#include <errno.h>
#include <stdbool.h>

#include <app_event_manager.h>

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

#include <lvgl_zephyr.h>
#include <zephyr/device.h>
#include <zephyr/drivers/display.h>
#include <zephyr/drivers/led.h>
#include <zephyr/logging/log.h>

#include "bat_state_event.h"
#include "ble_bond_multi_event.h"
#include "datetime_event.h"
#include "hid_led_event.h"
#include "module_lifecycle.h"
#include "mode_switch_event.h"
#include "settings_mode_event.h"
#include "settings_view_event.h"
#include "theme_rgb_update_event.h"
#include "theme_color.h"
#include "ui/ui_page.h"
#include "ui/ui_main.h"
#include "ui/ui_settings.h"

LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);

BUILD_ASSERT(DT_HAS_CHOSEN(zephyr_display), "Missing zephyr,display chosen node");
BUILD_ASSERT(DT_NODE_HAS_STATUS(DT_ALIAS(backlight), okay),
	     "Missing backlight alias");

struct display_module_ctx {
	struct module_lifecycle_ctx lc;
	const struct device *display_dev;
	const struct device *backlight_dev;
	uint32_t backlight_idx;
	struct ui_main_model ui_model;
	struct ui_settings_page *settings_page;
	bool settings_active;
	bool lvgl_initialized;
	char date_text[DATETIME_EVENT_DATE_TEXT_LEN];
	char time_text[DATETIME_EVENT_TIME_TEXT_LEN];
};

static int do_init(void);
static int do_start(void);
static int do_stop(void);

static const struct module_lifecycle_cfg lifecycle_cfg = {
	.mode = ML_MODE_POWER,
	.stopped_state = MODULE_STATE_STANDBY,
};

static const struct module_lifecycle_ops lifecycle_ops = {
	.do_init = do_init,
	.do_start = do_start,
	.do_stop = do_stop,
};

static struct display_module_ctx ctx = {
	.lc = {
		.state = LC_UNINIT,
		.cfg = &lifecycle_cfg,
		.ops = &lifecycle_ops,
	},
	.display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display)),
	.backlight_dev = DEVICE_DT_GET(DT_PARENT(DT_ALIAS(backlight))),
	.backlight_idx = DT_NODE_CHILD_IDX(DT_ALIAS(backlight)),
	.ui_model = {
		.theme_color = LV_COLOR_MAKE(BLINKY_THEME_DEFAULT_R,
					     BLINKY_THEME_DEFAULT_G,
					     BLINKY_THEME_DEFAULT_B),
		.inactive_border_color = LV_COLOR_MAKE(0x3A, 0x44, 0x52),
		.mode = MODE_SWITCH_BLE,
	},
	.date_text = "1970/01/01",
	.time_text = "00:00:00",
};

static struct ui_page *main_page(void)
{
	return ui_main_page_get(&ctx.ui_model, ctx.date_text, ctx.time_text);
}

static int backlight_set(bool on)
{
	if (on) {
		return led_on(ctx.backlight_dev, ctx.backlight_idx);
	}

	return led_off(ctx.backlight_dev, ctx.backlight_idx);
}

static int do_init(void)
{
	int err;

	LOG_INF("Display init on %s", ctx.display_dev->name);

	if (!device_is_ready(ctx.display_dev)) {
		LOG_ERR("Display device %s not ready", ctx.display_dev->name);
		return -ENODEV;
	}

	if (!device_is_ready(ctx.backlight_dev)) {
		LOG_ERR("Backlight device %s not ready", ctx.backlight_dev->name);
		return -ENODEV;
	}

	err = backlight_set(false);
	if (err) {
		LOG_ERR("Backlight off failed (%d)", err);
		return err;
	}

	return 0;
}

static int do_start(void)
{
	int err;

	if (module_lifecycle_is_running(&ctx.lc)) {
		return 0;
	}

	if (!ctx.lvgl_initialized) {
		err = lvgl_init();
		if (err) {
			LOG_ERR("lvgl_init failed (%d)", err);
			return err;
		}

		ctx.lvgl_initialized = true;

		lvgl_lock();
		ui_page_init(main_page());
		lvgl_unlock();
	}

	lvgl_lock();
	if (!ctx.settings_active) {
		ui_page_init(main_page());
	}
	lvgl_unlock();

	err = backlight_set(true);
	if (err) {
		LOG_ERR("Backlight enable failed (%d)", err);
		return err;
	}

	err = display_blanking_off(ctx.display_dev);
	if (err) {
		LOG_ERR("display_blanking_off failed (%d)", err);
		(void)backlight_set(false);
		return err;
	}

	LOG_INF("LVGL display started");

	return 0;
}

static int do_stop(void)
{
	if (!module_lifecycle_is_running(&ctx.lc)) {
		return 0;
	}

	(void)display_blanking_on(ctx.display_dev);
	(void)backlight_set(false);
	LOG_INF("LVGL display paused");

	return 0;
}

static void refresh_ui(void)
{
	if (!ctx.lvgl_initialized) {
		return;
	}

	lvgl_lock();
	if (ctx.settings_active && (ctx.settings_page != NULL)) {
		ui_settings_show(ctx.settings_page, true);
	} else {
		ui_page_refresh(main_page());
	}
	lvgl_unlock();
}

static bool app_event_handler(const struct app_event_header *aeh)
{
	if (is_bat_state_event(aeh)) {
		const struct bat_state_event *event = cast_bat_state_event(aeh);

		ctx.ui_model.battery_level = event->soc;
		ctx.ui_model.charging = event->charging;
		ctx.ui_model.full = event->full;
		refresh_ui();
		return false;
	}

	if (is_mode_switch_event(aeh)) {
		const struct mode_switch_event *event = cast_mode_switch_event(aeh);

		ctx.ui_model.mode = event->mode;
		refresh_ui();
		return false;
	}

	if (is_ble_bond_multi_event(aeh)) {
		refresh_ui();
		return false;
	}

	if (is_hid_led_event(aeh)) {
		const struct hid_led_event *event = cast_hid_led_event(aeh);

		ctx.ui_model.led_mask = event->led_bm;
		refresh_ui();
		return false;
	}

	if (is_theme_rgb_update_event(aeh)) {
		const struct theme_rgb_update_event *event =
			cast_theme_rgb_update_event(aeh);

		ctx.ui_model.theme_color = (lv_color_t)LV_COLOR_MAKE(event->theme.r,
								     event->theme.g,
								     event->theme.b);
		refresh_ui();
		return false;
	}

	if (is_settings_mode_event(aeh)) {
		const struct settings_mode_event *event =
			cast_settings_mode_event(aeh);

		ctx.settings_active = event->active;
		if (!ctx.settings_active) {
			ctx.settings_page = NULL;
		}
		if (!ctx.lvgl_initialized) {
			return false;
		}

		lvgl_lock();
		if (ctx.settings_active) {
			ui_page_deinit(main_page());
			ui_settings_init();
			if (ctx.settings_page != NULL) {
				ui_settings_show(ctx.settings_page, false);
			}
		} else {
			ui_settings_deinit();
			ui_page_init(main_page());
			ui_page_refresh(main_page());
		}
		lvgl_unlock();
		return false;
	}

	if (is_settings_view_event(aeh)) {
		const struct settings_view_event *event =
			cast_settings_view_event(aeh);

		ctx.settings_page = event->page;
		if (ctx.settings_active && ctx.lvgl_initialized) {
			lvgl_lock();
			ui_settings_show(ctx.settings_page, event->animate);
			lvgl_unlock();
		}

		return false;
	}

	if (is_datetime_event(aeh)) {
		const struct datetime_event *event = cast_datetime_event(aeh);

		strncpy(ctx.date_text, event->date_text, sizeof(ctx.date_text));
		ctx.date_text[sizeof(ctx.date_text) - 1] = '\0';
		strncpy(ctx.time_text, event->time_text, sizeof(ctx.time_text));
		ctx.time_text[sizeof(ctx.time_text) - 1] = '\0';
		refresh_ui();
		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)) {
			(void)module_set_lifecycle(&ctx.lc, LC_RUNNING);
		}

		return false;
	}

	if (is_power_down_event(aeh)) {
		if (module_lifecycle_is_initialized(&ctx.lc)) {
			(void)module_set_lifecycle(&ctx.lc, LC_STOPPED);
		}

		return false;
	}

	if (is_wake_up_event(aeh)) {
		if (module_lifecycle_is_initialized(&ctx.lc)) {
			(void)module_set_lifecycle(&ctx.lc, LC_RUNNING);
		}

		return false;
	}

	return false;
}

APP_EVENT_LISTENER(MODULE, app_event_handler);
APP_EVENT_SUBSCRIBE(MODULE, bat_state_event);
APP_EVENT_SUBSCRIBE(MODULE, ble_bond_multi_event);
APP_EVENT_SUBSCRIBE(MODULE, datetime_event);
APP_EVENT_SUBSCRIBE(MODULE, hid_led_event);
APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
APP_EVENT_SUBSCRIBE(MODULE, mode_switch_event);
APP_EVENT_SUBSCRIBE(MODULE, settings_mode_event);
APP_EVENT_SUBSCRIBE(MODULE, settings_view_event);
APP_EVENT_SUBSCRIBE(MODULE, theme_rgb_update_event);
APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);