/* $Id$ */

/***
  This file is part of ivam2.

  ivam2 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.
  
  ivam2 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 ivam2; 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 <stddef.h>
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <libdaemon/dlog.h>

#include "modemman.h"
#include "modem.h"
#include "main.h"

#define MAX_CHANNELS 10
#define TTY_START 12

struct llist {
    struct modem *modem;
    struct llist *next;
};

static struct llist *llist = NULL;
static int n_llist = 0;

static void modem_try_open(const char *dev, const char *msn) {
    struct modem *m;
    
    if ((m = modem_open(dev, msn))) {
        struct llist *l = malloc(sizeof(struct llist));
        assert(l);
        
        l->modem = m;
        l->next = llist;
        llist = l;
        n_llist++;
    }
}

const char *get_listen_msn(int i) {
    static int buf_valid = 0;
    static char buf[256];
    static char *buf_ptr[MAX_CHANNELS];
    static int n_buf_ptr;
        
    if (!args.listen_arg)
        return "*";

    if (!buf_valid) {
        char *p;

        strncpy(buf, args.listen_arg, sizeof(buf)-1);
        buf[sizeof(buf)-1] = 0;

        for (p = buf; *p; p++)
            if (*p == ',')
                *p = ';';
        
        for (p = buf, n_buf_ptr = 0; n_buf_ptr < MAX_CHANNELS;) {
            int l;
            buf_ptr[n_buf_ptr++] = p;
            l = strcspn(p, ":");
            if (p[l] == 0)
                break;

            p[l] = 0;
            p+=l+1;
        }

        buf_valid = 1;
    }

    assert(n_buf_ptr > 0);
    
    if (i >= n_buf_ptr)
        i = n_buf_ptr -1;

    return buf_ptr[i];
}

int modem_manager_init(int channels) {
    int i;
    
    assert(channels <= MAX_CHANNELS && channels > 0); 
    assert(n_llist == 0);

    daemon_log(LOG_INFO, "Allocating %i channels.", channels);

    if (args.device_arg) {
        char *p = args.device_arg;
        
        for (;;) {            
            char dev[PATH_MAX];
            size_t l, n = strcspn(p, ":");

            l = n;
            if (sizeof(dev)-1 < l)
                l = sizeof(dev)-1;
            
            strncpy(dev, p, l);
            dev[l] = 0;
                
            modem_try_open(dev, get_listen_msn(n_llist));

            if (p[n] == 0)
                break;

            p[n] = 0;
            p+=n+1;
        }
    }
    
    
    for (i = TTY_START; i < TTY_START+MAX_CHANNELS && n_llist < channels; i++) {
        char d[PATH_MAX];
        snprintf(d, sizeof(d), "/dev/ttyI%i", i);
        modem_try_open(d, get_listen_msn(n_llist));
    }

    if (n_llist < channels) {
        daemon_log(LOG_ERR, "Failed to allocate the requested channels. Got %i of %i.", n_llist, channels);
        modem_manager_done();
        return -1;
    }

    return 0;
}

void modem_manager_done(void) {

    while (llist) {
        struct llist *l;

        modem_close(llist->modem);
        l = llist;
        llist = llist->next;
        free(l);
        n_llist--;
    }

    assert(!n_llist && !llist);
}