/*
 * Copyright (C) 2025 Reiner Herrmann
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

#include <pebble.h>

static Window *main_window;
static TextLayer *clock_text;
static TextLayer *date_text;
static TextLayer *header_text;
static TextLayer *mem_text;
static TextLayer *content_text;
static TextLayer *batt_text;
static GFont font;
static GFont font_small;
static Layer *background_layer;
#ifdef PBL_HEALTH
static TextLayer *steps_text;
static bool health_available = false;
#endif

#if PBL_DISPLAY_HEIGHT == 228
#define FONT_SIZE_LARGE 58
#define FONT_SIZE_SMALL 16
#define BORDER_PERCENT 5
#define HEADER "*** COMMODORE 64 ***"
#define DATE_FMT "%a %d. %b %Y"
#define STEPS_FMT "Steps:%d"
#elif PBL_DISPLAY_HEIGHT == 168
#define FONT_SIZE_LARGE 48
#define FONT_SIZE_SMALL 15
#define BORDER_PERCENT 3
#define HEADER "* COMMODORE 64 *"
#define DATE_FMT "%a %d.%b %y"
#define STEPS_FMT "S:%d"
#endif

#define FONT2(SIZE) (RESOURCE_ID_FONT_COMMODORE_ ## SIZE)
#define FONT(SIZE) FONT2(SIZE)
#define FONT_SMALL FONT(FONT_SIZE_SMALL)
#define FONT_LARGE FONT(FONT_SIZE_LARGE)

#define PALETTE_COLODORE

#if defined(PALETTE_COLODORE)
// https://www.colodore.com/
#define GColor_Red       GColorFromHEX(0x813338)
#define GColor_Blue      GColorFromHEX(0x2e2c9b)
#define GColor_Orange    GColorFromHEX(0x8e5029)
#define GColor_Grey1     GColorFromHEX(0x4a4a4a)
#define GColor_Grey2     GColorFromHEX(0x7b7b7b)
#define GColor_LightBlue GColorFromHEX(0x6f6deb)
#define GColor_LightGrey GColorFromHEX(0xb2b2b2)
#elif defined(PALETTE_PEPTO)
// /usr/share/vice/C64/pepto-pal.vpl
#define GColor_Red       GColorFromHEX(0x68372b)
#define GColor_Blue      GColorFromHEX(0x352879)
#define GColor_Orange    GColorFromHEX(0x6f4f25)
#define GColor_Grey1     GColorFromHEX(0x444444)
#define GColor_Grey2     GColorFromHEX(0x6c6c6c)
#define GColor_LightBlue GColorFromHEX(0x6c5eb5)
#define GColor_LightGrey GColorFromHEX(0x959595)
#elif defined(PALETTE_WIKIPEDIA)
// https://en.wikipedia.org/wiki/Commodore_64#Graphics
#define GColor_Red       GColorFromHEX(0x9F4E44)
#define GColor_Blue      GColorFromHEX(0x50459B)
#define GColor_Orange    GColorFromHEX(0xA1683C)
#define GColor_Grey1     GColorFromHEX(0x626262)
#define GColor_Grey2     GColorFromHEX(0x898989)
#define GColor_LightBlue GColorFromHEX(0x887ECB)
#define GColor_LightGrey GColorFromHEX(0xADADAD)
#endif

#if defined(PBL_COLOR)
#define GColor_Border     GColor_LightBlue
#define GColor_Background GColor_Blue
#define GColor_Text       GColor_LightBlue
#define GColor_Clock      GColor_LightGrey
#define GColor_Bat_Med    GColor_Orange
#define GColor_Bat_Low    GColor_Red
#elif defined(PBL_BW)
#define GColor_Border     GColorWhite
#define GColor_Background GColorBlack
#define GColor_Text       GColorWhite
#define GColor_Clock      GColorWhite
#define GColor_Bat_Med    GColorWhite
#define GColor_Bat_Low    GColorWhite
#endif


static void background_update_proc(Layer *layer, GContext *ctx) {
	GRect bounds = layer_get_bounds(layer);
	graphics_context_set_fill_color(ctx, GColor_Background);
	graphics_fill_rect(ctx, bounds, 0, GCornerNone);
}

static void main_window_load(Window *window) {
	Layer *window_layer = window_get_root_layer(window);
	GRect bounds = layer_get_unobstructed_bounds(window_layer);
	font = fonts_load_custom_font(resource_get_handle(FONT_LARGE));
	font_small = fonts_load_custom_font(resource_get_handle(FONT_SMALL));

	/* inner background */
	int16_t border_width = bounds.size.w * BORDER_PERCENT / 100;
	GRect bg_bounds = GRect(border_width, border_width, bounds.size.w - 2*border_width, bounds.size.h - 2*border_width);
	background_layer = layer_create(bg_bounds);
	layer_set_update_proc(background_layer, background_update_proc);
	layer_add_child(window_layer, background_layer);

	/* header text */
	header_text = text_layer_create(GRect(bg_bounds.origin.x, bg_bounds.origin.y, bg_bounds.size.w, FONT_SIZE_SMALL+2));
	text_layer_set_background_color(header_text, GColorClear);
	text_layer_set_text_color(header_text, GColor_Text);
	text_layer_set_text_alignment(header_text, GTextAlignmentCenter);
	text_layer_set_font(header_text, font_small);
	text_layer_set_text(header_text, HEADER);
	layer_add_child(window_layer, text_layer_get_layer(header_text));

	/* free memory text */
	mem_text = text_layer_create(GRect(bg_bounds.origin.x, bg_bounds.origin.y + FONT_SIZE_SMALL, bg_bounds.size.w, FONT_SIZE_SMALL+2));
	text_layer_set_background_color(mem_text, GColorClear);
	text_layer_set_text_color(mem_text, GColor_Text);
	text_layer_set_text_alignment(mem_text, GTextAlignmentCenter);
	text_layer_set_font(mem_text, font_small);
	static char mem_buffer[20];
	snprintf(mem_buffer, sizeof(mem_buffer), "%d bytes free", heap_bytes_free());
	text_layer_set_text(mem_text, mem_buffer);
	layer_add_child(window_layer, text_layer_get_layer(mem_text));

	/* content text */
	content_text = text_layer_create(GRect(bg_bounds.origin.x, bg_bounds.origin.y + 3*FONT_SIZE_SMALL, bg_bounds.size.w, FONT_SIZE_SMALL+2));
	text_layer_set_background_color(content_text, GColorClear);
	text_layer_set_text_color(content_text, GColor_Text);
	text_layer_set_text_alignment(content_text, GTextAlignmentLeft);
	text_layer_set_font(content_text, font_small);
	text_layer_set_text(content_text, "READY.");
	layer_add_child(window_layer, text_layer_get_layer(content_text));

	/* clock text */
	clock_text = text_layer_create(GRect(bg_bounds.origin.x, bounds.size.h/2 - FONT_SIZE_LARGE/2, bg_bounds.size.w, FONT_SIZE_LARGE+2));
	text_layer_set_background_color(clock_text, GColorClear);
	text_layer_set_text_color(clock_text, GColor_Clock);
	text_layer_set_text_alignment(clock_text, GTextAlignmentCenter);
	text_layer_set_font(clock_text, font);
	layer_add_child(window_layer, text_layer_get_layer(clock_text));

	/* date text */
	date_text = text_layer_create(GRect(bg_bounds.origin.x, bounds.size.h/2 + FONT_SIZE_LARGE/2 + FONT_SIZE_SMALL, bg_bounds.size.w, FONT_SIZE_SMALL+2));
	text_layer_set_background_color(date_text, GColorClear);
	text_layer_set_text_color(date_text, GColor_Text);
	text_layer_set_text_alignment(date_text, GTextAlignmentCenter);
	text_layer_set_font(date_text, font_small);
	layer_add_child(window_layer, text_layer_get_layer(date_text));

#ifdef PBL_HEALTH
	/* step counter text */
	steps_text = text_layer_create(GRect(bg_bounds.origin.x, bg_bounds.origin.y + bg_bounds.size.h - FONT_SIZE_SMALL - 2, bg_bounds.size.w, FONT_SIZE_SMALL+2));
	text_layer_set_background_color(steps_text, GColorClear);
	text_layer_set_text_color(steps_text, GColor_Text);
	text_layer_set_text_alignment(steps_text, GTextAlignmentLeft);
	text_layer_set_font(steps_text, font_small);
	layer_add_child(window_layer, text_layer_get_layer(steps_text));
#endif

	/* battery text */
	batt_text = text_layer_create(GRect(bg_bounds.origin.x, bg_bounds.origin.y + bg_bounds.size.h - FONT_SIZE_SMALL - 2, bg_bounds.size.w, FONT_SIZE_SMALL+2));
	text_layer_set_background_color(batt_text, GColorClear);
	text_layer_set_text_color(batt_text, GColor_Text);
	text_layer_set_text_alignment(batt_text, GTextAlignmentRight);
	text_layer_set_font(batt_text, font_small);
	layer_add_child(window_layer, text_layer_get_layer(batt_text));
}

static void main_window_unload(Window *window) {
	text_layer_destroy(content_text);
	text_layer_destroy(header_text);
	text_layer_destroy(mem_text);
	text_layer_destroy(clock_text);
	text_layer_destroy(date_text);
	text_layer_destroy(batt_text);
#ifdef PBL_HEALTH
	text_layer_destroy(steps_text);
#endif
	layer_destroy(background_layer);
	fonts_unload_custom_font(font);
	fonts_unload_custom_font(font_small);
}

static void update_time() {
	time_t temp = time(NULL);
	struct tm *tick_time = localtime(&temp);

	static char buffer[8];
	if (clock_is_24h_style()) {
		strftime(buffer, sizeof(buffer), "%H:%M", tick_time);
	} else {
		strftime(buffer, sizeof(buffer), "%I:%M", tick_time);
	}

	text_layer_set_text(clock_text, buffer);
}

static void update_date() {
	time_t temp = time(NULL);
	struct tm *tick_time = localtime(&temp);

	static char buffer[20];
	strftime(buffer, sizeof(buffer), DATE_FMT, tick_time);

	text_layer_set_text(date_text, buffer);
}

static void tick_handler(struct tm *tick_time, TimeUnits units_changed) {
	if (units_changed & MINUTE_UNIT) {
		update_time();
	}
	if (units_changed & DAY_UNIT) {
		update_date();
	}
}

static void battery_handler(BatteryChargeState charge) {
	static char buffer[12];
	const char *charge_indicator = charge.is_charging ? "^" : "";
	snprintf(buffer, sizeof(buffer), "%sBat:%d%%", charge_indicator, charge.charge_percent);
	if (charge.charge_percent <= 20) {
		text_layer_set_text_color(batt_text, GColor_Bat_Med);
	} else if (charge.charge_percent <= 10) {
		text_layer_set_text_color(batt_text, GColor_Bat_Low);
	} else {
		text_layer_set_text_color(batt_text, GColor_Text);
	}
	text_layer_set_text(batt_text, buffer);
}

#ifdef PBL_HEALTH
static void health_handler(HealthEventType event, void *context) {
	static char buffer[24];
	HealthValue steps;

	switch (event) {
		case HealthEventSignificantUpdate:
		case HealthEventMovementUpdate:
			steps = health_service_sum_today(HealthMetricStepCount);
			snprintf(buffer, sizeof(buffer), STEPS_FMT, (int) steps);
			text_layer_set_text(steps_text, buffer);
			break;
		default:
			break;
	}
}
#endif

static void init() {
	main_window = window_create();
	window_set_window_handlers(main_window, (WindowHandlers) {
		.load = main_window_load,
		.unload = main_window_unload,
	});
	window_set_background_color(main_window, GColor_Border);
	window_stack_push(main_window, true);

	tick_timer_service_subscribe(MINUTE_UNIT | DAY_UNIT, tick_handler);
	battery_state_service_subscribe(battery_handler);
#ifdef PBL_HEALTH
	health_available = health_service_events_subscribe(health_handler, NULL);
#endif

	/* initialize dynamic texts */
	update_time();
	update_date();
	battery_handler(battery_state_service_peek());
}

static void deinit() {
#ifdef PBL_HEALTH
	health_service_events_unsubscribe();
#endif
	battery_state_service_unsubscribe();
	tick_timer_service_unsubscribe();
	window_destroy(main_window);
}

int main() {
	init();
	app_event_loop();
	deinit();
}