//
// Fl_Chart widget for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2023 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

#include <FL/math.h>
#include <FL/Fl.H>
#include <FL/Fl_Chart.H>
#include <FL/fl_draw.H>
#include "flstring.h"
#include <stdlib.h>

// this function is in fl_boxtype.cxx:
void fl_rectbound(int x, int y, int w, int h, Fl_Color color);

static const double ARCINC = (2.0 * M_PI / 360.0);


/**
  Draws a bar chart.

  \p x, \p y, \p w, \p h is the bounding box,
  \p entries the array of \p numb entries,
  and \p min and \p max the boundaries.

  \param[in]  x, y, w, h  Widget position and size
  \param[in]  numb        Number of values
  \param[in]  entries     Array of values
  \param[in]  min         Lower boundary
  \param[in]  max         Upper boundary
  \param[in]  autosize    Whether the chart autosizes
  \param[in]  maxnumb     Maximal number of entries
  \param[in]  textcolor   Text color
*/
void Fl_Chart::draw_barchart(int x, int y, int w, int h, int numb, FL_CHART_ENTRY entries[],
                             double min, double max, int autosize, int maxnumb, Fl_Color textcolor)
{
  double incr;
  int zeroh;
  double lh = fl_height();
  if (max == min)
    incr = h;
  else
    incr = h / (max - min);
  if ((-min * incr) < lh) {
    incr = (h - lh + min * incr) / (max - min);
    zeroh = int(y + h - lh);
  } else {
    zeroh = (int)rint(y + h + min * incr);
  }
  int bwidth = (int)rint(w / double(autosize ? numb : maxnumb));
  // Draw base line
  fl_color(textcolor);
  fl_line(x, zeroh, x + w, zeroh);
  if (min == 0.0 && max == 0.0)
    return; // Nothing else to draw
  int i;
  // Draw the bars
  for (i = 0; i < numb; i++) {
    int hh = (int)rint(entries[i].val * incr);
    if (hh < 0)
      fl_rectbound(x + i * bwidth, zeroh, bwidth + 1, -hh + 1, (Fl_Color)entries[i].col);
    else if (hh > 0)
      fl_rectbound(x + i * bwidth, zeroh - hh, bwidth + 1, hh + 1, (Fl_Color)entries[i].col);
  }
  // Draw the labels
  fl_color(textcolor);
  for (i = 0; i < numb; i++)
    fl_draw(entries[i].str, x + i * bwidth + bwidth / 2, zeroh, 0, 0, FL_ALIGN_TOP);
}


/**
  Draws a horizontal bar chart.

  \p x, \p y, \p w, \p h is the bounding box,
  \p entries the array of \p numb entries,
  and \p min and \p max the boundaries.

  \param[in]  x, y, w, h  Widget position and size
  \param[in]  numb        Number of values
  \param[in]  entries     Array of values
  \param[in]  min         Lower boundary
  \param[in]  max         Upper boundary
  \param[in]  autosize    Whether the chart autosizes
  \param[in]  maxnumb     Maximal number of entries
  \param[in]  textcolor   Text color
*/
void Fl_Chart::draw_horbarchart(int x, int y, int w, int h, int numb, FL_CHART_ENTRY entries[],
                                double min, double max, int autosize, int maxnumb,
                                Fl_Color textcolor)
{
  int i;
  double lw = 0.0; // Maximal label width
  // Compute maximal label width
  for (i = 0; i < numb; i++) {
    double w1 = fl_width(entries[i].str);
    if (w1 > lw)
      lw = w1;
  }
  if (lw > 0.0)
    lw += 4.0;
  double incr;
  int zeroh;
  if (max == min)
    incr = w;
  else
    incr = w / (max - min);
  if ((-min * incr) < lw) {
    incr = (w - lw + min * incr) / (max - min);
    zeroh = x + (int)rint(lw);
  } else {
    zeroh = (int)rint(x - min * incr);
  }
  int bwidth = (int)rint(h / double(autosize ? numb : maxnumb));
  // Draw base line
  fl_color(textcolor);
  fl_line(zeroh, y, zeroh, y + h);
  if (min == 0.0 && max == 0.0)
    return; // Nothing else to draw
  // Draw the bars
  for (i = 0; i < numb; i++) {
    int ww = (int)rint(entries[i].val * incr);
    if (ww > 0)
      fl_rectbound(zeroh, y + i * bwidth, ww + 1, bwidth + 1, (Fl_Color)entries[i].col);
    else if (ww < 0)
      fl_rectbound(zeroh + ww, y + i * bwidth, -ww + 1, bwidth + 1, (Fl_Color)entries[i].col);
  }
  // Draw the labels
  fl_color(textcolor);
  for (i = 0; i < numb; i++)
    fl_draw(entries[i].str, zeroh - 2, y + i * bwidth + bwidth / 2, 0, 0, FL_ALIGN_RIGHT);
}


/**
  Draws a line chart.

  \p x, \p y, \p w, \p h is the bounding box,
  \p entries the array of \p numb entries,
  and \p min and \p max the boundaries.

  \param[in]  type        Chart type
  \param[in]  x, y, w, h  Widget position and size
  \param[in]  numb        Number of values
  \param[in]  entries     Array of values
  \param[in]  min         Lower boundary
  \param[in]  max         Upper boundary
  \param[in]  autosize    Whether the chart autosizes
  \param[in]  maxnumb     Maximal number of entries
  \param[in]  textcolor   Text color
*/

void Fl_Chart::draw_linechart(int type, int x, int y, int w, int h, int numb,
                              FL_CHART_ENTRY entries[], double min, double max, int autosize,
                              int maxnumb, Fl_Color textcolor)
{
  int i;
  double lh = fl_height();
  double incr;
  if (max == min)
    incr = h - 2.0 * lh;
  else
    incr = (h - 2.0 * lh) / (max - min);
  int zeroh = (int)rint(y + h - lh + min * incr);
  double bwidth = w / double(autosize ? numb : maxnumb);
  // Draw the values
  for (i = 0; i < numb; i++) {
    int x0 = x + (int)rint((i - .5) * bwidth);
    int x1 = x + (int)rint((i + .5) * bwidth);
    int yy0 = i ? zeroh - (int)rint(entries[i - 1].val * incr) : 0;
    int yy1 = zeroh - (int)rint(entries[i].val * incr);
    if (type == FL_SPIKE_CHART) {
      fl_color((Fl_Color)entries[i].col);
      fl_line(x1, zeroh, x1, yy1);
    } else if (type == FL_LINE_CHART && i != 0) {
      fl_color((Fl_Color)entries[i - 1].col);
      fl_line(x0, yy0, x1, yy1);
    } else if (type == FL_FILLED_CHART && i != 0) {
      fl_color((Fl_Color)entries[i - 1].col);
      if ((entries[i - 1].val > 0.0) != (entries[i].val > 0.0)) {
        double ttt = entries[i - 1].val / (entries[i - 1].val - entries[i].val);
        int xt = x + (int)rint((i - .5 + ttt) * bwidth);
        fl_polygon(x0, zeroh, x0, yy0, xt, zeroh);
        fl_polygon(xt, zeroh, x1, yy1, x1, zeroh);
      } else {
        fl_polygon(x0, zeroh, x0, yy0, x1, yy1, x1, zeroh);
      }
      fl_color(textcolor);
      fl_line(x0, yy0, x1, yy1);
    }
  }
  // Draw base line
  fl_color(textcolor);
  fl_line(x, zeroh, x + w, zeroh);
  // Draw the labels
  for (i = 0; i < numb; i++) {
    fl_draw(entries[i].str, x + (int)rint((i + .5) * bwidth),
            zeroh - (int)rint(entries[i].val * incr), 0, 0,
            entries[i].val >= 0 ? FL_ALIGN_BOTTOM : FL_ALIGN_TOP);
  }
}


/**
  Draws a pie chart.

  \param[in]  x,y,w,h   bounding box
  \param[in]  numb      number of chart entries
  \param[in]  entries   array of chart entries
  \param[in]  special   special (?)
  \param[in]  textcolor text color
*/
void Fl_Chart::draw_piechart(int x, int y, int w, int h, int numb, FL_CHART_ENTRY entries[],
                             int special, Fl_Color textcolor) {
  int i;
  double xc, yc, rad; // center and radius
  double tot;         // sum of values
  double incr;        // increment in angle
  double curang;      // current angle we are drawing
  double txc, tyc;    // temporary center
  double lh = fl_height();

  // compute center and radius
  double h_denom = (special ? 2.3 : 2.0);
  rad = (h - 2 * lh) / h_denom / 1.1;
  xc = x + w / 2.0;
  yc = y + h - 1.1 * rad - lh;

  // compute sum of values
  tot = 0.0;
  for (i = 0; i < numb; i++) {
    if (entries[i].val > 0.0)
      tot += entries[i].val;
  }
  if (tot == 0.0)
    return;
  incr = 360.0 / tot;
  // Draw the pie
  curang = 0.0;
  for (i = 0; i < numb; i++) {
    if (entries[i].val > 0.0) {
      txc = xc;
      tyc = yc;
      // Correct for special pies
      if (special && i == 0) {
        txc += 0.3 * rad * cos(ARCINC * (curang + 0.5 * incr * entries[i].val));
        tyc -= 0.3 * rad * sin(ARCINC * (curang + 0.5 * incr * entries[i].val));
      }
      fl_color((Fl_Color)entries[i].col);
      fl_begin_polygon();
      fl_vertex(txc, tyc);
      fl_arc(txc, tyc, rad, curang, curang + incr * entries[i].val);
      fl_end_polygon();
      fl_color(textcolor);
      fl_begin_loop();
      fl_vertex(txc, tyc);
      fl_arc(txc, tyc, rad, curang, curang + incr * entries[i].val);
      fl_end_loop();
      curang += 0.5 * incr * entries[i].val;
      // draw the label
      double xl = txc + 1.1 * rad * cos(ARCINC * curang);
      fl_draw(entries[i].str, (int)rint(xl), (int)rint(tyc - 1.1 * rad * sin(ARCINC * curang)), 0,
              0, xl < txc ? FL_ALIGN_RIGHT : FL_ALIGN_LEFT);
      curang += 0.5 * incr * entries[i].val;
    }
  }
}

/**
  Draws the Fl_Chart widget.
*/
void Fl_Chart::draw() {

  draw_box();
  Fl_Boxtype b = box();
  int xx = x() + Fl::box_dx(b);
  int yy = y() + Fl::box_dy(b);
  int ww = w() - Fl::box_dw(b);
  int hh = h() - Fl::box_dh(b);
  fl_push_clip(xx, yy, ww, hh);

  ww--; hh--; // adjust for line thickness

  if (min >= max) {
    min = max = 0.0;
    for (int i = 0; i < numb; i++) {
      if (entries[i].val < min)
        min = entries[i].val;
      if (entries[i].val > max)
        max = entries[i].val;
    }
  }

  fl_font(textfont(), textsize());

  switch (type()) {
    case FL_BAR_CHART:
      ww++; // makes the bars fill box correctly
      draw_barchart(xx, yy, ww, hh, numb, entries, min, max, autosize(), maxnumb, textcolor());
      break;
    case FL_HORBAR_CHART:
      hh++; // makes the bars fill box correctly
      draw_horbarchart(xx, yy, ww, hh, numb, entries, min, max, autosize(), maxnumb, textcolor());
      break;
    case FL_PIE_CHART:
      draw_piechart(xx, yy, ww, hh, numb, entries, 0, textcolor());
      break;
    case FL_SPECIALPIE_CHART:
      draw_piechart(xx, yy, ww, hh, numb, entries, 1, textcolor());
      break;
    default:
      draw_linechart(type(), xx, yy, ww, hh, numb, entries, min, max, autosize(), maxnumb,
                     textcolor());
      break;
  }
  draw_label();
  fl_pop_clip();
}


/**
  Create a new Fl_Chart widget using the given position, size and label string.

  The default boxstyle is \c FL_NO_BOX.

  \param[in] X, Y, W, H position and size of the widget
  \param[in] L widget label, default is no label
*/
Fl_Chart::Fl_Chart(int X, int Y, int W, int H, const char *L)
  : Fl_Widget(X, Y, W, H, L) {
  box(FL_BORDER_BOX);
  align(FL_ALIGN_BOTTOM);
  numb = 0;
  maxnumb = 0;
  sizenumb = FL_CHART_MAX;
  autosize_ = 1;
  min = max = 0;
  textfont_ = FL_HELVETICA;
  textsize_ = 10;
  textcolor_ = FL_FOREGROUND_COLOR;
  entries = (FL_CHART_ENTRY *)calloc(sizeof(FL_CHART_ENTRY), FL_CHART_MAX + 1);
}

/**
  Destroys the Fl_Chart widget and all of its data.
*/
Fl_Chart::~Fl_Chart() {
  free(entries);
}

/**
  Removes all values from the chart.
*/
void Fl_Chart::clear() {
  numb = 0;
  min = max = 0;
  redraw();
}

/**
  Adds the data value \p val with optional label \p str and color \p col
  to the chart.

  \param[in] val data value
  \param[in] str optional data label
  \param[in] col optional data color
*/
void Fl_Chart::add(double val, const char *str, unsigned col) {
  // Allocate more entries if required
  if (numb >= sizenumb) {
    sizenumb += FL_CHART_MAX;
    entries = (FL_CHART_ENTRY *)realloc(entries, sizeof(FL_CHART_ENTRY) * (sizenumb + 1));
  }
  // Shift entries as needed
  if (numb >= maxnumb && maxnumb > 0) {
    memmove(entries, entries + 1, sizeof(FL_CHART_ENTRY) * (numb - 1));
    numb--;
  }
  entries[numb].val = float(val);
  entries[numb].col = col;
  if (str) {
    strlcpy(entries[numb].str, str, FL_CHART_LABEL_MAX + 1);
  } else {
    entries[numb].str[0] = 0;
  }
  numb++;
  redraw();
}

/**
  Inserts a data value \p val at the given position \p ind.

  Position 1 is the first data value.

  \param[in] ind insertion position
  \param[in] val data value
  \param[in] str optional data label
  \param[in] col optional data color
*/
void Fl_Chart::insert(int ind, double val, const char *str, unsigned col) {
  int i;
  if (ind < 1 || ind > numb + 1)
    return;
  // Allocate more entries if required
  if (numb >= sizenumb) {
    sizenumb += FL_CHART_MAX;
    entries = (FL_CHART_ENTRY *)realloc(entries, sizeof(FL_CHART_ENTRY) * (sizenumb + 1));
  }
  // Shift entries as needed
  for (i = numb; i >= ind; i--)
    entries[i] = entries[i - 1];
  if (numb < maxnumb || maxnumb == 0)
    numb++;
  // Fill in the new entry
  entries[ind - 1].val = float(val);
  entries[ind - 1].col = col;
  if (str) {
    strlcpy(entries[ind - 1].str, str, FL_CHART_LABEL_MAX + 1);
  } else {
    entries[ind - 1].str[0] = 0;
  }
  redraw();
}

/**
  Replaces a data value \p val at the given position \p ind.

  Position 1 is the first data value.

  \param[in] ind insertion position
  \param[in] val data value
  \param[in] str optional data label
  \param[in] col optional data color
*/
void Fl_Chart::replace(int ind, double val, const char *str, unsigned col) {
  if (ind < 1 || ind > numb)
    return;
  entries[ind - 1].val = float(val);
  entries[ind - 1].col = col;
  if (str) {
    strlcpy(entries[ind - 1].str, str, FL_CHART_LABEL_MAX + 1);
  } else {
    entries[ind - 1].str[0] = 0;
  }
  redraw();
}

/**
  Sets the lower and upper bounds of the chart values.

  \param[in] a, b are used to set lower, upper
*/
void Fl_Chart::bounds(double a, double b) {
  this->min = a;
  this->max = b;
  redraw();
}

/**
  Sets the maximum number of data values for a chart.

  If you do not call this method then the chart will be allowed to grow
  to any size depending on available memory.

  \param[in] m maximum number of data values allowed.
*/
void Fl_Chart::maxsize(int m) {
  int i;
  // Fill in the new number
  if (m < 0)
    return;
  maxnumb = m;
  // Shift entries if required
  if (numb > maxnumb) {
    for (i = 0; i < maxnumb; i++)
      entries[i] = entries[i + numb - maxnumb];
    numb = maxnumb;
    redraw();
  }
}