE);
}

// All touchscreen events during normal game
void gameEvents()
{
    if (display.touchscreen.touchInArea(15, 600, 215, 140)) // Go back
    {
        memset(board, '_', sizeof board);
        menu = 1;
        game = 0;
        move = 0;
        display.clearDisplay();
        mainDrawMenu();
        drawChoices();
        display.display();
    }
    // Check if any board field pressed
    for (int i = 0; i < 3; ++i)
        for (int j = 0; j < 3; ++j)
            if (display.touchscreen.touchInArea(268 + 243 * j, 20 + 243 * i, 243, 243))
            {
                // If field already pressed, skip
                if (board[i][j] != '_' || result(board) != 0)
                    continue;
                board[i][j] = (move + firstXO + 1) % 2 ? 'x' : 'o';

                ++move;
                display.clearDisplay();
                mainDrawGame();
                display.partialUpdate();

                // If game is against a compuer, make a move
                if (result(board) == 0 && difficulty != 3)
                {
                    delay(1000);
                    struct best bm = minimax((move + firstXO + 1) % 2 ? 'x' : 'o', (move + firstXO + 1) % 2 ? 'x' : 'o',
                                             board, difficultyDepth[difficulty]);
                    board[bm.move / 3][bm.move % 3] = (move + firstXO + 1) % 2 ? 'x' : 'o';

                    // Draw board again
                    ++move;
                    display.clearDisplay();
                    mainDrawGame();
                    display.partialUpdate();
                }
            }
}

// Draw game elements to screen
void mainDrawGame()
{
    // Draw board lines
    display.drawThickLine(511, 20, 511, 748, BLACK, 10);
    display.drawThickLine(754, 20, 754, 748, BLACK, 10);

    display.drawThickLine(268, 263, 996, 263, BLACK, 10);
    display.drawThickLine(268, 506, 996, 506, BLACK, 10);

    // Draw who's turn it is
    display.setFont(&FreeSerifBold24pt7b);
    display.setCursor(22, 100);
    display.print((move + firstXO + 1) % 2 ? "X's turn:" : "O's turn:");

    // Draw game state
    display.setCursor(22, 392);
    switch (result(board))
    {
    case 0:
        display.print("Game on!");
        break;
    case 1:
        display.print("X won!");
        break;
    case 2:
        display.print("O won!");
        break;
    case 3:
        display.print("Game is a tie");
        break;
    }

    // Draw back button to screen
    display.setCursor(30, 685);
    display.print("Go Back");
    display.drawRoundRect(15, 600, 215, 140, 10, BLACK);

    drawBoard();
}

// Draw X's and O's to screen
void drawBoard()
{
    for (int i = 0; i < 3; ++i)
        for (int j = 0; j < 3; ++j)
        {
            int x = 268 + 243 * j, y = 20 + 243 * i;
            if (board[i][j] == 'x')
            {
                display.drawThickLine(x + 15, y + 15, x + 223, y + 223, BLACK, 7);
                display.drawThickLine(x + 223, y + 15, x + 15, y + 223, BLACK, 7);
            }
            if (board[i][j] == 'o')
            {
                for (int k = 0; k < 7; ++k)
                    display.drawCircle(x + 121, y + 121, 100 - k, BLACK);
            }
        }
}
