#include <kernel/cpu/idt/idt.h>
#include <kernel/cpu/isr/isr.h>
#include <kernel/cpu/cpu.h>
#include <kernel/time/PIT.h>
#include <sys/string.h>

extern void load_idt(uint32_t);

extern isr_t interrupt_handlers[];

static struct idt_entry     idt_entries[256];
static struct idt_pointer   idt_ptr;

void idt_init()
{
    idt_ptr.limit = sizeof(struct idt_entry) * 256 - 1;
    idt_ptr.base  = (uint32_t)&idt_entries;

    memset((void *)&idt_entries, 0, (sizeof(struct idt_entry) * 256));
    memset((void *)&interrupt_handlers, 0, (sizeof(isr_t) * 256));

    /*
     * When the computer is booted, the default interrupt handlers are
     *      IRQ 0..7 - INT 0x8..0xF
     *      IRQ 8..15 - INT 0x70..0x77
     *
     * This causes a problem when we want to use the default handlers.
     * The master IRQ maps (0x8-0xF) conflict with the interrupt numbers
     * used by the CPU to signal exceptions and faults. The normal way
     * to solve this problem is to use the PIC (Programmable Interrupt
     * Controller) to remap the IRQs. (31 being the last CPU used ISR).
     */
    PIC_MASTER_CMD_OUT (0x11);
	PIC_SLAVE_CMD_OUT  (0x11);
	PIC_MASTER_DATA_OUT    (0x20);
	PIC_SLAVE_DATA_OUT     (0x28);
	PIC_MASTER_DATA_OUT    (0x04);
	PIC_SLAVE_DATA_OUT     (0x02);
	PIC_MASTER_DATA_OUT    (0x01);
	PIC_SLAVE_DATA_OUT     (0x01);
	PIC_MASTER_DATA_OUT    (0x00);
	PIC_SLAVE_DATA_OUT     (0x00);

    idt_set_gate( 0, (uint32_t)isr0 , 0x08, 0x8E);
	idt_set_gate( 1, (uint32_t)isr1 , 0x08, 0x8E);
	idt_set_gate( 2, (uint32_t)isr2 , 0x08, 0x8E);
	idt_set_gate( 3, (uint32_t)isr3 , 0x08, 0x8E);
	idt_set_gate( 4, (uint32_t)isr4 , 0x08, 0x8E);
	idt_set_gate( 5, (uint32_t)isr5 , 0x08, 0x8E);
	idt_set_gate( 6, (uint32_t)isr6 , 0x08, 0x8E);
	idt_set_gate( 7, (uint32_t)isr7 , 0x08, 0x8E);
	idt_set_gate( 8, (uint32_t)isr8 , 0x08, 0x8E);
	idt_set_gate( 9, (uint32_t)isr9 , 0x08, 0x8E);
	idt_set_gate(10, (uint32_t)isr10, 0x08, 0x8E);
	idt_set_gate(11, (uint32_t)isr11, 0x08, 0x8E);
	idt_set_gate(12, (uint32_t)isr12, 0x08, 0x8E);
	idt_set_gate(13, (uint32_t)isr13, 0x08, 0x8E);
	idt_set_gate(14, (uint32_t)isr14, 0x08, 0x8E);
	idt_set_gate(15, (uint32_t)isr15, 0x08, 0x8E);
	idt_set_gate(16, (uint32_t)isr16, 0x08, 0x8E);
	idt_set_gate(17, (uint32_t)isr17, 0x08, 0x8E);
	idt_set_gate(18, (uint32_t)isr18, 0x08, 0x8E);
	idt_set_gate(19, (uint32_t)isr19, 0x08, 0x8E);
	idt_set_gate(20, (uint32_t)isr20, 0x08, 0x8E);
	idt_set_gate(21, (uint32_t)isr21, 0x08, 0x8E);
	idt_set_gate(22, (uint32_t)isr22, 0x08, 0x8E);
	idt_set_gate(23, (uint32_t)isr23, 0x08, 0x8E);
	idt_set_gate(24, (uint32_t)isr24, 0x08, 0x8E);
	idt_set_gate(25, (uint32_t)isr25, 0x08, 0x8E);
	idt_set_gate(26, (uint32_t)isr26, 0x08, 0x8E);
	idt_set_gate(27, (uint32_t)isr27, 0x08, 0x8E);
	idt_set_gate(28, (uint32_t)isr28, 0x08, 0x8E);
	idt_set_gate(29, (uint32_t)isr29, 0x08, 0x8E);
	idt_set_gate(30, (uint32_t)isr30, 0x08, 0x8E);
	idt_set_gate(31, (uint32_t)isr31, 0x08, 0x8E);
	idt_set_gate(32, (uint32_t)irq0,  0x08, 0x8E);
	idt_set_gate(33, (uint32_t)irq1,  0x08, 0x8E);
	idt_set_gate(34, (uint32_t)irq2,  0x08, 0x8E);
	idt_set_gate(35, (uint32_t)irq3,  0x08, 0x8E);
	idt_set_gate(36, (uint32_t)irq4,  0x08, 0x8E);
	idt_set_gate(37, (uint32_t)irq5,  0x08, 0x8E);
	idt_set_gate(38, (uint32_t)irq6,  0x08, 0x8E);
	idt_set_gate(39, (uint32_t)irq7,  0x08, 0x8E);
	idt_set_gate(40, (uint32_t)irq8,  0x08, 0x8E);
	idt_set_gate(41, (uint32_t)irq9,  0x08, 0x8E);
	idt_set_gate(42, (uint32_t)irq10, 0x08, 0x8E);
	idt_set_gate(43, (uint32_t)irq11, 0x08, 0x8E);
	idt_set_gate(44, (uint32_t)irq12, 0x08, 0x8E);
	idt_set_gate(45, (uint32_t)irq13, 0x08, 0x8E);
	idt_set_gate(46, (uint32_t)irq14, 0x08, 0x8E);
	idt_set_gate(47, (uint32_t)irq15, 0x08, 0x8E);

    load_idt((uint32_t)&idt_ptr);
    qemu_success("IDT Loaded, base->%p\r\n", &idt_ptr.base);
}

void idt_set_gate(uint8_t num, uint32_t base,
                            uint16_t selector, uint8_t flags)
{
    idt_entries[num].base_low = base            & 0xFFFF;
    idt_entries[num].base_high = (base >> 16)   & 0xFFFF;

    idt_entries[num].selector = selector;
    idt_entries[num].always0 = 0;

    /*
     * We must uncomment the OR below when we get to using user-mode.
     * It sets the interrupt gate's privilege level to 3.
     */
    idt_entries[num].flags = flags; /* | 0x60 */
}
