/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/* Cherokee
 *
 * Authors:
 *      Alvaro Lopez Ortega <alvaro@alobbs.com>
 *
 * Copyright (C) 2001-2014 Alvaro Lopez Ortega
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include "common-internal.h"
#include "handler_error_nn.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>

#include "thread.h"
#include "connection.h"
#include "connection-protected.h"
#include "module.h"
#include "plugin_loader.h"
#include "connection.h"
#include "levenshtein_distance.h"
#include "handler_error.h"
#include "util.h"


/* Plug-in initialization
 */
PLUGIN_INFO_HANDLER_EASIEST_INIT (error_nn, http_all_methods);


/* Methods implementation
 */
ret_t
cherokee_handler_error_nn_configure (cherokee_config_node_t   *conf,
                                     cherokee_server_t        *srv,
                                     cherokee_module_props_t **_props)
{
	UNUSED(conf);
	UNUSED(srv);
	UNUSED(_props);

	return ret_ok;
}


static ret_t
get_nearest_from_directory (char *directory, char *request, cherokee_buffer_t *output)
{
	int                re;
	int                dis;
	DIR               *dir;
	char               entry_buf[512];
	struct dirent     *entry;
	int                min_diff = 9999;
	cherokee_boolean_t found    = false;

	dir = cherokee_opendir (directory);
	if (dir == NULL)
		goto go_out;

	for (;;) {
		re = cherokee_readdir (dir, (struct dirent *)entry_buf, &entry);
		if ((re != 0) || (entry == NULL))
			break;

		if (!strncmp (entry->d_name, ".",  1)) continue;
		if (!strncmp (entry->d_name, "..", 2)) continue;

		dis = distance ((char *)request, entry->d_name);
		if (dis < min_diff) {
			min_diff = dis;
			found    = true;

			cherokee_buffer_clean (output);
			cherokee_buffer_add (output, entry->d_name, strlen(entry->d_name));
		}

	}

	cherokee_closedir (dir);

go_out:
	return (found) ? ret_ok : ret_error;
}


static ret_t
get_nearest_name (cherokee_connection_t *conn,
                  cherokee_buffer_t     *local_dir,
                  cherokee_buffer_t     *request,
                  cherokee_buffer_t     *output)
{
	ret_t              ret;
	char              *rest;
	cherokee_thread_t *thread = CONN_THREAD(conn);
	cherokee_buffer_t *req    = THREAD_TMP_BUF1(thread);

	/* Build the local request path
	 */
	rest = strrchr (request->buf, '/');
	if (rest == NULL) {
		return ret_error;
	}
	rest++;

	cherokee_buffer_clean (req);
	cherokee_buffer_add_buffer (req, local_dir);
	cherokee_buffer_add (req, request->buf, rest - request->buf);

	/* Copy the new filename to the output buffer
	 */
	ret = get_nearest_from_directory (req->buf, rest, output);
	if (unlikely (ret != ret_ok)) {
		return ret_error;
	}

	/* Prepend the rest of the old request to the new filename
	 */
	cherokee_buffer_prepend (output, request->buf, rest - request->buf);
	return ret_ok;
}


static ret_t
error_nn_init (cherokee_handler_error_t *hdl)
{
	ret_t                  ret;
	cherokee_connection_t *conn = HANDLER_CONN(hdl);

	cherokee_buffer_clean (&conn->redirect);

	ret = get_nearest_name (conn, &conn->local_directory, &conn->request, &conn->redirect);
	if (unlikely (ret != ret_ok)) {
		conn->error_code = http_not_found;
		return ret_error;
	}

	conn->error_code = http_moved_temporarily;
	return ret_error;
}

static ret_t
error_nn_add_headers (cherokee_handler_error_t *hdl, cherokee_buffer_t *buffer)
{
	UNUSED(hdl);
	UNUSED(buffer);

	return ret_ok;
}

static ret_t
error_nn_step (cherokee_handler_error_t *hdl, cherokee_buffer_t *buffer)
{
	UNUSED(hdl);
	UNUSED(buffer);

	return ret_eof;
}

static ret_t
error_nn_free (cherokee_handler_error_t *hdl)
{
	UNUSED(hdl);

	return ret_ok;
}


ret_t
cherokee_handler_error_nn_new (cherokee_handler_t      **hdl,
                               cherokee_connection_t    *conn,
                               cherokee_module_props_t  *props)
{
	CHEROKEE_NEW_STRUCT (n, handler_error_nn);

	cherokee_handler_init_base (HANDLER(n), conn, HANDLER_PROPS(props), PLUGIN_INFO_HANDLER_PTR(error_nn));
	HANDLER(n)->support = hsupport_error | hsupport_length;

	MODULE(n)->init         = (handler_func_init_t) error_nn_init;
	MODULE(n)->free         = (module_func_free_t) error_nn_free;
	HANDLER(n)->step        = (handler_func_step_t) error_nn_step;
	HANDLER(n)->add_headers = (handler_func_add_headers_t) error_nn_add_headers;

	*hdl = HANDLER(n);
	return ret_ok;
}