//
//	aegis - project change supervisor
//	Copyright (C) 1999, 2003-2008 Peter Miller
//
//	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 3 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, see
//	<http://www.gnu.org/licenses/>.
//

#include <libaegis/change/file.h>
#include <libaegis/change/file/list_get.h>
#include <common/error.h> // for assert
#include <common/str_list.h>
#include <common/trace.h>


fstate_src_ty *
change_file_nth(change::pointer cp, size_t n, view_path_ty as_view_path)
{
    fstate_src_ty   *src_data;
    string_list_ty  *wlp;

    //
    // Special case the absence of a view path, it's slightly faster.
    //
    trace(("change_file_nth(cp = %8.8lX, n = %ld)\n{\n", (long)cp, (long)n));
    if (as_view_path == view_path_first)
    {
	fstate_ty       *fstate_data;

	fstate_data = change_fstate_get(cp);
	assert(fstate_data->src);
	if (n >= fstate_data->src->length)
	{
    	    trace(("return NULL;\n"));
    	    trace(("}\n"));
	    return 0;
	}
	src_data = fstate_data->src->list[n];
	trace(("return %8.8lX;\n", (long)src_data));
	trace(("}\n"));
	return src_data;
    }

    // do not free wlp, it's cached
    wlp = change_file_list_get(cp, as_view_path);

    if (n < wlp->nstrings)
    {
       	trace(("%s\n", wlp->string[n]->str_text));
       	src_data = change_file_find(cp, wlp->string[n], as_view_path);

       	//
	// If this assert fails, it means that change_file_list_get and
        // change_file_find are interpreting the view path differently.
        //
	assert(src_data);
    }
    else
	src_data = 0;
    trace(("return %8.8lX;\n", (long)src_data));
    trace(("}\n"));
    return src_data;
}