/*
 * Copyright (C) 2007 Intel Corporation
 * Copyright (C) 2016 Florent Revest <florent.revest@free-electrons.com>
 * Copyright (C) 2018 Paul Kocialkowski <paul.kocialkowski@bootlin.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "buffer.h"
#include "config.h"
#include "context.h"
#include "image.h"
#include "picture.h"
#include "subpicture.h"
#include "surface.h"

#include "autoconfig.h"

#include <va/va_backend.h>

#include "request.h"
#include "utils.h"
#include "v4l2.h"

#include <assert.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>

#include <fcntl.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>

#include <sys/ioctl.h>

#include <linux/media.h>
#include <linux/videodev2.h>

/*
 * fresnel-fourier iter4 Phase 6 commit Z: device-path auto-detect via media controller topology
 *
 * Pre-iter4 the backend hardcoded /dev/video0 + /dev/media0 as defaults
 * when no env override was set. On Linux 7.0 the udev/probe order
 * changed and rockchip-rga (an RGB color converter, no codec support)
 * now claims /dev/video0 — the legacy default returns an empty profile
 * list.
 *
 * Discovery is driven by the media controller graph (NOT by walking
 * /dev/video* in enumeration order — that approach can mispair the
 * video and media nodes when one driver registers multiple media
 * devices, and depends on probe-order luck):
 *
 *   1. Walk /dev/media0..N. For each, MEDIA_IOC_DEVICE_INFO names the
 *      driver. Match against the known-decoder list.
 *   2. MEDIA_IOC_G_TOPOLOGY returns the entity/interface graph. The
 *      MEDIA_INTF_T_V4L_VIDEO interface entries carry major:minor of
 *      the V4L2 video node owned by THIS media controller — guaranteed
 *      paired by the kernel.
 *   3. Resolve major:minor to /dev/videoN via /sys/dev/char/<M>:<N>
 *      (the kernel's char-device sysfs symlink whose basename is the
 *      device node name).
 *
 * Phase 5 C4: walk picks rkvdec on RK3399 (rkvdec's media controller
 * enumerates before hantro's). MPEG-2/VP8 (hantro) still need explicit
 * LIBVA_V4L2_REQUEST_VIDEO_PATH override; full multi-decoder dispatch
 * is iter4-B1 backlog.
 *
 * Escape hatch: LIBVA_V4L2_REQUEST_NO_AUTODETECT=1 reverts to legacy
 * hardcoded /dev/video0 + /dev/media0 for callers that relied on it.
 */
static const char * const known_decoder_drivers[] = {
	"rkvdec",
	"hantro-vpu",
	"cedrus",
	"sun4i_csi",
	NULL
};

static int resolve_dev_node(uint32_t major, uint32_t minor, char *out, size_t out_sz)
{
	char sysfs_path[64], target[256];
	ssize_t n;
	const char *base;

	snprintf(sysfs_path, sizeof sysfs_path, "/sys/dev/char/%u:%u", major, minor);
	n = readlink(sysfs_path, target, sizeof target - 1);
	if (n < 0)
		return -1;
	target[n] = '\0';
	base = strrchr(target, '/');
	base = base ? base + 1 : target;
	snprintf(out, out_sz, "/dev/%s", base);
	return 0;
}

static int find_video_node_via_topology(int media_fd, char *video_out, size_t video_out_sz)
{
	struct media_v2_topology topo;
	struct media_v2_interface *interfaces = NULL;
	int ret = -1;
	unsigned int i;

	memset(&topo, 0, sizeof topo);
	if (ioctl(media_fd, MEDIA_IOC_G_TOPOLOGY, &topo) < 0)
		return -1;
	if (topo.num_interfaces == 0)
		return -1;

	interfaces = calloc(topo.num_interfaces, sizeof *interfaces);
	if (!interfaces)
		return -1;

	memset(&topo, 0, sizeof topo);
	if (ioctl(media_fd, MEDIA_IOC_G_TOPOLOGY, &topo) < 0)
		goto out;
	topo.ptr_interfaces = (uintptr_t)interfaces;
	if (ioctl(media_fd, MEDIA_IOC_G_TOPOLOGY, &topo) < 0)
		goto out;

	for (i = 0; i < topo.num_interfaces; i++) {
		if (interfaces[i].intf_type != MEDIA_INTF_T_V4L_VIDEO)
			continue;
		if (resolve_dev_node(interfaces[i].devnode.major,
				     interfaces[i].devnode.minor,
				     video_out, video_out_sz) == 0) {
			ret = 0;
			break;
		}
	}
out:
	free(interfaces);
	return ret;
}

static int find_codec_device(char *video_out, size_t video_out_sz,
			     char *media_out, size_t media_out_sz)
{
	struct media_device_info info;
	char path[32];
	const char * const *kd;
	int fd, i;

	for (i = 0; i < 16; i++) {
		snprintf(path, sizeof path, "/dev/media%d", i);
		fd = open(path, O_RDWR | O_NONBLOCK);
		if (fd < 0)
			continue;
		memset(&info, 0, sizeof info);
		if (ioctl(fd, MEDIA_IOC_DEVICE_INFO, &info) == 0) {
			for (kd = known_decoder_drivers; *kd; kd++) {
				if (strcmp(info.driver, *kd) != 0)
					continue;
				if (find_video_node_via_topology(fd, video_out,
								 video_out_sz) == 0) {
					snprintf(media_out, media_out_sz, "%s", path);
					close(fd);
					return 0;
				}
				break;
			}
		}
		close(fd);
	}
	return -1;
}

/* Set default visibility for the init function only. */
VAStatus __attribute__((visibility("default")))
VA_DRIVER_INIT_FUNC(VADriverContextP context);

VAStatus VA_DRIVER_INIT_FUNC(VADriverContextP context)
{
	struct request_data *driver_data;
	struct VADriverVTable *vtable = context->vtable;
	VAStatus status;
	unsigned int capabilities;
	unsigned int capabilities_required;
	int video_fd = -1;
	int media_fd = -1;
	char *video_path;
	char *media_path;
	int rc;

	context->version_major = VA_MAJOR_VERSION;
	context->version_minor = VA_MINOR_VERSION;
	context->max_profiles = V4L2_REQUEST_MAX_PROFILES;
	context->max_entrypoints = V4L2_REQUEST_MAX_ENTRYPOINTS;
	context->max_attributes = V4L2_REQUEST_MAX_CONFIG_ATTRIBUTES;
	context->max_image_formats = V4L2_REQUEST_MAX_IMAGE_FORMATS;
	context->max_subpic_formats = V4L2_REQUEST_MAX_SUBPIC_FORMATS;
	context->max_display_attributes = V4L2_REQUEST_MAX_DISPLAY_ATTRIBUTES;
	context->str_vendor = V4L2_REQUEST_STR_VENDOR;

	vtable->vaTerminate = RequestTerminate;
	vtable->vaQueryConfigEntrypoints = RequestQueryConfigEntrypoints;
	vtable->vaQueryConfigProfiles = RequestQueryConfigProfiles;
	vtable->vaQueryConfigEntrypoints = RequestQueryConfigEntrypoints;
	vtable->vaQueryConfigAttributes = RequestQueryConfigAttributes;
	vtable->vaCreateConfig = RequestCreateConfig;
	vtable->vaDestroyConfig = RequestDestroyConfig;
	vtable->vaGetConfigAttributes = RequestGetConfigAttributes;
	vtable->vaCreateSurfaces = RequestCreateSurfaces;
	vtable->vaCreateSurfaces2 = RequestCreateSurfaces2;
	vtable->vaDestroySurfaces = RequestDestroySurfaces;
	vtable->vaExportSurfaceHandle = RequestExportSurfaceHandle;
	vtable->vaCreateContext = RequestCreateContext;
	vtable->vaDestroyContext = RequestDestroyContext;
	vtable->vaCreateBuffer = RequestCreateBuffer;
	vtable->vaBufferSetNumElements = RequestBufferSetNumElements;
	vtable->vaMapBuffer = RequestMapBuffer;
	vtable->vaUnmapBuffer = RequestUnmapBuffer;
	vtable->vaDestroyBuffer = RequestDestroyBuffer;
	vtable->vaBufferInfo = RequestBufferInfo;
	vtable->vaAcquireBufferHandle = RequestAcquireBufferHandle;
	vtable->vaReleaseBufferHandle = RequestReleaseBufferHandle;
	vtable->vaBeginPicture = RequestBeginPicture;
	vtable->vaRenderPicture = RequestRenderPicture;
	vtable->vaEndPicture = RequestEndPicture;
	vtable->vaSyncSurface = RequestSyncSurface;
	vtable->vaQuerySurfaceAttributes = RequestQuerySurfaceAttributes;
	vtable->vaQuerySurfaceStatus = RequestQuerySurfaceStatus;
	vtable->vaPutSurface = RequestPutSurface;
	vtable->vaQueryImageFormats = RequestQueryImageFormats;
	vtable->vaCreateImage = RequestCreateImage;
	vtable->vaDeriveImage = RequestDeriveImage;
	vtable->vaDestroyImage = RequestDestroyImage;
	vtable->vaSetImagePalette = RequestSetImagePalette;
	vtable->vaGetImage = RequestGetImage;
	vtable->vaPutImage = RequestPutImage;
	vtable->vaQuerySubpictureFormats = RequestQuerySubpictureFormats;
	vtable->vaCreateSubpicture = RequestCreateSubpicture;
	vtable->vaDestroySubpicture = RequestDestroySubpicture;
	vtable->vaSetSubpictureImage = RequestSetSubpictureImage;
	vtable->vaSetSubpictureChromakey = RequestSetSubpictureChromakey;
	vtable->vaSetSubpictureGlobalAlpha = RequestSetSubpictureGlobalAlpha;
	vtable->vaAssociateSubpicture = RequestAssociateSubpicture;
	vtable->vaDeassociateSubpicture = RequestDeassociateSubpicture;
	vtable->vaQueryDisplayAttributes = RequestQueryDisplayAttributes;
	vtable->vaGetDisplayAttributes = RequestGetDisplayAttributes;
	vtable->vaSetDisplayAttributes = RequestSetDisplayAttributes;
	vtable->vaLockSurface = RequestLockSurface;
	vtable->vaUnlockSurface = RequestUnlockSurface;

	driver_data = malloc(sizeof(*driver_data));
	memset(driver_data, 0, sizeof(*driver_data));

	context->pDriverData = driver_data;

	object_heap_init(&driver_data->config_heap,
			 sizeof(struct object_config), CONFIG_ID_OFFSET);
	object_heap_init(&driver_data->context_heap,
			 sizeof(struct object_context), CONTEXT_ID_OFFSET);
	object_heap_init(&driver_data->surface_heap,
			 sizeof(struct object_surface), SURFACE_ID_OFFSET);
	object_heap_init(&driver_data->buffer_heap,
			 sizeof(struct object_buffer), BUFFER_ID_OFFSET);
	object_heap_init(&driver_data->image_heap, sizeof(struct object_image),
			 IMAGE_ID_OFFSET);

	static char auto_video[32], auto_media[32];
	bool auto_media_set = false;

	video_path = getenv("LIBVA_V4L2_REQUEST_VIDEO_PATH");
	if (video_path == NULL) {
		if (getenv("LIBVA_V4L2_REQUEST_NO_AUTODETECT")) {
			video_path = "/dev/video0";
		} else if (find_codec_device(auto_video, sizeof auto_video,
					     auto_media, sizeof auto_media) == 0) {
			video_path = auto_video;
			auto_media_set = true;
			request_log("auto-selected codec device: %s + %s\n",
				    auto_video, auto_media);
		} else {
			video_path = "/dev/video0";
		}
	}

	video_fd = open(video_path, O_RDWR | O_NONBLOCK);
	if (video_fd < 0)
		return VA_STATUS_ERROR_OPERATION_FAILED;

	rc = v4l2_query_capabilities(video_fd, &capabilities);
	if (rc < 0) {
		status = VA_STATUS_ERROR_OPERATION_FAILED;
		goto error;
	}

	capabilities_required = V4L2_CAP_STREAMING;

	if ((capabilities & capabilities_required) != capabilities_required) {
		request_log("Missing required driver capabilities\n");
		status = VA_STATUS_ERROR_OPERATION_FAILED;
		goto error;
	}

	media_path = getenv("LIBVA_V4L2_REQUEST_MEDIA_PATH");
	if (media_path == NULL) {
		if (auto_media_set)
			media_path = auto_media;
		else
			media_path = "/dev/media0";
	}

	media_fd = open(media_path, O_RDWR | O_NONBLOCK);
	if (media_fd < 0)
		return VA_STATUS_ERROR_OPERATION_FAILED;

	driver_data->video_fd = video_fd;
	driver_data->media_fd = media_fd;

	status = VA_STATUS_SUCCESS;
	goto complete;

error:
	status = VA_STATUS_ERROR_OPERATION_FAILED;

	if (video_fd >= 0)
		close(video_fd);

	if (media_fd >= 0)
		close(media_fd);

complete:
	return status;
}

VAStatus RequestTerminate(VADriverContextP context)
{
	struct request_data *driver_data = context->pDriverData;
	struct object_buffer *buffer_object;
	struct object_image *image_object;
	struct object_surface *surface_object;
	struct object_context *context_object;
	struct object_config *config_object;
	int iterator;

	/*
	 * Tear down the OUTPUT buffer pool before closing video_fd so
	 * the munmap calls in request_pool_destroy() can still touch the
	 * mmap regions (which are tied to that fd's lifetime).
	 */
	request_pool_destroy(&driver_data->output_pool);

	close(driver_data->video_fd);
	close(driver_data->media_fd);

	/* Cleanup leftover buffers. */

	image_object = (struct object_image *)
		object_heap_first(&driver_data->image_heap, &iterator);
	while (image_object != NULL) {
		RequestDestroyImage(context, (VAImageID)image_object->base.id);
		image_object = (struct object_image *)
			object_heap_next(&driver_data->image_heap, &iterator);
	}

	object_heap_destroy(&driver_data->image_heap);

	buffer_object = (struct object_buffer *)
		object_heap_first(&driver_data->buffer_heap, &iterator);
	while (buffer_object != NULL) {
		RequestDestroyBuffer(context,
				     (VABufferID)buffer_object->base.id);
		buffer_object = (struct object_buffer *)
			object_heap_next(&driver_data->buffer_heap, &iterator);
	}

	object_heap_destroy(&driver_data->buffer_heap);

	surface_object = (struct object_surface *)
		object_heap_first(&driver_data->surface_heap, &iterator);
	while (surface_object != NULL) {
		RequestDestroySurfaces(context,
				      (VASurfaceID *)&surface_object->base.id, 1);
		surface_object = (struct object_surface *)
			object_heap_next(&driver_data->surface_heap, &iterator);
	}

	object_heap_destroy(&driver_data->surface_heap);

	context_object = (struct object_context *)
		object_heap_first(&driver_data->context_heap, &iterator);
	while (context_object != NULL) {
		RequestDestroyContext(context,
				      (VAContextID)context_object->base.id);
		context_object = (struct object_context *)
			object_heap_next(&driver_data->context_heap, &iterator);
	}

	object_heap_destroy(&driver_data->context_heap);

	config_object = (struct object_config *)
		object_heap_first(&driver_data->config_heap, &iterator);
	while (config_object != NULL) {
		RequestDestroyConfig(context,
				     (VAConfigID)config_object->base.id);
		config_object = (struct object_config *)
			object_heap_next(&driver_data->config_heap, &iterator);
	}

	object_heap_destroy(&driver_data->config_heap);

	free(context->pDriverData);
	context->pDriverData = NULL;

	return VA_STATUS_SUCCESS;
}