#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Bounce2.h>

#include <SD.h>

#define CS_PIN 10
File root;

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define MENU_SIZE 5
char *menu[MENU_SIZE] = {  "Universal remotes", "Learn New Remote", "Saved Remotes", "Toggle Led", "Back" };

#define UP 2
#define SELECT 3
#define DOWN 4
byte button_pins[] = {2,3,4}; // button pins, 2: up, 3: select, 4: down
#define NUMBUTTONS sizeof(button_pins)
Bounce * buttons = new Bounce[NUMBUTTONS];

int cursor = 0;

#define LED 5
bool ledIsOn = false;

void setup() {

  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(LED, OUTPUT);

  Serial.print("Initializing SD card... ");

  if (!SD.begin(CS_PIN)) {
    Serial.println("Card initialization failed!");
    while (true);
  }

  Serial.println("initialization done.");

  Serial.println("Files in the card:");
  root = SD.open("/");
  printDirectory(root, 0);
  Serial.println("");

  // Example of reading file from the card:
  File textFile = SD.open("libraries.txt");
  if (textFile) {
    Serial.print("libraries.txt: ");
    while (textFile.available()) {
      Serial.write(textFile.read());
    }
    textFile.close();
  } else {
    Serial.println("error opening libraries.txt!");
  }

  // Make input & enable pull-up resistors on switch pins
  for (int i=0; i<NUMBUTTONS; i++) {
    buttons[i].attach( button_pins[i], INPUT_PULLUP); // setup the bounce instance for the current button
    buttons[i].interval(25); // interval in ms
  }
  Serial.begin(9600);
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)  // initialize with the I2C addr 0x3D (for the 128x64)
  ) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  // Show initial display buffer contents on the screen --
  // the library initializes this with an Adafruit splash screen.
  //display.display();
  //delay(2000); // Pause for 2 seconds

  // Clear the buffer
  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
  showMenu();
}

void loop() {
  // process button press:
  for (int i = 0; i<NUMBUTTONS; i++) {
    buttons[i].update(); // Update the Bounce instance
    if ( buttons[i].fell() ) { // If it fell
      if (button_pins[i] == SELECT) { // select
          Serial.println("select");
         display.setCursor(0,7);
         display.print(">>");
         display.print(menu[cursor]);
         executeChoice(cursor);
      }
      else {
        // erase previous cursor:
        display.setCursor(0,cursor);
        display.print(' ');
        if (button_pins[i] == UP) { // up
          Serial.println("up");
          cursor--;
          if (cursor<0) cursor=(MENU_SIZE-1);
        }
        else { // down
        Serial.println("down");
          cursor++;          
          if (cursor>(MENU_SIZE-1)) cursor=0;
        }
        // show cursor at new line:
        display.setCursor(0,cursor);
        display.print('>');
      }
      showMenu();
    } // end if button fell...
  } // end for-loop of button check

}

/**
 * Clear display and show the menu.
 */
void showMenu() {
  display.clearDisplay();
  // show menu items:
  for (int i = 0; i<MENU_SIZE; i++) {
    if(i == cursor) {
      display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
    } else {
      display.setTextColor(SSD1306_WHITE, SSD1306_BLACK);
    }
    display.setCursor(0, i*8);
    display.print(menu[i]);
  }
  display.display();
}

/**
 * Execute the task which matches the chosen menu item.
 */
void executeChoice(int choice) {
  switch(choice) {
      case 0 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 1 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 2 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 3 :
                ledIsOn = !ledIsOn;
                digitalWrite(LED_BUILTIN, ledIsOn);
                digitalWrite(LED, ledIsOn);
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 4 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      default :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
  }
}

void printDirectory(File dir, int numTabs) {
  while (true) {

    File entry =  dir.openNextFile();
    if (! entry) {
      // no more files
      break;
    }
    for (uint8_t i = 0; i < numTabs; i++) {
      Serial.print('\t');
    }
    Serial.print(entry.name());
    if (entry.isDirectory()) {
      Serial.println("/");
      printDirectory(entry, numTabs + 1);
    } else {
      // files have sizes, directories do not
      Serial.print("\t\t");
      Serial.println(entry.size(), DEC);
    }
    entry.close();
  }
}