#include <kernel/util/disasm.h>
#include <kernel/devices/earlyterm.h>
#include <kernel/drivers/screen.h>
#include <lib/display.h>
#include <lib/stdio.h>
#include <lib/string.h>

static void check_special_addr(ubc_session_t *session, uint32_t address, int mode)
{
	extern struct earlyterm earlyterm;
	const char *addrname;
	char line[128];

	// Check address validity
	addrname = NULL;
	if ((mode & 1) != 0)
		addrname = disasm_check_peripheral(address);
	if (addrname == NULL && (mode & 2) != 0)
		addrname = disasm_check_syscalls(address);
	if (addrname == NULL)
		return;
	
	// Update vertical counter if needed
	if (session->menu.disassembly.print_offset.vertical != 0)
		session->menu.disassembly.print_offset.vertical += 1;

	// Generate and print line
	sprintf(line, "@note: 0x%.8x -> %s\n", address, addrname);
	dprint(&earlyterm.display,
		session->menu.disassembly.print_offset.horizontal,
		session->menu.disassembly.print_offset.vertical, line);

	// Update vertical counter
	session->menu.disassembly.print_offset.vertical += 1;
}

static uint32_t get_arg(ubc_session_t *session, uint16_t code,
				const struct opcode_s *opcode, int id)
{
	extern struct earlyterm earlyterm;
	uint32_t argument;
	int shift;

	// Get arg shift.
	shift = -1;
	while (++shift < 16 && !(opcode->arg[id].mask & (0x01 << shift)));

	// Get arguments
	argument = (code & opcode->arg[id].mask) >> shift;

	// Call specific argument function
	if (opcode->arg[id].special != NULL)
		argument = (*opcode->arg[id].special)(session->context, argument);

	// Check special address and return
	check_special_addr(session, argument, 3);
	return (argument);
}

static void display_mnemonic(ubc_session_t *session)
{
	extern struct earlyterm earlyterm;
	char line[128];
	uint16_t *area;
	uint32_t sspc;
	uint32_t spc;
	int i;
	int j;

	// Get starting area.
	area = session->menu.disassembly.memory;

	// Main Loop.
	i = -1;
	spc = (uint32_t)area;
	sspc = session->context->spc;
	session->context->spc = (uint32_t)area;
	session->menu.disassembly.print_offset.vertical= 0;
	while ((int)session->menu.disassembly.print_offset.vertical < earlyterm.display.ws_row)
	{
		// Generate first part.
		i = i + 1;
		memset(line, 0x00, 128);
		check_special_addr(session, (uint32_t)&area[i], 2);
		sprintf(line, "%.8x %.4x ", (uint32_t)&area[i], area[i]);

		// Try to find opcode.
		j = -1;
		while (opcode_list[++j].name != NULL)
		{
			// Check opcode.
			if ((area[i] & opcode_list[j].mask) != opcode_list[j].code)
				continue;

			// Generate common line.
			sprintf(&line[14],
				opcode_list[j].name,
				get_arg(session, area[i], &opcode_list[j], 0),
				get_arg(session, area[i], &opcode_list[j], 1),
				get_arg(session, area[i], &opcode_list[j], 2)
			);
			break;
		}
		
		// If no opcode are found, generate "empty" line.
		if (opcode_list[j].name == NULL)
			sprintf(&line[14], ".word 0x%.4x", area[i]);

		// Update internal context
		// TODO: update all registers (complet emulation ?)
		session->context->spc = session->context->spc + 2;

		// Display line
		dprint(&earlyterm.display,
				session->menu.disassembly.print_offset.horizontal,
				session->menu.disassembly.print_offset.vertical, line);

		// Highlight break line if needed.
		if ((uint32_t)&area[i] == sspc)
		{
			dreverse(&earlyterm.display,
				0, session->menu.disassembly.print_offset.vertical * (earlyterm.display.font->font.height + 1),
				128, earlyterm.display.font->font.height + 1);
		}
		if (session->menu.disassembly.next_break != sspc && (uint32_t)&area[i] == session->menu.disassembly.next_break) {
			drect(&earlyterm.display,
				0, session->menu.disassembly.print_offset.vertical * (earlyterm.display.font->font.height + 1) - 1,
				128, earlyterm.display.font->font.height + 1
			);
		}

		// Update vertical counter
		session->menu.disassembly.print_offset.vertical += 1;

	}

	// Restore saved SPC
	session->context->spc = sspc;
}

static void cursor_update(ubc_session_t *session)
{
	// Horizontal update.
	if (session->key.left == 1)
		session->menu.disassembly.print_offset.horizontal += 1;
	if (session->key.right == 1)
		session->menu.disassembly.print_offset.horizontal -= 1;

	// Vertical update.
	if (session->key.up == 1)
		session->menu.disassembly.memory = &session->menu.disassembly.memory[-1];
	if (session->key.down == 1)
		session->menu.disassembly.memory = &session->menu.disassembly.memory[1];

	// Move break point
	if (session->key.plus == 1)
		session->menu.disassembly.next_break += 2;
	if (session->key.minus == 1)
		session->menu.disassembly.next_break -= 2;
}

void disasm_menu_disassembly(ubc_session_t *session)
{
	extern struct earlyterm earlyterm;

	// Update cursor position.
	cursor_update(session);

	// display ASM.
	dclear(&earlyterm.display);
	display_mnemonic(session);
	screen_update(earlyterm.display.vram);
}