#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <inttypes.h>
#include <sys/time.h>

#include <ncurses.h>

#include <hexagram/can.h>

static int usage(int argc, char **argv, const char *message, ...) {
    if (message) {
        va_list args;

        va_start(args, message);
        vfprintf(stderr, message, args);
        va_end(args);
    }

    fprintf(stderr, "usage: %s canif\n", argv[0]);

    return 1;
}

int main(int argc, char **argv) {
    WINDOW *win;
    hexagram_can_if *can_if;
    struct can_frame frame;
    uint8_t last_gear = 0;

    struct timeval now, last;

    if (argc != 2) {
        return usage(argc, argv, NULL);
    }

    if ((can_if = hexagram_can_if_open(argv[1])) == NULL) {
        perror("hexagram_can_if_open()");

        goto error_can_if_open;
    }

    gettimeofday(&now, NULL);
    memcpy(&last, &now, sizeof(now));

    initscr();

    win = newwin(LINES, COLS, 0, 0);

    while (hexagram_can_if_read(can_if, &frame) >= 0) {
        gettimeofday(&now, NULL);

        char lever_states[16] = "  PRNDS         ";
        char manual_gears[16] = "  123456        ";

        if (frame.can_id == 0x280) {
            double rpm = 0.25 * (double)(frame.data[2] | (frame.data[3] << 8));

            wmove(win, 1, 0);

            wprintw(win, "%6.1lf RPM\n", rpm);
        } else if (frame.can_id == 0x540) {
            if (frame.data[7] != last_gear) {
                wmove(win, 3, 8);

                if ((frame.data[7] & 0xc) == 0xc) {
                    wprintw(win, " %c\n",
                        manual_gears[(frame.data[7] & 0xf0) >> 4]);

                } else {
                    wprintw(win, "%c \n",
                        lever_states[(frame.data[7] & 0xf0) >> 4]);
                }

                last_gear = frame.data[7];
            }
        } else if (frame.can_id == 0x5a0) {
            /*
             * Speed is expressed in units of 0.002 wheel cycles per second
             */
            double rps = 0.001 * (double)(((uint16_t)frame.data[1] >> 1)
                                        | ((uint16_t)frame.data[2] << 8));

            double kph = (2.032 * rps * 3600) / 1000.0;

            wmove(win, 2, 0);

            wprintw(win, "%6.1lf kph", kph);
        }

        if (((now.tv_sec * 1000000) + now.tv_usec) - ((last.tv_sec * 1000000) + last.tv_usec) > 100000) {
            memcpy(&last, &now, sizeof(now));

            wrefresh(win);
        }
    }

    hexagram_can_if_close(can_if);

    return 0;

error_can_if_open:
    return 1;
}