#include "evdev.h"
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <linux/input.h>

static int tap_timeout = 2000; // 3s

void evdev_init(evdev_drv_state_t *state, char* dev_path)
{
    LV_LOG_INFO("Opening evdev %s!", dev_path);
    state->fd = open(dev_path, O_RDWR | O_NOCTTY | O_NDELAY);

    if(state->fd == -1) {
        perror("unable to open evdev interface:");
        return;
    }

    fcntl(state->fd, F_SETFL, O_ASYNC | O_NONBLOCK);

    state->root_x = 0;
    state->root_y = 0;
    state->key_val = 0;
    state->button = LV_INDEV_STATE_REL;
}

void evdev_init_keypad(evdev_drv_state_t *state, char* dev_path)
{
    evdev_init(state, dev_path);
    state->key_raw = 0;
    state->timestamp_pr = 0;
    state->pressed_streak = 0;
}

int evdev_stop(evdev_drv_state_t *state)
{
    return close(state->fd);
}

static char get_key_from_map(multitap_keymap_t *key_map, int code, u_int32_t pcount)
{
    int i = 0;
    while (key_map[i].key != PKEY_UNDEFINED)
    {
        if (key_map[i].key == code)
        {
            return key_map[i].sequence[pcount % strlen(key_map[i].sequence)];
        }
        i++;
    }
    return '\0';
}

static int process_multitap(evdev_drv_state_t *state, lv_indev_drv_t *drv,
                        lv_indev_data_t *data, lv_indev_t *desc,
                        struct input_event *in)
{
    if (in->value == 1) { // OnPress update counters
        if (lv_tick_elaps(state->timestamp_pr) > tap_timeout) {
            state->pressed_streak = 0;
        } else {
            if (state->key_raw == in->code) {
                state->pressed_streak++;
            } else {
                state->pressed_streak = 0;
            }
        }
        state->key_raw = in->code;

        lv_group_t *g = desc->group;
        if (g == NULL) return 0;

        lv_obj_t *focus_obj = lv_group_get_focused(g);
        if(focus_obj == NULL) return 0;

        if(!lv_obj_check_type(focus_obj, &lv_textarea_class)) return 0;

        if (state->pressed_streak != 0 && in->value == 0) {
            lv_textarea_del_char(focus_obj);
        }
    }
    state->timestamp_pr = lv_tick_get();

    return get_key_from_map(input_get_active_keymap(), in->code, state->pressed_streak);
}

int handle_special_keys(evdev_drv_state_t *state, struct input_event *in)
{
    switch(in->code) {
        case KEY_BACKSPACE:
        case KEY_ENTER:
        case KEY_PREVIOUS:
        case KEY_NEXT:
        case KEY_UP:
        case KEY_LEFT:
        case KEY_RIGHT:
        case KEY_DOWN:
        case KEY_TAB:
            state->pressed_streak = 0;
            state->key_raw = 0;
    }

        switch(in->code) {
        case KEY_BACKSPACE:
            return LV_KEY_BACKSPACE;
            break;
        case KEY_ENTER:
            return LV_KEY_ENTER;
            break;
        case KEY_PREVIOUS:
            return LV_KEY_PREV;
            break;
        case KEY_NEXT:
            return LV_KEY_NEXT;
            break;
        case KEY_UP:
            return LV_KEY_UP;
            break;
        case KEY_LEFT:
            return LV_KEY_LEFT;
            break;
        case KEY_RIGHT:
            return LV_KEY_RIGHT;
            break;
        case KEY_DOWN:
            return LV_KEY_DOWN;
            break;
        case KEY_TAB:
            return LV_KEY_NEXT;
            break;
        default:
            return 0;
    }
}

void evdev_read(evdev_drv_state_t *state, lv_indev_drv_t *drv,
                lv_indev_t *desc, lv_indev_data_t *data)
{
    struct input_event in;

    while(read(state->fd, &in, sizeof(struct input_event)) > 0) {
        if(in.type == EV_REL) {
            if(in.code == REL_X)
				#if EVDEV_SWAP_AXES
					state->root_y += in.value;
				#else
					state->root_x += in.value;
				#endif
            else if(in.code == REL_Y)
				#if EVDEV_SWAP_AXES
					state->root_x += in.value;
				#else
					state->root_y += in.value;
				#endif
        } else if(in.type == EV_ABS) {
            if(in.code == ABS_X) {
				#if EVDEV_SWAP_AXES
					state->root_y = in.value;
				#else
					state->root_x = in.value;
				#endif
            } else if(in.code == ABS_Y) {
				#if EVDEV_SWAP_AXES
					state->root_x = in.value;
				#else
					state->root_y = in.value;
				#endif
            } else if(in.code == ABS_MT_POSITION_X) {
                                #if EVDEV_SWAP_AXES
                                        state->root_y = in.value;
                                #else
                                        state->root_x = in.value;
                                #endif
            } else if(in.code == ABS_MT_POSITION_Y) {
                                #if EVDEV_SWAP_AXES
                                        state->root_x = in.value;
                                #else
                                        state->root_y = in.value;
                                #endif
            } else if(in.code == ABS_MT_TRACKING_ID) {
                                if(in.value == -1)
                                    state->button = LV_INDEV_STATE_REL;
                                else if(in.value == 0)
                                    state->button = LV_INDEV_STATE_PR;
            }
        } else if(in.type == EV_KEY) {
            if(in.code == BTN_MOUSE || in.code == BTN_TOUCH) {
                if(in.value == 0)
                    state->button = LV_INDEV_STATE_REL;
                else if(in.value == 1)
                    state->button = LV_INDEV_STATE_PR;
            } else if(drv->type == LV_INDEV_TYPE_KEYPAD) {
                LV_LOG_WARN("Got key %d.", in.code);
                data->key = handle_special_keys(state, &in);
                if (data->key == 0) {
                    data->key = process_multitap(state, drv, data, desc, &in);
                }

                if (data->key != 0) {
                    /* Only record button state when actual output is produced to prevent widgets from refreshing */
                    data->state = (in.value) ? LV_INDEV_STATE_PR : LV_INDEV_STATE_REL;
                }
                state->key_val = data->key;
                state->button = data->state;
                return;
            }
        }
    }

    if(drv->type == LV_INDEV_TYPE_KEYPAD) {
        /* No data retrieved */
        data->key = state->key_val;
        data->state = state->button;
        return;
    }
    if(drv->type != LV_INDEV_TYPE_POINTER)
        return ;
    /*Store the collected data*/

    data->point.x = state->root_x;
    data->point.y = state->root_y;

    data->state = state->button;

    if(data->point.x < 0)
      data->point.x = 0;
    if(data->point.y < 0)
      data->point.y = 0;
    if(data->point.x >= drv->disp->driver->hor_res)
      data->point.x = drv->disp->driver->hor_res - 1;
    if(data->point.y >= drv->disp->driver->ver_res)
      data->point.y = drv->disp->driver->ver_res - 1;

    return ;
}