/***************************************************************************
 *   Copyright (C) 2008                                                    *
 *                                                                         *
 *   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  02111-1307, USA.             *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "tcl_server.h"

#include "../jim.h"
#include "log.h"
#include "command.h"

#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>

#define TCL_SERVER_VERSION     "TCL Server 0.1"
#define TCL_MAX_LINE           (4096)

typedef struct tcl_connection_s {
       int tc_linedrop;
       int tc_lineoffset;
       char tc_line[TCL_MAX_LINE];

       int tc_outerror; /* flag an output error */
} tcl_connection_t;

extern Jim_Interp *interp;
static unsigned short tcl_port = 0;

/* commands */
static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);

/* handlers */
static int tcl_new_connection(connection_t *connection);
static int tcl_input(connection_t *connection);
static int tcl_output(connection_t *connection, const void *buf, ssize_t len);
static int tcl_closed(connection_t *connection);

/* write data out to a socket.
 *
 * this is a blocking write, so the return value must equal the length, if
 * that is not the case then flag the connection with an output error.
 */
int tcl_output(connection_t *connection, const void *data, ssize_t len)
{
       ssize_t wlen;
       tcl_connection_t *tclc;

       tclc = connection->priv;
       if (tclc->tc_outerror)
               return ERROR_SERVER_REMOTE_CLOSED;

       wlen = write_socket(connection->fd, data, len);
       if (wlen == len)
               return ERROR_OK;

       LOG_ERROR("error during write: %d != %d", wlen, len);
       tclc->tc_outerror = 1;
       return ERROR_SERVER_REMOTE_CLOSED;
}


/* connections */
static int tcl_new_connection(connection_t *connection)
{
       int i;
       tcl_connection_t *tclc;

       tclc = malloc(sizeof(tcl_connection_t));
       if (tclc == NULL)
               return ERROR_CONNECTION_REJECTED;

       memset(tclc, 0, sizeof(tcl_connection_t));
       connection->priv = tclc;
       return ERROR_OK;
}

static int tcl_input(connection_t *connection)
{
       int retval;
       int i;
       ssize_t rlen;
       const char *result;
       int reslen;
       tcl_connection_t *tclc;
       char in[256];

       rlen = read_socket(connection->fd, &in, sizeof(in));
       if (rlen <= 0) {
               if (rlen < 0)
                       LOG_ERROR("error during read: %s", strerror(errno));
               return ERROR_SERVER_REMOTE_CLOSED;
       }

       tclc = connection->priv;
       if (tclc == NULL)
               return ERROR_CONNECTION_REJECTED;

       /* push as much data into the line as possible */
       for (i = 0; i < rlen; i++)
       {
               if (!isprint(in[i]) && !isspace(in[i]))
               {
                       /* drop this line */
                       tclc->tc_linedrop = 1;
                       continue;
               }

               /* buffer the data */
               tclc->tc_line[tclc->tc_lineoffset] = in[i];
               if (tclc->tc_lineoffset < TCL_MAX_LINE)
                       tclc->tc_lineoffset++;
               else
                       tclc->tc_linedrop = 1;

               if (in[i] != '\n')
                       continue;

               /* process the line */
               if (tclc->tc_linedrop) {
#define ESTR "line too long\n"
                       retval = tcl_output(connection, ESTR, sizeof(ESTR));
                       if (retval != ERROR_OK)
                               return retval;
#undef ESTR
               } else {
                       tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
                       retval = Jim_Eval(interp, tclc->tc_line);
                       result = Jim_GetString(Jim_GetResult(interp), &reslen);
                       retval = tcl_output(connection, result, reslen);
                       if (retval != ERROR_OK)
                               return retval;
                       if (memchr(result, '\n', reslen) == NULL)
                               tcl_output(connection, "\n", 1);
               }
               tclc->tc_lineoffset = 0;
               tclc->tc_linedrop = 0;
       }

       return ERROR_OK;
}

static int tcl_closed(connection_t *connection)
{
       /* cleanup connection context */
       if (connection->priv) {
               free(connection->priv);
               connection->priv = NULL;
       }
       return ERROR_OK;
}

int tcl_init(void)
{
       int retval;

       if (tcl_port == 0)
       {
               LOG_WARNING("no tcl port specified, using default port 5555");
               tcl_port = 5555;
       }

       retval = add_service("tcl", CONNECTION_TCL, tcl_port, 1, tcl_new_connection, tcl_input, tcl_closed, NULL);
       return retval;
}


int tcl_register_commands(command_context_t *cmd_ctx)
{
       register_command(cmd_ctx, NULL, "tcl_port", handle_tcl_port_command, COMMAND_CONFIG, "");
       return ERROR_OK;
}

static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
       if (argc == 1) {
               tcl_port = strtoul(args[0], NULL, 0);
       }
       return ERROR_OK;
}