#include <stdbool.h>
#include <stdint.h>
#include <string.h>

#include <app_event_manager.h>

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

#include <zephyr/logging/log.h>
#include <zephyr/sys/printk.h>

#include "encoder_event.h"
#include "module_lifecycle.h"
#include "settings_mode_event.h"
#include "settings_ui.h"
#include "settings_view_event.h"
#include "theme_color.h"
#include "theme_rgb_update_event.h"

LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);

#define SETTINGS_MUTE_KEY_ID 0x180U

enum root_menu_item {
	ROOT_MENU_ITEM_BLUETOOTH = 0,
	ROOT_MENU_ITEM_THEME,
};

enum ble_menu_item {
	BLE_MENU_ITEM_SLOT_1 = 0,
	BLE_MENU_ITEM_SLOT_2,
	BLE_MENU_ITEM_SLOT_3,
	BLE_MENU_ITEM_ERASE_BOND,
};

struct named_theme {
	const char *name;
	struct theme_rgb color;
};

struct ble_slot_state {
	char label[SETTINGS_UI_VALUE_MAX];
};

struct settings_module_ctx {
	struct module_lifecycle_ctx lc;
	bool active;
	enum settings_ui_page page;
	uint8_t root_selected;
	uint8_t ble_selected;
	uint8_t theme_selected;
	uint8_t active_ble_slot;
	struct ble_slot_state ble_slots[SETTINGS_UI_BLE_SLOT_COUNT];
	struct theme_rgb current_theme;
	uint8_t current_theme_index;
	bool theme_matches_palette;
};

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 const struct named_theme theme_palette[SETTINGS_UI_THEME_OPTION_COUNT] = {
	{
		.name = "Red",
		.color = { .r = 0xFF, .g = 0x00, .b = 0x00 },
	},
	{
		.name = "Amber",
		.color = { .r = 0xFF, .g = 0x95, .b = 0x00 },
	},
	{
		.name = "Default",
		.color = {
			.r = BLINKY_THEME_DEFAULT_R,
			.g = BLINKY_THEME_DEFAULT_G,
			.b = BLINKY_THEME_DEFAULT_B,
		},
	},
	{
		.name = "Green",
		.color = { .r = 0x34, .g = 0xC7, .b = 0x59 },
	},
	{
		.name = "Purple",
		.color = { .r = 0xBF, .g = 0x5A, .b = 0xF2 },
	},
	{
		.name = "White",
		.color = { .r = 0xF2, .g = 0xF2, .b = 0xF7 },
	},
};

static struct settings_module_ctx ctx = {
	.lc = {
		.state = LC_UNINIT,
		.cfg = &lifecycle_cfg,
		.ops = &lifecycle_ops,
	},
};

static bool theme_equal(const struct theme_rgb *lhs, const struct theme_rgb *rhs)
{
	return (lhs->r == rhs->r) && (lhs->g == rhs->g) && (lhs->b == rhs->b);
}

static uint8_t wrap_index(uint8_t current, uint8_t count, int8_t delta)
{
	int32_t next = current;

	if (count == 0U) {
		return 0U;
	}

	next += delta;
	while (next < 0) {
		next += count;
	}

	return (uint8_t)(next % count);
}

static void set_text(char *dst, size_t dst_size, const char *src)
{
	if ((dst == NULL) || (dst_size == 0U) || (src == NULL)) {
		return;
	}

	strncpy(dst, src, dst_size);
	dst[dst_size - 1U] = '\0';
}

static const char *current_theme_name_get(void)
{
	if (!ctx.theme_matches_palette) {
		return "Custom";
	}

	return theme_palette[ctx.current_theme_index].name;
}

static void update_theme_match_state(void)
{
	ctx.theme_matches_palette = false;
	ctx.current_theme_index = 0U;

	for (uint8_t i = 0; i < SETTINGS_UI_THEME_OPTION_COUNT; i++) {
		if (!theme_equal(&ctx.current_theme, &theme_palette[i].color)) {
			continue;
		}

		ctx.current_theme_index = i;
		ctx.theme_matches_palette = true;
		return;
	}
}

static void publish_view_state(void)
{
	struct settings_ui_state state = {
		.active = ctx.active,
		.page = ctx.page,
		.root_selected = ctx.root_selected,
		.ble_selected = ctx.ble_selected,
		.theme_selected = ctx.theme_selected,
		.active_ble_slot = ctx.active_ble_slot,
		.accent = ctx.current_theme,
		.theme_option_count = SETTINGS_UI_THEME_OPTION_COUNT,
	};

	set_text(state.root_items[ROOT_MENU_ITEM_BLUETOOTH].title,
		 sizeof(state.root_items[ROOT_MENU_ITEM_BLUETOOTH].title),
		 "Bluetooth");
	set_text(state.root_items[ROOT_MENU_ITEM_BLUETOOTH].value,
		 sizeof(state.root_items[ROOT_MENU_ITEM_BLUETOOTH].value),
		 (ctx.active_ble_slot == 0U) ? "Slot 1" :
		 (ctx.active_ble_slot == 1U) ? "Slot 2" : "Slot 3");

	set_text(state.root_items[ROOT_MENU_ITEM_THEME].title,
		 sizeof(state.root_items[ROOT_MENU_ITEM_THEME].title), "Theme");
	set_text(state.root_items[ROOT_MENU_ITEM_THEME].value,
		 sizeof(state.root_items[ROOT_MENU_ITEM_THEME].value),
		 current_theme_name_get());

	for (uint8_t i = 0; i < SETTINGS_UI_BLE_SLOT_COUNT; i++) {
		char slot_name[SETTINGS_UI_TITLE_MAX];

		snprintk(slot_name, sizeof(slot_name), "Slot %u", i + 1U);
		set_text(state.ble_items[i].title, sizeof(state.ble_items[i].title),
			 slot_name);
		set_text(state.ble_items[i].value, sizeof(state.ble_items[i].value),
			 ctx.ble_slots[i].label);
	}

	set_text(state.ble_items[BLE_MENU_ITEM_ERASE_BOND].title,
		 sizeof(state.ble_items[BLE_MENU_ITEM_ERASE_BOND].title),
		 "Erase Bond");
	set_text(state.ble_items[BLE_MENU_ITEM_ERASE_BOND].value,
		 sizeof(state.ble_items[BLE_MENU_ITEM_ERASE_BOND].value),
		 (ctx.active_ble_slot == 0U) ? "Slot 1" :
		 (ctx.active_ble_slot == 1U) ? "Slot 2" : "Slot 3");

	for (uint8_t i = 0; i < SETTINGS_UI_THEME_OPTION_COUNT; i++) {
		set_text(state.theme_options[i].name,
			 sizeof(state.theme_options[i].name),
			 theme_palette[i].name);
		state.theme_options[i].color = theme_palette[i].color;
	}

	submit_settings_view_event(&state);
}

static void settings_exit(void)
{
	if (!ctx.active) {
		return;
	}

	ctx.active = false;
	ctx.page = SETTINGS_UI_PAGE_ROOT;
	submit_settings_mode_event(false);
	publish_view_state();
}

static void settings_enter(void)
{
	if (ctx.active) {
		return;
	}

	ctx.active = true;
	ctx.page = SETTINGS_UI_PAGE_ROOT;
	ctx.root_selected = ROOT_MENU_ITEM_BLUETOOTH;
	ctx.ble_selected = ctx.active_ble_slot;
	ctx.theme_selected = ctx.current_theme_index;
	submit_settings_mode_event(true);
	publish_view_state();
}

static void apply_theme_selection(uint8_t index)
{
	if (index >= SETTINGS_UI_THEME_OPTION_COUNT) {
		return;
	}

	ctx.theme_selected = index;
	ctx.current_theme_index = index;
	ctx.current_theme = theme_palette[index].color;
	ctx.theme_matches_palette = true;
	submit_theme_rgb_update_event(ctx.current_theme);
}

static void handle_confirm(void)
{
	switch (ctx.page) {
	case SETTINGS_UI_PAGE_ROOT:
		ctx.page = (ctx.root_selected == ROOT_MENU_ITEM_BLUETOOTH) ?
				   SETTINGS_UI_PAGE_BLE :
				   SETTINGS_UI_PAGE_THEME;
		ctx.ble_selected = ctx.active_ble_slot;
		ctx.theme_selected = ctx.current_theme_index;
		publish_view_state();
		break;

	case SETTINGS_UI_PAGE_BLE:
		if (ctx.ble_selected < SETTINGS_UI_BLE_SLOT_COUNT) {
			ctx.active_ble_slot = ctx.ble_selected;
		} else {
			set_text(ctx.ble_slots[ctx.active_ble_slot].label,
				 sizeof(ctx.ble_slots[ctx.active_ble_slot].label),
				 "Empty");
		}

		ctx.page = SETTINGS_UI_PAGE_ROOT;
		ctx.root_selected = ROOT_MENU_ITEM_BLUETOOTH;
		publish_view_state();
		break;

	case SETTINGS_UI_PAGE_THEME:
		apply_theme_selection(ctx.theme_selected);
		ctx.page = SETTINGS_UI_PAGE_ROOT;
		ctx.root_selected = ROOT_MENU_ITEM_THEME;
		publish_view_state();
		break;

	default:
		break;
	}
}

static void handle_back(void)
{
	switch (ctx.page) {
	case SETTINGS_UI_PAGE_ROOT:
		settings_exit();
		break;

	case SETTINGS_UI_PAGE_BLE:
		ctx.page = SETTINGS_UI_PAGE_ROOT;
		ctx.root_selected = ROOT_MENU_ITEM_BLUETOOTH;
		publish_view_state();
		break;

	case SETTINGS_UI_PAGE_THEME:
		ctx.page = SETTINGS_UI_PAGE_ROOT;
		ctx.root_selected = ROOT_MENU_ITEM_THEME;
		publish_view_state();
		break;

	default:
		break;
	}
}

static void handle_navigation(int8_t detents)
{
	if (detents == 0) {
		return;
	}

	switch (ctx.page) {
	case SETTINGS_UI_PAGE_ROOT:
		ctx.root_selected = wrap_index(ctx.root_selected,
					       SETTINGS_UI_ROOT_ITEM_COUNT,
					       detents);
		publish_view_state();
		break;

	case SETTINGS_UI_PAGE_BLE:
		ctx.ble_selected = wrap_index(ctx.ble_selected,
					      SETTINGS_UI_BLE_ITEM_COUNT,
					      detents);
		publish_view_state();
		break;

	case SETTINGS_UI_PAGE_THEME:
		ctx.theme_selected = wrap_index(ctx.theme_selected,
						SETTINGS_UI_THEME_OPTION_COUNT,
						detents);
		publish_view_state();
		break;

	default:
		break;
	}
}

static int do_init(void)
{
	ctx.active = false;
	ctx.page = SETTINGS_UI_PAGE_ROOT;
	ctx.root_selected = ROOT_MENU_ITEM_BLUETOOTH;
	ctx.ble_selected = BLE_MENU_ITEM_SLOT_1;
	ctx.theme_selected = 0U;
	ctx.active_ble_slot = 0U;
	ctx.current_theme = (struct theme_rgb) {
		.r = BLINKY_THEME_DEFAULT_R,
		.g = BLINKY_THEME_DEFAULT_G,
		.b = BLINKY_THEME_DEFAULT_B,
	};
	update_theme_match_state();
	set_text(ctx.ble_slots[0].label, sizeof(ctx.ble_slots[0].label), "Host A");
	set_text(ctx.ble_slots[1].label, sizeof(ctx.ble_slots[1].label), "Host B");
	set_text(ctx.ble_slots[2].label, sizeof(ctx.ble_slots[2].label), "Empty");

	return 0;
}

static int do_start(void)
{
	return 0;
}

static int do_stop(void)
{
	settings_exit();
	return 0;
}

static bool handle_click_event(const struct click_event *event)
{
	if (!module_lifecycle_is_running(&ctx.lc) ||
	    (event->key_id != SETTINGS_MUTE_KEY_ID)) {
		return false;
	}

	if (!ctx.active) {
		if (event->click == CLICK_LONG) {
			settings_enter();
		}

		return false;
	}

	switch (event->click) {
	case CLICK_SHORT:
		handle_confirm();
		break;

	case CLICK_LONG:
		handle_back();
		break;

	default:
		break;
	}

	return false;
}

static bool handle_encoder_event(const struct encoder_event *event)
{
	if (!module_lifecycle_is_running(&ctx.lc) || !ctx.active) {
		return false;
	}

	handle_navigation(event->detents);
	return false;
}

static bool handle_theme_rgb_update_event(
	const struct theme_rgb_update_event *event)
{
	ctx.current_theme = event->theme;
	update_theme_match_state();

	if (ctx.page == SETTINGS_UI_PAGE_THEME) {
		ctx.theme_selected = ctx.current_theme_index;
	}

	if (ctx.active) {
		publish_view_state();
	}

	return false;
}

static bool app_event_handler(const struct app_event_header *aeh)
{
	if (is_click_event(aeh)) {
		return handle_click_event(cast_click_event(aeh));
	}

	if (is_encoder_event(aeh)) {
		return handle_encoder_event(cast_encoder_event(aeh));
	}

	if (is_theme_rgb_update_event(aeh)) {
		return handle_theme_rgb_update_event(
			cast_theme_rgb_update_event(aeh));
	}

	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, click_event);
APP_EVENT_SUBSCRIBE(MODULE, encoder_event);
APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
APP_EVENT_SUBSCRIBE(MODULE, theme_rgb_update_event);
APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);