#include <kernel/io/io.h>
#include <kernel/interrupts/interrupts.h>
#include <kernel/system.h>

extern void irq0();

extern void irq1();

extern void irq2();

extern void irq3();

extern void irq4();

extern void irq5();

extern void irq6();

extern void irq7();

extern void irq8();

extern void irq9();

extern void irq10();

extern void irq11();

extern void irq12();

extern void irq13();

extern void irq14();

extern void irq15();

// Array to handle custom IRQ handlers
void *irq_routines[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Install custom IRQ handler
void irq_install_handler(int irq, void (*handler)(struct regs *r))
{
	irq_routines[irq] = handler;
}

// Removes the custom IRQ handler
void irq_uninstall_handler(int irq)
{
	irq_routines[irq] = 0;
}

int irq_is_installed(int irq)
{
	return irq_routines[irq] != 0;
}

// Remap IRQs for protected mode compatibility via the PIC
void irq_remap(void)
{
	outb(0x20, 0x11);
	outb(0xA0, 0x11);
	outb(0x21, 0x20);
	outb(0xA1, 0x28);
	outb(0x21, 0x04);
	outb(0xA1, 0x02);
	outb(0x21, 0x01);
	outb(0xA1, 0x01);
	outb(0x21, 0x0);
	outb(0xA1, 0x0);
}

// Map ISRs to the correct entries in the IDT
void irq_install()
{
	irq_remap();
	idt_set_gate(32, (unsigned)irq0, 0x08, 0x8E);
	idt_set_gate(33, (unsigned)irq1, 0x08, 0x8E);
	idt_set_gate(34, (unsigned)irq2, 0x08, 0x8E);
	idt_set_gate(35, (unsigned)irq3, 0x08, 0x8E);
	idt_set_gate(36, (unsigned)irq4, 0x08, 0x8E);
	idt_set_gate(37, (unsigned)irq5, 0x08, 0x8E);
	idt_set_gate(38, (unsigned)irq6, 0x08, 0x8E);
	idt_set_gate(39, (unsigned)irq7, 0x08, 0x8E);
	idt_set_gate(40, (unsigned)irq8, 0x08, 0x8E);
	idt_set_gate(41, (unsigned)irq9, 0x08, 0x8E);
	idt_set_gate(42, (unsigned)irq10, 0x08, 0x8E);
	idt_set_gate(43, (unsigned)irq11, 0x08, 0x8E);
	idt_set_gate(44, (unsigned)irq12, 0x08, 0x8E);
	idt_set_gate(45, (unsigned)irq13, 0x08, 0x8E);
	idt_set_gate(46, (unsigned)irq14, 0x08, 0x8E);
	idt_set_gate(47, (unsigned)irq15, 0x08, 0x8E);
	vga_log("Installed Interrupt Requests");
}

// Handle IRQ ISRs
void irq_handler(struct regs *r)
{
	void (*handler)(struct regs * r);

	// Execute custom handler if exists
	handler = irq_routines[r->int_no - 32];
	if (handler)
		handler(r);

	// Send end of interrupt to second (slave) IRQ controller
	if (r->int_no >= 40)
		outb(0xA0, 0x20);

	// Send end of interrupt to master interrupt controller
	outb(0x20, 0x20);
}