#include "idt.h"
#include "io.h"

#define KERNEL_CS 0x08  // Kernel code segment selector

idt_entry_t idt[IDT_ENTRIES];
idt_ptr_t idt_ptr;

// External assembly stubs for ISRs (provided below)
extern void isr0();
extern void isr1();
extern void isr2();
extern void isr3();
extern void isr4();
extern void isr5();
extern void isr6();
extern void isr7();
extern void isr8();
extern void isr9();
extern void isr10();
extern void isr11();
extern void isr12();
extern void isr13();
extern void isr14();
extern void isr15();
extern void isr16();
extern void isr17();
extern void isr18();
extern void isr19();
extern void isr20();
extern void isr21();
extern void isr22();
extern void isr23();
extern void isr24();
extern void isr25();
extern void isr26();
extern void isr27();
extern void isr28();
extern void isr29();
extern void isr30();
extern void isr31();
extern void isr_default();

// Helper to set an IDT gate
void idt_set_gate(int n, uint32_t handler) {
    idt[n].offset_low = handler & 0xFFFF;
    idt[n].selector = KERNEL_CS;
    idt[n].zero = 0;
    idt[n].type_attr = 0x8E;  // Present, ring 0, 32-bit interrupt gate
    idt[n].offset_high = (handler >> 16) & 0xFFFF;
}

// Load IDT via lidt
static void idt_load() {
    asm volatile("lidt (%0)" : : "r" (&idt_ptr));
}

// IDT initialization
void idt_init() {
    idt_ptr.limit = sizeof(idt_entry_t) * IDT_ENTRIES - 1;
    idt_ptr.base = (uint32_t)&idt;

    // Clear all entries
    for (int i = 0; i < IDT_ENTRIES; i++) {
        idt_set_gate(i, (uint32_t)isr_default);
    }

    // Set specific handlers
    // Assign CPU exception handlers
    idt_set_gate(0, (uint32_t)isr0);
    idt_set_gate(1, (uint32_t)isr1);
    idt_set_gate(2, (uint32_t)isr2);
    idt_set_gate(3, (uint32_t)isr3);
    idt_set_gate(4, (uint32_t)isr4);
    idt_set_gate(5, (uint32_t)isr5);
    idt_set_gate(6, (uint32_t)isr6);
    idt_set_gate(7, (uint32_t)isr7);
    idt_set_gate(8, (uint32_t)isr8);
    idt_set_gate(9, (uint32_t)isr9);
    idt_set_gate(10, (uint32_t)isr10);
    idt_set_gate(11, (uint32_t)isr11);
    idt_set_gate(12, (uint32_t)isr12);
    idt_set_gate(13, (uint32_t)isr13);
    idt_set_gate(14, (uint32_t)isr14);
    idt_set_gate(15, (uint32_t)isr15);
    idt_set_gate(16, (uint32_t)isr16);
    idt_set_gate(17, (uint32_t)isr17);
    idt_set_gate(18, (uint32_t)isr18);
    idt_set_gate(19, (uint32_t)isr19);
    idt_set_gate(20, (uint32_t)isr20);
    idt_set_gate(21, (uint32_t)isr21);
    idt_set_gate(22, (uint32_t)isr22);
    idt_set_gate(23, (uint32_t)isr23);
    idt_set_gate(24, (uint32_t)isr24);
    idt_set_gate(25, (uint32_t)isr25);
    idt_set_gate(26, (uint32_t)isr26);
    idt_set_gate(27, (uint32_t)isr27);
    idt_set_gate(28, (uint32_t)isr28);
    idt_set_gate(29, (uint32_t)isr29);
    idt_set_gate(30, (uint32_t)isr30);
    idt_set_gate(31, (uint32_t)isr31);


    idt_load();
}