#include <linux/anon_inodes.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <asm/uaccess.h>

#include "private_data.h"
#include "harddoom.h"
#include "surface.h"
#include "util.h"
#include "harddoomdev.h"

void free_texture(struct texture_data *texture_data);
int texture_release(struct inode *inode, struct file *filp)
{
	struct texture_data *texture_data;

	texture_data = filp->private_data;

	free_texture(texture_data);

	kfree(texture_data);

	return 0;
}

struct file_operations texture_fops = {
	.owner = THIS_MODULE,
	.release = texture_release

};

int verify_texture_params(struct doomdev_ioctl_create_texture *params)
{
	if (params->size > 4 * 1024 * 1024) {
		return -EOVERFLOW;
	}

	if (params->height > 1023) {
		return -EOVERFLOW;
	}

	return 0;
}

int alloc_texture(struct doomdev_ioctl_create_texture *params,
		struct texture_data *texture_data)
{
	int err;
	int i;
	int not_written;
	int pages_needed;

	texture_data->size = params->size;
	texture_data->height = params->height;

	pages_needed = (params->size / HARDDOOM_PAGE_SIZE);
	if (params->size % HARDDOOM_PAGE_SIZE != 0) {
		pages_needed += 1;
	}

	texture_data->pages = pages_needed;
	texture_data->texture_cpu =
		dma_alloc_coherent(texture_data->doom_data->pci_device,
				params->size, &texture_data->texture_dev,
				GFP_KERNEL);
	ORFAIL_NULL(texture_data->texture_cpu, -ENOMEM, error_texture);

	texture_data->page_table_cpu =
		dma_alloc_coherent(texture_data->doom_data->pci_device,
				pages_needed * 4, &texture_data->page_table_dev,
				GFP_KERNEL);
	ORFAIL_NULL(texture_data->page_table_cpu, -ENOMEM, error_pt);

	for (i = 0; i < pages_needed; i++) {
		texture_data->page_table_cpu[i] =
			(HARDDOOM_PTE_PHYS_MASK &
			 (texture_data->texture_dev + HARDDOOM_PAGE_SIZE * i)) |
			HARDDOOM_PTE_VALID;
	}

	not_written = copy_from_user(texture_data->texture_cpu,
			(void __user *) params->data_ptr,
			params->size);

	if (not_written) {
		err = -EFAULT;
		goto error_copy;
	}

	return 0;

error_copy:
	dma_free_coherent(texture_data->doom_data->pci_device,
			texture_data->pages * 4, texture_data->page_table_cpu,
			texture_data->page_table_dev);
error_pt:
	dma_free_coherent(texture_data->doom_data->pci_device,
			texture_data->size, texture_data->texture_cpu,
			texture_data->texture_dev);
error_texture:
	return err;
}

void free_texture(struct texture_data *texture_data)
{
	dma_free_coherent(texture_data->doom_data->pci_device,
			texture_data->pages * 4, texture_data->page_table_cpu,
			texture_data->page_table_dev);

	dma_free_coherent(texture_data->doom_data->pci_device,
			texture_data->size, texture_data->texture_cpu,
			texture_data->texture_dev);
}

int new_texture(struct file *filp, struct doomdev_ioctl_create_texture *arg)
{
	int err;
	struct doomdev_ioctl_create_texture *params;
	struct texture_data *texture_data;
	int fd;
	struct doom_data *doom_data;

	params = (struct doomdev_ioctl_create_texture *) arg;

	err = verify_texture_params(params);
	if (err < 0) {
		return err;
	}

	texture_data = kmalloc(sizeof(*texture_data), GFP_KERNEL);
	ORFAIL_NULL(texture_data, -ENOMEM, error_data);
	doom_data = container_of(filp->f_inode->i_cdev, struct doom_data, cdev);
	texture_data->doom_data = doom_data;

	ORFAIL(alloc_texture(params, texture_data), error_texture);

	fd = anon_inode_getfd("doom_texture", &texture_fops, texture_data, 0);
	ORFAIL(fd, error_inode);

	return fd;

error_inode:
	free_texture(texture_data);
error_texture:
	kfree(texture_data);
error_data:
	return err;
}

void free_flat(struct flat_data *flat_data);
int flat_release(struct inode *inode, struct file *filp)
{
	struct flat_data *flat_data;

	flat_data = filp->private_data;

	free_flat(flat_data);

	kfree(flat_data);

	return 0;
}

struct file_operations flat_fops = {
	.owner = THIS_MODULE,
	.release = flat_release

};

int alloc_flat(struct doomdev_ioctl_create_flat *params,
		struct flat_data *flat_data)
{
	int err;
	int not_written;

	flat_data->flat_cpu =
		dma_alloc_coherent(flat_data->doom_data->pci_device,
				HARDDOOM_FLAT_SIZE, &flat_data->flat_dev,
				GFP_KERNEL);
	ORFAIL_NULL(flat_data->flat_cpu, -ENOMEM, error_flat);

	not_written = copy_from_user(flat_data->flat_cpu,
			(void __user *) params->data_ptr, HARDDOOM_FLAT_SIZE);

	if (not_written) {
		err = -EFAULT;
		goto error_copy;
	}

	return 0;

error_copy:
	dma_free_coherent(flat_data->doom_data->pci_device, HARDDOOM_FLAT_SIZE,
			flat_data->flat_cpu, flat_data->flat_dev);
error_flat:
	return err;

}

void free_flat(struct flat_data *flat_data)
{
	dma_free_coherent(flat_data->doom_data->pci_device, HARDDOOM_FLAT_SIZE,
			flat_data->flat_cpu, flat_data->flat_dev);
}

int new_flat(struct file *filp, struct doomdev_ioctl_create_flat *arg)
{
	int err;
	struct doomdev_ioctl_create_flat *params;
	struct flat_data *flat_data;
	int fd;
	struct doom_data *doom_data;

	params = (struct doomdev_ioctl_create_flat *) arg;

	flat_data = kmalloc(sizeof(*flat_data), GFP_KERNEL);
	ORFAIL_NULL(flat_data, -ENOMEM, error_data);
	doom_data = container_of(filp->f_inode->i_cdev, struct doom_data, cdev);
	flat_data->doom_data = doom_data;

	ORFAIL(alloc_flat(params, flat_data), error_flat);

	fd = anon_inode_getfd("doom_flat", &flat_fops, flat_data, 0);
	ORFAIL(fd, error_inode);

	return fd;

error_inode:
	free_flat(flat_data);
error_flat:
	kfree(flat_data);
error_data:
	return err;
}

void free_colors(struct colors_data *colors_data);
int colors_release(struct inode *inode, struct file *filp)
{
	struct colors_data *colors_data;

	colors_data = filp->private_data;

	free_colors(colors_data);

	kfree(colors_data);

	return 0;
}

struct file_operations colors_fops = {
	.owner = THIS_MODULE,
	.release = colors_release

};

int alloc_colors(struct doomdev_ioctl_create_colormaps *params,
		struct colors_data *colors_data)
{
	int err;
	int not_written;

	colors_data->number = params->num;

	colors_data->colors_cpu =
		dma_alloc_coherent(colors_data->doom_data->pci_device,
				HARDDOOM_COLORMAP_SIZE * params->num,
				&colors_data->colors_dev,
				GFP_KERNEL);
	ORFAIL_NULL(colors_data->colors_cpu, -ENOMEM, error_colors);

	not_written = copy_from_user(colors_data->colors_cpu,
			(void __user *) params->data_ptr,
			HARDDOOM_COLORMAP_SIZE * params->num);

	if (not_written) {
		err = -EFAULT;
		goto error_copy;
	}

	return 0;

error_copy:
	dma_free_coherent(colors_data->doom_data->pci_device,
			HARDDOOM_COLORMAP_SIZE * params->num,
			colors_data->colors_cpu, colors_data->colors_dev);
error_colors:
	return err;

}

void free_colors(struct colors_data *colors_data)
{
	dma_free_coherent(colors_data->doom_data->pci_device,
			HARDDOOM_COLORMAP_SIZE * colors_data->number,
			colors_data->colors_cpu, colors_data->colors_dev);
}

int new_colors(struct file *filp, struct doomdev_ioctl_create_colormaps *arg)
{
	int err;
	struct doomdev_ioctl_create_colormaps *params;
	struct colors_data *colors_data;
	int fd;
	struct doom_data *doom_data;

	params = (struct doomdev_ioctl_create_colormaps *) arg;

	colors_data = kmalloc(sizeof(*colors_data), GFP_KERNEL);
	ORFAIL_NULL(colors_data, -ENOMEM, error_data);
	doom_data = container_of(filp->f_inode->i_cdev, struct doom_data, cdev);
	colors_data->doom_data = doom_data;

	ORFAIL(alloc_colors(params, colors_data), error_colors);

	fd = anon_inode_getfd("doom_colors", &colors_fops, colors_data, 0);
	ORFAIL(fd, error_inode);

	return fd;

error_inode:
	free_colors(colors_data);
error_colors:
	kfree(colors_data);
error_data:
	return err;
}

long draw_lines(struct file *filp, unsigned long arg)
{
	struct surface_data *surface_data;
	struct doomdev_surf_ioctl_draw_lines *param;
	struct doomdev_line *lines;
	int i;

	surface_data = filp->private_data;
	param = (struct doomdev_surf_ioctl_draw_lines *) arg;
	lines = (struct doomdev_line *) param->lines_ptr;

	mutex_lock(&surface_data->doom_data->cmd_mutex);

	for (i = 0; i < param->lines_num; i++) {
		draw_line(surface_data, lines[i]);
	}

	mutex_unlock(&surface_data->doom_data->cmd_mutex);

	return param->lines_num;
}

long fill_rects(struct file *filp, unsigned long arg)
{
	struct surface_data *surface_data;
	struct doomdev_surf_ioctl_fill_rects *param;
	struct doomdev_fill_rect *rects;
	int i;

	surface_data = filp->private_data;
	param = (struct doomdev_surf_ioctl_fill_rects *) arg;
	rects = (struct doomdev_fill_rect *) param->rects_ptr;

	mutex_lock(&surface_data->doom_data->cmd_mutex);

	for (i = 0; i < param->rects_num; i++) {
		fill_rect(surface_data, rects[i]);
	}

	mutex_unlock(&surface_data->doom_data->cmd_mutex);

	return param->rects_num;
}

struct file_operations surface_fops;

long copy_rects(struct file *filp, unsigned long arg)
{
	struct surface_data *dst_data;
	struct surface_data *src_data;
	struct doomdev_surf_ioctl_copy_rects *param;
	struct doomdev_copy_rect *rects;
	struct fd src_fds;
	int i;
	int err;

	dst_data = filp->private_data;
	param = (struct doomdev_surf_ioctl_copy_rects *) arg;
	rects = (struct doomdev_copy_rect *) param->rects_ptr;

	src_fds = fdget(param->surf_src_fd);
	if (src_fds.file->f_op != &surface_fops) {
		err = -EINVAL;
		goto error_fdget;
	}

	src_data = src_fds.file->private_data;
	if (dst_data->doom_data != src_data->doom_data) {
		err = -EINVAL;
		goto error_fdget;
	}

	mutex_lock(&dst_data->doom_data->cmd_mutex);

	for (i = 0; i < param->rects_num; i++) {
		copy_rect(dst_data, src_data, rects[i]);
	}

	err = param->rects_num;

	mutex_unlock(&dst_data->doom_data->cmd_mutex);

error_fdget:
	fdput(src_fds);

	return err;
}

long draw_columns(struct file *filp, unsigned long arg)
{
	struct doomdev_surf_ioctl_draw_columns *param;
	struct surface_data *surface_data;
	struct texture_data *texture_data;
	struct colors_data *colors_data;
	struct colors_data *trans_data;
	struct doomdev_column *columns;
	struct fd texture_fds;
	struct fd colors_fds;
	struct fd trans_fds;
	uint8_t flags;
	bool got_colors = false;
	bool got_trans = false;
	bool got_texture = false;
	int i;
	int err;

	surface_data = filp->private_data;

	param = (struct doomdev_surf_ioctl_draw_columns *) arg;

	flags = param->draw_flags;

	if (flags & DOOMDEV_DRAW_FLAGS_FUZZ ||
			flags & DOOMDEV_DRAW_FLAGS_COLORMAP) {
		if (flags & DOOMDEV_DRAW_FLAGS_FUZZ) {
			flags = DOOMDEV_DRAW_FLAGS_FUZZ;
		}

		colors_fds = fdget(param->colormaps_fd);
		got_colors = true;
		if (colors_fds.file->f_op != &colors_fops) {
			err = -EINVAL;
			goto error_fdget;
		}

		colors_data = colors_fds.file->private_data;
		if (surface_data->doom_data != colors_data->doom_data) {
			err = -EINVAL;
			goto error_fdget;
		}
	}

	if (flags & DOOMDEV_DRAW_FLAGS_TRANSLATE) {
		trans_fds = fdget(param->translations_fd);
		got_trans = true;
		if (trans_fds.file->f_op != &colors_fops) {
			err = -EINVAL;
			goto error_fdget;
		}

		trans_data = trans_fds.file->private_data;
		if (surface_data->doom_data != trans_data->doom_data) {
			err = -EINVAL;
			goto error_fdget;
		}
	}

	texture_fds = fdget(param->texture_fd);
	got_texture = true;
	if (texture_fds.file->f_op != &texture_fops) {
		err = -EINVAL;
		goto error_fdget;
	}

	texture_data = texture_fds.file->private_data;
	if (surface_data->doom_data != texture_data->doom_data) {
		err = -EINVAL;
		goto error_fdget;
	}

	columns = (struct doomdev_column *) param->columns_ptr;

	mutex_lock(&surface_data->doom_data->cmd_mutex);

	for (i = 0; i < param->columns_num; i++) {
		draw_column(surface_data, texture_data, columns[i], colors_data,
				trans_data, flags, param->translation_idx);
	}

	err = param->columns_num;

	mutex_unlock(&surface_data->doom_data->cmd_mutex);

error_fdget:

	if (got_texture) {
		fdput(texture_fds);
	}

	if (got_colors) {
		fdput(colors_fds);
	}

	if (got_trans) {
		fdput(trans_fds);
	}

	return param->columns_num;
}

long draw_spans(struct file *filp, unsigned long arg)
{
	struct doomdev_surf_ioctl_draw_spans *param;
	struct surface_data *surface_data;
	struct flat_data *flat_data;
	struct doomdev_span *spans;
	struct fd flat_fds;
	int i;
	int err;

	surface_data = filp->private_data;

	param = (struct doomdev_surf_ioctl_draw_spans *) arg;

	flat_fds = fdget(param->flat_fd);
	if (flat_fds.file->f_op != &flat_fops) {
		err = -EINVAL;
		goto error_fdget;
	}

	flat_data = flat_fds.file->private_data;
	if (surface_data->doom_data != flat_data->doom_data) {
		err = -EINVAL;
		goto error_fdget;
	}

	spans = (struct doomdev_span *) param->spans_ptr;

	mutex_lock(&surface_data->doom_data->cmd_mutex);

	for (i = 0; i < param->spans_num; i++) {
		draw_span(surface_data, flat_data, spans[i]);
	}

	err = param->spans_num;

	mutex_unlock(&surface_data->doom_data->cmd_mutex);

error_fdget:
	fdput(flat_fds);

	return err;
}

long do_draw_background(struct file *filp, unsigned long arg)
{
	struct doomdev_surf_ioctl_draw_background *param;
	struct surface_data *surface_data;
	struct flat_data *flat_data;
	struct fd flat_fds;
	int err = 0;

	surface_data = filp->private_data;

	param = (struct doomdev_surf_ioctl_draw_background *) arg;

	flat_fds = fdget(param->flat_fd);
	if (flat_fds.file->f_op != &flat_fops) {
		err = -EINVAL;
		goto error_fdget;
	}

	flat_data = flat_fds.file->private_data;
	if (surface_data->doom_data != flat_data->doom_data) {
		err = -EINVAL;
		goto error_fdget;
	}

	mutex_lock(&surface_data->doom_data->cmd_mutex);

	draw_background(surface_data, flat_data);

	mutex_unlock(&surface_data->doom_data->cmd_mutex);

error_fdget:
	fdput(flat_fds);

	return err;
}

long surface_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	switch (cmd) {
	case DOOMDEV_SURF_IOCTL_DRAW_LINES:
		return draw_lines(filp, arg);
	case DOOMDEV_SURF_IOCTL_FILL_RECTS:
		return fill_rects(filp, arg);
	case DOOMDEV_SURF_IOCTL_COPY_RECTS:
		return copy_rects(filp, arg);
	case DOOMDEV_SURF_IOCTL_DRAW_COLUMNS:
		return draw_columns(filp, arg);
	case DOOMDEV_SURF_IOCTL_DRAW_SPANS:
		return draw_spans(filp, arg);
	case DOOMDEV_SURF_IOCTL_DRAW_BACKGROUND:
		return do_draw_background(filp, arg);
	default:
		return -ENOTTY;
	}
}

ssize_t surface_read(struct file *filp, char __user *buf, size_t count,
		loff_t *offset)
{
	struct surface_data *surface_data;
	unsigned long not_written;

	surface_data = (struct surface_data *) filp->private_data;
	if (*offset >= surface_data->surface_size || *offset < 0) {
		return 0;
	}

	if (*offset + count > surface_data->surface_size) {
		count = surface_data->surface_size - *offset;
	}

	mutex_lock(&surface_data->doom_data->ping_mutex);
	ping_sync(surface_data->doom_data);
	down(&surface_data->doom_data->pong_sem);

	not_written = copy_to_user(buf, surface_data->surface_cpu + (*offset),
			count);

	*offset += count - not_written;

	mutex_unlock(&surface_data->doom_data->ping_mutex);

	return count - not_written;
}

loff_t surface_llseek(struct file *filp, loff_t offset, int origin)
{
	struct surface_data *surface_data;
	loff_t new_pos;

	surface_data = filp->private_data;

	switch (origin) {
	case SEEK_SET:
		new_pos = offset;
		break;
	case SEEK_CUR:
		new_pos = filp->f_pos + offset;
		break;
	case SEEK_END:
		new_pos = surface_data->surface_size + offset;
		break;
	default:
		return -EINVAL;
	}

	if (new_pos < 0) {
		return -EINVAL;
	}

	filp->f_pos = new_pos;

	return new_pos;
}

void free_surface_buffer(struct surface_data *surface_data);

int surface_release(struct inode *inode, struct file *filp)
{
	struct surface_data *surface_data;

	surface_data = filp->private_data;

	mutex_lock(&surface_data->doom_data->ping_mutex);
	ping_sync(surface_data->doom_data);
	down(&surface_data->doom_data->pong_sem);
	mutex_unlock(&surface_data->doom_data->ping_mutex);

	free_surface_buffer(surface_data);

	kfree(surface_data);

	return 0;
}

struct file_operations surface_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = surface_ioctl,
	.compat_ioctl = surface_ioctl,
	.llseek = surface_llseek,
	.read = surface_read,
	.release = surface_release

};

int verify_params(struct doomdev_ioctl_create_surface *params)
{
	if (params->width < 64) {
		return -EINVAL;
	}

	if (params->width > 2048) {
		return -EOVERFLOW;
	}

	if (params->width % 64 != 0) {
		return -EINVAL;
	}

	if (params->height < 1) {
		return -EINVAL;
	}

	if (params->height > 2048) {
		return -EOVERFLOW;
	}

	return 0;
}

int alloc_surface_buffer(struct doomdev_ioctl_create_surface *params,
		struct surface_data *surface_data)
{
	int bytes_needed;
	int pages_needed;
	int i;
	int err;

	bytes_needed = params->width * params->height;
	surface_data->surface_size = bytes_needed;
	surface_data->width = params->width;
	surface_data->height = params->height;
	pages_needed = (bytes_needed / HARDDOOM_PAGE_SIZE);
	if (bytes_needed % HARDDOOM_PAGE_SIZE != 0) {
		pages_needed += 1;
	}

	if (pages_needed > 1024) {
		return -ENOMEM;
	}

	surface_data->pages = pages_needed;

	surface_data->surface_cpu =
		dma_alloc_coherent(surface_data->doom_data->pci_device,
			bytes_needed, &surface_data->surface_dev, GFP_KERNEL);

	ORFAIL_NULL(surface_data->surface_cpu, -ENOMEM, error_surface);

	surface_data->page_table_cpu =
		dma_alloc_coherent(surface_data->doom_data->pci_device,
			pages_needed * 4, &surface_data->page_table_dev, GFP_KERNEL);

	ORFAIL_NULL(surface_data->page_table_cpu, -ENOMEM, error_pt);

	for (i = 0; i < pages_needed; i++) {
		surface_data->page_table_cpu[i] =
			(HARDDOOM_PTE_PHYS_MASK &
			 (surface_data->surface_dev + HARDDOOM_PAGE_SIZE * i)) |
			HARDDOOM_PTE_VALID;
	}

	return 0;

error_pt:
	dma_free_coherent(surface_data->doom_data->pci_device,
			surface_data->surface_size,
			surface_data->surface_cpu, surface_data->surface_dev);
error_surface:
	return err;
}

void free_surface_buffer(struct surface_data *surface_data)
{
	dma_free_coherent(surface_data->doom_data->pci_device,
			surface_data->surface_size,
			surface_data->surface_cpu, surface_data->surface_dev);

	dma_free_coherent(surface_data->doom_data->pci_device,
			surface_data->pages * 4,
			surface_data->page_table_cpu, surface_data->page_table_dev);
}

int new_surface(struct file *filp, struct doomdev_ioctl_create_surface *params)
{
	int err;
	int fd;
	struct fd fd_s;
	struct surface_data *surface_data;
	struct doom_data *doom_data;

	err = verify_params(params);
	if (err < 0) {
		return err;
	}

	surface_data = kmalloc(sizeof(*surface_data), GFP_KERNEL);
	ORFAIL_NULL(surface_data, -ENOMEM, error_data);
	doom_data = container_of(filp->f_inode->i_cdev, struct doom_data, cdev);
	surface_data->doom_data = doom_data;

	ORFAIL(alloc_surface_buffer(params, surface_data), error_buffer);

	fd = anon_inode_getfd("doom_surface", &surface_fops, surface_data, 0);
	fd_s = fdget(fd);
	if (fd_s.file->f_op != &surface_fops) {
		err = -ENOENT;
		goto error_fdget;
	}

	fd_s.file->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;

	fdput(fd_s);

	return fd;

error_fdget:
	free_surface_buffer(surface_data);
error_buffer:
	kfree(surface_data);
error_data:
	return err;
}