/*
 * Agg vector rasterization interface
 * Copyright (C) 2007 - 2017 Rene Rebe, ExactCODE GmbH
 * Copyright (C) 2007 Susanne Klaus, ExactCODE GmbH
 *
 * based on GSMP/plugins-gtk/GUI-gtk/Pixmap.cc:
 * Copyright (C) 2000 - 2002 René Rebe and Valentin Ziegler, GSMP
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2. A copy of the GNU General
 * Public License can be found in the file LICENSE.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANT-
 * ABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 * 
 * Alternatively, commercial licensing options are available from the
 * copyright holder ExactCODE GmbH Germany.
 */

#include "vectorial.hh"
#include "C.h" // ARRAY_SIZE
#include <iostream>
#include <cmath>

#include "agg.hh"
#include "Image.hh"

#include "Encodings.hh"

#include "agg_conv_dash.h"
#include "agg_conv_curve.h"
#include "agg_conv_contour.h"
#include "agg_conv_segmentator.h"
#include "agg_conv_smooth_poly1.h"
#include "agg_path_storage.h"
#include "agg_conv_stroke.h"
#include "agg_trans_single_path.h"
#include "agg_bounding_rect.h"

#if WITHFREETYPE == 1
#include "agg_font_freetype.h"
#endif

// ---

Path::Path ()
  : line_width (1.0), dashes_start_offset (0.0),
    line_cap (agg::butt_cap), line_join (agg::miter_join)
{
}

Path::~Path ()
{
}

void Path::moveTo (double x, double y)
{
  path.move_to (x, y);
}

void Path::addLine (double x, double y)
{
  path.line_rel (x, y);
}

void Path::addLineTo (double x, double y)
{
  path.line_to (x, y);
}

void Path::addRect (double x, double y, double x2, double y2)
{
  moveTo (x, y);
  addLineTo (x2, y);
  addLineTo (x2, y2);
  addLineTo (x, y2);
  close ();
}

void Path::addArcTo (double rx, double ry,  double angle,
		     double x, double y)
{
  path.arc_to (rx, ry, angle,
	       false /*large arc */, false /* sweep */,
	       x, y);
}

void Path::addArc (double rx, double ry,  double angle,
		     double dx, double dy)
{
  path.arc_rel (rx, ry, angle,
	        false /*large arc */, false /* sweep */,
	        dx, dy);
}

void Path::addCurveTo (double c1x, double c1y,
		       double x, double y)
{
  path.curve3 (c1x, c1y, x, y);
}

void Path::addCurveTo (double c1x, double c1y, double c2x, double c2y,
		       double x, double y)
{
  path.curve4 (c1x, c1y, c2x, c2y, x, y);
}

void Path::end ()
{
  // do not close the path, we have ::close() for that purpose
  path.end_poly (agg::path_flags_none);
}

void Path::close ()
{
  path.close_polygon ();
}

void Path::clear ()
{
  path.remove_all ();
}

void Path::setFillColor (double _r, double _g, double _b, double _a)
{
  r = _r;
  g = _g;
  b = _b;
  a = _a;
}

void Path::setLineWidth (double width)
{
  line_width = width;
}

void Path::setLineDash (double offset, const std::vector<double>& _dashes)
{
  dashes_start_offset = offset;
  dashes = _dashes;
}

void Path::setLineDash (double offset, const double* _dashes, int n)
{
  dashes_start_offset = offset;
  dashes.clear ();
  for (; n; n--, _dashes++)
    dashes.push_back (*_dashes);
}

void Path::setLineCap (line_cap_t cap)
{
  line_cap = cap;
}

void Path::setLineJoin (line_join_t join)
{
  line_join = join;
}

void Path::draw (Image& image, filling_rule_t fill,
		 agg::trans_affine mtx)
{
  renderer_exact_image ren_base (image);
  
  /* the rederer_bin type would "avoid" anti-aliasing */
  renderer_aa ren (ren_base);
  ren.color (agg::rgba (r, g, b, a));
  
  rasterizer_scanline ras;
  scanline sl;

  agg::conv_curve<agg::path_storage> smooth (path);
  agg::conv_transform<agg::conv_curve<agg::path_storage> > smooth_mtx(smooth, mtx);
    
  if (fill == fill_none)
    {
      agg::line_profile_aa profile;
      profile.gamma (agg::gamma_power(1.2)); // optional
      //profile.min_width (0.75); // optional
      //profile.smoother_width (3.0); //optional
      
      if (dashes.empty ())
	{
	  agg::conv_stroke<agg::conv_transform<agg::conv_curve<agg::path_storage> > > stroke (smooth_mtx);
	  
	  stroke.line_cap (line_cap);
	  stroke.line_join (line_join);
	  stroke.width (line_width);
	  
	  ras.add_path (stroke);
	}
      else
	{
	  typedef agg::conv_dash<agg::conv_transform<agg::conv_curve<agg::path_storage> > > dash_t;
	  dash_t dash (smooth_mtx);
	  dash.dash_start (dashes_start_offset);
	  for (std::vector<double>::const_iterator i = dashes.begin ();
	       i != dashes.end ();) {
	    double a = *i++, b;
	    if (i != dashes.end ())
	      b = *i++;
	    else
	      break; // TODO: warn or exception ?
	    dash.add_dash (a, b);
	  }
	  
	  agg::conv_stroke<dash_t> stroke (dash);
	  
	  stroke.line_cap (line_cap);
	  stroke.line_join (line_join);
	  stroke.width (line_width);
	  
	  ras.add_path (stroke);
	}
    }
  else {
    // just cast, we use a toll-free enum bridge
    ras.filling_rule ((agg::filling_rule_e)fill);
    ras.add_path (smooth_mtx);
  }
  
  agg::render_scanlines (ras, sl, ren);
  image.setRawData(); // invalidate cache
}

#if WITHFREETYPE == 1

static const bool hinting = true;
static const bool kerning = true;

typedef agg::font_engine_freetype_int32 font_engine_type;
typedef agg::font_cache_manager<font_engine_type> font_manager_type;
static agg::glyph_rendering gren = agg::glyph_ren_outline;

static const char* fonts[] = {
 "/usr/X11/share/fonts/TTF/DejaVuSans.ttf",
 "/usr/X11/share/fonts/TTF/Vera.ttf",
};

static bool load_font(font_engine_type& m_feng, const char* fontfile)
{
  if (fontfile) {
    if (m_feng.load_font (fontfile, 0, gren))
      return true;
    
    std::cerr << "failed to load ttf font: " << fontfile << std::endl;
    return false;
  }
  else {
    for (unsigned int i = 0; i < ARRAY_SIZE(fonts); ++i)
      {
	if (m_feng.load_font (fonts[i], 0, gren))
	  return true;
	
	std::cerr << "failed to load ttf font: " << fonts[i] << std::endl;
      }
  }
  return false;
}

bool Path::drawText (Image& image, const char* text, double height,
		     const char* fontfile, agg::trans_affine mtx,
		     filling_rule_t fill,
		     double* w, double* h, double* dx, double* dy)
{
  if (!text) return false;
  renderer_exact_image ren_base (image);
  
  rasterizer_scanline ras;
  scanline sl;
  
  renderer_aa ren_solid (ren_base);
  ren_solid.color (agg::rgba (r, g, b, a));

  renderer_bin ren_bin (ren_base);
  ren_bin.color (agg::rgba (r, g, b, a));
  
  font_engine_type m_feng;
  font_manager_type m_fman (m_feng);
 
  mtx *= agg::trans_affine_translation(path.last_x(), path.last_y());
  
  // Pipeline to process the vectors glyph paths
  agg::conv_curve<font_manager_type::path_adaptor_type>
    m_curves(m_fman.path_adaptor());
  agg::conv_transform<agg::conv_curve<font_manager_type::path_adaptor_type> >
    m_curves_mtx(m_curves, mtx);
  
  agg::conv_stroke<agg::conv_curve<font_manager_type::path_adaptor_type> >
    m_stroke(m_curves);
  m_stroke.width(line_width);
  agg::conv_transform<agg::conv_stroke<agg::conv_curve<font_manager_type::path_adaptor_type> > >
    m_stroke_mtx(m_stroke, mtx);
 
  m_feng.height (height);
  if (!load_font(m_feng, fontfile))
    return false;
  
  m_feng.hinting (hinting);
  m_feng.height (height);
  m_feng.flip_y (true);
  
  
  agg::rect_d bbox(0, 0, -1, -1);
  
  std::vector<uint32_t> utf8 = DecodeUtf8(text, strlen(text));
  double x = 0, y = 0;
  for (unsigned int i = 0, n = 0; i < utf8.size(); ++i)
    {
      switch (utf8[i]) {
      case '\n':
	n = 0;
	x = path.last_x();
	y += height * 1.2;
	continue;
	
      case '\t':
	{
	  const agg::glyph_cache* glyph = m_fman.glyph(' ');
	  int skip = 8 - n % 8;
	  x += glyph->advance_x * skip;
	  y += glyph->advance_y * skip;
	  n += skip;
	}
	continue;
      }
      
      const agg::glyph_cache* glyph = m_fman.glyph(utf8[i]);
      if (glyph)
	{
	  if (kerning)
	    m_fman.add_kerning(&x, &y);
	  m_fman.init_embedded_adaptors(glyph, x, y);

	  switch (glyph->data_type)
	    {
	    case agg::glyph_data_mono:
	      if (!w && !h)
		agg::render_scanlines (m_fman.mono_adaptor(), 
				       m_fman.mono_scanline(), 
				       ren_bin);
	      break;

	    case agg::glyph_data_gray8:
	      if (!w && !h)
		agg::render_scanlines (m_fman.gray8_adaptor(), 
				       m_fman.gray8_scanline(), 
				       ren_solid);
	      break;

	    case agg::glyph_data_outline:
	      if (fill != fill_none) {
		if (w && h) {
		  agg::rect_d r;
		  agg::bounding_rect_single(m_curves_mtx, 0,
					    &r.x1, &r.y1, &r.x2, &r.y2);
		  if (!bbox.is_valid())
		    bbox = r;
		  else
		    bbox = agg::unite_rectangles(bbox, r);
		} else
		  ras.add_path (m_curves_mtx);
	      }
	      else {
		if (w && h) {
		  agg::rect_d r;
		  agg::bounding_rect_single(m_stroke_mtx, 0,
					    &r.x1, &r.y1, &r.x2, &r.y2);
		  if (!bbox.is_valid())
		    bbox = r;
		  else
		    bbox = agg::unite_rectangles(bbox, r);
		} else
		  ras.add_path (m_stroke_mtx);
	      }
	      break;
	      
	    default:
	      break;
	    }

	  // increment pen position
	  x += glyph->advance_x;
	  y += glyph->advance_y;
	}
    }
  
  if (w || h) {
    *w = bbox.x2 - bbox.x1 + 1;
    *h = bbox.y2 - bbox.y1 + 1;
    
    *dx = *dy = 0;
    mtx.transform(dx, dy);
    *dx -= bbox.x1;
    *dy -= bbox.y1;
    
    return true;
  }
  
  agg::render_scanlines(ras, sl, ren_solid);
  image.setRawData(); // invalidate cache
  
  mtx.transform(&x, &y);
  path.move_to(x, y); // save last point for further drawing

  return true;
}

bool Path::drawTextOnPath (Image& image, const char* text, double height,
			   const char* fontfile) // TODO: , filling_rule_t fill)
{
  if (!text) return false;
  renderer_exact_image ren_base (image);
  
  renderer_aa ren_solid (ren_base);
  ren_solid.color (agg::rgba (r, g, b, a));

  rasterizer_scanline ras;
  scanline sl;
  
  agg::conv_curve<agg::path_storage> smooth (path);
  agg::trans_single_path tcurve;
  tcurve.add_path (smooth);
  // tcurve.preserve_x_scale(m_preserve_x_scale.status());
  
  font_engine_type m_feng;
  font_manager_type m_fman (m_feng);
  
  // Pipeline to process the vectors glyph paths
  agg::conv_curve<font_manager_type::path_adaptor_type> m_curves (m_fman.path_adaptor());
  
  m_feng.height (height);
  if (!load_font(m_feng, fontfile))
      return false;
  
  // Transform pipeline
  typedef agg::conv_curve<font_manager_type::path_adaptor_type> conv_font_curve_type;
  typedef agg::conv_segmentator<conv_font_curve_type> conv_font_segm_type;
  typedef agg::conv_transform<conv_font_segm_type, agg::trans_single_path> conv_font_trans_type;
  conv_font_curve_type fcurves (m_fman.path_adaptor());
  
  conv_font_segm_type  fsegm (fcurves);
  conv_font_trans_type ftrans (fsegm, tcurve);
  fsegm.approximation_scale (3.0);
  fcurves.approximation_scale (2.0);
  
  m_feng.hinting (hinting);
  m_feng.height (height);
  m_feng.flip_y (true);
  
  ras.reset ();
  
  double x = 0, y = 0;
  
  std::vector<uint32_t> utf8 = DecodeUtf8(text, strlen(text));
  for (unsigned int i = 0, n = 0; i < utf8.size(); ++i)
    {
      switch (utf8[i]) {
      case '\n':
	n = 0;
	x = 0;
	y += height * 1.2;
	continue;
      case '\t':
	{
	  const agg::glyph_cache* glyph = m_fman.glyph(' ');
	  int skip = 8 - n % 8;
	  x += glyph->advance_x * skip;
	  y += glyph->advance_y * skip;
	  n += skip;
	}
	continue;
      }
      
      const agg::glyph_cache* glyph = m_fman.glyph(utf8[i]);
      if (glyph)
	{
	  if (kerning)
	    m_fman.add_kerning(&x, &y);
	  
	  m_fman.init_embedded_adaptors(glyph, x, y);
	  
	  if (glyph->data_type == agg::glyph_data_outline)
	    {
	      ras.add_path (ftrans);
	    }
	  else
	    std::cerr << "Warning: unexpected glyph type!" << std::endl;
	  
	  // increment pen position
	  x += glyph->advance_x;
	  y += glyph->advance_y;
	}
    }
  
  agg::render_scanlines(ras, sl, ren_solid);
  image.setRawData(); // invalidate cache

  path.move_to(x, y); // save last point for further drawing
  return true;
}

#endif