#include <stdbool.h>

#include <app_event_manager.h>

#define MODULE mode_policy_module
#include <caf/events/module_state_event.h>
#include <caf/events/module_suspend_event.h>
#include <caf/events/power_event.h>

#include <zephyr/logging/log.h>

#include "mode_switch_event.h"

LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);

static bool initialized;
static bool running;
static bool ble_adv_suspended = true;
static bool usb_enabled;

static void broadcast_ble_adv_req(bool suspend)
{
	if (suspend) {
		struct module_suspend_req_event *event = new_module_suspend_req_event();

		event->sink_module_id = MODULE_ID(ble_adv);
		event->src_module_id = MODULE_ID(MODULE);
		APP_EVENT_SUBMIT(event);
	} else {
		struct module_resume_req_event *event = new_module_resume_req_event();

		event->sink_module_id = MODULE_ID(ble_adv);
		event->src_module_id = MODULE_ID(MODULE);
		APP_EVENT_SUBMIT(event);
	}
}

static void apply_mode_policy(enum mode_switch_mode mode)
{
	bool should_suspend_ble_adv = (mode != MODE_SWITCH_BLE);
	bool should_enable_usb = (mode == MODE_SWITCH_USB);

	if (should_suspend_ble_adv != ble_adv_suspended) {
		ble_adv_suspended = should_suspend_ble_adv;
		broadcast_ble_adv_req(should_suspend_ble_adv);
	}

	if (should_enable_usb != usb_enabled) {
		usb_enabled = should_enable_usb;
		if (usb_enabled) {
			struct module_resume_req_event *event =
				new_module_resume_req_event();

			event->sink_module_id = MODULE_ID(usb_device_module);
			event->src_module_id = MODULE_ID(MODULE);
			APP_EVENT_SUBMIT(event);
		} else {
			struct module_suspend_req_event *event =
				new_module_suspend_req_event();

			event->sink_module_id = MODULE_ID(usb_device_module);
			event->src_module_id = MODULE_ID(MODULE);
			APP_EVENT_SUBMIT(event);
		}
	}
}

static int module_init(void)
{
	ble_adv_suspended = true;
	usb_enabled = false;
	return 0;
}

static int module_start(void)
{
	if (running) {
		return 0;
	}

	running = true;
	return 0;
}

static void module_pause(void)
{
	running = false;
}

static bool app_event_handler(const struct app_event_header *aeh)
{
	if (is_mode_switch_event(aeh)) {
		const struct mode_switch_event *event = cast_mode_switch_event(aeh);

		if (running) {
			apply_mode_policy(event->mode);
		}

		return false;
	}

	if (is_module_state_event(aeh)) {
		const struct module_state_event *event = cast_module_state_event(aeh);

		if (check_state(event, MODULE_ID(main), MODULE_STATE_READY)) {
			int err;

			if (!initialized) {
				err = module_init();
				if (err) {
					module_set_state(MODULE_STATE_ERROR);
					return false;
				}

				initialized = true;
			}

			err = module_start();
			if (err) {
				module_set_state(MODULE_STATE_ERROR);
			} else {
				module_set_state(MODULE_STATE_READY);
			}
		}

		return false;
	}

	if (is_power_down_event(aeh)) {
		if (initialized) {
			module_pause();
			module_set_state(MODULE_STATE_STANDBY);
		}

		return false;
	}

	if (is_wake_up_event(aeh)) {
		if (initialized) {
			int err = module_start();

			if (err) {
				module_set_state(MODULE_STATE_ERROR);
			} else {
				module_set_state(MODULE_STATE_READY);
			}
		}

		return false;
	}

	return false;
}

APP_EVENT_LISTENER(MODULE, app_event_handler);
APP_EVENT_SUBSCRIBE(MODULE, mode_switch_event);
APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);