/* assuan-client.c - client functions
 *	Copyright (C) 2001, 2002, 2005 Free Software Foundation, Inc.
 *
 * This file is part of Assuan.
 *
 * Assuan is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * Assuan 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <assert.h>

#include "assuan-defs.h"

#define xtoi_1(p)   (*(p) <= '9'? (*(p)- '0'): \
                     *(p) <= 'F'? (*(p)-'A'+10):(*(p)-'a'+10))
#define xtoi_2(p)   ((xtoi_1(p) * 16) + xtoi_1((p)+1))


assuan_error_t
_assuan_read_from_server (assuan_context_t ctx, int *okay, int *off)
{
  char *line;
  int linelen;
  assuan_error_t rc;

  *okay = 0;
  *off = 0;
  do 
    {
      rc = _assuan_read_line (ctx);
      if (rc)
        return rc;
      line = ctx->inbound.line;
      linelen = ctx->inbound.linelen;
    }
  while (*line == '#' || !linelen);

  if (linelen >= 1
      && line[0] == 'D' && line[1] == ' ')
    {
      *okay = 2; /* data line */
      *off = 2;
    }
  else if (linelen >= 1
           && line[0] == 'S' 
           && (line[1] == '\0' || line[1] == ' '))
    {
      *okay = 4;
      *off = 1;
      while (line[*off] == ' ')
        ++*off;
    }  
  else if (linelen >= 2
           && line[0] == 'O' && line[1] == 'K'
           && (line[2] == '\0' || line[2] == ' '))
    {
      *okay = 1;
      *off = 2;
      while (line[*off] == ' ')
        ++*off;
    }
  else if (linelen >= 3
           && line[0] == 'E' && line[1] == 'R' && line[2] == 'R'
           && (line[3] == '\0' || line[3] == ' '))
    {
      *okay = 0;
      *off = 3;
      while (line[*off] == ' ')
        ++*off;
    }  
  else if (linelen >= 7
           && line[0] == 'I' && line[1] == 'N' && line[2] == 'Q'
           && line[3] == 'U' && line[4] == 'I' && line[5] == 'R'
           && line[6] == 'E' 
           && (line[7] == '\0' || line[7] == ' '))
    {
      *okay = 3;
      *off = 7;
      while (line[*off] == ' ')
        ++*off;
    }
  else if (linelen >= 3
           && line[0] == 'E' && line[1] == 'N' && line[2] == 'D'
           && (line[3] == '\0' || line[3] == ' '))
    {
      *okay = 5; /* end line */
      *off = 3;
    }
  else
    rc = _assuan_error (ASSUAN_Invalid_Response);
  return rc;
}



/**
 * assuan_transact:
 * @ctx: The Assuan context
 * @command: Command line to be send to the server
 * @data_cb: Callback function for data lines
 * @data_cb_arg: first argument passed to @data_cb
 * @inquire_cb: Callback function for a inquire response
 * @inquire_cb_arg: first argument passed to @inquire_cb
 * @status_cb: Callback function for a status response
 * @status_cb_arg: first argument passed to @status_cb
 * 
 * FIXME: Write documentation
 * 
 * Return value: 0 on success or error code.  The error code may be
 * the one one returned by the server in error lines or from the
 * callback functions.  Take care: When a callback returns an error
 * this function returns immediately with an error and thus the caller
 * will altter return an Assuan error (write erro in most cases).
 **/
assuan_error_t
assuan_transact (assuan_context_t ctx,
                 const char *command,
                 int (*data_cb)(void *, const void *, size_t),
                 void *data_cb_arg,
                 int (*inquire_cb)(void*, const char *),
                 void *inquire_cb_arg,
                 int (*status_cb)(void*, const char *),
                 void *status_cb_arg)
{
  assuan_error_t rc;
  int okay, off;
  char *line;
  int linelen;

  rc = assuan_write_line (ctx, command);
  if (rc)
    return rc;

  if (*command == '#' || !*command)
    return 0; /* Don't expect a response for a comment line.  */

 again:
  rc = _assuan_read_from_server (ctx, &okay, &off);
  if (rc)
    return rc; /* error reading from server */

  line = ctx->inbound.line + off;
  linelen = ctx->inbound.linelen - off;

  if (!okay)
    {
      rc = atoi (line);
      if (rc > 0 && rc < 100)
        rc = _assuan_error (ASSUAN_Server_Fault);
      else if (rc > 0 && rc <= 405)
        rc = _assuan_error (rc);
    }
  else if (okay == 2)
    {
      if (!data_cb)
        rc = _assuan_error (ASSUAN_No_Data_Callback);
      else 
        {
          char *s, *d;

          for (s=d=line; linelen; linelen--)
            {
              if (*s == '%' && linelen > 2)
                { /* handle escaping */
                  s++;
                  *d++ = xtoi_2 (s);
                  s += 2;
                  linelen -= 2;
                }
              else
                *d++ = *s++;
            }
          *d = 0; /* add a hidden string terminator */
          rc = data_cb (data_cb_arg, line, d - line);
          if (!rc)
            goto again;
        }
    }
  else if (okay == 3)
    {
      if (!inquire_cb)
        {
          assuan_write_line (ctx, "END"); /* get out of inquire mode */
          _assuan_read_from_server (ctx, &okay, &off); /* dummy read */
          rc = _assuan_error (ASSUAN_No_Inquire_Callback);
        }
      else
        {
          rc = inquire_cb (inquire_cb_arg, line);
          if (!rc)
            rc = assuan_send_data (ctx, NULL, 0); /* flush and send END */
          if (!rc)
            goto again;
        }
    }
  else if (okay == 4)
    {
      if (status_cb)
        rc = status_cb (status_cb_arg, line);
      if (!rc)
        goto again;
    }
  else if (okay == 5)
    {
      if (!data_cb)
        rc = _assuan_error (ASSUAN_No_Data_Callback);
      else 
        {
          rc = data_cb (data_cb_arg, NULL, 0);
          if (!rc)
            goto again;
        }
    }

  return rc;
}