#include <ioapic.h>
#include <apic.h>
#include <paging.h>
#include <libk/stdio.h>
#include <msr.h>
#include <idt.h>

void ioapic_eoi()
{
	*((__volatile__ uint32_t *)((uint64_t)lapic_addr + 0xB0)) = 0;
}

uint32_t ioapic_read(const uint8_t offset)
{
	/* tell IOREGSEL where we want to read from */
	*(__volatile__ uint32_t *)(uint64_t)ioapic_addr = offset;
	/* return the data from IOWIN */
	return *(__volatile__ uint32_t *)((uint64_t)ioapic_addr + 0x10);
}

void ioapic_write(const uint8_t offset, const uint32_t val)
{
	/* tell IOREGSEL where we want to write to */
	*(__volatile__ uint32_t *)(uint64_t)ioapic_addr = offset;
	/* write the value to IOWIN */
	*(__volatile__ uint32_t *)((uint64_t)ioapic_addr + 0x10) = val;
}

void ioapic_set_irq(uint8_t irq, uint64_t apic_id, uint8_t vector)
{
	const uint32_t low_index = (uint32_t)0x10 + irq * 2;
	const uint32_t high_index = (uint32_t)0x10 + irq * 2 + 1;
	uint32_t high;
	uint32_t low;

	high = ioapic_read((uint8_t)high_index);
	/* set APIC ID */
	high &= (uint32_t)~0xff000000;
	high |= (uint32_t)apic_id << 24;
	ioapic_write((uint8_t)high_index, high);

	low = ioapic_read((uint8_t)low_index);

	/* unmask the IRQ */
	low &= (uint32_t) ~(1 << 16);

	/* set to physical delivery mode */
	low &= (uint32_t) ~(1 << 11);

	/* set to fixed delivery mode */
	low &= (uint32_t)~0x700;

	/* set delivery vector */
	low &= (uint32_t)~0xff;
	low |= vector;

	ioapic_write((uint8_t)low_index, low);
}

void apic_remap_interrupts()
{
	uint8_t bspid;

	map_addr(ioapic_addr, ioapic_addr, FLAG_PRESENT);
	map_addr(lapic_addr, lapic_addr, FLAG_PRESENT);

	bspid = curr_cpu_apic_id();

	/* irq is 2 because of gsi remap */
	ioapic_set_irq(0x2, bspid, 0x20); /* timer */
	ioapic_set_irq(0x1, bspid, 0x21); /* keyboard */

	write_msr(APIC_BASE_MSR, read_msr(APIC_BASE_MSR) | (1 << 11));
	*((__volatile__ uint32_t *)(lapic_addr + 0xF0)) =
		(*(__volatile__ uint32_t *)(lapic_addr + 0xF0) | 0x1FF);
}