/* 30 Days - Lost in Space
   Day 28 - Landing Gear
   Shun Wang */

#include "Arduino.h"
#include <U8g2lib.h>
#include "Wire.h"

U8G2_SH1106_128X64_NONAME_2_HW_I2C lander_display(U8G2_R0, U8X8_PIN_NONE);

#include "landing_gear_bitmaps.h"

const static char* LANDER_BITMAPS[] = {LANDING_1, LANDING_2, LANDING_3, LANDING_4};

#include <TM1637Display.h>

const byte BITMAP_NUMBER_DISPLAY_DIO_PIN = A1;
const byte BITMAP_NUMBER_DISPLAY_CLK_PIN = A2; 
TM1637Display bitmap_number_display(BITMAP_NUMBER_DISPLAY_CLK_PIN, BITMAP_NUMBER_DISPLAY_DIO_PIN);

const byte CONFIRM_LEVER_PIN = 4; 
const byte SYSTEMS_LEVER_PIN = 3; 
const byte THRUST_LEVER_PIN = 2; 

#include <Keypad.h> 
const byte ROWS = 4;
const byte COLS = 4;

byte colPins[ROWS] = { 10, 11, 12, 13 }; 
byte rowPins[COLS] = { 9, 8, 7};

char buttons[ROWS][COLS] = { 
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};

Keypad myAwesomePad = Keypad(makeKeymap(buttons), rowPins, colPins, ROWS, COLS);

enum APPROACH_STATE {APPROACH_INIT, APPROACH_PREFLIGHT, APPROACH_FINAL};

const int GEAR_BITMAP_COUNT = sizeof(LANDER_BITMAPS) / sizeof(LANDER_BITMAPS[0]);
enum GEAR_STATE {GEAR_IDLE = 0, GEAR_LOWERING = 1, GEAR_RAISING = -1};

void setup(void) {
  Serial.begin(9600);

  bitmap_number_display.setBrightness(7);
  bitmap_number_display.clear();

  pinMode(CONFIRM_LEVER_PIN, INPUT); 
  pinMode(SYSTEMS_LEVER_PIN, INPUT);
  pinMode(THRUST_LEVER_PIN, INPUT); 

  lander_display.begin(); 
  lander_display.setFont(u8g2_font_6x10_tr); 
  lander_display.setFontRefHeightText(); 
  lander_display.setFontPosTop(); }

void loop(void) {
  static int current_gear_bitmap = 0;
  static enum APPROACH_STATE approach_state = APPROACH_INIT;

  static enum GEAR_STATE gear_state = GEAR_IDLE;
  static char last_key = -1;

  bool thrust_lever = digitalRead(THRUST_LEVER_PIN);
  bool systems_lever = digitalRead(SYSTEMS_LEVER_PIN);
  bool confirm_lever = digitalRead(CONFIRM_LEVER_PIN);

  switch (approach_state) { 
    case APPROACH_INIT:
      if (!thrust_lever && !systems_lever && !confirm_lever) {
        approach_state = APPROACH_PREFLIGHT; }
      break;

    case APPROACH_PREFLIGHT:
      if (thrust_lever && systems_lever && confirm_lever) {
        approach_state = APPROACH_FINAL; }
      break;

    case APPROACH_FINAL:
      char customKey = myAwesomePad.getKey(); 
      if (customKey && customKey != last_key) {
        Serial.println(customKey);
        last_key = customKey; }

        switch (customKey) {
          case 'A':
            if (current_gear_bitmap != GEAR_BITMAP_COUNT - 1) {
              gear_state = GEAR_LOWERING; }
          break;
          case 'B': 
            if (current_gear_bitmap != 0) { 
              gear_state = GEAR_RAISING; } 
          }
      break; }

  current_gear_bitmap += gear_state;

  if (current_gear_bitmap == 0 || current_gear_bitmap == GEAR_BITMAP_COUNT - 1) {
    gear_state = GEAR_IDLE; }

  Serial.print("Gear: ");
  Serial.println(current_gear_bitmap);

  lander_display.firstPage();
  do {
    switch (approach_state) {
      case APPROACH_INIT: case APPROACH_PREFLIGHT:
        preflightDisplay(approach_state, thrust_lever, systems_lever, confirm_lever);
        break;
      
      case APPROACH_FINAL:
        finalDisplay(current_gear_bitmap);
        break; }
    } while (lander_display.nextPage());
    
    delay(100); }

void preflightDisplay(enum APPROACH_STATE approach_state, bool thruster_lever, 
                      bool systems_lever, bool confirm_lever) { 
  lander_display.setFontPosTop();
  byte y_offset = drawString(0, 0, "Exploration Lander");
  y_offset = drawString(0, y_offset, "Approach Sequence");
  y_offset = lander_display.getDisplayHeight() - (4 * lander_display.getMaxCharHeight());
  y_offset = drawString(0, y_offset, (String("Thrusters: ") + String(thruster_lever ? "ON" : "OFF")).c_str()); 
  y_offset = drawString(0, y_offset, (String("Systems : ") + String(systems_lever ? "ON" : "OFF")).c_str()); 
  y_offset = drawString(0, y_offset, (String("Confirm : ") + String(confirm_lever ? "ON" : "OFF")).c_str());
  
  y_offset = lander_display.getDisplayHeight() - lander_display.getMaxCharHeight();
  drawString(0, y_offset, (String("Countdown ") + liftoffStateToString(approach_state)).c_str()); }

void finalDisplay(int current_gear_bitmap) {
  byte x_offset = (lander_display.getDisplayWidth() - LANDING_GEAR_BITMAP_WIDTH) / 2; 
  byte y_offset = (lander_display.getDisplayHeight() - LANDING_GEAR_BITMAP_HEIGHT) / 2;
  lander_display.drawXBMP(x_offset, y_offset, LANDING_GEAR_BITMAP_WIDTH, LANDING_GEAR_BITMAP_HEIGHT, LANDER_BITMAPS[current_gear_bitmap]); }

String liftoffStateToString(enum APPROACH_STATE approach_state) {
  switch (approach_state) { 
    case APPROACH_INIT:
      return ("Init");
      break;
    case APPROACH_PREFLIGHT:
      return ("Preflight"); 
      break; }
  }

byte drawString(byte x, byte y, char* string) {
  lander_display.drawStr(x, y, string);
  return (y + lander_display.getMaxCharHeight()); }