/*
 * Stairs lighting
 * Copyright 2017 (c) Mark van Renswoude
 *
 * https://git.x2software.net/pub/Stairs
*/
#include "display.h"
#include <Fonts/FreeSans12pt7b.h>
#include "config.h"
#include "icons.h"
#include "global.h"


const uint8_t WaitAnimationInterval = 150;


void Display::init()
{
  mDisplay = new Adafruit_SSD1306(128, 32, &Wire, -1);
  mDisplay->begin(SSD1306_SWITCHCAPVCC, 0x3C);
}


void Display::update()
{
  // TODO invalidate when comm state changes

  switch (state)
  {
    case State::WaitingForComm:
      drawWaitingForComm();
      break;

    case State::Linking:
    case State::LinkingRequest:
      drawLinking();
      break;

    case State::LinkingSet:
      drawModuleIndex();
      break;

    case State::DisplayModuleIndex:
      if (mLastDrawnState == state && currentTime - mLastStateChange >= DisplayIdleTimeout)
      {
        state = State::DisplayOff;
        off();
      }
      else
        drawModuleIndex();

      break;

    case State::DisplayOff:
      off();
      break;
  }

  setLastDrawnState();
}


void Display::drawWaitingForComm()
{
  if (mLastDrawnState == State::WaitingForComm && currentTime - mLastWaiting < WaitAnimationInterval)
    return;

  checkOn();
  mDisplay->clearDisplay();
  drawTitle("Waiting for signal");

  uint8_t xOffset = (mWaitAnimationStep == 1 || mWaitAnimationStep == 2) ? WaitCursorSegmentWidth : 0;
  uint8_t yOffset = (mWaitAnimationStep == 2 || mWaitAnimationStep == 3) ? WaitCursorSegmentHeight : 0;
  drawRotatedBitmap(xOffset, mDisplay->height() - (WaitCursorSegmentHeight * 2) + yOffset, WaitCursorSegment, WaitCursorSegmentWidth, WaitCursorSegmentHeight, mWaitAnimationStep);

  mDisplay->display();

  mWaitAnimationStep++;
  if (mWaitAnimationStep > 3)
    mWaitAnimationStep = 0;

  mLastWaiting = currentTime;
}


void Display::drawModuleIndex()
{
  uint8_t moduleIndex = settings.getModuleIndex();
  if (mLastDrawnState == State::DisplayModuleIndex && mLastModuleIndex == moduleIndex)
    return;

  checkOn();
  mDisplay->clearDisplay();
  drawTitle("Steps");
  drawCommIcon();

  mDisplay->setFont(&FreeSans12pt7b);
  mDisplay->setCursor(0, mDisplay->height() - 1);

  if (moduleIndex == ModuleIndexUndefined)
  {
    mDisplay->print("Not set");
  }
  else
  {
    uint8_t firstStep = (moduleIndex * 2) + 1;
    mDisplay->print(firstStep);
    mDisplay->print(" - ");
    mDisplay->print(firstStep + 1);
  }

  mDisplay->display();
}


void Display::drawLinking()
{
  if (mLastDrawnState == State::Linking)
    return;

  checkOn();
  mDisplay->clearDisplay();
  drawTitle("Steps");
  drawCommIcon();

  mDisplay->setFont(&FreeSans12pt7b);
  mDisplay->setCursor(0, mDisplay->height() - 1);
  mDisplay->print("Click to set");
  mDisplay->display();
}


void Display::setLastDrawnState()
{
  if (state != mLastDrawnState)
  {
    mLastDrawnState = state;
    mLastStateChange = currentTime;
  }
}


void Display::off()
{
  if (mLastDrawnState != State::DisplayOff)
  {
    // I've had trouble waking the display up again, so just clear it for now
    mDisplay->ssd1306_command(SSD1306_DISPLAYOFF);
    mDisplay->ssd1306_command(SSD1306_CHARGEPUMP);
    mDisplay->ssd1306_command(0x10); // disable charge pump
    //mDisplay->clearDisplay();
    //mDisplay->display();
  }
}


void Display::checkOn()
{
  if (mLastDrawnState == State::DisplayOff)
  {
    mDisplay->ssd1306_command(SSD1306_CHARGEPUMP);
    mDisplay->ssd1306_command(0x14); // enable charge pump

    mDisplay->ssd1306_command(SSD1306_DISPLAYON);
  }
}


void Display::drawTitle(const char* title)
{
  mDisplay->setTextSize(1);
  mDisplay->setTextColor(WHITE);

  mDisplay->setFont(NULL);
  mDisplay->setCursor(0, 0);
  mDisplay->print(title);
}


void Display::drawCommIcon()
{
  mDisplay->drawBitmap(mDisplay->width() - IconCommWidth, 0,
    currentTime - comm.getPacketStartTime() <= CommIdleTimeout ? IconCommOn : IconCommOff,
    IconCommWidth, IconCommHeight, 1);
}



typedef void (*WritePixelProc)(Adafruit_SSD1306* display, int8_t boundsX, int8_t boundsY, int8_t boundsW, int8_t boundsH, int8_t relativeX, int8_t relativeY);


void writePixel0(Adafruit_SSD1306* display, int8_t boundsX, int8_t boundsY, int8_t boundsW, int8_t boundsH, int8_t relativeX, int8_t relativeY)
{
  display->writePixel(boundsX + relativeX, boundsY + relativeY, 1);
}

void writePixel90(Adafruit_SSD1306* display, int8_t boundsX, int8_t boundsY, int8_t boundsW, int8_t boundsH, int8_t relativeX, int8_t relativeY)
{
  display->writePixel(boundsX + boundsW - relativeY, boundsY + relativeX, 1);
}

void writePixel180(Adafruit_SSD1306* display, int8_t boundsX, int8_t boundsY, int8_t boundsW, int8_t boundsH, int8_t relativeX, int8_t relativeY)
{
  display->writePixel(boundsX + boundsW - relativeX, boundsY + boundsH - relativeY, 1);
}

void writePixel270(Adafruit_SSD1306* display, int8_t boundsX, int8_t boundsY, int8_t boundsW, int8_t boundsH, int8_t relativeX, int8_t relativeY)
{
  display->writePixel(boundsX + relativeY, boundsY + boundsH - relativeX, 1);
}


void Display::drawRotatedBitmap(int8_t x, int8_t y, const uint8_t bitmap[], int8_t w, int8_t h, uint8_t rotation)
{
  int16_t byteWidth = (w + 7) / 8;
  int8_t byte = 0;

  mDisplay->startWrite();

  WritePixelProc writePixel;
  switch (rotation)
  {
    case 1: // 90 degrees
      writePixel = writePixel90;
      break;

    case 2: // 180 degrees
      writePixel = writePixel180;
      break;

    case 3: // 270 degrees
      writePixel = writePixel270;
      break;

    default: // 0 degrees
      writePixel = writePixel0;
      break;
  }

  for(int8_t relativeY = 0; relativeY < h; relativeY++)
  {
    for(int8_t relativeX = 0; relativeX < w; relativeX++)
    {
      if(relativeX & 7)
        byte <<= 1;
      else
        byte   = pgm_read_byte(&bitmap[relativeY * byteWidth + relativeX / 8]);

      if (byte & 0x80)
        writePixel(mDisplay, x, y, w, h, relativeX, relativeY);
    }
  }

  mDisplay->endWrite();
}