/*
 * Copyright (c) 2020 The ZMK Contributors
 *
 * SPDX-License-Identifier: MIT
 */
 
#include <zephyr.h>
#include <logging/log.h>

LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);

#include <zmk/event-manager.h>

extern struct zmk_event_type* __event_type_start[];
extern struct zmk_event_type* __event_type_end[];

extern struct zmk_event_subscription __event_subscriptions_start[];
extern struct zmk_event_subscription __event_subscriptions_end[];


int zmk_event_manager_handle_from(struct zmk_event_header *event, u8_t start_index)
{
    int ret = 0;
    u8_t len = __event_subscriptions_end - __event_subscriptions_start;
    for (int i = start_index; i < len; i++) {
        struct zmk_event_subscription *ev_sub = __event_subscriptions_start + i;
        if (ev_sub->event_type == event->event) {
            ret = ev_sub->listener->callback(event);
            if (ret < 0) {
                LOG_DBG("Listener returned an error: %d", ret);
                goto release;
            } else if (ret > 0) {
                switch (ret) {
                    case ZMK_EV_EVENT_HANDLED:
                        LOG_DBG("Listener handled the event");
                        ret = 0;
                        goto release;
                    case ZMK_EV_EVENT_CAPTURED:
                        LOG_DBG("Listener captured the event");
                        event->last_listener_index = i;
                        // Listeners are expected to free events they capture
                        return 0;
                }
            }
        }
    }

release:
    k_free(event);
    return ret;
}

int zmk_event_manager_raise(struct zmk_event_header *event)
{
    return zmk_event_manager_handle_from(event, 0);
}

int zmk_event_manager_raise_after(struct zmk_event_header *event, const struct zmk_listener *listener)
{
    u8_t len = __event_subscriptions_end - __event_subscriptions_start;
    for (int i = 0; i < len; i++) {
        struct zmk_event_subscription *ev_sub = __event_subscriptions_start + i;

        if (ev_sub->event_type == event->event && ev_sub->listener == listener) {
            return zmk_event_manager_handle_from(event, i+1);
        }
    }

    LOG_WRN("Unable to find where to raise this after event");

    return -EINVAL;
}

int zmk_event_manager_raise_at(struct zmk_event_header *event, const struct zmk_listener *listener)
{
    u8_t len = __event_subscriptions_end - __event_subscriptions_start;
    for (int i = 0; i < len; i++) {
        struct zmk_event_subscription *ev_sub = __event_subscriptions_start + i;

        if (ev_sub->event_type == event->event && ev_sub->listener == listener) {
            return zmk_event_manager_handle_from(event, i);
        }
    }

    LOG_WRN("Unable to find where to raise this event");

    return -EINVAL;
}

int zmk_event_manager_release(struct zmk_event_header *event)
{
    return zmk_event_manager_handle_from(event, event->last_listener_index + 1);
}