/*
 *	aegis - project change supervisor
 *	Copyright (C) 2002, 2003 Peter Miller;
 *	All rights reserved.
 *
 *	This program 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 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program 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 this program; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: functions to manipulate emitfilelists
 */

#include <shell.h>
#include <str_list.h>
#include <symtab.h>


static size_t
how_much_in_common(string_ty *s1, string_ty *s2)
{
    size_t          n;
    const char      *cp1;
    const char      *cp2;

    for
    (
	cp1 = s1->str_text, cp2 = s2->str_text, n = 0;
	*cp1 && *cp2;
	++n, ++cp1, ++cp2
    )
    {
	if (*cp1 != *cp2)
	    return n;
    }
    return n;
}


static string_ty *
following_slash(string_ty *s, size_t len)
{
    for (;;)
    {
	if (s->str_length <= len)
	    return str_copy(s);
	if (s->str_text[len] == '/')
	    return str_n_from_c(s->str_text, len + 1);
	++len;
    }
}


void
shell_emit_file_list(shell_ty *sh, string_list_ty *slp)
{
    symtab_ty       *stp;
    size_t          j;
    size_t          longest;

    /*
     * Give up if nothing matches.
     */
    if (slp->nstrings == 0)
	return;

    /*
     * Look for longest common prefix.
     */
    longest = slp->string[0]->str_length;
    for (j = 1; j < slp->nstrings; ++j)
    {
	size_t          n;

	n = how_much_in_common(slp->string[0], slp->string[j]);
	if (n < longest)
	    longest = n;
    }

    /*
     * Rewrite the file names to only use from the longest common prefix
     * to the following slash (or end of string if no slash).
     * Use the symtab to make it an O(n) operation.
     */
    stp = symtab_alloc(slp->nstrings);
    for (j = 0; j < slp->nstrings; ++j)
    {
	string_ty       *s;

	s = following_slash(slp->string[j], longest);
	if (symtab_query(stp, s))
	{
	    str_free(s);
	    continue;
	}
	shell_emit(sh, s);
	symtab_assign(stp, s, s);
	str_free(s);
    }
    symtab_free(stp);
}
