#ifndef IDT_H
#define IDT_H

#include "stdint.h"
#include "screen.h"

#define TRAP_GATE_FLAGS    0x8f // P = 1, DPL = 00, S = 0, Type = 1111 (32-bit Trap gate)
#define INT_GATE_FLAGS     0x8e // P = 1, DPL = 00, S = 0, Type = 1110 (32-bit Int gate)
#define USR_INT_GAME_FLAGS 0xee // P = 1, DPL = 11, S = 0, Type = 1110 (32-bit Int gate)

typedef struct {
    uint16_t offsetLow;
    uint16_t selector;
    uint8_t zero;
    uint8_t typeAttr;
    uint16_t offsetHigh;
} __attribute__ ((packed)) idtEntry_t;

typedef struct {
    uint16_t limit;
    uint32_t base;
} __attribute__ ((packed)) idtp_t;

typedef struct {
    uint32_t eip;
    uint32_t cs;
    uint32_t eflags;
    uint32_t esp;
    uint32_t ss;
} __attribute__ ((packed)) intFrame_t;

__attribute__ ((aligned(0x10))) // For performance
idtEntry_t idt[256] = { 0 };
idtp_t idtp;

void idtSetGate(uint8_t i, void* handler, uint8_t flags) {
    uint32_t offset = (uint32_t)handler;
    idtEntry_t* entry = &idt[i];

    entry->offsetLow = (uint16_t)offset;
    entry->selector = 0x08;
    entry->zero = 0;
    entry->typeAttr = flags;
    entry->offsetHigh = (uint16_t)(offset >> 16);
}

void setupIdt() {
    idtp.limit = sizeof(idtEntry_t) * 256;
    idtp.base = (uint32_t)&idt;

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

#endif