// Copyright (C) 2004-2021 Artifex Software, Inc.
//
// This file is part of MuPDF.
//
// MuPDF is free software: you can redistribute it and/or modify it under the
// terms of the GNU Affero General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// MuPDF 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 Affero General Public License for more
// details.
//
// You should have received a copy of the GNU Affero General Public License
// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
//
// Alternative licensing terms are available from the licensor.
// For commercial licensing, see <https://www.artifex.com/> or contact
// Artifex Software, Inc., 1305 Grant Avenue - Suite 200, Novato,
// CA 94945, U.S.A., +1(415)492-9861, for further information.

#ifndef PDF_INTERPRET_H
#define PDF_INTERPRET_H

#include "mupdf/pdf/font.h"
#include "mupdf/pdf/resource.h"
#include "mupdf/pdf/document.h"

typedef struct pdf_gstate pdf_gstate;
typedef struct pdf_processor pdf_processor;

void *pdf_new_processor(fz_context *ctx, int size);
pdf_processor *pdf_keep_processor(fz_context *ctx, pdf_processor *proc);
void pdf_close_processor(fz_context *ctx, pdf_processor *proc);
void pdf_drop_processor(fz_context *ctx, pdf_processor *proc);

struct pdf_processor
{
	int refs;
	void (*close_processor)(fz_context *ctx, pdf_processor *proc);
	void (*drop_processor)(fz_context *ctx, pdf_processor *proc);

	/* general graphics state */
	void (*op_w)(fz_context *ctx, pdf_processor *proc, float linewidth);
	void (*op_j)(fz_context *ctx, pdf_processor *proc, int linejoin);
	void (*op_J)(fz_context *ctx, pdf_processor *proc, int linecap);
	void (*op_M)(fz_context *ctx, pdf_processor *proc, float miterlimit);
	void (*op_d)(fz_context *ctx, pdf_processor *proc, pdf_obj *array, float phase);
	void (*op_ri)(fz_context *ctx, pdf_processor *proc, const char *intent);
	void (*op_i)(fz_context *ctx, pdf_processor *proc, float flatness);

	void (*op_gs_begin)(fz_context *ctx, pdf_processor *proc, const char *name, pdf_obj *extgstate);
	void (*op_gs_BM)(fz_context *ctx, pdf_processor *proc, const char *blendmode);
	void (*op_gs_ca)(fz_context *ctx, pdf_processor *proc, float alpha);
	void (*op_gs_CA)(fz_context *ctx, pdf_processor *proc, float alpha);
	void (*op_gs_SMask)(fz_context *ctx, pdf_processor *proc, pdf_obj *smask, pdf_obj *page_resources, float *bc, int luminosity);
	void (*op_gs_end)(fz_context *ctx, pdf_processor *proc);

	/* special graphics state */
	void (*op_q)(fz_context *ctx, pdf_processor *proc);
	void (*op_Q)(fz_context *ctx, pdf_processor *proc);
	void (*op_cm)(fz_context *ctx, pdf_processor *proc, float a, float b, float c, float d, float e, float f);

	/* path construction */
	void (*op_m)(fz_context *ctx, pdf_processor *proc, float x, float y);
	void (*op_l)(fz_context *ctx, pdf_processor *proc, float x, float y);
	void (*op_c)(fz_context *ctx, pdf_processor *proc, float x1, float y1, float x2, float y2, float x3, float y3);
	void (*op_v)(fz_context *ctx, pdf_processor *proc, float x2, float y2, float x3, float y3);
	void (*op_y)(fz_context *ctx, pdf_processor *proc, float x1, float y1, float x3, float y3);
	void (*op_h)(fz_context *ctx, pdf_processor *proc);
	void (*op_re)(fz_context *ctx, pdf_processor *proc, float x, float y, float w, float h);

	/* path painting */
	void (*op_S)(fz_context *ctx, pdf_processor *proc);
	void (*op_s)(fz_context *ctx, pdf_processor *proc);
	void (*op_F)(fz_context *ctx, pdf_processor *proc);
	void (*op_f)(fz_context *ctx, pdf_processor *proc);
	void (*op_fstar)(fz_context *ctx, pdf_processor *proc);
	void (*op_B)(fz_context *ctx, pdf_processor *proc);
	void (*op_Bstar)(fz_context *ctx, pdf_processor *proc);
	void (*op_b)(fz_context *ctx, pdf_processor *proc);
	void (*op_bstar)(fz_context *ctx, pdf_processor *proc);
	void (*op_n)(fz_context *ctx, pdf_processor *proc);

	/* clipping paths */
	void (*op_W)(fz_context *ctx, pdf_processor *proc);
	void (*op_Wstar)(fz_context *ctx, pdf_processor *proc);

	/* text objects */
	void (*op_BT)(fz_context *ctx, pdf_processor *proc);
	void (*op_ET)(fz_context *ctx, pdf_processor *proc);

	/* text state */
	void (*op_Tc)(fz_context *ctx, pdf_processor *proc, float charspace);
	void (*op_Tw)(fz_context *ctx, pdf_processor *proc, float wordspace);
	void (*op_Tz)(fz_context *ctx, pdf_processor *proc, float scale);
	void (*op_TL)(fz_context *ctx, pdf_processor *proc, float leading);
	void (*op_Tf)(fz_context *ctx, pdf_processor *proc, const char *name, pdf_font_desc *font, float size);
	void (*op_Tr)(fz_context *ctx, pdf_processor *proc, int render);
	void (*op_Ts)(fz_context *ctx, pdf_processor *proc, float rise);

	/* text positioning */
	void (*op_Td)(fz_context *ctx, pdf_processor *proc, float tx, float ty);
	void (*op_TD)(fz_context *ctx, pdf_processor *proc, float tx, float ty);
	void (*op_Tm)(fz_context *ctx, pdf_processor *proc, float a, float b, float c, float d, float e, float f);
	void (*op_Tstar)(fz_context *ctx, pdf_processor *proc);

	/* text showing */
	void (*op_TJ)(fz_context *ctx, pdf_processor *proc, pdf_obj *array);
	void (*op_Tj)(fz_context *ctx, pdf_processor *proc, char *str, size_t len);
	void (*op_squote)(fz_context *ctx, pdf_processor *proc, char *str, size_t len);
	void (*op_dquote)(fz_context *ctx, pdf_processor *proc, float aw, float ac, char *str, size_t len);

	/* type 3 fonts */
	void (*op_d0)(fz_context *ctx, pdf_processor *proc, float wx, float wy);
	void (*op_d1)(fz_context *ctx, pdf_processor *proc, float wx, float wy, float llx, float lly, float urx, float ury);

	/* color */
	void (*op_CS)(fz_context *ctx, pdf_processor *proc, const char *name, fz_colorspace *cs);
	void (*op_cs)(fz_context *ctx, pdf_processor *proc, const char *name, fz_colorspace *cs);
	void (*op_SC_pattern)(fz_context *ctx, pdf_processor *proc, const char *name, pdf_pattern *pat, int n, float *color);
	void (*op_sc_pattern)(fz_context *ctx, pdf_processor *proc, const char *name, pdf_pattern *pat, int n, float *color);
	void (*op_SC_shade)(fz_context *ctx, pdf_processor *proc, const char *name, fz_shade *shade);
	void (*op_sc_shade)(fz_context *ctx, pdf_processor *proc, const char *name, fz_shade *shade);
	void (*op_SC_color)(fz_context *ctx, pdf_processor *proc, int n, float *color);
	void (*op_sc_color)(fz_context *ctx, pdf_processor *proc, int n, float *color);

	void (*op_G)(fz_context *ctx, pdf_processor *proc, float g);
	void (*op_g)(fz_context *ctx, pdf_processor *proc, float g);
	void (*op_RG)(fz_context *ctx, pdf_processor *proc, float r, float g, float b);
	void (*op_rg)(fz_context *ctx, pdf_processor *proc, float r, float g, float b);
	void (*op_K)(fz_context *ctx, pdf_processor *proc, float c, float m, float y, float k);
	void (*op_k)(fz_context *ctx, pdf_processor *proc, float c, float m, float y, float k);

	/* shadings, images, xobjects */
	void (*op_BI)(fz_context *ctx, pdf_processor *proc, fz_image *image, const char *colorspace_name);
	void (*op_sh)(fz_context *ctx, pdf_processor *proc, const char *name, fz_shade *shade);
	void (*op_Do_image)(fz_context *ctx, pdf_processor *proc, const char *name, fz_image *image);
	void (*op_Do_form)(fz_context *ctx, pdf_processor *proc, const char *name, pdf_obj *form, pdf_obj *page_resources);

	/* marked content */
	void (*op_MP)(fz_context *ctx, pdf_processor *proc, const char *tag);
	void (*op_DP)(fz_context *ctx, pdf_processor *proc, const char *tag, pdf_obj *raw, pdf_obj *cooked);
	void (*op_BMC)(fz_context *ctx, pdf_processor *proc, const char *tag);
	void (*op_BDC)(fz_context *ctx, pdf_processor *proc, const char *tag, pdf_obj *raw, pdf_obj *cooked);
	void (*op_EMC)(fz_context *ctx, pdf_processor *proc);

	/* compatibility */
	void (*op_BX)(fz_context *ctx, pdf_processor *proc);
	void (*op_EX)(fz_context *ctx, pdf_processor *proc);

	/* Virtual ops for ExtGState entries */
	void (*op_gs_OP)(fz_context *ctx, pdf_processor *proc, int b);
	void (*op_gs_op)(fz_context *ctx, pdf_processor *proc, int b);
	void (*op_gs_OPM)(fz_context *ctx, pdf_processor *proc, int i);
	void (*op_gs_UseBlackPtComp)(fz_context *ctx, pdf_processor *proc, pdf_obj *name);

	/* END is used to signify end of stream (finalise and close down) */
	void (*op_END)(fz_context *ctx, pdf_processor *proc);

	/* interpreter state that persists across content streams */
	const char *usage;
	int hidden;
};

typedef struct
{
	/* input */
	pdf_document *doc;
	pdf_obj *rdb;
	pdf_lexbuf *buf;
	fz_cookie *cookie;

	/* state */
	int gstate;
	int xbalance;
	int in_text;
	fz_rect d1_rect;

	/* stack */
	pdf_obj *obj;
	char name[256];
	char string[256];
	size_t string_len;
	int top;
	float stack[32];
} pdf_csi;

/* Functions to set up pdf_process structures */

pdf_processor *pdf_new_run_processor(fz_context *ctx, fz_device *dev, fz_matrix ctm, const char *usage, pdf_gstate *gstate, fz_default_colorspaces *default_cs, fz_cookie *cookie);

/*
	Create a buffer processor.

	This collects the incoming PDF operator stream into an fz_buffer.

	buffer: The (possibly empty) buffer to which operators will be
	appended.

	ahxencode: If 0, then image streams will be send as binary,
	otherwise they will be asciihexencoded.
*/
pdf_processor *pdf_new_buffer_processor(fz_context *ctx, fz_buffer *buffer, int ahxencode);

/*
	Create an output processor. This
	sends the incoming PDF operator stream to an fz_output stream.

	out: The output stream to which operators will be sent.

	ahxencode: If 0, then image streams will be send as binary,
	otherwise they will be asciihexencoded.
*/
pdf_processor *pdf_new_output_processor(fz_context *ctx, fz_output *out, int ahxencode);

/*
	opaque: Opaque value that is passed to all the filter functions.

	image_filter: A function called to assess whether a given
	image should be removed or not.

	text_filter: A function called to assess whether a given
	character should be removed or not.

	after_text_object: A function called after each text object.
	This allows the caller to insert some extra content if
	desired.

	end_page: A function called at the end of a page.
	This allows the caller to insert some extra content after
	all other content.

	sanitize: If false, will only clean the syntax. This disables all filtering!

	recurse: Clean/sanitize/filter resources recursively.

	instance_forms: Always recurse on XObject Form resources, but will
	create a new instance of each XObject Form that is used, filtered
	individually.

	ascii: If true, escape all binary data in the output.
*/
typedef struct
{
	void *opaque;
	fz_image *(*image_filter)(fz_context *ctx, void *opaque, fz_matrix ctm, const char *name, fz_image *image);
	int (*text_filter)(fz_context *ctx, void *opaque, int *ucsbuf, int ucslen, fz_matrix trm, fz_matrix ctm, fz_rect bbox);
	void (*after_text_object)(fz_context *ctx, void *opaque, pdf_document *doc, pdf_processor *chain, fz_matrix ctm);
	void (*end_page)(fz_context *ctx, fz_buffer *buffer, void *arg);

	int recurse;
	int instance_forms;
	int sanitize;
	int ascii;
} pdf_filter_options;

/*
	Create a filter processor. This filters the PDF operators
	it is fed, and passes them down (with some changes) to the
	child filter.

	The changes made by the filter are:

	* No operations are allowed to change the top level gstate.
	Additional q/Q operators are inserted to prevent this.

	* Repeated/unnecessary colour operators are removed (so,
	for example, "0 0 0 rg 0 1 rg 0.5 g" would be sanitised to
	"0.5 g")

	The intention of these changes is to provide a simpler,
	but equivalent stream, repairing problems with mismatched
	operators, maintaining structure (such as BMC, EMC calls)
	and leaving the graphics state in an known (default) state
	so that subsequent operations (such as synthesising new
	operators to be appended to the stream) are easier.

	The net graphical effect of the filtered operator stream
	should be identical to the incoming operator stream.

	chain: The child processor to which the filtered operators
	will be fed.

	old_res: The incoming resource dictionary.

	new_res: An (initially empty) resource dictionary that will
	be populated by copying entries from the old dictionary to
	the new one as they are used. At the end therefore, this
	contains exactly those resource objects actually required.

	The filter options struct allows you to filter objects using callbacks.
*/
pdf_processor *pdf_new_filter_processor(fz_context *ctx, pdf_document *doc, pdf_processor *chain, pdf_obj *old_res, pdf_obj *new_res, int struct_parents, fz_matrix transform, pdf_filter_options *filter);
pdf_obj *pdf_filter_xobject_instance(fz_context *ctx, pdf_obj *old_xobj, pdf_obj *page_res, fz_matrix ctm, pdf_filter_options *filter, pdf_cycle_list *cycle_up);

/*
	Functions to actually process annotations, glyphs and general stream objects.
*/
void pdf_process_contents(fz_context *ctx, pdf_processor *proc, pdf_document *doc, pdf_obj *obj, pdf_obj *res, fz_cookie *cookie);
void pdf_process_annot(fz_context *ctx, pdf_processor *proc, pdf_annot *annot, fz_cookie *cookie);
void pdf_process_glyph(fz_context *ctx, pdf_processor *proc, pdf_document *doc, pdf_obj *resources, fz_buffer *contents);

/* Text handling helper functions */
typedef struct
{
	float char_space;
	float word_space;
	float scale;
	float leading;
	pdf_font_desc *font;
	float size;
	int render;
	float rise;
} pdf_text_state;

typedef struct
{
	fz_text *text;
	fz_rect text_bbox;
	fz_matrix tlm;
	fz_matrix tm;
	int text_mode;

	int cid;
	int gid;
	fz_rect char_bbox;
	pdf_font_desc *fontdesc;
	float char_tx;
	float char_ty;
} pdf_text_object_state;

void pdf_tos_save(fz_context *ctx, pdf_text_object_state *tos, fz_matrix save[2]);
void pdf_tos_restore(fz_context *ctx, pdf_text_object_state *tos, fz_matrix save[2]);
fz_text *pdf_tos_get_text(fz_context *ctx, pdf_text_object_state *tos);
void pdf_tos_reset(fz_context *ctx, pdf_text_object_state *tos, int render);
int pdf_tos_make_trm(fz_context *ctx, pdf_text_object_state *tos, pdf_text_state *text, pdf_font_desc *fontdesc, int cid, fz_matrix *trm);
void pdf_tos_move_after_char(fz_context *ctx, pdf_text_object_state *tos);
void pdf_tos_translate(pdf_text_object_state *tos, float tx, float ty);
void pdf_tos_set_matrix(pdf_text_object_state *tos, float a, float b, float c, float d, float e, float f);
void pdf_tos_newline(pdf_text_object_state *tos, float leading);

#endif
