/*----------------*\
|Nanite OS         |
|Copyright (C) 2024|
|Tyler McGurrin    |
\*----------------*/
#include "irq.h"
#include "pic.h"
#include "io.h"
#include <stddef.h>
#include <stdio.h>

#define PIC_REMAP_OFFSET        0x20

IRQHandler g_IRQHandlers[16];

void i686_IRQ_Handler(Registers* regs)
{
    int irq = regs->interrupt - PIC_REMAP_OFFSET;

    if (g_IRQHandlers[irq] != NULL)
    {
        // handle IRQ
        g_IRQHandlers[irq](regs);
    }
    else
    {
        printf("Unhandled IRQ %d...\n", irq);
    }

    i686_PIC_SendEndOfInterrupt(irq);
}

void i686_IRQ_Initialize()
{
    i686_PIC_Configure(PIC_REMAP_OFFSET, PIC_REMAP_OFFSET + 8);

    // register ISR handlers for each of the 16 IRQ lines
    for (int i = 0; i < 16; i++)
        i686_ISR_RegisterHandler(PIC_REMAP_OFFSET + i, i686_IRQ_Handler);

    // enable interrupts 
    i686_EnableInterrupts();
}

void i686_IRQ_RegisterHandler(int irq, IRQHandler handler)
{
    g_IRQHandlers[irq] = handler;
}