/*
	Neutrino-GUI  -   DBoxII-Project

	Copyright (C) 2001 Steffen Hehn 'McClean'
        Copyright (C) 2003 thegoodguy

	License: GPL

	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; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>

// this method is recommended for FreeType >2.0.x:
#include <ft2build.h>
#include FT_FREETYPE_H

#include <driver/fontrenderer.h>

#include <system/debug.h>
#include <global.h>

/* Drawing pixels is actually faster without the GXA accelerator (wich OTOH is
   faster for drawing lines, so disable it here. */
#undef USE_NEVIS_GXA

FT_Error FBFontRenderClass::myFTC_Face_Requester(FTC_FaceID  face_id,
        FT_Library  /*library*/,
        FT_Pointer  request_data,
        FT_Face*    aface)
{
	return ((FBFontRenderClass*)request_data)->FTC_Face_Requester(face_id, aface);
}


FBFontRenderClass::FBFontRenderClass(const int xr, const int yr)
{
	dprintf(DEBUG_DEBUG, "[FONT] initializing core...\n");
	if (FT_Init_FreeType(&library))
	{
		dprintf(DEBUG_NORMAL, "[FONT] initializing core failed.\n");
		return;
	}

	font = NULL;

	xres = xr;
	yres = yr;

	int maxbytes= 4 *1024*1024;
	dprintf(DEBUG_INFO, "[FONT] Intializing font cache, using max. %dMB...\n", maxbytes/1024/1024);
	fflush(stdout);
	if (FTC_Manager_New(library, 10, 20, maxbytes, myFTC_Face_Requester, this, &cacheManager))
	{
		dprintf(DEBUG_NORMAL, "[FONT] manager failed!\n");
		return;
	}
	if (!cacheManager)
	{
		dprintf(DEBUG_NORMAL, "[FONT] error.\n");
		return;
	}
	if (FTC_SBitCache_New(cacheManager, &sbitsCache))
	{
		dprintf(DEBUG_NORMAL, "[FONT] sbit failed!\n");
		return;
	}
/*	if (FTC_ImageCache_New(cacheManager, &imageCache))
	{
		printf(" imagecache failed!\n");
	}
*/
	pthread_mutex_init( &render_mutex, NULL );
}

FBFontRenderClass::~FBFontRenderClass()
{
	fontListEntry * g;

	for (fontListEntry * f = font; f; f = g)
	{
		g = f->next;
		delete f;
	}

	FTC_Manager_Done(cacheManager);
	FT_Done_FreeType(library);
}

FT_Error FBFontRenderClass::FTC_Face_Requester(FTC_FaceID face_id, FT_Face* aface)
{
	fontListEntry *lfont=(fontListEntry *)face_id;
	if (!lfont)
		return -1;
	dprintf(DEBUG_DEBUG, "[FONT] FTC_Face_Requester (%s/%s)\n", lfont->family, lfont->style);

	int error;
	if ((error=FT_New_Face(library, lfont->filename, 0, aface)))
	{
		dprintf(DEBUG_NORMAL, "[FONT] FTC_Face_Requester (%s/%s) failed: %i\n", lfont->family, lfont->style, error);
		return error;
	}

	if (strcmp(lfont->style, (*aface)->style_name) != 0)
	{
		FT_Matrix matrix; // Italics

		matrix.xx = 1 * 0x10000;
		matrix.xy = (0x10000 >> 3);
		matrix.yx = 0 * 0x10000;
		matrix.yy = 1 * 0x10000;

		FT_Set_Transform(*aface, &matrix, NULL);
	}
	return 0;
}

FTC_FaceID FBFontRenderClass::getFaceID(const char * const family, const char * const style)
{
	for (fontListEntry *f=font; f; f=f->next)
	{
		if ((!strcmp(f->family, family)) && (!strcmp(f->style, style)))
			return (FTC_FaceID)f;
	}
	if (strncmp(style, "Bold ", 5) == 0)
	{
		for (fontListEntry *f=font; f; f=f->next)
		{
			if ((!strcmp(f->family, family)) && (!strcmp(f->style, &(style[5]))))
				return (FTC_FaceID)f;
		}
	}
	for (fontListEntry *f=font; f; f=f->next)
	{
		if (!strcmp(f->family, family))
		{
			if (f->next) // the first font always seems to be italic, skip if possible
				continue;
			return (FTC_FaceID)f;
		}
	}
	return 0;
}

FT_Error FBFontRenderClass::getGlyphBitmap(FTC_ImageTypeRec *pfont, FT_ULong glyph_index, FTC_SBit *sbit)
{
	return FTC_SBitCache_Lookup(sbitsCache, pfont, glyph_index, sbit, NULL);
}

FT_Error FBFontRenderClass::getGlyphBitmap(FTC_ScalerRec *sc, FT_ULong glyph_index, FTC_SBit *sbit)
{
	return FTC_SBitCache_LookupScaler(sbitsCache, sc, FT_LOAD_DEFAULT, glyph_index, sbit, NULL);
}

const char *FBFontRenderClass::AddFont(const char * const filename, const bool make_italics)
{
	fflush(stdout);
	int error;
	fontListEntry *n=new fontListEntry;

	FT_Face face;
	if ((error=FT_New_Face(library, filename, 0, &face)))
	{
		dprintf(DEBUG_NORMAL, "[FONT] adding font %s, failed: %i\n", filename, error);
		delete n;//Memory leak: n
		return NULL;
	}
	n->filename = strdup(filename);
	n->family   = strdup(face->family_name);
	n->style    = strdup(make_italics ? "Italic" : face->style_name);
	FT_Done_Face(face);
	n->next=font;
	dprintf(DEBUG_DEBUG, "[FONT] adding font %s... family %s, style %s ok\n", filename, n->family, n->style);
	font=n;
	return n->style;
}

FBFontRenderClass::fontListEntry::~fontListEntry()
{
	free(filename);
	free(family);
	free(style);
}

Font *FBFontRenderClass::getFont(const char * const family, const char * const style, int size)
{
	FTC_FaceID id = getFaceID(family, style);
	if (!id) {
		dprintf(DEBUG_DEBUG, "[FONT] getFont: family %s, style %s failed!\n", family, style);
		return 0;
	}
	dprintf(DEBUG_DEBUG, "[FONT] getFont: family %s, style %s ok\n", family, style);
	return new Font(this, id, size, (strcmp(((fontListEntry *)id)->style, style) == 0) ? Font::Regular : Font::Embolden);
}

std::string FBFontRenderClass::getFamily(const char * const filename) const
{
	for (fontListEntry *f=font; f; f=f->next)
	{
		if (!strcmp(f->filename, filename))
			return f->family;
	}

  return "";
}

Font::Font(FBFontRenderClass *render, FTC_FaceID faceid, const int isize, const fontmodifier _stylemodifier)
{
	stylemodifier           = _stylemodifier;

	frameBuffer 		= CFrameBuffer::getInstance();
	renderer 		= render;
	font.face_id 	= faceid;
	font.width  	= isize;
	font.height 	= isize;
	//font.image_type 	= ftc_image_grays;
	//font.image_type 	|= ftc_image_flag_autohinted;
	font.flags = FT_LOAD_RENDER | FT_LOAD_FORCE_AUTOHINT;

	scaler.face_id = font.face_id;
	scaler.width   = isize * 64;
	scaler.height  = isize * 64;
	scaler.pixel   = false;
	scaler.x_res   = render->xres;
	scaler.y_res   = render->yres;

	setSize(isize);
}

FT_Error Font::getGlyphBitmap(FT_ULong glyph_index, FTC_SBit *sbit)
{
	return renderer->getGlyphBitmap(&scaler, glyph_index, sbit);
}

int Font::setSize(int isize)
{
	int temp = font.width;
	font.width = font.height = isize;
	scaler.width  = isize * 64;
	scaler.height = isize * 64;

	FT_Error err = FTC_Manager_LookupSize(renderer->cacheManager, &scaler, &size);
	if (err != 0)
	{
		dprintf(DEBUG_NORMAL, "%s:FTC_Manager_LookupSize failed (0x%x)\n", __FUNCTION__, err);
		return 0;
	}
	face = size->face;
#if 0
//FIXME test

	ascender = face->ascender;
	descender = face->descender;
	height = face->height;
	lower = -descender+(-(descender>>1))+1;
return 0;
#endif
	// hack begin (this is a hack to get correct font metrics, didn't find any other way which gave correct values)
	FTC_SBit glyph;
	int index;

	index=FT_Get_Char_Index(face, 'M'); // "M" gives us ascender
	getGlyphBitmap(index, &glyph);
	int tM=glyph->top;
	fontwidth = glyph->width;

	index=FT_Get_Char_Index(face, 'g'); // "g" gives us descender
	getGlyphBitmap(index, &glyph);
	int hg=glyph->height;
	int tg=glyph->top;

	ascender=tM;
	descender=tg-hg; //this is a negative value!
	int halflinegap= -(descender>>1); // |descender/2| - we use descender as linegap, half at top, half at bottom
	upper = halflinegap+ascender+3;   // we add 3 at top
	lower = -descender+halflinegap+1; // we add 1 at bottom
	height=upper+lower;               // this is total height == distance of lines
	DigitHeight = ascender+2;
	DigitOffset = -descender+halflinegap;
	// hack end

	//printf("glyph: hM=%d tM=%d hg=%d tg=%d ascender=%d descender=%d height=%d linegap/2=%d upper=%d lower=%d\n",
	//       hM,tM,hg,tg,ascender,descender,height,halflinegap,upper,lower);
	//printf("font metrics: height=%ld\n", (size->metrics.height+32) >> 6);
	return temp;
}

int Font::getWidth(void)
{
	return fontwidth;
}

int Font::getHeight(void)
{
	return height;
}

int Font::getDigitHeight(void)
{
	return DigitHeight;
}

int Font::getDigitOffset(void)
{
	return DigitOffset;
}

int UTF8ToUnicode(const char * &text, const bool utf8_encoded) // returns -1 on error
{
	int unicode_value;
//printf("%c ", (unsigned char)(*text));
	if (utf8_encoded && ((((unsigned char)(*text)) & 0x80) != 0))
	{
		int remaining_unicode_length;
		if ((((unsigned char)(*text)) & 0xf8) == 0xf0)
		{
			unicode_value = ((unsigned char)(*text)) & 0x07;
			remaining_unicode_length = 3;
		}
		else if ((((unsigned char)(*text)) & 0xf0) == 0xe0)
		{
			unicode_value = ((unsigned char)(*text)) & 0x0f;
			remaining_unicode_length = 2;
		}
		else if ((((unsigned char)(*text)) & 0xe0) == 0xc0)
		{
			unicode_value = ((unsigned char)(*text)) & 0x1f;
			remaining_unicode_length = 1;
		}
		else                     // cf.: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
			return -1;       // corrupted character or a character with > 4 bytes utf-8 representation

		for (int i = 0; i < remaining_unicode_length; i++)
		{
			text++;
			if (((*text) & 0xc0) != 0x80)
			{
				remaining_unicode_length = -1;
				return -1;          // incomplete or corrupted character
			}
			unicode_value <<= 6;
			unicode_value |= ((unsigned char)(*text)) & 0x3f;
		}
		if (remaining_unicode_length == -1)
			return -1;                  // incomplete or corrupted character
	}
	else
		unicode_value = (unsigned char)(*text);

	return unicode_value;
}

void Font::RenderString(int x, int y, const int width, const char *text, const unsigned char color, const int boxheight, const bool utf8_encoded)
{
	if (!frameBuffer->getActive())
		return;

	pthread_mutex_lock( &renderer->render_mutex );

	FT_Error err = FTC_Manager_LookupSize(renderer->cacheManager, &scaler, &size);
	if (err != 0)
	{
		dprintf(DEBUG_NORMAL, "%s:FTC_Manager_LookupSize failed (0x%x)\n", __FUNCTION__, err);
		pthread_mutex_unlock(&renderer->render_mutex);
		return;
	}
	face = size->face;

	int use_kerning=FT_HAS_KERNING(face);

	int left=x;
	int step_y=height;

	// ----------------------------------- box upper end (this is NOT a font metric, this is our method for y centering)
	//
	// **  -------------------------------- y=baseline-upper
	// ||
	// |u  --------------------*----------- y=baseline+ascender
	// |p                     * *
	// hp                    *   *
	// ee     *        *    *     *
	// ir      *      *     *******
	// g|       *    *      *     *
	// h|        *  *       *     *
	// t*  -------**--------*-----*-------- y=baseline
	// |l         *
	// |o        *
	// |w  -----**------------------------- y=baseline+descender   // descender is a NEGATIVE value
	// |r
	// **  -------------------------------- y=baseline+lower == YCALLER
	//
	// ----------------------------------- box lower end (this is NOT a font metric, this is our method for y centering)

	// height = ascender + -1*descender + linegap           // descender is negative!

	// now we adjust the given y value (which is the line marked as YCALLER) to be the baseline after adjustment:
	y -= lower;
	// y coordinate now gives font baseline which is used for drawing

	// caution: this only works if we print a single line of text
	// if we have multiple lines, don't use boxheight or specify boxheight==0.
	// if boxheight is !=0, we further adjust y, so that text is y-centered in the box
	if(boxheight)
	{
		if(boxheight>step_y)			// this is a real box (bigger than text)
			y -= ((boxheight-step_y)>>1);
		else if(boxheight<0)			// this normally would be wrong, so we just use it to define a "border"
			y += (boxheight>>1);		// half of border value at lower end, half at upper end
	}

	int lastindex=0; // 0 == missing glyph (never has kerning values)
	FT_Vector kerning;
	int pen1=-1; // "pen" positions for kerning, pen2 is "x"

	static fb_pixel_t oldbgcolor = 0, oldfgcolor = 0;
	static fb_pixel_t colors[256]={0};

	fb_pixel_t bgcolor = frameBuffer->realcolor[color];
	fb_pixel_t fgcolor = frameBuffer->realcolor[(((((int)color) + 2) | 7) - 2)];

	if((oldbgcolor != bgcolor) || (oldfgcolor != fgcolor)) {

		oldbgcolor = bgcolor;
		oldfgcolor = fgcolor;
		t_fb_var_screeninfo * screeninfo = frameBuffer->getScreenInfo();
		int rl = screeninfo->red.length;
		int ro = screeninfo->red.offset;
		int gl = screeninfo->green.length;
		int go = screeninfo->green.offset;
		int bl = screeninfo->blue.length;
		int bo = screeninfo->blue.offset;
		int tl = screeninfo->transp.length;
		int to = screeninfo->transp.offset;
		int fgr = (((int)fgcolor >> ro) & ((1 << rl) - 1));
		int fgg = (((int)fgcolor >> go) & ((1 << gl) - 1));
		int fgb = (((int)fgcolor >> bo) & ((1 << bl) - 1));
		int fgt = (((int)fgcolor >> to) & ((1 << tl) - 1));
		int deltar = (((int)bgcolor >> ro) & ((1 << rl) - 1)) - fgr;
		int deltag = (((int)bgcolor >> go) & ((1 << gl) - 1)) - fgg;
		int deltab = (((int)bgcolor >> bo) & ((1 << bl) - 1)) - fgb;
		int deltat = (((int)bgcolor >> to) & ((1 << tl) - 1)) - fgt;


		for (int i = 0; i < 256; i++) {
			colors[255 - i] =
				((((fgr + deltar * i / 255) & ((1 << rl) - 1)) << ro) |
				 (((fgg + deltag * i / 255) & ((1 << gl) - 1)) << go) |
				 (((fgb + deltab * i / 255) & ((1 << bl) - 1)) << bo) |
				 (((fgt + deltat * i / 255) & ((1 << tl) - 1)) << to));
			/* FIXME must be better solution */
			if(g_settings.contrast_fonts && ((255-i) > 128))
				colors[255 - i] |=  0xFF << to;
		}
	}

	int spread_by = 0;
	if (stylemodifier == Font::Embolden)
	{
		spread_by = (fontwidth / 6) - 1;
		if (spread_by < 1)
			spread_by = 1;
	}

	/* the GXA seems to do it's job asynchonously, so we need to wait until
	   it's ready, otherwise the font will sometimes "be overwritten" with
	   background color */
#ifndef USE_NEVIS_GXA
	frameBuffer->waitForIdle();
#endif
	for (; *text; text++)
	{
		FTC_SBit glyph;

		int unicode_value = UTF8ToUnicode(text, utf8_encoded);

		if (unicode_value == -1)
			break;

		if (*text=='\n')
		{
			/* a '\n' in the text is basically an error, it should not have come
			   until here. To find the offenders, we replace it with a paragraph
			   marker */
			unicode_value = 0x00b6; /* &para;  PILCROW SIGN */
			/* this did not work anyway - pen1 overrides x value down below :-)
			   and there are no checks that we don't leave our assigned box
			x  = left;
			y += step_y;
			 */
		}

		int index = FT_Get_Char_Index(face, unicode_value);

		if (!index)
			continue;
		if (getGlyphBitmap(index, &glyph))
		{
			dprintf(DEBUG_NORMAL, "failed to get glyph bitmap.\n");
			continue;
		}

		//kerning
		if (use_kerning)
		{
			FT_Get_Kerning(face, lastindex, index, 0, &kerning);
			//x+=(kerning.x+32)>>6; // kerning!
			x += (kerning.x) >> 6; // kerning!
		}

		// width clip
		if (x + glyph->xadvance + spread_by > left + width)
			break;

		#ifndef USE_NEVIS_GXA
		int stride  = frameBuffer->getStride();
		int ap=(x + glyph->left) * sizeof(fb_pixel_t) + stride * (y - glyph->top);
		uint8_t * d = ((uint8_t *)frameBuffer->getFrameBufferPointer()) + ap;
		#endif
		uint8_t * s = glyph->buffer;
		int w       = glyph->width;
		int h       = glyph->height;
		int pitch   = glyph->pitch;
		#ifndef USE_NEVIS_GXA
		if(ap>-1){
		#endif
			for (int ay=0; ay<h; ay++)
			{
				#ifndef USE_NEVIS_GXA
				fb_pixel_t * td = (fb_pixel_t *)d;
				#endif

				int ax;
				for (ax=0; ax < w + spread_by; ax++)
				{
					if (stylemodifier != Font::Embolden)
					{
						#ifdef USE_NEVIS_GXA
						/* not nice (and also slower), but currently the easiest way to prevent visible errors */
						frameBuffer->paintPixel(x + glyph->left + ax, y - glyph->top + ay, colors[*s++]);
						#else
						/* do not paint the backgroundcolor, see below */
						//if (colors[*s] != bgcolor)
						// from code above bgcolor index should be always 0
						if(*s != 0)
							*td = colors[*s];
						td++; s++;
						#endif
					}
					else
					{
						int start, end;
						int lcolor = -1;

						if (ax < w)
							start = 0;
						else
							start = ax - w + 1;

						if (ax < spread_by)
							end = ax + 1;
						else
							end = spread_by + 1;

						for (int i = start; i < end; i++)
							if (lcolor < *(s - i))
								lcolor = *(s - i);
						#ifdef USE_NEVIS_GXA
						frameBuffer->paintPixel(x + glyph->left + ax, y - glyph->top + ay, colors[lcolor]);
						#else
						/* we make the font "transparent" by not painting the background color
						   colored boxes are painted beneath the fonts anyway
						   note that this is not totally correct, because of subpixel hinting etc,
						   but that should be barely visible in reality ;) */
						//if (colors[lcolor] != bgcolor)
						// from code above bgcolor index should be always 0
						if (lcolor != 0)
							*td = colors[lcolor];
						td++;
						#endif
						s++;
					}
				}
				s += pitch- ax;
				#ifndef USE_NEVIS_GXA
				d += stride;
				#endif
			}
		#ifndef USE_NEVIS_GXA
		}
		#endif
		x+=glyph->xadvance+1;
		//x+=glyph->xadvance;
		if(pen1>x)
			x=pen1;
		pen1=x;
		lastindex=index;
	}
//printf("RenderStat: %d %d %d \n", renderer->cacheManager->num_nodes, renderer->cacheManager->num_bytes, renderer->cacheManager->max_bytes);
	pthread_mutex_unlock( &renderer->render_mutex );
}

void Font::RenderString(int x, int y, const int width, const std::string & text, const unsigned char color, const int boxheight, const bool utf8_encoded)
{
	RenderString(x, y, width, text.c_str(), color, boxheight, utf8_encoded);
}

int Font::getRenderWidth(const char *text, const bool utf8_encoded)
{
	pthread_mutex_lock( &renderer->render_mutex );

	FT_Error err = FTC_Manager_LookupSize(renderer->cacheManager, &scaler, &size);
	if (err != 0)
	{
		dprintf(DEBUG_NORMAL, "%s:FTC_Manager_LookupSize failed (0x%x)\n", __FUNCTION__, err);
		pthread_mutex_unlock(&renderer->render_mutex);
		return -1;
	}
	face = size->face;

	int use_kerning=FT_HAS_KERNING(face);
	int x=0;
	int lastindex=0; // 0==missing glyph (never has kerning)
	FT_Vector kerning;
	int pen1=-1; // "pen" positions for kerning, pen2 is "x"
	for (; *text; text++)
	{
		FTC_SBit glyph;

		int unicode_value = UTF8ToUnicode(text, utf8_encoded);

		if (unicode_value == -1)
			break;

		int index=FT_Get_Char_Index(face, unicode_value);

		if (!index)
			continue;
		if (getGlyphBitmap(index, &glyph))
		{
			dprintf(DEBUG_NORMAL, "failed to get glyph bitmap.\n");
			continue;
		}
		//kerning
		if (use_kerning)
		{
			FT_Get_Kerning(face, lastindex, index, 0, &kerning);
			x += (kerning.x) >> 6; // kerning!
		}

		x+=glyph->xadvance+1;
		if(pen1>x)
			x=pen1;
		pen1=x;
		lastindex=index;
	}

	if (stylemodifier == Font::Embolden)
	{
		int spread_by = (fontwidth / 6) - 1;
		if (spread_by < 1)
			spread_by = 1;

		x += spread_by;
	}

	pthread_mutex_unlock( &renderer->render_mutex );

	return x;
}

int Font::getRenderWidth(const std::string & text, const bool utf8_encoded)
{
	return getRenderWidth(text.c_str(), utf8_encoded);
}