// Copyright (c) 2020- PPSSPP Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.

#include "Camera.h"

#if PPSSPP_PLATFORM(LINUX) && !PPSSPP_PLATFORM(ANDROID)

std::vector<std::string> __v4l_getDeviceList() {
	std::vector<std::string> deviceList;
	for (int i = 0; i < 64; i++) {
		char path[256];
		snprintf(path, sizeof(path), "/dev/video%d", i);
		if (access(path, F_OK) < 0) {
			break;
		}
		int fd = -1;
		if((fd = open(path, O_RDONLY)) < 0) {
			ERROR_LOG(HLE, "Cannot open '%s'; errno=%d(%s)", path, errno, strerror(errno));
			continue;
		}
		struct v4l2_capability video_cap;
		if(ioctl(fd, VIDIOC_QUERYCAP, &video_cap) < 0) {
			ERROR_LOG(HLE, "VIDIOC_QUERYCAP");
			goto cont;
		} else {
			char device[256];
			snprintf(device, sizeof(device), "%d:%s", i, video_cap.card);
			deviceList.push_back(device);
		}
cont:
		close(fd);
		fd = -1;
	}
	return deviceList;
}

void convert_frame(unsigned char *inData, AVPixelFormat inFormat, unsigned char **outData, int *outLen) {
	// resize
	uint8_t *src[4] = {0};
	uint8_t *dst[4] = {0};
	int srcStride[4], dstStride[4];

	unsigned char *rgbData = (unsigned char*)malloc(v4l_ideal_width * v4l_ideal_height * 3);

	av_image_fill_linesizes(srcStride, inFormat,         v4l_hw_width);
	av_image_fill_linesizes(dstStride, AV_PIX_FMT_RGB24, v4l_ideal_width);

	av_image_fill_pointers(src, inFormat,         v4l_hw_height,    inData,  srcStride);
	av_image_fill_pointers(dst, AV_PIX_FMT_RGB24, v4l_ideal_height, rgbData, dstStride);

	sws_scale(sws_context,
		src, srcStride, 0, v4l_height_fixed_aspect,
		dst, dstStride);

	// compress jpeg
	*outLen = v4l_ideal_width * v4l_ideal_height * 3;
	*outData = (unsigned char*)malloc(*outLen);

	jpge::params params;
	params.m_quality = 60;
	params.m_subsampling = jpge::H2V2;
	params.m_two_pass_flag = false;
	jpge::compress_image_to_jpeg_file_in_memory(
		*outData, *outLen, v4l_ideal_width, v4l_ideal_height, 3, rgbData, params);
	free(rgbData);
}

void *v4l_loop(void *data) {
	setCurrentThreadName("v4l_loop");
	while (v4l_fd >= 0) {
		struct v4l2_buffer buf;
		memset(&buf, 0, sizeof(buf));
		buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
		buf.memory = V4L2_MEMORY_MMAP;

		if (ioctl(v4l_fd, VIDIOC_DQBUF, &buf) == -1) {
			ERROR_LOG(HLE, "VIDIOC_DQBUF; errno=%d(%s)", errno, strerror(errno));
			switch (errno) {
				case EAGAIN:
					continue;
				default:
					return NULL;
			}
		}

		unsigned char *jpegData;
		int jpegLen;

		if (v4l_format == V4L2_PIX_FMT_YUYV) {
			convert_frame((unsigned char*)v4l_buffer, AV_PIX_FMT_YUYV422, &jpegData, &jpegLen);
		} else if (v4l_format == V4L2_PIX_FMT_MJPEG) {
			// decompress jpeg
			int width, height, req_comps;
			unsigned char *rgbData = jpgd::decompress_jpeg_image_from_memory(
				(unsigned char*)v4l_buffer, buf.bytesused, &width, &height, &req_comps, 3);

			convert_frame(rgbData, AV_PIX_FMT_RGB24, &jpegData, &jpegLen);
			free(rgbData);
		}

		Camera::pushCameraImage(jpegLen, jpegData);
		free(jpegData);

		buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
		buf.memory = V4L2_MEMORY_MMAP;
		if (ioctl(v4l_fd, VIDIOC_QBUF, &buf) == -1) {
			ERROR_LOG(HLE, "VIDIOC_QBUF");
			return NULL;
		}
	}
}

int __v4l_startCapture(int ideal_width, int ideal_height) {
	if (v4l_fd >= 0) {
		__v4l_stopCapture();
	}
	v4l_ideal_width  = ideal_width;
	v4l_ideal_height = ideal_height;

	int dev_index = 0;
	char dev_name[64];
	sscanf(g_Config.sCameraDevice.c_str(), "%d:", &dev_index);
	snprintf(dev_name, sizeof(dev_name), "/dev/video%d", dev_index);

	if ((v4l_fd = open(dev_name, O_RDWR)) == -1) {
		ERROR_LOG(HLE, "Cannot open '%s'; errno=%d(%s)", dev_name, errno, strerror(errno));
		return -1;
	}

	struct v4l2_capability cap;
	memset(&cap, 0, sizeof(cap));
	if (ioctl(v4l_fd, VIDIOC_QUERYCAP, &cap) == -1) {
		ERROR_LOG(HLE, "VIDIOC_QUERYCAP");
		return -1;
	}
	if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
		ERROR_LOG(HLE, "V4L2_CAP_VIDEO_CAPTURE");
		return -1;
	}
	if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
		ERROR_LOG(HLE, "V4L2_CAP_STREAMING");
		return -1;
	}

	struct v4l2_format fmt;
	memset(&fmt, 0, sizeof(fmt));
	fmt.type                = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	fmt.fmt.pix.pixelformat = 0;

	// select a pixel format
	struct v4l2_fmtdesc desc;
	memset(&desc, 0, sizeof(desc));
	desc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	while (ioctl(v4l_fd, VIDIOC_ENUM_FMT, &desc) == 0) {
		desc.index++;
		INFO_LOG(HLE, "V4L2: pixel format supported: %s", desc.description);
		if (fmt.fmt.pix.pixelformat != 0) {
			continue;
		} else if (desc.pixelformat == V4L2_PIX_FMT_YUYV
			    || desc.pixelformat == V4L2_PIX_FMT_MJPEG) {
			INFO_LOG(HLE, "V4L2: %s selected", desc.description);
			fmt.fmt.pix.pixelformat = desc.pixelformat;
			v4l_format              = desc.pixelformat;
		}
	}
	if (fmt.fmt.pix.pixelformat == 0) {
		ERROR_LOG(HLE, "V4L2: No supported format found");
		return -1;
	}

	// select a frame size
	fmt.fmt.pix.width  = 0;
	fmt.fmt.pix.height = 0;
	struct v4l2_frmsizeenum frmsize;
	memset(&frmsize, 0, sizeof(frmsize));
	frmsize.pixel_format = fmt.fmt.pix.pixelformat;
	while (ioctl(v4l_fd, VIDIOC_ENUM_FRAMESIZES, &frmsize) == 0) {
		frmsize.index++;
		if (frmsize.type == V4L2_FRMSIZE_TYPE_DISCRETE) {
			INFO_LOG(HLE, "V4L2: frame size supported: %dx%d", frmsize.discrete.width, frmsize.discrete.height);
			if (fmt.fmt.pix.width != 0 && fmt.fmt.pix.height != 0) {
				continue;
			} else if (frmsize.discrete.width >= ideal_width && frmsize.discrete.height >= ideal_height) {
				fmt.fmt.pix.width  = frmsize.discrete.width;
				fmt.fmt.pix.height = frmsize.discrete.height;
			}
		}
	}

	if (fmt.fmt.pix.width == 0 && fmt.fmt.pix.height == 0) {
		fmt.fmt.pix.width  = ideal_width;
		fmt.fmt.pix.height = ideal_height;
	}
	INFO_LOG(HLE, "V4L2: asking for   %dx%d", fmt.fmt.pix.width, fmt.fmt.pix.height);
	if (ioctl(v4l_fd, VIDIOC_S_FMT, &fmt) == -1) {
		ERROR_LOG(HLE, "VIDIOC_S_FMT");
		return -1;
	}
	v4l_hw_width  = fmt.fmt.pix.width;
	v4l_hw_height = fmt.fmt.pix.height;
	INFO_LOG(HLE, "V4L2: will receive %dx%d", v4l_hw_width, v4l_hw_height);
	v4l_height_fixed_aspect = v4l_hw_width * ideal_height / ideal_width;
	INFO_LOG(HLE, "V4L2: will use     %dx%d", v4l_hw_width, v4l_height_fixed_aspect);

	// create a converter context
	if (v4l_format == V4L2_PIX_FMT_YUYV) {
		sws_context = sws_getContext(
			v4l_hw_width, v4l_height_fixed_aspect, AV_PIX_FMT_YUYV422,
			ideal_width, ideal_height, AV_PIX_FMT_RGB24,
			SWS_BICUBIC, NULL, NULL, NULL);
	} else if (v4l_format == V4L2_PIX_FMT_MJPEG) {
		sws_context = sws_getContext(
			v4l_hw_width, v4l_height_fixed_aspect, AV_PIX_FMT_RGB24,
			ideal_width, ideal_height, AV_PIX_FMT_RGB24,
			SWS_BICUBIC, NULL, NULL, NULL);
	}


	struct v4l2_requestbuffers req;
	memset(&req, 0, sizeof(req));
	req.count  = 1;
	req.type   = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	req.memory = V4L2_MEMORY_MMAP;
	if (ioctl(v4l_fd, VIDIOC_REQBUFS, &req) == -1) {
		ERROR_LOG(HLE, "VIDIOC_REQBUFS");
		return -1;
	}

	struct v4l2_buffer buf;
	memset(&buf, 0, sizeof(buf));
	buf.type   = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	buf.memory = V4L2_MEMORY_MMAP;
	buf.index  = 0;
	if (ioctl(v4l_fd, VIDIOC_QUERYBUF, &buf) == -1) {
		ERROR_LOG(HLE, "VIDIOC_QUERYBUF");
		return -1;
	}

	v4l_length = buf.length;
	v4l_buffer = mmap(NULL,
			v4l_length,
			PROT_READ | PROT_WRITE,
			MAP_SHARED,
			v4l_fd, buf.m.offset);
	if (v4l_buffer == MAP_FAILED) {
		ERROR_LOG(HLE, "MAP_FAILED");
		return -1;
	}

	memset(&buf, 0, sizeof(buf));
	enum v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	buf.type   = type;
	buf.memory = V4L2_MEMORY_MMAP;
	buf.index  = 0;
	if (ioctl(v4l_fd, VIDIOC_QBUF, &buf) == -1) {
		ERROR_LOG(HLE, "VIDIOC_QBUF");
		return -1;
	}

	if (ioctl(v4l_fd, VIDIOC_STREAMON, &type) == -1) {
		ERROR_LOG(HLE, "VIDIOC_STREAMON");
		return -1;
	}

	pthread_create(&v4l_thread, NULL, v4l_loop, NULL);

	return 0;
}

int __v4l_stopCapture() {
	enum v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

	if (v4l_fd < 0) {
		goto exit;
	}

	if (ioctl(v4l_fd, VIDIOC_STREAMOFF, &type) == -1) {
		ERROR_LOG(HLE, "VIDIOC_STREAMOFF");
		goto exit;
	}

	if (munmap(v4l_buffer, v4l_length) == -1) {
		ERROR_LOG(HLE, "munmap");
		goto exit;
	}

	if (close(v4l_fd) == -1) {
		ERROR_LOG(HLE, "close");
		goto exit;
	}

	v4l_fd = -1;
	//pthread_join(v4l_thread, NULL);

exit:
	v4l_fd = -1;
	return 0;
}

#endif // PPSSPP_PLATFORM(LINUX) && !PPSSPP_PLATFORM(ANDROID)