/* Reflow Oven Controller
*
* Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
*
* This file is part of the Reflow Oven Controller Project.
*
* The reflow oven controller is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* The Reflow Oven Control Firmware is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the reflow oven controller project.
* If not, see <http://www.gnu.org/licenses/>.
*/

#include <reflow-controller/ui/gui.h>
#include <reflow-controller/ui/gui-config.h>
#include <reflow-controller/ui/menu.h>
#include <reflow-controller/ui/lcd.h>
#include <reflow-controller/ui/rotary-encoder.h>
#include <reflow-controller/systick.h>
#include <reflow-controller/adc-meas.h>
#include <reflow-controller/safety/safety-controller.h>
#include <reflow-controller/settings/settings.h>
#include <reflow-controller/temp-converter.h>
#include <reflow-controller/updater/updater.h>
#include <helper-macros/helper-macros.h>
#include <stm-periph/unique-id.h>
#include <stddef.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <reflow-controller/oven-driver.h>
#include <fatfs/ff.h>
#include <reflow-controller/temp-profile/temp-profile-executer.h>
#include <linklist-lib/singly-linked-list.h>
#include <stdlib.h>

static char IN_SECTION(.ccm.bss) display_buffer[4][21] = {0};
static struct lcd_menu IN_SECTION(.ccm.bss) reflow_menu;
#define reflow_menu_ptr (&reflow_menu)

static void update_display_buffer(uint8_t row, const char *data)
{
	int i;

	if (row > 4)
		return;
	if (!data)
		return;

	for (i = 0; data[i] && i < LCD_CHAR_WIDTH; i++) {
		display_buffer[row][i] = data[i];
	}

	display_buffer[row][i] = 0;
}

static void gui_menu_monitor(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	static void *my_parent;
	static uint64_t my_timestamp = 0;
	char line[17];
	float tmp;
	int res;
	const char *prefix;

	if (entry_type == MENU_ENTRY_FIRST_ENTER) {
		my_parent = parent;
		menu_display_clear(menu);
	}

	if (systick_ticks_have_passed(my_timestamp, GUI_MONITORING_INTERVAL_MS)) {
		my_timestamp = systick_get_global_tick();
		adc_pt1000_get_current_resistance(&tmp);
		snprintf(line, sizeof(line), "Res: %.1f " LCD_OHM_SYMBOL_STRING, tmp);
		menu->update_display(0, line);

		res = temp_converter_convert_resistance_to_temp(tmp, &tmp);
		switch (res) {
		case -1:
			prefix = "<";
			break;
		case 1:
			prefix = ">";
			break;
		default:
			prefix = "";
			break;
		}

		snprintf(line, sizeof(line), "Temp: %s%.1f " LCD_DEGREE_SYMBOL_STRING "C", prefix, tmp);
		menu->update_display(1, line);

		(void)safety_controller_get_analog_mon_value(ERR_AMON_UC_TEMP, &tmp);
		snprintf(line, sizeof(line), "Tj: %.1f " LCD_DEGREE_SYMBOL_STRING "C", tmp);
		menu->update_display(2, line);

		(void)safety_controller_get_analog_mon_value(ERR_AMON_VREF, &tmp);
		snprintf(line, sizeof(line), "Vref: %.1f mV", tmp);
		menu->update_display(3, line);
	}

	if (menu->inputs.push_button == BUTTON_SHORT_RELEASED || menu->inputs.push_button == BUTTON_LONG) {
		menu_entry_dropback(menu, my_parent);
	}
}

static void gui_menu_about(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	static void *my_parent;
	static int page = 0;
	static int last_page = -1;
	static uint32_t uptime_secs;
	uint32_t new_uptime_secs;
	uint32_t uptime_mins;
	uint32_t uptime_hours;
	uint32_t uptime_days;
	int16_t rot_delta;
	uint32_t ser1, ser2, ser3;
	enum button_state push_button;
	bool button_ready;

	if (entry_type == MENU_ENTRY_FIRST_ENTER) {
		uptime_secs = 0ULL;
		page = 0;
		last_page = -1;
		my_parent = parent;
		menu_display_clear(menu);
		menu_ack_rotary_delta(menu);
	}

	rot_delta = menu_get_rotary_delta(menu);
	if (rot_delta >= 4) {
		menu_ack_rotary_delta(menu);
		if (page < 4) {
			page++;
			menu_display_clear(menu);
		}
	} else if (rot_delta <= -4) {
		menu_ack_rotary_delta(menu);
		if (page > 0) {
			page--;
			menu_display_clear(menu);
		}
	}

	switch (page) {
	case 0:
		if (last_page == 0)
			break;
		last_page = 0;
		menu_lcd_output(menu, 0, LCD_SHIMATTA_STRING "    Shimatta");
		menu_lcd_output(menu, 1, "Oven Controller");
		menu_lcd_output(menu, 2, "(c) Mario H\xF5ttel");
		menu_lcd_output(menu, 3, "Page 1/5");
		break;
	case 1:
		if (last_page == 1)
			break;
		last_page = 1;
		menu_lcd_output(menu, 0, "Version Number:");
		menu_lcd_outputf(menu, 1, "%.*s", LCD_CHAR_WIDTH, xstr(GIT_VER));
		if (strlen(xstr(GIT_VER)) > LCD_CHAR_WIDTH) {
			menu_lcd_outputf(menu, 2, "%s", &xstr(GIT_VER)[LCD_CHAR_WIDTH]);
		}
#ifdef DEBUGBUILD
		menu_lcd_output(menu, 3, "Page 2/5 [DEBUG]");
#else
		menu_lcd_output(menu, 3, "Page 2/5");
#endif
		break;
	case 2:
		if (last_page == 2)
			break;
		last_page = 2;
		menu_lcd_output(menu, 0, "Compile Info");
		menu_lcd_output(menu, 1, __DATE__);
		menu_lcd_output(menu, 2, __TIME__);
		menu_lcd_output(menu, 3, "Page 3/5");
		break;
	case 3:
		if (last_page == 3)
			break;
		last_page = 3;
		unique_id_get(&ser1, &ser2, &ser3);

		menu_lcd_outputf(menu, 0, "Serial: %08X", ser1);
		menu_lcd_outputf(menu, 1, "        %08X", ser2);
		menu_lcd_outputf(menu, 2, "        %08X", ser3);
		menu_lcd_output(menu, 3, "Page 4/5");
		break;
	case 4:
		last_page = 4;
		systick_get_uptime_from_tick(&uptime_days, &uptime_hours, &uptime_mins, &new_uptime_secs);
		if (new_uptime_secs != uptime_secs) {
			uptime_secs = new_uptime_secs;
			menu_lcd_output(menu, 0, "Uptime:");
			menu_lcd_outputf(menu, 1, "%lu day%s %02lu:%02lu:%02lu",
					 uptime_days, (uptime_days == 1 ? "" : "s"), uptime_hours, uptime_mins, uptime_secs);
			menu_lcd_output(menu, 3, "Page 5/5");
		}
		break;
	default:
		page = 0;
		last_page = -1;
		break;
	}

	push_button = menu_get_button_state(menu);
	button_ready = menu_get_button_ready_state(menu);

	if (push_button == BUTTON_IDLE)
		button_ready = true;

	if (button_ready &&
			(push_button == BUTTON_SHORT_RELEASED || push_button == BUTTON_LONG)) {
		menu_entry_dropback(menu, my_parent);
	}
}

static void gui_menu_err_flags(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	static void *my_parent = NULL;
	static uint8_t offset;
	static uint64_t timestamp;
	static bool end_of_list_reached = true;
	bool state;
	enum button_state push_button;
	int16_t rot;
	uint32_t i;
	char name[64];
	int32_t line_counter;
	bool skip_err_flag_prefix;
	bool try_ack = false;
	enum safety_flag flag;
	bool button_ready;
	const char *err_flag_prefix = "ERR_FLAG_";

	push_button = menu_get_button_state(menu);
	rot = menu_get_rotary_delta(menu);

	if (entry_type != MENU_ENTRY_CONTINUE) {
		if (entry_type == MENU_ENTRY_FIRST_ENTER) {
			my_parent = parent;
			offset = 0;
			end_of_list_reached = true;
		}
	} else {
		if (push_button == BUTTON_IDLE && rot == 0) {
			if (!systick_ticks_have_passed(timestamp, 150))
				return;
		}

	}

	button_ready = menu_get_button_ready_state(menu);
	if (push_button == BUTTON_SHORT_RELEASED && button_ready) {
		menu_entry_dropback(menu, my_parent);
	} if (push_button == BUTTON_LONG && button_ready) {
		try_ack = true;
	}

	if (rot >= 4 || rot <= -4) {
		menu_ack_rotary_delta(menu);
		if (rot > 0) {
			if (!end_of_list_reached)
				offset++;
		} else {
			if (offset > 0)
				offset--;
		}
	}

	menu_display_clear(menu);

	line_counter = -offset;
	for (i = 0; i < safety_controller_get_flag_count(); i++) {
		(void)safety_controller_get_flag_by_index(i, &state, &flag);
		if (try_ack)
			safety_controller_ack_flag(flag);
		if (state) {
			if (line_counter >= 0 && line_counter < 4) {
				safety_controller_get_flag_name_by_index(i, name, sizeof(name));
				if (!strncmp(name, err_flag_prefix, 9)) {
					skip_err_flag_prefix = true;
				} else {
					skip_err_flag_prefix = false;
				}
				menu_lcd_outputf(menu, line_counter, "%s",
						 (skip_err_flag_prefix ? &name[9] : name));
			}
			line_counter++;
		}
	}

	end_of_list_reached = (line_counter > 4 ? false : true);

	timestamp = systick_get_global_tick();
}

static void gui_menu_constant_temperature_driver(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	static void IN_SECTION(.ccm.bss) *my_parent;
	static int16_t IN_SECTION(.ccm.bss) temperature;
	static bool IN_SECTION(.ccm.bss) fine;
	static uint64_t IN_SECTION(.ccm.bss) last_temp_refresh;
	static float IN_SECTION(.ccm.bss) last_temp;
	enum button_state button;
	float current_temp;
	int status;
	int16_t rot;
	int16_t temp_old;

	if (entry_type == MENU_ENTRY_FIRST_ENTER) {
		my_parent = parent;
		last_temp = -2000.0f;
		temperature = 30;
		menu_display_clear(menu);
		menu_lcd_outputf(menu, 0, "Temp Controller");
		temp_old = 0;
	} else {
		temp_old = temperature;
	}
	if (menu_get_button_ready_state(menu)) {
		button = menu_get_button_state(menu);
		rot = menu_get_rotary_delta(menu);
		if (rot >= 4 || rot <= -4) {
			menu_ack_rotary_delta(menu);
			if (rot > 0)
				temperature += (fine ? 1 : 10);
			else
				temperature -= (fine ? 1 : 10);
			if (temperature > 300)
				temperature = 300;
			else if (temperature < 0)
				temperature = 0;
		}

		switch (button) {
		case BUTTON_SHORT_RELEASED:
			fine = !fine;
			break;
		case BUTTON_LONG:
			oven_pid_stop();
			menu_entry_dropback(menu, my_parent);
			break;
		default:
			break;
		}
	}
	if (oven_pid_get_status() != OVEN_PID_RUNNING) {
		menu_lcd_output(menu, 1, "PID stopped!");
		menu_lcd_output(menu, 2, "Check Flags!");
	} else {
		if (temperature != temp_old) {
			oven_pid_set_target_temperature((float)temperature);
			menu_lcd_outputf(menu, 1, "Target: %d " LCD_DEGREE_SYMBOL_STRING "C", (int)temperature);
		}

		if (entry_type == MENU_ENTRY_FIRST_ENTER || systick_ticks_have_passed(last_temp_refresh, GUI_TEMP_DRIVER_REFRESH_MS)) {
			(void)adc_pt1000_get_current_resistance(&current_temp);
			status = temp_converter_convert_resistance_to_temp(current_temp, &current_temp);
			if (current_temp != last_temp) {
				last_temp = current_temp;
				menu_lcd_outputf(menu, 2, "Current: %s%.1f", current_temp, (status < 0 ? "<" : status > 0 ? ">" : ""));
			}
			last_temp_refresh = systick_get_global_tick();
		}
	}

}

static void delete_file_list_entry(void *obj)
{
	if (obj)
		free(obj);
}

static SlList *load_file_list_from_sdcard(int *error, const char *file_pattern)
{
	DIR directory;
	FILINFO finfo;
	FRESULT fres;

	SlList *list = NULL;
	char *name;

	/* find the frist file */
	fres = f_findfirst(&directory, &finfo, "/", file_pattern);
	while (fres == FR_OK && finfo.fname[0]) {
		name = malloc(strlen(finfo.fname) + 1);
		strcpy(name, finfo.fname);
		list = sl_list_append(list, name);
		fres = f_findnext(&directory, &finfo);
	}

	if (fres != FR_OK) {
		sl_list_free_full(list, delete_file_list_entry);
		list = NULL;
		if (error)
			*error = -1;
	}

	return list;
}

static void gui_menu_temp_profile_execute(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void* parent)
{
	static void *my_parent;
	const struct tpe_current_state *state;
	static uint64_t last_tick;
	float temperature;
	float resistance;
	int res;

	if (entry_type == MENU_ENTRY_FIRST_ENTER) {
		my_parent = parent;
		menu_display_clear(menu);
		last_tick = 0ULL;
	}

	if (systick_ticks_have_passed(last_tick, 250)) {
		state = temp_profile_executer_status();
		if (state->status == TPE_RUNNING) {
			menu_lcd_outputf(menu, 0, "Executing...");
			menu_lcd_outputf(menu, 1, "Step %u/%u", state->step, state->profile_steps);
			(void)adc_pt1000_get_current_resistance(&resistance);
			res = temp_converter_convert_resistance_to_temp(resistance, &temperature);
			menu_lcd_outputf(menu, 2, "Temp: %s%.1f " LCD_DEGREE_SYMBOL_STRING "C",
					 (res < 0 ? "<" : (res > 0 ? ">" : "")), temperature);
			if (oven_pid_get_status() == OVEN_PID_RUNNING) {
				menu_lcd_outputf(menu, 3, "Target: %.0f " LCD_DEGREE_SYMBOL_STRING "C", state->setpoint);
			} else {
				menu_lcd_outputf(menu, 3, "Temp Off");
			}
		} else if (state->status == TPE_OFF) {
			menu_lcd_outputf(menu, 0, "Finished!");
			menu_lcd_outputf(menu, 1, "Press button");
			menu_lcd_outputf(menu, 2, "to return.");
			(void)adc_pt1000_get_current_resistance(&resistance);
			res = temp_converter_convert_resistance_to_temp(resistance, &temperature);
			menu_lcd_outputf(menu, 3, "Temp: %.1f ", LCD_DEGREE_SYMBOL_STRING "C", temperature);
		} else {
			menu_lcd_outputf(menu, 0, "Profile aborted!");
			menu_lcd_outputf(menu, 1, "Check flags!");
			menu_lcd_outputf(menu, 2, "");
			menu_lcd_outputf(menu, 3, "Press button");
		}

		last_tick = systick_get_global_tick();
	}

	if (menu_get_button_ready_state(menu)) {
		if (menu_get_button_state(menu) != BUTTON_IDLE) {
			temp_profile_executer_stop();
			menu_entry_dropback(menu, my_parent);
		}
	}
}

static void gui_menu_temp_profile_select(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	static void *my_parent;
	static SlList *file_list = NULL;
	static int file_error = 0;
	static enum pl_ret_val profile_ret_val = PL_RET_SUCCESS;
	static uint8_t currently_selected = 0U;
	static uint8_t loaded;
	int16_t delta;
	enum button_state button;

	if (entry_type == MENU_ENTRY_FIRST_ENTER) {
		menu_display_clear(menu);
		my_parent = parent;
		file_error = 0;
		loaded = 0;

		if (file_list) {
			sl_list_free_full(file_list, delete_file_list_entry);
		}

		file_list = load_file_list_from_sdcard(&file_error, "*.tpr");

		currently_selected = 0u;
		profile_ret_val = PL_RET_SUCCESS;
		loaded = sl_list_length(file_list);
		menu_lcd_outputf(menu, 0, "Select:");
	} else if (entry_type == MENU_ENTRY_DROPBACK) {
		menu_entry_dropback(menu, my_parent);
		return;
	}

	if (menu_get_button_ready_state(menu)) {
		delta = menu_get_rotary_delta(menu);
		button = menu_get_button_state(menu);

		if (button == BUTTON_LONG) {
			menu_entry_dropback(menu, my_parent);
		}

		if (file_error) {
			menu_lcd_outputf(menu, 0, "Disk Error");
			menu_lcd_outputf(menu, 1, "SD inserted?");
			if (button == BUTTON_SHORT_RELEASED) {
				sl_list_free_full(file_list, delete_file_list_entry);
				file_list = NULL;
				menu_entry_dropback(menu, my_parent);
			}
			return;
		} else if (loaded == 0) {
			menu_lcd_outputf(menu, 0, "No profiles");
			menu_lcd_outputf(menu, 1, "found");
			if (button == BUTTON_SHORT_RELEASED) {
				sl_list_free_full(file_list, delete_file_list_entry);
				file_list = NULL;
				menu_entry_dropback(menu, my_parent);
			}
			return;
		} else if (profile_ret_val != PL_RET_SUCCESS) {
			menu_lcd_outputf(menu, 0, "ERROR");
			switch (profile_ret_val) {
			case PL_RET_SCRIPT_ERR:
				menu_lcd_outputf(menu, 1, "Syntax Error");
				break;
			case PL_RET_DISK_ERR:
				menu_lcd_outputf(menu, 1, "Disk Error");
				break;
			case PL_RET_LIST_FULL:
				menu_lcd_output(menu, 1, "Too many com-");
				menu_lcd_output(menu, 2, "mands in file");
				break;
			default:
				menu_lcd_output(menu, 1, "Unknown error");
				break;
			}

			if (button == BUTTON_SHORT_RELEASED) {
				sl_list_free_full(file_list, delete_file_list_entry);
				file_list = NULL;
				menu_entry_dropback(menu, my_parent);
			}
			return;
		} else if (currently_selected < loaded) {
			/* Show currently selected profile */
			menu_lcd_outputf(menu, 1, "%s", sl_list_nth(file_list, currently_selected)->data);

			if (button == BUTTON_SHORT_RELEASED) {
				/* Execute selected profile */
				profile_ret_val = temp_profile_executer_start(sl_list_nth(file_list, currently_selected)->data);
				if (profile_ret_val == PL_RET_SUCCESS) {
					sl_list_free_full(file_list, delete_file_list_entry);
					file_list = NULL;
					menu_entry_enter(menu, gui_menu_temp_profile_execute, true);
					return;
				}
			}

			if (delta >= 4) {
				menu_ack_rotary_delta(menu);
				if (currently_selected < (loaded - 1))
					currently_selected++;
			} else if (delta <= -4) {
				menu_ack_rotary_delta(menu);
				if (currently_selected > 0)
					currently_selected--;
			}
		}
	}
}

static void gui_menu_constant_temperature_driver_setup(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	static void IN_SECTION(.ccm.bss) *my_parent;
	struct oven_pid_settings pid_settings;
	enum button_state button;
	struct pid_controller pid_controller;

	if (entry_type == MENU_ENTRY_FIRST_ENTER) {
		my_parent = parent;

		/* Try loading PID parameters */
		if (settings_load_pid_oven_parameters(&pid_settings)) {
			menu_display_clear(menu);
			menu_lcd_output(menu, 0, "Could not load");
			menu_lcd_output(menu, 1, "PID parameters");
		} else {
			pid_init(&pid_controller, pid_settings.kd, pid_settings.ki, pid_settings.kp, 0, 100,
				 pid_settings.max_integral, pid_settings.kd_tau, pid_settings.t_sample);
			oven_pid_init(&pid_controller);
			menu_entry_enter(menu, gui_menu_constant_temperature_driver, true);
		}
	} else if (entry_type == MENU_ENTRY_DROPBACK) {
		menu_entry_dropback(menu, my_parent);
	}

	if (menu_get_button_ready_state(menu)) {
		button = menu_get_button_state(menu);
		if (button == BUTTON_SHORT_RELEASED || button == BUTTON_LONG) {
			menu_entry_dropback(menu, my_parent);
		}
	}
}

static void gui_update_firmware(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	static void *my_parent;
	static SlList *file_list = NULL;
	static int error;
	enum button_state button;
	static uint32_t currently_selected_file;
	uint32_t previously_selected_file;
	static uint32_t list_length;
	const char *fname;
	int16_t rotary;

	if (entry_type == MENU_ENTRY_FIRST_ENTER) {
		my_parent = parent;
		error = 0;
		list_length = 0;
		if (file_list)
			sl_list_free_full(file_list, delete_file_list_entry);
		file_list = load_file_list_from_sdcard(&error, "*.hex");
		if (error) {
			if (file_list)
				sl_list_free_full(file_list, delete_file_list_entry);
			file_list = NULL;
		} else {
			list_length = sl_list_length(file_list);
		}
		currently_selected_file = 0;
		menu_display_clear(menu);
	}

	if (menu_get_button_ready_state(menu)) {
		button = menu_get_button_state(menu);
		rotary = menu_get_rotary_delta(menu);

		if (error) {
			menu_lcd_output(menu, 0, "Error reading");
			menu_lcd_output(menu, 1, "file list");
			if (button == BUTTON_LONG || button == BUTTON_SHORT_RELEASED)
				menu_entry_dropback(menu, my_parent);
		} else {
			previously_selected_file = currently_selected_file;

			/* Display the list */
			if (rotary <= -4) {
				menu_ack_rotary_delta(menu);
				if (currently_selected_file > 0) {
					currently_selected_file--;
				}
			} else if (rotary >= 4) {
				menu_ack_rotary_delta(menu);
				if (currently_selected_file < (list_length - 1)) {
					currently_selected_file++;
				}
			}

			if (entry_type == MENU_ENTRY_FIRST_ENTER ||
					previously_selected_file != currently_selected_file) {
				fname = sl_list_nth(file_list, currently_selected_file)->data;
				menu_lcd_output(menu, 0, "Select File:");
				if (fname)
					menu_lcd_output(menu, 1, fname);
			}
			if (button == BUTTON_SHORT_RELEASED) {
				fname = sl_list_nth(file_list, currently_selected_file)->data;
				menu_display_clear(menu);
				file_list = NULL;
				updater_update_from_file(fname);
				/* This code is here for completeness. It will never be reached! */
				sl_list_free_full(file_list, delete_file_list_entry);
			} else if (button == BUTTON_LONG) {
				sl_list_free_full(file_list, delete_file_list_entry);
				file_list = NULL;
				menu_entry_dropback(menu, my_parent);
			}
		}
	}
}

static char *overlay_heading = NULL;
static char *overlay_text = NULL;

static void gui_menu_overlay_entry(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	static void *my_parent;
	enum button_state button;

	if (entry_type == MENU_ENTRY_FIRST_ENTER) {
		my_parent = parent;
		menu_display_clear(menu);
		if (overlay_heading)
			menu_lcd_output(menu, 0, overlay_heading);
		if (overlay_text) {
			menu_lcd_output(menu, 2, overlay_text);
			if (strlen(overlay_text) > 16) {
				menu_lcd_output(menu, 3, &overlay_text[16]);
			}
		}
	}

	if (menu_get_button_ready_state(menu)) {
		button = menu_get_button_state(menu);
		menu_ack_rotary_delta(menu);

		if (button != BUTTON_IDLE) {
			if (overlay_heading)
				free(overlay_heading);
			if (overlay_text)
				free(overlay_text);
			overlay_heading = NULL;
			overlay_text = NULL;
			menu_entry_dropback(menu, my_parent);
		}
	}
}

static void gui_menu_root_entry(struct lcd_menu *menu, enum menu_entry_func_entry entry_type, void *parent)
{
	(void)parent;
	static struct menu_list list;
	bool menu_changed = false;
	static const char * const root_entry_names[] = {
		"Constant Temp",
		"Temp Profile",
		"Monitoring",
		"Error Flags",
		"About",
		"Update",
		NULL
	};
	static const menu_func_t root_entry_funcs[] = {
		gui_menu_constant_temperature_driver_setup,
		gui_menu_temp_profile_select,
		gui_menu_monitor,
		gui_menu_err_flags,
		gui_menu_about,
		gui_update_firmware,
	};
	enum button_state push_button;
	int16_t rot_delta;

	if (entry_type != MENU_ENTRY_CONTINUE) {
		menu_changed = true;
		menu_display_clear(menu);
		update_display_buffer(0, "Main Menu");
		menu_ack_rotary_delta(menu);
		if (entry_type == MENU_ENTRY_FIRST_ENTER) {
			list.entry_names = root_entry_names;
			list.submenu_list = root_entry_funcs;
			list.update_display = menu->update_display;
			list.currently_selected = 0;
			menu_list_compute_count(&list);
		}
	}

	push_button = menu_get_button_state(menu);
	rot_delta = menu_get_rotary_delta(menu);

	if (menu_get_button_ready_state(menu)) {
		if (menu_get_button_ready_state(menu) && push_button == BUTTON_SHORT_RELEASED) {
			/* Enter currently selected menu_entry */
			menu_list_enter_selected_entry(&list, menu);
		}

		if (rot_delta >= 4) {
			menu_list_scroll_down(&list);
			menu_ack_rotary_delta(menu);
			menu_changed = true;
		} else if (rot_delta <= -4) {
			menu_list_scroll_up(&list);
			menu_ack_rotary_delta(menu);
			menu_changed = true;
		}
	}

	/* Display the message overlay in case it is set */
	if (overlay_heading || overlay_text) {
		menu_entry_enter(menu, gui_menu_overlay_entry, true);
		return;
	} else if (menu_changed) {
		menu_list_display(&list, 1, 3);
	}
}

int gui_handle()
{
	int32_t rot_delta;
	enum button_state button;
	static enum lcd_fsm_ret lcd_ret = LCD_FSM_NOP;

	rot_delta = rotary_encoder_get_change_val();
	button = button_read_event();

	menu_handle(reflow_menu_ptr, (int16_t)rot_delta, button);

	if (lcd_ret == LCD_FSM_CALL_AGAIN || lcd_tick_100us >= 5) {
		lcd_ret = lcd_fsm_write_buffer(display_buffer);
		lcd_tick_100us = 0UL;
	}

	if (lcd_ret == LCD_FSM_CALL_AGAIN)
		return 0;
	else
		return 1;
}

void gui_init()
{
	rotary_encoder_setup();
	button_init();
	lcd_init();

	if (overlay_heading)
		free(overlay_heading);
	if (overlay_text)
		free(overlay_text);

	overlay_heading = NULL;
	overlay_text = NULL;

	menu_init(reflow_menu_ptr, gui_menu_root_entry, update_display_buffer);
}

void gui_root_menu_message_set(const char *heading, const char *text)
{
	if (heading) {
		overlay_heading = (char *)malloc(strlen(heading) + 1);
		strcpy(overlay_heading, heading);
	}

	if (text) {
		overlay_text = (char *)malloc(strlen(text) + 1);
		strcpy(overlay_text, text);
	}
}

void gui_lcd_write_direct_blocking(uint8_t line, const char *text)
{
	if (!text)
		return;
	if (line > 3)
		return;

	lcd_setcursor(0, line);
	lcd_string(text);
}