// Varous system includes
#include <Arduino.h>

// Various library includes
#include <Adafruit_NeoPixel.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <BBQ10Keyboard.h>
#include <CircularBuffer.h>

// Debugging via serial monitor (don't turn this on unless you're hacking on the firmware code)
#define DEBUG true

// Battery level measurement
#define VBATPIN A6
float measuredVBat;
float batteryPercent;

// TFT Setup
#define TFT_CS 9
#define TFT_DC 10
Adafruit_ILI9341 tft(TFT_CS, TFT_DC);
#include <Fonts/FreeMono9pt7b.h>
#define CHARS_HORIZONTAL 28
#define CHARS_ROWS 13
CircularBuffer<char,364> textBuffer;

// Keyboard
BBQ10Keyboard keyboard;
#define KBD_BTN_1 0x06
#define KBD_BTN_2 0x11
#define KBD_BTN_3 0x07
#define KBD_BTN_4 0x12
#define KBD_SW_UP 0x01
#define KBD_SW_DN 0x02
#define KBD_SW_LF 0x03
#define KBD_SW_RT 0x04
#define KBD_SW_OK 0x05

// NeoPixels
#define PIXELS_NUM_BOARD 1
#define PIXELS_NUM_WING 1
#define PIXELS_WING_PIN 11
Adafruit_NeoPixel pixels_board(PIXELS_NUM_BOARD, PIN_NEOPIXEL, NEO_GRB + NEO_KHZ800);
Adafruit_NeoPixel pixels_wing(PIXELS_NUM_WING, PIXELS_WING_PIN, NEO_GRB + NEO_KHZ800);

// Various loop handlers
void handlerKeyboard();
void handlerBatteryLevel();

// UI screens
void screenClear();

// Color conversion (RGB888 -> RGB565 used by Adafruit GFX)
uint16_t RGB565(uint8_t r, uint8_t g, uint8_t b) {
  return ((r & 0b11111000) << 8) | ((g & 0b11111100) << 3) | (b >> 3);
}

// Various things that need to be setup via the Arduino standard methods
void setup() {
  // Setup red LED to indicate device is on (in case we disable NeoPixel battery level later)
  pinMode(3, OUTPUT);
  digitalWrite(3, HIGH);

  // Setup NeoPixels
  pixels_board.begin();
  pixels_wing.begin();
  pixels_board.clear();
  pixels_wing.clear();
  pixels_board.setBrightness(10);
  pixels_wing.setBrightness(5);

  // Start with blank wing indicator
  pixels_wing.show();

  // Green : pixels.Color(0, 255, 0)
  // Yellow : pixels.Color(255, 255, 0)
  // Orange : pixels.Color(255, 128, 0)
  // Red : pixels.Color(255, 0, 0)
  pixels_board.setPixelColor(0, pixels_board.Color(0, 0, 255));
  pixels_board.show();

  // Setup TFT
  tft.begin();
  tft.setRotation(1);
  screenClear();
  tft.println("");
  tft.setFont(&FreeMono9pt7b);

  // Setup BBQ10Keyboard
  Wire.begin();
  keyboard.begin();
  keyboard.setBacklight(0.5f);
}

// Main program via the Arduino standard methods
void loop() {
  // Handle keyboard events
  handlerKeyboard();

  // Update battery level as appropriate
  handlerBatteryLevel();
}

void handlerKeyboard() {
  // Check if keys were pressed
  if (keyboard.keyCount()) {
    // Get keyboard event
    const BBQ10Keyboard::KeyEvent key = keyboard.keyEvent();

    char output[28];
    snprintf(output, 28, "key: '%c' (dec %d, hex %02x)", key.key, key.key, key.key);
    for (int i=0; i<sizeof(output); i++) {
      char toPush = output[i];
      if (toPush != '\0') {
        textBuffer.push(toPush);
      }
      else if (toPush == '\0') {
        textBuffer.push('\n');
        break;
      }
    }
    
    screenClear();
    for (int i=0; i<textBuffer.size(); i++) {
      tft.print(textBuffer[i]);
    }

    // Pick color for signaling a key was pressed (short or long press)
    uint32_t keyboard_pixel_color = pixels_wing.Color(0, 0, 255);
    if (key.state == BBQ10Keyboard::StateLongPress) {
      keyboard_pixel_color = pixels_wing.Color(0, 255, 255);
    }
  
    // Display indicator accordingly
    if (key.state == BBQ10Keyboard::StatePress || key.state == BBQ10Keyboard::StateLongPress) {
      pixels_wing.setPixelColor(0, keyboard_pixel_color);
      pixels_wing.show(); 
    } 
    else {
      pixels_wing.clear();
      pixels_wing.show();
    }
  }
}

// Measure battery level and change NeoPixel accordingly
void handlerBatteryLevel() {
  measuredVBat = analogRead(VBATPIN);
  measuredVBat *= 2;    // we divided by 2, so multiply back
  measuredVBat *= 3.3;  // Multiply by 3.3V, our reference voltage
  measuredVBat /= 1024; // convert to voltage
  batteryPercent = measuredVBat / 3.3;
  if (batteryPercent >= 0.75) {
    pixels_board.setPixelColor(0, pixels_board.Color(0, 255, 0));
  }
  else if (batteryPercent >= 0.50) {
    pixels_board.setPixelColor(0, pixels_board.Color(255, 255, 0));
  }
  else if (batteryPercent >= 0.25) {
    pixels_board.setPixelColor(0, pixels_board.Color(255, 128, 0));
  }
  else {
    pixels_board.setPixelColor(0, pixels_board.Color(255, 0, 0));
  }
  pixels_board.show();
}

// Clear the screen
void screenClear() {
  tft.setCursor(0, 0);
  tft.fillScreen(RGB565(0, 0, 0));
}