/******************************************************************************
 * pdf.h 
 *
 * pdfresurrect - PDF history extraction tool
 *
 * Copyright (C) 2008, 2009 Matt Davis (enferex) of 757Labs (www.757labs.com)
 *
 * pdf.h is part of pdfresurrect.
 * pdfresurrect 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 3 of the License, or
 * (at your option) any later version.
 *
 * pdfresurrect 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 pdfresurrect.  If not, see <http://www.gnu.org/licenses/>.
 *****************************************************************************/

#ifndef PDF_H_INCLUDE
#define PDF_H_INCLUDE

#include <stdio.h>


/* Bit-maskable flags */
typedef unsigned short pdf_flag_t;
#define PDF_FLAG_NONE         0
#define PDF_FLAG_QUIET        1
#define PDF_FLAG_DISP_CREATOR 2


/* Generic key/value structure */
#define KV_MAX_KEY_LENGTH   32
#define KV_MAX_VALUE_LENGTH 128
typedef struct _kv_t
{
    char key[KV_MAX_KEY_LENGTH];
    char value[KV_MAX_VALUE_LENGTH];
} kv_t;


/* Information about who/what created the PDF 
 * From 1.7 Spec for non-metadata entries
 */
typedef kv_t pdf_creator_t;


typedef struct _xref_entry
{
    int obj_id;
    long offset;
    int gen_num; 
    char f_or_n;
} xref_entry_t;


#define KIDS_PER_ALLOC 64
#define KID_SIZE sizeof(int)
typedef struct _xref_t
{
    long start;
    long end;

    /* Array of metadata about the pdf */    
    pdf_creator_t *creator;
    int n_creator_entries;

    int n_entries;
    xref_entry_t *entries;

    int  n_kids;
    int *kids;
    int  n_kids_allocs;
    
    /* PDF 1.5 or greater: xref can be encoded as a stream */
    int is_stream;
    
    /* If the PDF is linear multiple xrefs make up one single version */
    int is_linear;
    
    /* Version of the document this xref belongs */
    int version;
} xref_t;


typedef struct _pdf_t
{
    char  *name;
    short  pdf_major_version;
    short  pdf_minor_version;

    int     n_xrefs;
    xref_t *xrefs;
    
    /* PDF 1.5 or greater: xref can be encoded as a stream */
    int has_xref_streams;
} pdf_t;


extern pdf_t *pdf_new(const char *name);
extern void pdf_delete(pdf_t *pdf);

extern int pdf_is_pdf(FILE *fp);
extern void pdf_get_version(FILE *fp, pdf_t *pdf);

extern int pdf_load_xrefs(FILE *fp, pdf_t *pdf);
extern void pdf_load_pages_kids(FILE *fp, pdf_t *pdf);

extern char pdf_get_object_status(
    const pdf_t *pdf,
    int          xref_idx,
    int          entry_idx);

extern void pdf_zero_object(
    FILE        *fp,
    const pdf_t *pdf,
    int          xref_idx,
    int          entry_idx);

extern void pdf_summarize(
    FILE        *fp,
    const pdf_t *pdf,
    const char  *name,
    pdf_flag_t   flags);

/* Returns '1' if we successfully display data (means its probably not xml) */
extern int pdf_display_creator(const pdf_t *pdf, int xref_idx);


#endif /* PDF_H_INCLUDE */