#include <kernel/pci/pci.h>
#include <stdint.h>
#include <kernel/io/io.h>
#include <kernel/lib/lib.h>

void pci_write_field(uint32_t device, int field, int size, uint32_t value)
{
	outl(PCI_ADDRESS_PORT, pci_get_addr(device, field));
	outl(PCI_VALUE_PORT, value);
}

uint32_t pci_read_field(uint32_t device, int field, int size)
{
	outl(PCI_ADDRESS_PORT, pci_get_addr(device, field));

	if (size == 4) {
		uint32_t t = inl(PCI_VALUE_PORT);
		return t;
	} else if (size == 2) {
		uint16_t t = inw((uint16_t)(PCI_VALUE_PORT + (field & 2)));
		return t;
	} else if (size == 1) {
		uint8_t t = inb((uint16_t)(PCI_VALUE_PORT + (field & 3)));
		return t;
	}
	return 0xFFFF;
}

uint16_t pci_find_type(uint32_t dev)
{
	return (uint16_t)((pci_read_field(dev, PCI_CLASS, 1) << 8) |
			  pci_read_field(dev, PCI_SUBCLASS, 1));
}

void pci_scan_hit(pci_func_t f, uint32_t dev, void *extra)
{
	int dev_vend = (int)pci_read_field(dev, PCI_VENDOR_ID, 2);
	int dev_dvid = (int)pci_read_field(dev, PCI_DEVICE_ID, 2);

	f(dev, (uint16_t)dev_vend, (uint16_t)dev_dvid, extra);
}

void pci_scan_func(pci_func_t f, int type, int bus, int slot, int func, void *extra)
{
	uint32_t dev = pci_box_device(bus, slot, func);
	if (type == -1 || type == pci_find_type(dev))
		pci_scan_hit(f, dev, extra);
	if (pci_find_type(dev) == PCI_TYPE_BRIDGE)
		pci_scan_bus(f, type, (int)pci_read_field(dev, PCI_SECONDARY_BUS, 1), extra);
}

void pci_scan_slot(pci_func_t f, int type, int bus, int slot, void *extra)
{
	uint32_t dev = pci_box_device(bus, slot, 0);
	if (pci_read_field(dev, PCI_VENDOR_ID, 2) == PCI_NONE)
		return;
	pci_scan_func(f, type, bus, slot, 0, extra);
	if (!pci_read_field(dev, PCI_HEADER_TYPE, 1))
		return;
	for (int func = 1; func < 8; func++) {
		dev = pci_box_device(bus, slot, func);
		if (pci_read_field(dev, PCI_VENDOR_ID, 2) != PCI_NONE)
			pci_scan_func(f, type, bus, slot, func, extra);
	}
}

void pci_scan_bus(pci_func_t f, int type, int bus, void *extra)
{
	for (int slot = 0; slot < 32; ++slot)
		pci_scan_slot(f, type, bus, slot, extra);
}

void pci_scan(pci_func_t f, int type, void *extra)
{
	if ((pci_read_field(0, PCI_HEADER_TYPE, 1) & 0x80) == 0) {
		pci_scan_bus(f, type, 0, extra);
		return;
	}

	for (int func = 0; func < 8; ++func) {
		uint32_t dev = pci_box_device(0, 0, func);
		if (pci_read_field(dev, PCI_VENDOR_ID, 2) != PCI_NONE)
			pci_scan_bus(f, type, func, extra);
		else
			break;
	}
}

static void find_isa_bridge(uint32_t device, uint16_t vendor_id, uint16_t device_id, void *extra)
{
	if (vendor_id == 0x8086 && (device_id == 0x7000 || device_id == 0x7110))
		*((uint32_t *)extra) = device;
}

static uint32_t pci_isa = 0;
static uint8_t pci_remaps[4] = { 0 };

void pci_remap()
{
	pci_scan(&find_isa_bridge, -1, &pci_isa);
	if (pci_isa) {
		for (int i = 0; i < 4; ++i) {
			pci_remaps[i] = (uint8_t)pci_read_field(pci_isa, 0x60 + i, 1);
			if (pci_remaps[i] == 0x80) {
				pci_remaps[i] = (uint8_t)(10 + (i % 1));
			}
		}
		uint32_t out = 0;
		memcpy(&out, &pci_remaps, 4);
		pci_write_field(pci_isa, 0x60, 4, out);
	}
}

int pci_get_interrupt(uint32_t device)
{
	if (pci_isa) {
		uint32_t irq_pin = pci_read_field(device, 0x3D, 1);
		if (irq_pin == 0)
			return (int)pci_read_field(device, PCI_INTERRUPT_LINE, 1);
		int pirq = (int)(irq_pin + pci_extract_slot(device) - 2) % 4;
		int int_line = (int)pci_read_field(device, PCI_INTERRUPT_LINE, 1);

		if (pci_remaps[pirq] >= 0x80) {
			if (int_line == 0xFF) {
				int_line = 10;
				pci_write_field(device, PCI_INTERRUPT_LINE, 1, (uint32_t)int_line);
			}
			pci_remaps[pirq] = (uint8_t)int_line;
			uint32_t out = 0;
			memcpy(&out, &pci_remaps, 4);
			pci_write_field(pci_isa, 0x60, 4, out);
			return int_line;
		}
		pci_write_field(device, PCI_INTERRUPT_LINE, 1, pci_remaps[pirq]);
		return pci_remaps[pirq];
	} else {
		return (int)pci_read_field(device, PCI_INTERRUPT_LINE, 1);
	}
}