#include "common_tool.h"

#include <errno.h>
#include <sys/stat.h>
#include <unistd.h>

#include "la-log.h"

void Common_Tool::init_config()
{
    if (config_filename == NULL) {
        abort();
    }
    struct stat buf;
    if (stat(config_filename, &buf) == -1) {
        if (errno == ENOENT) {
            if (!streq(default_config_filename, config_filename)) {
                la_log(LOG_CRIT, "Config file (%s) does not exist", config_filename);
                exit(1);
            }
        } else {
            la_log(LOG_CRIT, "Failed to stat (%s): %s\n", config_filename, strerror(errno));
            exit(1);
        }
    }
    _config = new INIReader(config_filename);
    if (_config == NULL) {
        la_log(LOG_CRIT, "Failed to create config from (%s)\n", config_filename);
        exit(1);
    }
    if (_config == NULL) {
        _config = new INIReader("/dev/null");
    }
}

void Common_Tool::check_fds_are_empty_after_select(fd_set &fds_read, fd_set &fds_write,
                                                   fd_set &fds_err, uint8_t nfds)
{
    for (uint8_t i = 0; i < nfds; i++) {
        if (FD_ISSET(i, &fds_read)) {
            la_log(LOG_ERR, "fds_read not empty");
            break;
        }
        if (FD_ISSET(i, &fds_write)) {
            la_log(LOG_ERR, "fds_write not empty");
            break;
        }
        if (FD_ISSET(i, &fds_err)) {
            la_log(LOG_ERR, "fds_err not empty");
            break;
        }
    }
}

void Common_Tool::pack_select_fds(fd_set &fds_read UNUSED, fd_set &fds_write UNUSED,
                                  fd_set &fds_err UNUSED, uint8_t &nfds UNUSED)
{
}

void Common_Tool::handle_select_fds(fd_set &fds_read UNUSED, fd_set &fds_write UNUSED,
                                    fd_set &fds_err UNUSED, uint8_t &nfds UNUSED)
{
}

void Common_Tool::sighup_received_tophalf()
{
}
void Common_Tool::sighup_handler(int signal UNUSED)
{
    _sighup_received = true;
}
void Common_Tool::do_idle_callbacks()
{
}

uint32_t Common_Tool::select_timeout_us()
{
    return 200000;
}

void Common_Tool::select_loop()
{
    fd_set fds_read;
    fd_set fds_write;
    fd_set fds_err;
    uint8_t nfds;
    while (1) {
        if (_sighup_received) {
            sighup_received_tophalf();
            _sighup_received = false;
        }
        /* Wait for a packet, or time out if no packets arrive so we always
           periodically log status and check for new destinations. Downlink
           packets are on the order of 100/sec, so the timeout is such that
           we don't expect timeouts unless solo stops sending packets. We
           almost always get a packet with a 200 msec timeout, but not with
           a 100 msec timeout. (Timeouts don't really matter though.) */

        struct timeval timeout;

        FD_ZERO(&fds_read);
        FD_ZERO(&fds_write);
        FD_ZERO(&fds_err);
        nfds = 0;
        pack_select_fds(fds_read, fds_write, fds_err, nfds);

        timeout.tv_sec = 0;
        timeout.tv_usec = select_timeout_us();
        int res = select(nfds, &fds_read, &fds_write, &fds_err, &timeout);

        if (res < 0) {
            unsigned skipped = 0;
            // if ((skipped = can_log_error()) >= 0)
            la_log(LOG_ERR, "[%u] select: %s", skipped, strerror(errno));
            /* this sleep is to avoid soaking the CPU if select starts
               returning immediately for some reason */
            /* previous code was not checking errfds; we are now, so
               perhaps this usleep can go away -pb20150730 */
            usleep(10000);
            continue;
        }

        if (res == 0) {
            // select timeout
        }

        handle_select_fds(fds_read, fds_write, fds_err, nfds);

        check_fds_are_empty_after_select(fds_read, fds_write, fds_err, nfds);

        do_idle_callbacks();
    } /* while (1) */
}

void Common_Tool::parse_fd(Format_Reader *reader, int fd)
{
    char buf[1 << 16];
    ssize_t buf_start = 0;
    while (true) {
        ssize_t bytes_read = read(fd, &buf[buf_start], sizeof(buf) - buf_start);
        if (bytes_read == -1) {
            fprintf(stderr, "Read failed: %s\n", strerror(errno));
            exit(1);
        }
        if (bytes_read == 0) {
            while (reader->feed((uint8_t *)buf, buf_start + bytes_read)) {
            }
            break;
        }

        bytes_read += buf_start;
        ssize_t total_bytes_used = 0;
        while (total_bytes_used < bytes_read) {
            ssize_t bytes_used =
                reader->feed((uint8_t *)(&buf[total_bytes_used]), bytes_read - total_bytes_used);
            if (bytes_used > bytes_read - total_bytes_used) {
                abort();
            }
            if (bytes_used == 0) {
                break;
            }
            total_bytes_used += bytes_used;
        }
        // ::fprintf(stderr, "total_bytes_used = %u\n", total_bytes_used);
        // ::fprintf(stderr, "bytes_read = %u\n", bytes_read);
        memcpy(&buf[0], (uint8_t *)(&(buf[total_bytes_used])), bytes_read - total_bytes_used);
        buf_start = bytes_read - total_bytes_used;
    }

    reader->end_of_log();

    // ::fprintf(stderr, "Packet count: %d\n", packet_count);
}