// Gmsh - Copyright (C) 1997-2021 C. Geuzaine, J.-F. Remacle
//
// See the LICENSE.txt file for license information. Please report all
// issues on https://gitlab.onelab.info/gmsh/gmsh/issues.

// This class was inspired by the colorbar widget provided in Vis5d, a
// program for visualizing five dimensional gridded data sets
// Copyright (C) 1990 - 1995 Bill Hibbard, Brian Paul, Dave Santek,
// and Andre Battaiola.

#include <FL/fl_draw.H>
#include "colorbarWindow.h"
#include "ColorTable.h"
#include "Context.h"

#define EPS 1.e-10

colorbarWindow::colorbarWindow(int x, int y, int w, int h, const char *l)
  : Fl_Window(x, y, w, h, l)
{
  ct = nullptr;
  label = nullptr;
  help_flag = 1;
  font_height = FL_NORMAL_SIZE - 1; // use slightly smaller font
  marker_height = font_height;
  wedge_height = marker_height;
  marker_pos = 0;
  minval = maxval = 0.0;
}

int colorbarWindow::x_to_index(int x)
{
  int index;
  index = (int)(x * (double)ct->size / (double)w());
  if(index < 0)
    index = 0;
  else if(index >= ct->size)
    index = ct->size - 1;
  return index;
}

int colorbarWindow::index_to_x(int index)
{
  int x;
  x = (int)(index * (double)w() / (double)(ct->size - 1));
  if(x >= w()) x = w() - 1;
  return x;
}

int colorbarWindow::y_to_intensity(int y)
{
  int intensity;
  intensity = (int)((wedge_y - y) * 255. / (double)wedge_y);
  if(intensity < 0)
    intensity = 0;
  else if(intensity > 255)
    intensity = 255;
  return intensity;
}

int colorbarWindow::intensity_to_y(int intensity)
{
  int y;
  y = (int)(wedge_y - intensity * (double)wedge_y / 255.);
  if(y < 0)
    y = 0;
  else if(y >= wedge_y)
    y = wedge_y - 1;
  return y;
}

void colorbarWindow::redraw_range(int a, int b)
{
  int i;
  int x, y, px = 0, py = 0;
  int x1, y1, x2, y2;
  int intensity = 0;
  double H, S, V;

  if(a < 0) a = 0;
  if(b >= ct->size) b = ct->size - 1;

  // calculate region to update
  x1 = index_to_x(a);
  x2 = index_to_x(b);
  y1 = intensity_to_y(255);
  y2 = intensity_to_y(0);

  // erase region
  fl_color(color_bg);
  fl_rectf(x1, y1, x2 - x1 + 1, y2 - y1 + 1);

  // redraw region of entries in interval [a,b]
  if(a > 0) a--;
  if(b < ct->size - 1) b++;

  // draw red or hue levels
  for(i = a; i <= b; i++) {
    x = index_to_x(i);
    if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_RGB)
      intensity = CTX::instance()->unpackRed(ct->table[i]);
    else if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_HSV) {
      RGB_to_HSV(CTX::instance()->unpackRed(ct->table[i]) / 255.,
                 CTX::instance()->unpackGreen(ct->table[i]) / 255.,
                 CTX::instance()->unpackBlue(ct->table[i]) / 255., &H, &S, &V);
      intensity = (int)(H / 6. * 255. + EPS);
    }
    y = intensity_to_y(intensity);
    if(i != a) {
      fl_color(FL_RED);
      fl_line(px, py, x, y);
    }
    px = x;
    py = y;
  }

  // draw green or saturation levels
  for(i = a; i <= b; i++) {
    x = index_to_x(i);
    if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_RGB)
      intensity = CTX::instance()->unpackGreen(ct->table[i]);
    else if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_HSV) {
      RGB_to_HSV(CTX::instance()->unpackRed(ct->table[i]) / 255.,
                 CTX::instance()->unpackGreen(ct->table[i]) / 255.,
                 CTX::instance()->unpackBlue(ct->table[i]) / 255., &H, &S, &V);
      intensity = (int)(S * 255.);
    }
    y = intensity_to_y(intensity);
    if(i != a) {
      fl_color(FL_GREEN);
      fl_line(px, py, x, y);
    }
    px = x;
    py = y;
  }

  // draw blue or value levels
  for(i = a; i <= b; i++) {
    x = index_to_x(i);
    if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_RGB)
      intensity = CTX::instance()->unpackBlue(ct->table[i]);
    else if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_HSV) {
      RGB_to_HSV(CTX::instance()->unpackRed(ct->table[i]) / 255.,
                 CTX::instance()->unpackGreen(ct->table[i]) / 255.,
                 CTX::instance()->unpackBlue(ct->table[i]) / 255., &H, &S, &V);
      intensity = (int)(V * 255.);
    }
    y = intensity_to_y(intensity);
    if(i != a) {
      fl_color(FL_BLUE);
      fl_line(px, py, x, y);
    }
    px = x;
    py = y;
  }

  // draw alpha levels
  for(i = a; i <= b; i++) {
    x = index_to_x(i);
    y = intensity_to_y(CTX::instance()->unpackAlpha(ct->table[i]));
    if(i != a) {
      fl_color(fl_contrast(FL_BLACK, color_bg));
      fl_line(px, py, x, y);
    }
    px = x;
    py = y;
  }

  // draw the color bar
  for(x = x1; x <= x2; x++) {
    int r, g, b;
    unsigned int color;
    i = x_to_index(x);
    color = ct->table[i];
    r = CTX::instance()->unpackRed(color);
    g = CTX::instance()->unpackGreen(color);
    b = CTX::instance()->unpackBlue(color);
    fl_color(r, g, b);
    fl_line(x, wedge_y, x, wedge_y + wedge_height - 1);
  }

  // print colortable mode and help
  fl_font(FL_HELVETICA, font_height);
  fl_color(fl_contrast(FL_BLACK, color_bg));

  int fh = font_height + 1;
  int xx0 = 6, xx1 = 11 * fh, yy0 = 10;
  if(help_flag) {
    i = 0;
    fl_draw("0, 1, 2, 3, ..., 9", xx0, yy0 + (i + 1) * fh);
    fl_draw("Select predefined colormap 0...9", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("Ctrl+0, ..., Ctrl+9", xx0, yy0 + (i + 1) * fh);
    fl_draw("Select predefined colormap 10...19", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("F1, ..., F5", xx0, yy0 + (i + 1) * fh);
    fl_draw("Select predefined colormap 20...24", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("mouse1", xx0, yy0 + (i + 1) * fh);
    fl_draw("Draw red or hue channel", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("mouse2", xx0, yy0 + (i + 1) * fh);
    fl_draw("Draw green or saturation channel", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("mouse3", xx0, yy0 + (i + 1) * fh);
    fl_draw("Draw blue or value channel", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("Ctrl+mouse1", xx0, yy0 + (i + 1) * fh);
    fl_draw("Draw alpha channel", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("Ctrl+c, Ctrl+v, r", xx0, yy0 + (i + 1) * fh);
    fl_draw("Copy, paste or reset colormap", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("m", xx0, yy0 + (i + 1) * fh);
    fl_draw("Toggle RGB/HSV mode", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("left, right", xx0, yy0 + (i + 1) * fh);
    fl_draw("Translate abscissa", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("Ctrl+left, Ctrl+right", xx0, yy0 + (i + 1) * fh);
    fl_draw("Rotate abscissa", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("i, Ctrl+i", xx0, yy0 + (i + 1) * fh);
    fl_draw("Invert abscissa or ordinate", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("up, down", xx0, yy0 + (i + 1) * fh);
    fl_draw("Modify color channel curvature", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("a, Ctrl+a", xx0, yy0 + (i + 1) * fh);
    fl_draw("Modify alpha coefficient", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("p, Ctrl+p", xx0, yy0 + (i + 1) * fh);
    fl_draw("Modify alpha channel power law", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("b, Ctrl+b", xx0, yy0 + (i + 1) * fh);
    fl_draw("Modify gamma correction", xx1, yy0 + (i + 1) * fh);
    i++;
    fl_draw("h", xx0, yy0 + (i + 1) * fh);
    fl_draw("Show this help message", xx1, yy0 + (i + 1) * fh);
    i++;
  }
  else if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_RGB)
    fl_draw("RGB", xx0, yy0 + font_height);
  else if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_HSV)
    fl_draw("HSV", xx0, yy0 + font_height);
}

void colorbarWindow::redraw_marker()
{
  int x, y0, y1;
  char str[50];
  double val;

  y0 = marker_y;
  y1 = h() - 1;

  fl_color(color_bg);
  fl_rectf(0, y0, w(), y1 - y0 + 1);

  // draw marker below color wedge
  x = index_to_x(marker_pos);
  fl_color(fl_contrast(FL_BLACK, color_bg));
  fl_line(x, marker_y, x, marker_y + marker_height);
  fl_line(x, marker_y, x - 3, marker_y + 6);
  fl_line(x, marker_y, x + 3, marker_y + 6);

  // draw marker value
  fl_font(FL_HELVETICA, font_height);
  val =
    minval + (maxval - minval) * ((double)marker_pos / (double)(ct->size - 1));
  sprintf(str, "%g", val);
  fl_draw(str, 10, label_y);
}

void colorbarWindow::draw()
{
  if(!ct) return;

  label_y = h() - 5;
  marker_y = label_y - marker_height - font_height;
  wedge_y = marker_y - wedge_height;
  color_bg = fl_color_cube(
    CTX::instance()->unpackRed(CTX::instance()->color.bg) * FL_NUM_RED / 256,
    CTX::instance()->unpackGreen(CTX::instance()->color.bg) * FL_NUM_GREEN /
      256,
    CTX::instance()->unpackBlue(CTX::instance()->color.bg) * FL_NUM_BLUE / 256);
  redraw_range(0, ct->size - 1);
  redraw_marker();
}

void colorbarWindow::update(const char *name, double min, double max,
                            GmshColorTable *table, bool *changed)
{
  label = name;
  ct = table;
  viewchanged = changed;
  minval = min;
  maxval = max;
  redraw();
}

int colorbarWindow::handle(int event)
{
  if(!ct) return Fl_Window::handle(event);

  static int p1 = 0, p2 = 0, p3 = 0, p4 = 0;
  static int pentry, move_marker;
  int i, ibut, xpos, ypos, modify, entry, compute;

  modify = 0;
  compute = 0;

  switch(event) {
  case FL_FOCUS: // accept focus events when asked
  case FL_UNFOCUS: return 1;

  case FL_ENTER:
    take_focus(); // force keyboard focus as soon as the mouse enters
    return 1;

  case FL_LEAVE: return 1;

  case FL_SHORTCUT:
  case FL_KEYBOARD:
    if(Fl::test_shortcut('0')) {
      ColorTable_InitParam(0, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('1')) {
      ColorTable_InitParam(1, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('2')) {
      ColorTable_InitParam(2, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('3')) {
      ColorTable_InitParam(3, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('4')) {
      ColorTable_InitParam(4, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('5')) {
      ColorTable_InitParam(5, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('6')) {
      ColorTable_InitParam(6, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('7')) {
      ColorTable_InitParam(7, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('8')) {
      ColorTable_InitParam(8, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('9')) {
      ColorTable_InitParam(9, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '0') ||
            Fl::test_shortcut(FL_META + '0')) {
      ColorTable_InitParam(10, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '1') ||
            Fl::test_shortcut(FL_META + '1')) {
      ColorTable_InitParam(11, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '2') ||
            Fl::test_shortcut(FL_META + '2')) {
      ColorTable_InitParam(12, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '3') ||
            Fl::test_shortcut(FL_META + '3')) {
      ColorTable_InitParam(13, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '4') ||
            Fl::test_shortcut(FL_META + '4')) {
      ColorTable_InitParam(14, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '5') ||
            Fl::test_shortcut(FL_META + '5')) {
      ColorTable_InitParam(15, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '6') ||
            Fl::test_shortcut(FL_META + '6')) {
      ColorTable_InitParam(16, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '7') ||
            Fl::test_shortcut(FL_META + '7')) {
      ColorTable_InitParam(17, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '8') ||
            Fl::test_shortcut(FL_META + '8')) {
      ColorTable_InitParam(18, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + '9') ||
            Fl::test_shortcut(FL_META + '9')) {
      ColorTable_InitParam(19, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_F + 1)) {
      ColorTable_InitParam(20, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_F + 2)) {
      ColorTable_InitParam(21, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_F + 3)) {
      ColorTable_InitParam(22, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_F + 4)) {
      ColorTable_InitParam(23, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_F + 5)) {
      ColorTable_InitParam(24, ct);
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + 'c') ||
            Fl::test_shortcut(FL_META + 'c')) {
      ColorTable_Copy(ct);
    }
    else if(Fl::test_shortcut(FL_CTRL + 'v') ||
            Fl::test_shortcut(FL_META + 'v')) {
      ColorTable_Paste(ct);
      redraw();
      *viewchanged = true;
    }
    else if(Fl::test_shortcut('h')) {
      help_flag = !help_flag;
      redraw();
    }
    else if(Fl::test_shortcut('r')) {
      ColorTable_InitParam(ct->ipar[COLORTABLE_NUMBER], ct);
      compute = 1;
    }
    else if(Fl::test_shortcut('m')) {
      if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_RGB)
        ct->ipar[COLORTABLE_MODE] = COLORTABLE_HSV;
      else
        ct->ipar[COLORTABLE_MODE] = COLORTABLE_RGB;
      redraw();
    }
    else if(Fl::test_shortcut('i')) {
      ct->ipar[COLORTABLE_SWAP] = !ct->ipar[COLORTABLE_SWAP];
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + 'i') ||
            Fl::test_shortcut(FL_META + 'i')) {
      ct->ipar[COLORTABLE_INVERT] = !ct->ipar[COLORTABLE_INVERT];
      compute = 1;
    }
    else if(Fl::test_shortcut('b')) {
      ct->dpar[COLORTABLE_BETA] += 0.05;
      if(ct->dpar[COLORTABLE_BETA] > 1.0) ct->dpar[COLORTABLE_BETA] = 1.0;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + 'b') ||
            Fl::test_shortcut(FL_META + 'b')) {
      ct->dpar[COLORTABLE_BETA] -= 0.05;
      if(ct->dpar[COLORTABLE_BETA] < -1.0) ct->dpar[COLORTABLE_BETA] = -1.0;
      compute = 1;
    }
    else if(Fl::test_shortcut('a')) {
      ct->dpar[COLORTABLE_ALPHA] -= 0.05;
      if(ct->dpar[COLORTABLE_ALPHA] < 0.0) ct->dpar[COLORTABLE_ALPHA] = 0.0;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + 'a') ||
            Fl::test_shortcut(FL_META + 'a')) {
      ct->dpar[COLORTABLE_ALPHA] += 0.05;
      if(ct->dpar[COLORTABLE_ALPHA] > 1.0) ct->dpar[COLORTABLE_ALPHA] = 1.0;
      compute = 1;
    }
    else if(Fl::test_shortcut('p')) {
      ct->dpar[COLORTABLE_ALPHAPOW] += 0.05;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + 'p') ||
            Fl::test_shortcut(FL_META + 'p')) {
      ct->dpar[COLORTABLE_ALPHAPOW] -= 0.05;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_Left)) {
      ct->dpar[COLORTABLE_BIAS] -= 0.05;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + FL_Left) ||
            Fl::test_shortcut(FL_META + FL_Left)) {
      ct->ipar[COLORTABLE_ROTATION] += 5;
      if(ct->ipar[COLORTABLE_ROTATION] > ct->size - 1)
        ct->ipar[COLORTABLE_ROTATION] -= ct->size - 1;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_Right)) {
      ct->dpar[COLORTABLE_BIAS] += 0.05;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_CTRL + FL_Right) ||
            Fl::test_shortcut(FL_META + FL_Right)) {
      ct->ipar[COLORTABLE_ROTATION] -= 5;
      if(ct->ipar[COLORTABLE_ROTATION] < -(ct->size - 1))
        ct->ipar[COLORTABLE_ROTATION] += ct->size - 1;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_Up)) {
      ct->dpar[COLORTABLE_CURVATURE] -= 0.05;
      compute = 1;
    }
    else if(Fl::test_shortcut(FL_Down)) {
      ct->dpar[COLORTABLE_CURVATURE] += 0.05;
      compute = 1;
    }
    else {
      return Fl_Window::handle(event);
    }

    if(compute) {
      ColorTable_Recompute(ct);
      redraw();
      *viewchanged = true;
      do_callback();
    }
    return 1;

  case FL_PUSH:
    ibut = Fl::event_button();
    xpos = Fl::event_x();
    ypos = Fl::event_y();
    if(help_flag) {
      help_flag = 0;
      redraw();
    }
    // change color function or marker position
    if(ypos < wedge_y)
      move_marker = 0;
    else
      move_marker = 1;

    // determine which curve to modify
    if(Fl::event_state(FL_CTRL) || Fl::event_state(FL_META))
      p4 = 1;
    else if(ibut == 1 && !Fl::event_state(FL_SHIFT) && !Fl::event_state(FL_ALT))
      p1 = 1;
    else if(ibut == 2 || (ibut == 1 && Fl::event_state(FL_SHIFT)))
      p2 = 1;
    else
      p3 = 1;
    pentry = x_to_index(xpos);
    modify = 1;
    break;

  case FL_RELEASE:
    ibut = Fl::event_button();
    xpos = Fl::event_x();
    ypos = Fl::event_y();
    p1 = 0;
    p2 = 0;
    p3 = 0;
    p4 = 0;
    if(*viewchanged) do_callback();
    break;

  case FL_DRAG:
    ibut = Fl::event_button();
    xpos = Fl::event_x();
    ypos = Fl::event_y();
    modify = 1;
    break;

  default:
    // don't know what to do with the event: passing it to parent
    return Fl_Window::handle(event);
  }

  // Modify one or more of the color curves

  if(modify && (p1 || p2 || p3 || p4)) {
    // calculate which entry in color table to change
    entry = x_to_index(xpos);
    // update
    if(move_marker) {
      // changing marker position
      marker_pos = entry;
    }
    else {
      // changing color graph
      int a, b, value;
      value = y_to_intensity(ypos);
      if(pentry <= entry) {
        a = pentry;
        b = entry;
      }
      else {
        a = entry;
        b = pentry;
      }
      // update entries from 'pentry' to 'entry'
      for(i = a; i <= b; i++) {
        int red, green, blue, alpha;
        double R, G, B, H, S, V;
        red = CTX::instance()->unpackRed(ct->table[i]);
        green = CTX::instance()->unpackGreen(ct->table[i]);
        blue = CTX::instance()->unpackBlue(ct->table[i]);
        alpha = CTX::instance()->unpackAlpha(ct->table[i]);
        if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_RGB) {
          if(p1) red = value;
          if(p2) green = value;
          if(p3) blue = value;
          if(p4) alpha = value;
        }
        else if(ct->ipar[COLORTABLE_MODE] == COLORTABLE_HSV) {
          RGB_to_HSV((double)red / 255., (double)green / 255.,
                     (double)blue / 255., &H, &S, &V);
          if(p1) H = 6. * (double)value / 255. + EPS;
          if(p2) S = (double)value / 255.;
          if(p3) V = (double)value / 255.;
          if(p4) alpha = value;
          HSV_to_RGB(H, S, V, &R, &G, &B);
          red = (int)(255 * R);
          green = (int)(255 * G);
          blue = (int)(255 * B);
        }
        ct->table[i] = CTX::instance()->packColor(red, green, blue, alpha);
      }
      pentry = entry;
      *viewchanged = true;
    }
    redraw();
    return 1;
  }

  return 1;
}