#include "fitz.h"
#include "mupdf.h"

static void
pdf_run_glyph_func(void *doc, void *rdb_, fz_buffer *contents, fz_device *dev, fz_matrix ctm, void *gstate)
{
	pdf_obj *rdb = (pdf_obj *)rdb_;
	pdf_run_glyph(doc, rdb, contents, dev, ctm, gstate);
}

static void
pdf_t3_free_resources(void *doc, void *rdb_)
{
	pdf_obj *rdb = (pdf_obj *)rdb_;
	pdf_drop_obj(rdb);
}


pdf_font_desc *
pdf_load_type3_font(pdf_document *xref, pdf_obj *rdb, pdf_obj *dict)
{
	char buf[256];
	char *estrings[256];
	pdf_font_desc *fontdesc = NULL;
	pdf_obj *encoding;
	pdf_obj *widths;
	pdf_obj *charprocs;
	pdf_obj *obj;
	int first, last;
	int i, k, n;
	fz_rect bbox;
	fz_matrix matrix;
	fz_context *ctx = xref->ctx;

	fz_var(fontdesc);

	fz_try(ctx)
	{
		obj = pdf_dict_gets(dict, "Name");
		if (pdf_is_name(obj))
			fz_strlcpy(buf, pdf_to_name(obj), sizeof buf);
		else
			sprintf(buf, "Unnamed-T3");

		fontdesc = pdf_new_font_desc(ctx);

		obj = pdf_dict_gets(dict, "FontMatrix");
		matrix = pdf_to_matrix(ctx, obj);

		obj = pdf_dict_gets(dict, "FontBBox");
		bbox = pdf_to_rect(ctx, obj);
		bbox = fz_transform_rect(matrix, bbox);

		fontdesc->font = fz_new_type3_font(ctx, buf, matrix);
		fontdesc->size += sizeof(fz_font) + 256 * (sizeof(fz_buffer*) + sizeof(float));

		fz_set_font_bbox(ctx, fontdesc->font, bbox.x0, bbox.y0, bbox.x1, bbox.y1);

		/* Encoding */

		for (i = 0; i < 256; i++)
			estrings[i] = NULL;

		encoding = pdf_dict_gets(dict, "Encoding");
		if (!encoding)
		{
			fz_throw(ctx, "syntaxerror: Type3 font missing Encoding");
		}

		if (pdf_is_name(encoding))
			pdf_load_encoding(estrings, pdf_to_name(encoding));

		if (pdf_is_dict(encoding))
		{
			pdf_obj *base, *diff, *item;

			base = pdf_dict_gets(encoding, "BaseEncoding");
			if (pdf_is_name(base))
				pdf_load_encoding(estrings, pdf_to_name(base));

			diff = pdf_dict_gets(encoding, "Differences");
			if (pdf_is_array(diff))
			{
				n = pdf_array_len(diff);
				k = 0;
				for (i = 0; i < n; i++)
				{
					item = pdf_array_get(diff, i);
					if (pdf_is_int(item))
						k = pdf_to_int(item);
					if (pdf_is_name(item))
						estrings[k++] = pdf_to_name(item);
					if (k < 0) k = 0;
					if (k > 255) k = 255;
				}
			}
		}

		fontdesc->encoding = pdf_new_identity_cmap(ctx, 0, 1);
		fontdesc->size += pdf_cmap_size(ctx, fontdesc->encoding);

		pdf_load_to_unicode(xref, fontdesc, estrings, NULL, pdf_dict_gets(dict, "ToUnicode"));

		/* Widths */

		pdf_set_default_hmtx(ctx, fontdesc, 0);

		first = pdf_to_int(pdf_dict_gets(dict, "FirstChar"));
		last = pdf_to_int(pdf_dict_gets(dict, "LastChar"));

		widths = pdf_dict_gets(dict, "Widths");
		if (!widths)
		{
			fz_throw(ctx, "syntaxerror: Type3 font missing Widths");
		}

		for (i = first; i <= last; i++)
		{
			float w = pdf_to_real(pdf_array_get(widths, i - first));
			w = fontdesc->font->t3matrix.a * w * 1000;
			fontdesc->font->t3widths[i] = w * 0.001f;
			pdf_add_hmtx(ctx, fontdesc, i, i, w);
		}

		pdf_end_hmtx(ctx, fontdesc);

		/* Resources -- inherit page resources if the font doesn't have its own */

		fontdesc->font->t3freeres = pdf_t3_free_resources;
		fontdesc->font->t3resources = pdf_dict_gets(dict, "Resources");
		if (!fontdesc->font->t3resources)
			fontdesc->font->t3resources = rdb;
		if (fontdesc->font->t3resources)
			pdf_keep_obj(fontdesc->font->t3resources);
		if (!fontdesc->font->t3resources)
			fz_warn(ctx, "no resource dictionary for type 3 font!");

		fontdesc->font->t3doc = xref;
		fontdesc->font->t3run = pdf_run_glyph_func;

		/* CharProcs */

		charprocs = pdf_dict_gets(dict, "CharProcs");
		if (!charprocs)
		{
			fz_throw(ctx, "syntaxerror: Type3 font missing CharProcs");
		}

		for (i = 0; i < 256; i++)
		{
			if (estrings[i])
			{
				obj = pdf_dict_gets(charprocs, estrings[i]);
				if (pdf_is_stream(xref, pdf_to_num(obj), pdf_to_gen(obj)))
				{
					fontdesc->font->t3procs[i] = pdf_load_stream(xref, pdf_to_num(obj), pdf_to_gen(obj));
					fontdesc->size += fontdesc->font->t3procs[i]->cap;
				}
			}
		}
	}
	fz_catch(ctx)
	{
		if (fontdesc)
			fz_drop_font(ctx, fontdesc->font);
		fz_free(ctx, fontdesc);
		fz_throw(ctx, "cannot load type3 font (%d %d R)", pdf_to_num(dict), pdf_to_gen(dict));
	}
	return fontdesc;
}