#include <lcrash/driver/sysbus.h>

#include <lcrash/debug/debug.h>
#include <lcrash/mm/kmalloc.h>

struct SysbusDeviceDescription* SysbusRootDeviceDescription = 0;
struct SysbusDevice* SysbusRootDevice = 0;

/**
 * Create a new device description
 */
struct SysbusDeviceDescription* SysbusCreateDeviceDescriptionInternal() {
	struct SysbusDeviceDescription* Description = KernelHeapAlloc(sizeof(struct SysbusDeviceDescription), 1, 0);

	Description->DeviceName = 0;
	Description->Instances = KernelHeapAlloc(sizeof(struct SysbusDevice*) * 4, 1, 0);
	Description->InstanceCount = 0;
	Description->InstanceSlots = 4;
	Description->CreateDevice = 0;
	Description->DeleteDevice = 0;
	Description->GetCapability = 0;

	return Description;
}

/**
 * Attach a device to another device
 */
void SysbusAttachChildDeviceInternal(struct SysbusDevice* Parent, struct SysbusDevice* Child) {
	// See if we need to grow the list
	if (Parent->ChildCount >= Parent->ChildSlots) {
		struct SysbusDevice** NewList = KernelHeapAlloc(sizeof(struct SysbusDevice*) * Parent->ChildSlots * 2, 1, 0);
		for (int i = 0; i < Parent->ChildCount; i++) {
			NewList[i] = Parent->Children[i];
		}

		KernelHeapFree(Parent->Children);
		Parent->Children = NewList;
		Parent->ChildSlots *= 2;
	}

	// Add the child
	Parent->Children[Parent->ChildCount++] = Child;

	return;
}

/**
 * Create a new device
 *
 * \param Description device description
 * \param Parent parent device
 * \param DeviceData device specific data
 * \param IsRootDevice device has no parent
 */
struct SysbusDevice* SysbusCreateDeviceInternal(
	struct SysbusDeviceDescription* Description,
	struct SysbusDevice* Parent,
	void* DeviceData,
	bool IsRootDevice
) {
	struct SysbusDevice* Device = KernelHeapAlloc(sizeof(struct SysbusDevice), 1, 0);
	Device->DeviceDescription = Description;
	Device->DeviceName = 0;
	Device->DeviceData = 0;
	Device->Parent = Parent;
	Device->Children = KernelHeapAlloc(sizeof(struct SysbusDevice*) * 4, 1, 0);
	Device->ChildCount = 0;
	Device->ChildSlots = 4;

	// Attach to parent
	if (Parent != NULL) SysbusAttachChildDeviceInternal(Parent, Device);
	
	// See if we need to grow the instance list
	if (Description->InstanceCount >= Description->InstanceSlots) {
		struct SysbusDevice** NewList = KernelHeapAlloc(sizeof(struct SysbusDevice*) * Description->InstanceSlots * 2, 1, 0);
		for (int i = 0; i < Description->InstanceCount; i++) {
			NewList[i] = Description->Instances[i];
		}

		KernelHeapFree(Description->Instances);
		Description->Instances = NewList;
		Description->InstanceSlots *= 2;
	}

	// Add us as an instance
	Description->Instances[Description->InstanceCount++] = Device;

	return Device;
}

struct SysbusDeviceDescription* SysbusCreateDeviceDescription() {
	return SysbusCreateDeviceDescriptionInternal();
}

void SysbusDeleteDeviceDescription(struct SysbusDeviceDescription* Description) {
	Panic("todo");
}

struct SysbusDevice* SysbusCreateDevice(
	struct SysbusDeviceDescription* Description,
	struct SysbusDevice* Parent,
	void* Data
) {
	return SysbusCreateDeviceInternal(Description, Parent, Data, false);
}

void SysbusDeleteDevice(struct SysbusDevice* Device) {
	Panic("todo");
}

void SysbusInitialize() {
	// Create the sysbus root
	SysbusRootDeviceDescription = SysbusCreateDeviceDescriptionInternal();
	SysbusRootDeviceDescription->DeviceName = "Lcrash System Bus";

	SysbusRootDevice = SysbusCreateDeviceInternal(
		SysbusRootDeviceDescription,
		NULL,
		NULL,
		true
	);
	SysbusRootDevice->DeviceName = "Lcrash System Bus";

	return;
}