/*
 * ipdb.h
 *  Image Viewer PDB file functions.
 *
 * Copyright (C) 1997 Eric A. Howe
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This library 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 Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *   Authors: Eric A. Howe (mu@trends.net)
 *            Bryan Henderson 2010
 */
#ifndef IPDB_H_INCLUDED
#define IPDB_H_INCLUDED

#include <stdio.h>
#include <errno.h>

/*
 * Extra error numbers, feed these (or errno values) to ipdb_err()
 * to get strings.
 */
#define E_BADCOLORS -1
#define E_NOTIMAGE  -2
#define E_IMAGETHERE    -3
#define E_IMAGENOTTHERE -4
#define E_TEXTTHERE -5
#define E_NOTRECHDR -6
#define E_UNKNOWNRECHDR -7
#define E_TOOBIGG   -8
#define E_TOOBIGM   -9
#define E_LAST      -9

/*
 * The standard pdb header.
 */
typedef struct {
    char      name[32];       /* nul terminated   */
    uint16_t  flags;          /* 0            */
    uint16_t  version;        /* 0            */
    uint32_t  ctime;          /* mac time     */
    uint32_t  mtime;          /* mac time     */
    uint32_t  btime;          /* mac time     */
    uint32_t  mod_num;        /* 0            */
    uint32_t  app_info;       /* 0            */
    uint32_t  sort_info;      /* 0            */
    uint8_t   type[4];        /* vIMG         */
    uint8_t   id[4];          /* View         */
    uint32_t  uniq_seed;      /* 0            */
    uint32_t  next_rec;       /* 0            */
    uint16_t  num_recs;       /* 1            */
} PDBHEAD;
#define PDBHEAD_SIZE    (32 + 2*2 + 6*4 + 4 + 4 + 2*4 + 2)

/*
 * Between the pdb header and the image header we find some "mystery" bytes,
 * these are supposed to be eight byte record headers but sometimes there
 * are ten bytes.  Version zero files use eight bytes, version 1 files appear
 * to use ten bytes, files with attached notes (version 2?) use two sets of
 * eight bytes.  Note that this version isn't the same as the `version' field
 * in IMAGE, that version only indicates if the file is compressed or not.
 *
 * The first four bytes of each piece are a four byte offset to the start
 * of the corresponding image header or text record; the next three bytes
 * (40 6f 80) are some kind of magic (they are always the same); the next
 * byte is zero for image records and 1 for text records; any remaining
 * mystery bytes (zero or two) are always zero.
 */
typedef struct {
    uint32_t offset;     /* offset, from zero, to the image  */
    uint8_t  unknown[3]; /* 40 6f 80             */
    uint8_t  rec_type;   /* byte seven, TEXT_REC || IMG_REC  */
    size_t   n_extra;    /* bytes in extra           */
    uint8_t  *extra;     /* extra unknown end bytes      */
} RECHDR;
#define IMG_REC     (uint8_t)(0x00)
#define TEXT_REC    (uint8_t)(0x01)

/*
 * The image headers.
 */
typedef struct {
    RECHDR  * r;

    /*
     * Whether the image was originally compressed.  Since compressed
     * data can cross row boundaries we have to uncompress the whole
     * thing during reads so `data' is always in the uncompressed
     * (but packed) format.  I think we can just use the `version'
     * field for this but a little extra paranoia is worth a couple
     * of bytes. This is also set after a write to indicate if
     * compression was used.
     */
    int       compressed;

    /*
     * The actual image header, this starts at `m->offset'.
     */
    char      name[32];   /* nul terminated           */
    uint8_t   version;    /* 0 => uncompressed, 1 => compressed   */
    uint8_t   type;       /* GRAYSCALE || MONOCHROME      */
    uint8_t   reserved1[4];   /* zero                 */
    uint8_t   note[4];    /* zero                 */
    uint16_t  x_last;     /* zero                 */
    uint16_t  y_last;     /* zero                 */
    uint8_t   reserved2[4];   /* zero                 */
    uint16_t  x_anchor;   /* 0xffff               */
    uint16_t  y_anchor;   /* 0xffff               */
    uint16_t  width;      /* pixels (must be 0 mod 16)        */
    uint16_t  height;     /* pixels               */

    /*
     * And finally, the actual image data.  We always store the
     * image data as 4 pixels per byte uncompressed.  Any compression
     * or decompression is done at I/O time.
     */
    uint8_t  * data;
} IMAGE;

#define IMAGESIZE   (32 + 1 + 1 + 4 + 4 + 2*2 + 4 + 2*2 + 2*2)

/*
 * Image types for IMAGE.type.
 */
#define IMG_GRAY16  ((uint8_t)2)
#define IMG_GRAY    ((uint8_t)0)
#define IMG_MONO    ((uint8_t)0xff)

const char *
ipdb_typeName(uint8_t const type);


/*
 * Compression constants for IMAGE.version.
 */
#define IMG_COMPRESSED      ((uint8_t)0x01)
#define IMG_UNCOMPRESSED    ((uint8_t)0x00)

/*
 * The notes record.  If this exists, it will follow the image record.
 */
typedef struct {
    RECHDR  *r;
    char    *data;      /* the actual text as a normal string   */
} TEXT;

/*
 * One PDB file.  The `t' field will be NULL if there is no note.
 */
typedef struct {
    PDBHEAD * p;
    IMAGE   * i;
    TEXT    * t;
} IPDB;

/*
 * Only use four bytes of these.
 */
#define IPDB_vIMG   "vIMG"
#define IPDB_View   "View"
/*
 * Only use three bytes of this.
 */
#define IPDB_MYST   "\x40\x6f\x80"

/*
 * Flags for ipdb_write().
 */
#define IPDB_COMPMAYBE  0       /* compress if it does any good */
#define IPDB_NOCOMPRESS (1 << 1)    /* don't compress       */
#define IPDB_COMPRESS   (1 << 2)    /* compress         */

#define ipdb_width(pdb)     ((pdb)->i->width)
#define ipdb_height(pdb)    ((pdb)->i->height)
#define ipdb_text(pdb)      ((pdb)->t == NULL ? NULL : (pdb)->t->data)
#define ipdb_compressed(pdb)    ((pdb)->i->compressed)
#define ipdb_ctime(pdb)     ((time_t)((pdb)->p->ctime - UNIXEPOCH))
#define ipdb_mtime(pdb)     ((time_t)((pdb)->p->mtime - UNIXEPOCH))
#define ipdb_btime(pdb)     ((time_t)((pdb)->p->btime - UNIXEPOCH))
#define ipdb_iname(pdb)     ((pdb)->i->name)
#define ipdb_pname(pdb)     ((pdb)->p->name)
#define ipdb_version(pdb)   ((pdb)->i->version)
#define ipdb_type(pdb)      ((pdb)->i->type)
#define ipdb_xlast(pdb)     ((pdb)->i->x_last)
#define ipdb_ylast(pdb)     ((pdb)->i->y_last)
#define ipdb_xanchor(pdb)   ((pdb)->i->x_anchor)
#define ipdb_yanchor(pdb)   ((pdb)->i->y_anchor)

const char *
ipdb_err(int error);

size_t
ipdb_imgSize(IMAGE * const imgP);

unsigned int
ipdb_imgPpb(IMAGE * const imgP);

uint8_t *
ipdb_imgRow(IMAGE *      const imgP,
             unsigned int const row);

void
ipdb_free(IPDB *);

IPDB *
ipdb_alloc(void);

PDBHEAD *
ipdb_pdbheadAlloc(void);

void
ipdb_pdbheadFree(PDBHEAD * const headP);

IMAGE *
ipdb_imageCreate(const char * const name,
                 int          const type,
                 int          const w,
                 int          const h);

void
ipdb_imageFree(IMAGE * const imgP);

void
ipdb_textFree(TEXT * const textP);

TEXT *
ipdb_textAlloc(void);

#endif