#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys.h>

#include "idt.h"
#include "pic.h"
#include "../term.h"
#include "../panic.h"
#include "../drivers/ps2kb.h"
#include "../drivers/ps2ctrl.h"

static int timer = 0;

void idt_pic_generic(uint8_t exception) {
	pic_eoi(exception - PIC_REMAP_OFFSET);
}

void idt_pic_timer(void) {
	uint32_t state = term_save();
	term_setcol(0x0a);
	term_setpos(60, 0);
	puts("        ");
	term_setpos(60, 0);
	printf("%d", timer);
	term_flush();
	timer += 1;
	term_load(state);
}

void idt_pic_keyboard(void) {
	ps2kb_recv();
}

void idt_exception_handler(uint8_t exception) {
	char* msg;
	switch(exception) {
		case 0x00:
			msg = "Division by zero";
			break;
		case 0x02:
			msg = "NMI";
			break;
		case 0x04:
			msg = "Overflow";
			break;
		case 0x06:
			msg = "invalid opcode";
			break;
		case 0x08:
			msg = "double fault";
			break;
		case 0x0A:
			msg = "invalid task state segment";
			break;
		case 0x0C:
			msg = "stack segment fault";
			break;
		case 0x0D:
			msg = "general protection fault";
			break;
		case 0x0E:
			msg = "page fault";
			break;
		default:
			msg = "unknown exception";
			break;
	}
	panic("E%u: %s", exception, msg);
}

__attribute__((aligned(0x10)))
static struct IdtEntry idt[256];
static struct Idtr idtr;
extern void* isr_stub_table[];

static void set_descriptor(uint8_t vector, void* isr, uint8_t flags) {
	struct IdtEntry* entry = &idt[vector];
	entry->isr_low = (size_t)isr & 0xffff;
	entry->kernel_cs = 0x08;
	entry->attributes = flags;
	entry->isr_high = (size_t)isr >> 16;
	entry->_reserved = 0;
}

void idt_init(void) {
	idtr.base = (uintptr_t)&idt[0];
	idtr.limit = (uint16_t)sizeof(struct IdtEntry) * IDT_SIZE - 1;

	for(int i = 0; i < IDT_INTERRUPTS; i++) {
		set_descriptor(i, isr_stub_table[i], 0x8e);
	}

	__asm__ volatile ("lidt %0" : : "m"(idtr));
}