#include <socks/device.h>
#include <socks/input.h>
#include <socks/bitmap.h>
#include <socks/libc/stdio.h>

static DECLARE_BITMAP(input_device_ids, INPUT_DEVICE_MAX);
static spin_lock_t input_device_ids_lock = SPIN_LOCK_INIT;

struct input_device *input_device_create(void)
{
	struct device *dev = device_alloc();
	if (!dev) {
		return NULL;
	}

	dev->dev_type = DEV_TYPE_INPUT;

	struct input_device *input_dev = INPUT_DEVICE(dev);
	if (ringbuffer_init(&input_dev->i_events, INPUT_DEVICE_EVENT_QUEUE_SIZE * sizeof(struct input_event)) != KERN_OK) {
		/* TODO destroy device */
		return NULL;
	}

	return INPUT_DEVICE(dev);
}

struct input_device *input_device_from_generic(struct device *dev)
{
	dev->dev_type = DEV_TYPE_INPUT;
	return INPUT_DEVICE(dev);
}

kern_status_t input_device_report_event(struct input_device *dev, const struct input_event *ev, bool noblock)
{
	struct ringbuffer *event_queue = &dev->i_events;
	socks_flags_t flags = S_NORMAL;
	if (noblock) {
		flags = S_NOBLOCK;
	}

	struct input_event new_ev = *ev;
	enum input_event_hook_flags hook_flags = 0;

	queue_foreach (struct input_event_hook, hook, &dev->i_hooks, hook_head) {
		if (hook->hook_callback) {
			hook->hook_callback(input_device_base(dev), &new_ev, &hook_flags, hook->hook_arg);
		}

		if (hook_flags & INPUT_HOOK_SQUASH_EVENT) {
			break;
		}
	}

	if (hook_flags & INPUT_HOOK_SQUASH_EVENT) {
		return KERN_OK;
	}

	size_t r = ringbuffer_write(event_queue, sizeof new_ev, &new_ev, flags);

	return r == sizeof *ev ? KERN_OK : KERN_WOULD_BLOCK;
}

kern_status_t input_device_read(struct device *dev, void *buf, size_t size, size_t *bytes_read, socks_flags_t flags)
{
	if (dev->dev_type != DEV_TYPE_INPUT || (size % sizeof (struct input_event)) != 0) {
		return KERN_INVALID_ARGUMENT;
	}

	struct input_device *input_dev = INPUT_DEVICE(dev);
	struct ringbuffer *event_queue = &input_dev->i_events;

	size_t r = ringbuffer_read(event_queue, size, buf, flags);

	if (bytes_read) {
		*bytes_read = r;
	}

	return KERN_OK;
}

kern_status_t input_device_add_hook(struct device *dev, struct input_event_hook *hook)
{
	struct input_device *inputdev = INPUT_DEVICE(dev);
	if (!inputdev) {
		return KERN_INVALID_ARGUMENT;
	}

	queue_push_back(&inputdev->i_hooks, &hook->hook_head);

	return KERN_OK;
}

kern_status_t input_device_remove_hook(struct device *dev, struct input_event_hook *hook)
{
	struct input_device *inputdev = INPUT_DEVICE(dev);
	if (!inputdev) {
		return KERN_INVALID_ARGUMENT;
	}

	queue_delete(&inputdev->i_hooks, &hook->hook_head);

	return KERN_OK;
}

static kern_status_t generate_name(struct input_device *dev, char out[DEV_NAME_MAX])
{
	snprintf(out, DEV_NAME_MAX, "input%u", dev->i_id);
	return KERN_OK;
}

kern_status_t input_device_register(struct device *dev)
{
	unsigned long flags;
	spin_lock_irqsave(&input_device_ids_lock, &flags);
	unsigned int id = bitmap_lowest_clear(input_device_ids, INPUT_DEVICE_MAX);
	bitmap_set(input_device_ids, id);
	spin_unlock_irqrestore(&input_device_ids_lock, flags);

	struct input_device *inputdev = &dev->input;
	inputdev->i_id = id;

	char name[DEV_NAME_MAX];
	generate_name(inputdev, name);
	char path[OBJECT_PATH_MAX];
	snprintf(path, sizeof path, "/dev/input/%s", name);

	return object_namespace_create_link(global_namespace(), path, &dev->dev_base);
}

struct device_type_ops input_type_ops = {
	.register_device = input_device_register,
	.read = input_device_read,
};