/*
 * Status:
 *
 * - Can map keys from some keyboard to keys on a joystick.
 * - Has programmable config format (see config.h)
 *
 * TODO:
 * - Allow multiple keymaps per input key event; currently we override previous
 *   values.
 * - Allow multiple inputs, modify config file to allow for mapping from
 *   specific inputs.
 *
 */


#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <unistd.h>
#include <fcntl.h>

#include <signal.h>

#include <linux/input.h>
#include <linux/uinput.h>

#include <err.h>
#include <poll.h>
#include <errno.h>

#include "config.h"

/* Reverse mapping, for later use */
static const struct _key_to_str {
    char *name;
    int num;
} key_map[] = {
#define DEF_KEY(NAME) \
    {#NAME,NAME},
    #include "def_keys.h"
    {NULL, -1}
};

static const struct _btn_to_str {
    char *name;
    int num;
} btn_map[] = {
#define DEF_BTN(NAME) \
    {#NAME,NAME},
    #include "def_buttons.h"
    {NULL, -1}
};

static int get_key_num(char* name)
{
    int i = 0;

    while (key_map[i].name) {
        if (!strcmp(key_map[i].name, name))
            return key_map[i].num;

        i++;
    }

    return -1;
}

static int js[JOYCOUNT];

void free_js(int sig) {
    int j;

    (void) sig;
    for(j = 0; j < JOYCOUNT; j++) {
        printf("Freeing joystick: %d\n", j);
        if (ioctl(js[j], UI_DEV_DESTROY) < 0) {
            perror("Error freeing joystick");
        }
        close(js[j]);
    }
    exit(1);
}

int scan_device(char *f, int nfd) {
#define BITS_PER_LONG (sizeof(long) * 8)
#define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
#define OFF(x)  ((x)%BITS_PER_LONG)
#define BIT(x)  (1UL<<OFF(x))
#define LONG(x) ((x)/BITS_PER_LONG)
#define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)
        int i, j;
        int version;
        unsigned short id[4];
        char name[256] = "Unknown";
        unsigned long bit[EV_MAX][NBITS(KEY_MAX)];
        int fd;

        fd = open(f, O_RDONLY);

        if (ioctl(fd, EVIOCGVERSION, &version)) {
                perror("evtest: can't get version");
                return 1;
        }

        printf("Input driver version is %d.%d.%d\n",
                version >> 16, (version >> 8) & 0xff, version & 0xff);

        ioctl(fd, EVIOCGID, id);
        printf("Input device ID: bus 0x%x vendor 0x%x product 0x%x version 0x%x\n",
                id[ID_BUS], id[ID_VENDOR], id[ID_PRODUCT], id[ID_VERSION]);

        ioctl(fd, EVIOCGNAME(sizeof(name)), name);
        printf("Input device name: \"%s\"\n", name);

        memset(bit, 0, sizeof(bit));
        ioctl(fd, EVIOCGBIT(0, EV_MAX), bit[0]);
        printf("Supported events:\n");

        for (i = 0; i < EV_MAX; i++)
                if (test_bit(i, bit[0])) {
                        /*printf("  Event type %d (%s)\n", i, events[i] ? events[i] : "?");*/
                        if (!i) continue;

                        /* Skip ev_syn; daarna kan je ook storen in bit[i], want i != 0*/
                        printf("major ioctl: %d, %ld, %d\n", nfd, UI_SET_EVBIT, i);
                        printf("major ioctl: %d\n", ioctl(nfd, UI_SET_EVBIT, i));

                        ioctl(fd, EVIOCGBIT(i, KEY_MAX), bit[i]);
                        for (j = 0; j < KEY_MAX; j++)
                                if (test_bit(j, bit[i])) {
                                        long kbit = 0;
                                        switch (i) {
                                            case EV_KEY: kbit = UI_SET_KEYBIT; break;
                                            case EV_REL: kbit = UI_SET_RELBIT; break;
                                            case EV_ABS: kbit = UI_SET_ABSBIT; break;
                                        }
                                        if (!kbit)
                                            continue;

                                        printf("Setting key: %d\n", j);
                                        printf("ioctl: %d\n", ioctl(nfd, kbit, j));
                                        /*printf("    Event code %d (%s)\n", j, names[i] ? (names[i][j] ? names[i][j] : "?") : "?");*/
                                        if (i == EV_ABS) {
                                            /* XXX: TODO */
                                                /*print_absdata(fd, j);*/
                                        }
                                }
                }

        return 0;
}

int main(int argc, char** argv) {
    int j, nowrite, rfds, fdrr = 0;
    int in[INPUT_DEVICE_COUNT]; /* fds */
    struct pollfd pin[INPUT_DEVICE_COUNT];
    struct input_event e, je;
    struct uinput_user_dev uidev;


    (void)argc;
    (void)argv;

    (void)get_key_num;

    /* Open required input devices */
    #define H_CONFIGURE_EVENTS
    #include "config.h"

    /* Now setup poll structure */
    for (j = 0; j < INPUT_DEVICE_COUNT; j++)
    {
        pin[j].fd = in[j];
        pin[j].events = POLLIN;
    }

    if(signal(SIGINT, free_js) == SIG_ERR) {
        printf("SIGINT handler registration failed\n");
        return 1;
    }

    for(j = 0; j < JOYCOUNT; j++) {
        /* Memset because we are already setting the absmax/absmin */
        memset(&uidev, '\0', sizeof(struct uinput_user_dev));
        js[j] = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
        if (js[j] < 0) {
            perror("(NOT FATAL YET) Could not open: /dev/uinput");
            js[j] = open("/dev/input/uinput", O_WRONLY | O_NONBLOCK);
            if (js[j] < 0) {
                perror("(FATAL) Could not open: /dev/input/uinput");
                return 1;
            }
        }


        printf("js[j] %d\n", js[j]);
        #define H_CONFIGURE_JOYSTICKS
        #include "config.h"
        scan_device("/dev/input/event8", js[j]);

        /* Allocate device info */
        snprintf(uidev.name, UINPUT_MAX_NAME_SIZE, "key2joy:%d", j);

        uidev.id.bustype = BUS_USB;
        uidev.id.vendor  = 0x42;
        uidev.id.product = 0xbebe;
        uidev.id.version = 1;

        if (write(js[j], &uidev, sizeof(uidev)) < 0) {
            perror("write");
            return EXIT_FAILURE;
        }

        if (ioctl(js[j], UI_DEV_CREATE)) {
            perror("ioctl create");
            return EXIT_FAILURE;
        }
    }

    /* Do it! */
    while (1) {
        printf("Entering poll..\n");
        /* Any data available? */
        if ((rfds = poll(pin, INPUT_DEVICE_COUNT, -1)) < 0) {
            /* Interrupted by signal */
            if (errno == EINTR)
                continue;
            perror("poll");
            return EXIT_FAILURE;
        }
        printf("Leaving poll..\n");

        /* Round-robin check readers */
        while (rfds) {
            if (pin[fdrr].revents & POLLIN) {
                printf("Device %d has input\n", fdrr);
                /* XXX: Need checking for complete read? */
                if (read(in[fdrr], &e, sizeof(struct input_event)) < 0) {
                    /* Interrupted by singal? Retry */
                    if (errno == EINTR)
                        continue;

#if 0
                    if (errno == EWOULDBLOCK || errno == EAGAIN) {
                        printf("poll tells us device %d is readable.. it is not\n", fdrr);
                        rfds -= 1;
                        fdrr = (fdrr + 1) % INPUT_DEVICE_COUNT;
                        continue;
                    }
#endif

                    err(EXIT_FAILURE, "reading input device nr. %d failed", fdrr);
                }

                printf("Event: (Type: %d, Code: %d, Value %d)\n", e.type, e.code, e.value);
            } else {
                /* Update poll read mechanism */
                fdrr = (fdrr + 1) % INPUT_DEVICE_COUNT;
                continue;
            }

            /* Now handle received event */
            memset(&je, '\0', sizeof(struct input_event));
            nowrite = 1;
            j = 0;

            je.type = e.type;
            je.code = e.code;
            je.value = e.value;
            nowrite = 0;
            /*
            #define H_JOYMAP
            #include "config.h"
            */

            /* Update poll read mechanism */
            fdrr = (fdrr + 1) % INPUT_DEVICE_COUNT;
            rfds -= 1;

            if (nowrite == 0) {
                printf("Writing %d to %d\n", e.code, j);
                if(write(js[j], &je, sizeof(struct input_event)) < 0) {
                    perror("Event write event");
                    return EXIT_FAILURE;
                }
            }

            /* Synchronisation events */
            if (e.type == EV_SYN) {
                memset(&je, '\0', sizeof(struct input_event));
                printf("SYN event\n");

                je.type = EV_SYN;
                je.code = 0;
                je.value = 0;

                if (write(js[j], &je, sizeof(struct input_event)) < 0) {
                    perror("SYN write event");
                    return EXIT_FAILURE;
                }
            }

        } /* End reader check loop */

    } /* End main loop */

    return 0;
}