#include <tabby/link.h>
#include <tabby/command.h>

int tabby_link_open(const char *dev) {
    int fd;
    struct termios attr;

    if ((fd = open(dev, O_RDWR | O_NOCTTY)) < 0) {
        goto error_open;
    }

    if (fcntl(fd, F_SETFL) < 0) {
        goto error_io;
    }

    attr.c_cflag = CS8 | CREAD;
    attr.c_ispeed = TABBY_LINK_BAUD;
    attr.c_ospeed = TABBY_LINK_BAUD;
    attr.c_iflag  = IGNPAR;
    attr.c_oflag  = 0;
    attr.c_lflag  = 0;

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

    if (tcsetattr(fd, TCSANOW, &attr) < 0) {
        goto error_io;
    }

    return fd;

error_io:
    close(fd);

error_open:
    return -1;
}

int tabby_link_close(int fd) {
    return close(fd);
}

ssize_t tabby_link_send(int fd, void *buf, uint16_t len) {
    uint8_t header[3] = {
        TABBY_COMMAND_SEND, (len & 0xff00) >> 8, len & 0xff
    };

    if (write(fd, &header, sizeof(header)) < 0) {
        goto error_write_header;
    }

    return write(fd, buf, (size_t)len);

error_write_header:
    return -1;
}

ssize_t tabby_link_recv(int fd, void *buf, uint16_t len) {
    return read(fd, buf, (size_t)len);
}

int tabby_link_set_clock_source(int fd, tabby_clock_source source) {
    uint8_t packet[2] = {
        TABBY_COMMAND_CLOCK_SOURCE, source
    };

    return write(fd, &packet, sizeof(packet));
}

int tabby_link_set_clock_speed(int fd, tabby_clock_speed speed) {
    uint8_t packet[2] = {
        TABBY_COMMAND_CLOCK_SPEED, speed
    };

    return write(fd, &packet, sizeof(packet));
}