// MIT License, Copyright (c) 2021 Marvin Borner
// GUI - selection interface

#include <config.h>
#include <cpu.h>
#include <def.h>
#include <gui.h>
#include <interrupt.h>
#include <log.h>
#include <panic.h>

static struct {
	struct config_entry *cfg;
} gui_entries[16] = { 0 };

static u8 gui_entry_add(struct config_entry *entry)
{
	static u8 index = 0;
	assert(index + 1 < (u8)sizeof(gui_entries));

	gui_entries[index].cfg = entry;

	index++;
	return 0;
}

static u8 gui_entry_exists(u8 entry)
{
	return !!gui_entries[entry].cfg;
}

static void gui_entry_select(u8 entry)
{
	if (gui_entry_exists(entry))
		config_exec(gui_entries[entry].cfg);
	else
		log("Invalid selection\n");
}

static void gui_entries_draw(void)
{
	for (u8 i = 0; gui_entry_exists(i); i++)
		vga_log("> '%s' (%s)\n", gui_entries[i].cfg->name, gui_entries[i].cfg->path);
}

// Using PS2 magic
static void gui_keyboard_handler(void)
{
	static u8 row = 0;

	while (!(inb(0x64) & 1)) // Wait for data (bit 0 gets set)
		;
	u8 data = inb(0x60);

	// Reset previous selection
	vga_put_at('>', 0, row + 2, 0x07);

	if (data == 0x24 && gui_entry_exists(row + 1)) // j/down key
		row++;
	else if (data == 0x25 && row > 0) // k/up key
		row--;
	else if (data == (0x1c | 0x80)) // enter key release (| 0x80)
		gui_entry_select(row);

	// Draw selection
	vga_put_at('#', 0, row + 2, 0x03);
}

void gui_draw(void)
{
	vga_clear();
	vga_log("SegelBoot by Marvin Borner\n\n");

	config_foreach(&gui_entry_add);
	gui_entries_draw();

	interrupt_event_handler_add(1, &gui_keyboard_handler);
}