#include "modem.h"
#include "lock.h"

/* Baudrate for the TTY. Should be greater the 64000. */
#define BAUD_RATE B115200

struct modem *modem_open(const char *dev) {
    struct modem *m;
    int fd = -1, n;
    struct termios ts, ts2;

    assert(dev);

    if (device_lock(dev) != 0)
        return -1;

    if ((fd = open(dev, O_RDWR|O_NDELAY)) < 0) {
        daemon_log(LOG_ERR, "Failed to open device <%s>: %s", dev, strerror(errno));
        goto fail;
    }

    if ((n = fcntl(fd, F_GETFL, 0)) < 0 || fcntl(fd, F_SETFL, n & ~O_NDELAY) < 0) {
        daemon_log(LOG_ERR, "Failed to remove O_NDELAY flag from device: %s", strerror(errno));
        goto fail;
    }
    
    memset(&ts, 0, sizeof ts);
    ts.c_cflag = CRTSCTS | IGNPAR | HUPCL | CS8;
    ts.c_iflag = IGNPAR;
    ts.c_oflag = 0;
    ts.c_lflag = 0;

    ts.c_cc[VMIN] = 1;
    ts.c_cc[VTIME] = 0;

    cfsetospeed(&ts, BAUD_RATE);
    cfsetispeed(&ts, BAUD_RATE);

    tcflush(fd, TCIFLUSH);

    if (tcsetattr(fd, TCSANOW, &ts) < 0) {
        daemon_log(LOG_ERR, "Failed to set TTY attributes: %s", strerror(errno));
        goto fail;
    }

    if (tcgetattr(fd, &ts2) < 0 || memcmp(&ts, &ts2) != 0) {
        daemon_log(LOG_ERR, "Failed to set TTY attributes");
        goto fail;
    }

    m = malloc(sizeof(struct modem));
    assert(m);
    memset(m, 0, sizeof(struct modem));
    m->dev = strdup(dev);
    assert(m->dev);
    m->fd = fd;
    m->state = MODEM_STATE_INIT;
    m->child_pid = -1;

    return m;

fail:
    if (fd >= 0)
        close(fd);

    device_unlock(dev);
    
    return NULL;
    
}

void modem_close(struct modem *m) {
    assert(m);

    if (m->child_pid != -1)
        child_process_kill(m->child_pid);
    
    close(m->fd);
    device_unlock(m->dev);
    free(m->dev);
    free(m);
}

static int modem_read(struct modem *m) {
    char *p;
    ssize_t s;
    assert(m && m->input_buf);

    p = m->input_buf+m->input_buf_len;
    if ((s = read(m->fd, &p, MODEM_BUF_LEN-m->input_buf_len)) <= 0) {
        daemon_log(LOG_ERR, "Failed to read() from modem: %s", !s ? "EOF" : strerror(errno));
        return -1;
    }

    m->input_buf_len += s;
}

static void* oop_timeout_cb(oop_source *source,struct timeval tv,void *user) {
    struct modem *m = (struct modem*) user;
    assert(source && user);

    daemon_log(LOG_ERR, "Timeout reached for device <%s>", m->device);
    return OOP_HALT;
}

static void modem_timeout(struct modem *m, int t) {
    struct timeval tv = { t, 0 };
    assert(m);

    assert(event_source && event_source->on_time);
    event_source->cancel_time(event_source, m->timeout, oop_timeout_cb, m);

    if (t > 0) {
        gettimeofday(&m->timeout);
        m->tv_sec += t;
        
        assert(event_source && event_source->on_time);
        event_source->on_time(event_source, m->timeout, oop_timeout_cb, m);
    }
}

static void* oop_init_cb(oop_source *source, int fd, oop_event event, void *user) {
    struct modem *m = (struct modem*) user;
    assert(source && user);
    assert(m && m->fd == fd && m->mode == MODEM_STATE_INIT);

    if (event == OOP_READ) {
        if (modem_read(m) < 0)
            return OOP_HALT;
        
    } else if (event == OOP_WRITE) {
        modem_write(m);
    }
    
    return OOP_CONTINUE;
}

static void* oop_audio_simple_cb(oop_source *source, int fd, oop_event event, void *user) {
    struct modem *m = (struct modem*) user;
    assert(source && user);
    assert(m && m->mode == MODEM_STATE_AUDIO_SIMPLE);

    if (event == OOP_READ) {
        modem_read(m);
    } else if (event == OOP_WRITE) {
        modem_write(m);
    }
    
    return OOP_CONTINUE;
}

static void* oop_audio_shbuf_cb(oop_source *source, int fd, oop_event event, void *user) {
    struct modem *m = (struct modem*) user;
    assert(source && user);
    assert(m && m->mode == MODEM_STATE_AUDIO_SHBUF);
    
    if (event == OOP_READ) {
        modem_read(m);
    } else if (event == OOP_WRITE) {
        modem_write(m);
    }
    return OOP_CONTINUE;
}