/*
    Description: Use UART communication to control the LED matrix on microbit.
*/
#include <M5Stack.h>
#include <M5StackUpdater.h>

#define WIDTH       320
#define HEIGHT      240
#define BLOCK_SIZE  40
#define UNIT_WIDTH  5
#define UNIT_HEIGHT 5
#define UNIT_SIZE   25
#define GETX(i)     ((i) % (5))
#define GETY(i)     ((i) / (5))
int world[UNIT_SIZE];
int i;

void setup() {
    M5.begin();
    M5.Power.begin();
    Wire.begin();
    if (digitalRead(BUTTON_A_PIN) == 0) {
        Serial.println("Will load menu binary");
        updateFromFS(SD);
        ESP.restart();
    }
    Serial2.begin(115200, SERIAL_8N1, 16, 17);
    M5.Lcd.fillScreen(BLACK);
    M5.Lcd.setTextSize(2);
    M5.Lcd.setCursor(35, 220);
    M5.Lcd.println("  <       *       >");
    for (i = 0; i < UNIT_SIZE; i++) {
        world[i] = 0;
    }
    i = UNIT_SIZE / 2;
}

void loop() {
    M5.update();
    int x = GETX(i) + 1;
    int y = GETY(i);
    if (world[i] > 0)
        M5.Lcd.fillRect(x * BLOCK_SIZE + 1, y * BLOCK_SIZE + 1, BLOCK_SIZE - 2,
                        BLOCK_SIZE - 2, LIGHTGREY);
    else
        M5.Lcd.fillRect(x * BLOCK_SIZE + 1, y * BLOCK_SIZE + 1, BLOCK_SIZE - 2,
                        BLOCK_SIZE - 2, BLUE);
    if (M5.BtnC.wasPressed()) {
        if (world[i] > 0)
            M5.Lcd.fillRect(x * BLOCK_SIZE + 1, y * BLOCK_SIZE + 1,
                            BLOCK_SIZE - 2, BLOCK_SIZE - 2, WHITE);
        else
            M5.Lcd.fillRect(x * BLOCK_SIZE, y * BLOCK_SIZE, BLOCK_SIZE,
                            BLOCK_SIZE, BLACK);
        ++i;
        if (i >= UNIT_SIZE) i = 0;
    }
    if (M5.BtnA.wasPressed()) {
        if (world[i] > 0)
            M5.Lcd.fillRect(x * BLOCK_SIZE + 1, y * BLOCK_SIZE + 1,
                            BLOCK_SIZE - 2, BLOCK_SIZE - 2, WHITE);
        else
            M5.Lcd.fillRect(x * BLOCK_SIZE, y * BLOCK_SIZE, BLOCK_SIZE,
                            BLOCK_SIZE, BLACK);
        --i;
        if (i < 0) i = UNIT_SIZE - 1;
    }
    if (M5.BtnB.wasPressed()) {
        if (world[i] > 0)
            world[i] = 0;
        else
            world[i] = 1;
        Serial2.print(world[i]);
        Serial2.print(GETX(i));
        Serial2.println(GETY(i));
    }
}