/*
 * This software is copyrighted as noted below.  It may be freely copied,
 * modified, and redistributed, provided that the copyright notice is 
 * preserved on all copies.
 * 
 * There is no warranty or other guarantee of fitness for this software,
 * it is provided solely "as is".  Bug reports or fixes may be sent
 * to the author, who may or may not act on them as he desires.
 *
 * You may not include this software in a program or other software product
 * without supplying the source, or without informing the end-user that the 
 * source is available for no extra charge.
 *
 * If you modify this software, you should include a notice giving the
 * name of the person performing the modification, the date of modification,
 * and the reason for such modification.
 */
/* 
 * rle_addhist.c - Add to the HISTORY comment in header
 * 
 * Author:  Andrew Marriott.
 *      School of Computer Science 
 *      Curtin University of Technology
 * Date:    Mon Sept 10 1988
 * Copyright (c) 1988, Curtin University of Technology
 */

#include <string.h>
#include <stdio.h>
#include <time.h>

#include "netpbm/mallocvar.h"
#include "rle.h"


/*****************************************************************
 * TAG( rle_addhist )
 * 
 * Put a history comment into the header struct.
 * Inputs:
 *  argv:       Command line history to add to comments.
 *  in_hdr:     Incoming header struct to use.
 * Outputs:
 *  out_hdr:    Outgoing header struct to add to.
 * Assumptions:
 *  If no incoming struct then value is NULL.
 * Algorithm:
 *  Calculate length of all comment strings, malloc and then set via
 *  rle_putcom.
 */

void
rle_addhist(char *          argv[],
            rle_hdr * const in_hdr,
            rle_hdr * const out_hdr) {

    const char * const histoire = "HISTORY";
    const char * const padding = "\t";

    int length;
    int i;
    time_t  temp;
    /* padding must give number of characters in histoire   */
    /*     plus one for "="                 */
    char * timedate;
    const char * old;
    static char * newc;

    if (getenv("NO_ADD_RLE_HISTORY"))
        return;
    
    length = 0;
    for (i = 0; argv[i]; ++i)
        length += strlen(argv[i]) +1;   /* length of each arg plus space. */

    time(&temp);
    timedate = ctime(&temp);
    length += strlen(timedate);        /* length of date and time in ASCII. */

    length += strlen(padding) + 3 + strlen(histoire) + 1;
        /* length of padding, "on "  and length of history name plus "="*/
    if (in_hdr) /* if we are interested in the old comments... */
        old = rle_getcom(histoire, in_hdr);     /* get old comment. */
    else
        old = NULL;
    
    if (old && *old)
        length += strlen(old);       /* add length if there. */

    ++length;                               /*Cater for the null. */

    MALLOCARRAY(newc, length);

    if (newc == NULL)
        return;

    strcpy(newc,histoire);(void)strcat(newc,"=");
    if (old && *old)
        strcat(newc, old); /* add old string if there. */
    for (i=0;argv[i];i++) {
        strcat(newc, argv[i]);
        strcat(newc, " ");
    }
    strcat(newc,"on ");
    strcat(newc,timedate);         /* \n supplied by time. */
    strcat(newc,padding);          /* to line up multiple histories.*/
    
    rle_putcom(newc, out_hdr);
}