/* PipeWire */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

/*
 [title]
 Video input stream using \ref pw_stream_trigger_process, for pull mode.
 [title]
 */

#include <stdio.h>
#include <unistd.h>
#include <signal.h>

#include <spa/utils/result.h>
#include <spa/param/video/format-utils.h>
#include <spa/param/props.h>
#include <spa/debug/format.h>

#include <pipewire/pipewire.h>

#define WIDTH   640
#define HEIGHT  480
#define RATE	30

#define MAX_BUFFERS	64

#include "sdl.h"

struct pixel {
	float r, g, b, a;
};

struct data {
	const char *path;

	SDL_Renderer *renderer;
	SDL_Window *window;
	SDL_Texture *texture;
	SDL_Texture *cursor;

	struct pw_main_loop *loop;
	struct spa_source *timer;

	struct pw_stream *stream;
	struct spa_hook stream_listener;

	struct spa_io_position *position;

	struct spa_video_info format;
	int32_t stride;
	struct spa_rectangle size;

	int counter;
	SDL_Rect rect;
	SDL_Rect cursor_rect;
	bool is_yuv;
	bool have_request_process;
};

static void handle_events(struct data *data)
{
	SDL_Event event;
	while (SDL_PollEvent(&event)) {
		switch (event.type) {
		case SDL_QUIT:
			pw_main_loop_quit(data->loop);
			break;
		}
	}
}

/* our data processing function is in general:
 *
 *  struct pw_buffer *b;
 *  b = pw_stream_dequeue_buffer(stream);
 *
 *  .. do stuff with buffer ...
 *
 *  pw_stream_queue_buffer(stream, b);
 */
static void
on_process(void *_data)
{
	struct data *data = _data;
	struct pw_stream *stream = data->stream;
	struct pw_buffer *b;
	struct spa_buffer *buf;
	void *sdata, *ddata;
	int sstride, dstride, ostride;
	struct spa_meta_region *mc;
	struct spa_meta_cursor *mcs;
	uint32_t i, j;
	uint8_t *src, *dst;
	bool render_cursor = false;

	b = NULL;
	while (true) {
		struct pw_buffer *t;
		if ((t = pw_stream_dequeue_buffer(stream)) == NULL)
			break;
		if (b)
			pw_stream_queue_buffer(stream, b);
		b = t;
	}
	if (b == NULL) {
		pw_log_warn("out of buffers: %m");
		return;
	}

	buf = b->buffer;

	pw_log_trace("new buffer %p", buf);

	handle_events(data);

	if ((sdata = buf->datas[0].data) == NULL)
		goto done;

	/* get the videocrop metadata if any */
	if ((mc = spa_buffer_find_meta_data(buf, SPA_META_VideoCrop, sizeof(*mc))) &&
	    spa_meta_region_is_valid(mc)) {
		data->rect.x = mc->region.position.x;
		data->rect.y = mc->region.position.y;
		data->rect.w = mc->region.size.width;
		data->rect.h = mc->region.size.height;
	}
	/* get cursor metadata */
	if ((mcs = spa_buffer_find_meta_data(buf, SPA_META_Cursor, sizeof(*mcs))) &&
	    spa_meta_cursor_is_valid(mcs)) {
		struct spa_meta_bitmap *mb;
		void *cdata;
		int cstride;

		data->cursor_rect.x = mcs->position.x;
		data->cursor_rect.y = mcs->position.y;

		mb = SPA_PTROFF(mcs, mcs->bitmap_offset, struct spa_meta_bitmap);
		data->cursor_rect.w = mb->size.width;
		data->cursor_rect.h = mb->size.height;

		if (data->cursor == NULL) {
			data->cursor = SDL_CreateTexture(data->renderer,
						 id_to_sdl_format(mb->format),
						 SDL_TEXTUREACCESS_STREAMING,
						 mb->size.width, mb->size.height);
			SDL_SetTextureBlendMode(data->cursor, SDL_BLENDMODE_BLEND);
		}


		if (SDL_LockTexture(data->cursor, NULL, &cdata, &cstride) < 0) {
			fprintf(stderr, "Couldn't lock cursor texture: %s\n", SDL_GetError());
			goto done;
		}

		/* copy the cursor bitmap into the texture */
		src = SPA_PTROFF(mb, mb->offset, uint8_t);
		dst = cdata;
		ostride = SPA_MIN(cstride, mb->stride);

		for (i = 0; i < mb->size.height; i++) {
			memcpy(dst, src, ostride);
			dst += cstride;
			src += mb->stride;
		}
		SDL_UnlockTexture(data->cursor);

		render_cursor = true;
	}

	/* copy video image in texture */
	if (data->is_yuv) {
		sstride = data->stride;
		SDL_UpdateYUVTexture(data->texture,
				NULL,
				sdata,
				sstride,
				SPA_PTROFF(sdata, sstride * data->size.height, void),
				sstride / 2,
				SPA_PTROFF(sdata, 5 * (sstride * data->size.height) / 4, void),
				sstride / 2);
	}
	else {
		if (SDL_LockTexture(data->texture, NULL, &ddata, &dstride) < 0) {
			fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
			goto done;
		}

		sstride = buf->datas[0].chunk->stride;
		if (sstride == 0)
			sstride = buf->datas[0].chunk->size / data->size.height;
		ostride = SPA_MIN(sstride, dstride);

		src = sdata;
		dst = ddata;

		if (data->format.media_subtype == SPA_MEDIA_SUBTYPE_dsp) {
			for (i = 0; i < data->size.height; i++) {
				struct pixel *p = (struct pixel *) src;
				for (j = 0; j < data->size.width; j++) {
					dst[j * 4 + 0] = SPA_CLAMP((uint8_t)(p[j].r * 255.0f), 0u, 255u);
					dst[j * 4 + 1] = SPA_CLAMP((uint8_t)(p[j].g * 255.0f), 0u, 255u);
					dst[j * 4 + 2] = SPA_CLAMP((uint8_t)(p[j].b * 255.0f), 0u, 255u);
					dst[j * 4 + 3] = SPA_CLAMP((uint8_t)(p[j].a * 255.0f), 0u, 255u);
				}
				src += sstride;
				dst += dstride;
			}
		} else {
			for (i = 0; i < data->size.height; i++) {
				memcpy(dst, src, ostride);
				src += sstride;
				dst += dstride;
			}
		}
		SDL_UnlockTexture(data->texture);
	}

	SDL_RenderClear(data->renderer);
	/* now render the video and then the cursor if any */
	SDL_RenderCopy(data->renderer, data->texture, &data->rect, NULL);
	if (render_cursor) {
		SDL_RenderCopy(data->renderer, data->cursor, NULL, &data->cursor_rect);
	}
	SDL_RenderPresent(data->renderer);

      done:
	pw_stream_queue_buffer(stream, b);
}

static void enable_timeouts(struct data *data, bool enabled)
{
	struct timespec timeout, interval, *to, *iv;

	if (!enabled || data->have_request_process) {
		to = iv = NULL;
	} else {
		timeout.tv_sec = 0;
		timeout.tv_nsec = 1;
		interval.tv_sec = 0;
		interval.tv_nsec = 80 * SPA_NSEC_PER_MSEC;
		to = &timeout;
		iv = &interval;
	}
	pw_loop_update_timer(pw_main_loop_get_loop(data->loop),
				data->timer, to, iv, false);
}


static void on_stream_state_changed(void *_data, enum pw_stream_state old,
				    enum pw_stream_state state, const char *error)
{
	struct data *data = _data;
	fprintf(stderr, "stream state: \"%s\"\n", pw_stream_state_as_string(state));
	switch (state) {
	case PW_STREAM_STATE_UNCONNECTED:
		pw_main_loop_quit(data->loop);
		break;
	case PW_STREAM_STATE_PAUSED:
		enable_timeouts(data, false);
		break;
	case PW_STREAM_STATE_STREAMING:
		printf("driving:%d lazy:%d\n",
				pw_stream_is_driving(data->stream),
				pw_stream_is_lazy(data->stream));
		if (pw_stream_is_driving(data->stream) != pw_stream_is_lazy(data->stream))
			enable_timeouts(data, true);
		break;
	default:
		break;
	}
}

static void
on_stream_io_changed(void *_data, uint32_t id, void *area, uint32_t size)
{
	struct data *data = _data;

	switch (id) {
	case SPA_IO_Position:
		data->position = area;
		break;
	}
}

static void
on_trigger_done(void *_data)
{
	struct data *data = _data;
	pw_log_trace("%p trigger done", data);
}

static void on_timeout(void *userdata, uint64_t expirations)
{
	struct data *data = userdata;
	pw_stream_trigger_process(data->stream);
}

static void
on_command(void *_data, const struct spa_command *command)
{
	struct data *data = _data;
	switch (SPA_NODE_COMMAND_ID(command)) {
	case SPA_NODE_COMMAND_RequestProcess:
		pw_log_trace("%p trigger", data);
		pw_stream_trigger_process(data->stream);
		break;
	default:
		break;
	}
}

/* Be notified when the stream param changes. We're only looking at the
 * format changes.
 *
 * We are now supposed to call pw_stream_finish_format() with success or
 * failure, depending on if we can support the format. Because we gave
 * a list of supported formats, this should be ok.
 *
 * As part of pw_stream_finish_format() we can provide parameters that
 * will control the buffer memory allocation. This includes the metadata
 * that we would like on our buffer, the size, alignment, etc.
 */
static void
on_stream_param_changed(void *_data, uint32_t id, const struct spa_pod *param)
{
	struct data *data = _data;
	struct pw_stream *stream = data->stream;
	uint8_t params_buffer[1024];
	struct spa_pod_builder b = SPA_POD_BUILDER_INIT(params_buffer, sizeof(params_buffer));
	const struct spa_pod *params[5];
	Uint32 sdl_format;
	void *d;
	int32_t mult, size;

	/* NULL means to clear the format */
	if (param == NULL || id != SPA_PARAM_Format)
		return;

	fprintf(stderr, "got format:\n");
	spa_debug_format(2, NULL, param);

	if (spa_format_parse(param, &data->format.media_type, &data->format.media_subtype) < 0)
		return;

	if (data->format.media_type != SPA_MEDIA_TYPE_video)
		return;

	switch (data->format.media_subtype) {
	case SPA_MEDIA_SUBTYPE_raw:
		/* call a helper function to parse the format for us. */
		spa_format_video_raw_parse(param, &data->format.info.raw);
		sdl_format = id_to_sdl_format(data->format.info.raw.format);
		data->size = SPA_RECTANGLE(data->format.info.raw.size.width,
				data->format.info.raw.size.height);
		mult = 1;
		break;
	case SPA_MEDIA_SUBTYPE_dsp:
		spa_format_video_dsp_parse(param, &data->format.info.dsp);
		if (data->format.info.dsp.format != SPA_VIDEO_FORMAT_DSP_F32)
			return;
		sdl_format = SDL_PIXELFORMAT_RGBA32;
		data->size = SPA_RECTANGLE(data->position->video.size.width,
				data->position->video.size.height);
		mult = 4;
		break;
	default:
		sdl_format = SDL_PIXELFORMAT_UNKNOWN;
		break;
	}

	if (sdl_format == SDL_PIXELFORMAT_UNKNOWN) {
		pw_stream_set_error(stream, -EINVAL, "unknown pixel format");
		return;
	}
	if (data->size.width == 0 || data->size.height == 0) {
		pw_stream_set_error(stream, -EINVAL, "invalid size");
		return;
	}

	data->texture = SDL_CreateTexture(data->renderer,
					  sdl_format,
					  SDL_TEXTUREACCESS_STREAMING,
					  data->size.width,
					  data->size.height);
	if (SDL_LockTexture(data->texture, NULL, &d, &data->stride) < 0) {
		pw_stream_set_error(stream, -EINVAL, "invalid texture format");
		return;
	}
	SDL_UnlockTexture(data->texture);

	switch(sdl_format) {
	case SDL_PIXELFORMAT_YV12:
	case SDL_PIXELFORMAT_IYUV:
		size = (data->stride * data->size.height) * 3 / 2;
		data->is_yuv = true;
		break;
	default:
		size = data->stride * data->size.height;
		break;
	}

	data->rect.x = 0;
	data->rect.y = 0;
	data->rect.w = data->size.width;
	data->rect.h = data->size.height;

	/* a SPA_TYPE_OBJECT_ParamBuffers object defines the acceptable size,
	 * number, stride etc of the buffers */
	params[0] = spa_pod_builder_add_object(&b,
		SPA_TYPE_OBJECT_ParamBuffers, SPA_PARAM_Buffers,
		SPA_PARAM_BUFFERS_buffers, SPA_POD_CHOICE_RANGE_Int(8, 2, MAX_BUFFERS),
		SPA_PARAM_BUFFERS_blocks,  SPA_POD_Int(1),
		SPA_PARAM_BUFFERS_size,    SPA_POD_Int(size * mult),
		SPA_PARAM_BUFFERS_stride,  SPA_POD_Int(data->stride * mult),
		SPA_PARAM_BUFFERS_dataType, SPA_POD_CHOICE_FLAGS_Int((1<<SPA_DATA_MemPtr)));

	/* a header metadata with timing information */
	params[1] = spa_pod_builder_add_object(&b,
		SPA_TYPE_OBJECT_ParamMeta, SPA_PARAM_Meta,
		SPA_PARAM_META_type, SPA_POD_Id(SPA_META_Header),
		SPA_PARAM_META_size, SPA_POD_Int(sizeof(struct spa_meta_header)));
	/* video cropping information */
	params[2] = spa_pod_builder_add_object(&b,
		SPA_TYPE_OBJECT_ParamMeta, SPA_PARAM_Meta,
		SPA_PARAM_META_type, SPA_POD_Id(SPA_META_VideoCrop),
		SPA_PARAM_META_size, SPA_POD_Int(sizeof(struct spa_meta_region)));
#define CURSOR_META_SIZE(w,h)	(sizeof(struct spa_meta_cursor) + \
				 sizeof(struct spa_meta_bitmap) + w * h * 4)
	/* cursor information */
	params[3] = spa_pod_builder_add_object(&b,
		SPA_TYPE_OBJECT_ParamMeta, SPA_PARAM_Meta,
		SPA_PARAM_META_type, SPA_POD_Id(SPA_META_Cursor),
		SPA_PARAM_META_size, SPA_POD_CHOICE_RANGE_Int(
				CURSOR_META_SIZE(64,64),
				CURSOR_META_SIZE(1,1),
				CURSOR_META_SIZE(256,256)));

	/* we are done */
	pw_stream_update_params(stream, params, 4);
}

/* these are the stream events we listen for */
static const struct pw_stream_events stream_events = {
	PW_VERSION_STREAM_EVENTS,
	.state_changed = on_stream_state_changed,
	.io_changed = on_stream_io_changed,
	.param_changed = on_stream_param_changed,
	.process = on_process,
	.trigger_done = on_trigger_done,
	.command = on_command,
};

static int build_format(struct data *data, struct spa_pod_builder *b, const struct spa_pod **params)
{
	SDL_RendererInfo info;

	SDL_GetRendererInfo(data->renderer, &info);
	params[0] = sdl_build_formats(&info, b);

	fprintf(stderr, "supported SDL formats:\n");
	spa_debug_format(2, NULL, params[0]);

	params[1] = spa_pod_builder_add_object(b,
			SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
			SPA_FORMAT_mediaType,		SPA_POD_Id(SPA_MEDIA_TYPE_video),
			SPA_FORMAT_mediaSubtype,	SPA_POD_Id(SPA_MEDIA_SUBTYPE_dsp),
			SPA_FORMAT_VIDEO_format,	SPA_POD_Id(SPA_VIDEO_FORMAT_DSP_F32));

	fprintf(stderr, "supported DSP formats:\n");
	spa_debug_format(2, NULL, params[1]);

	return 2;
}

static void do_quit(void *userdata, int signal_number)
{
	struct data *data = userdata;
	pw_main_loop_quit(data->loop);
}

int main(int argc, char *argv[])
{
	struct data data = { 0, };
	const struct spa_pod *params[2];
	uint8_t buffer[1024];
	struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buffer, sizeof(buffer));
	struct pw_properties *props;
	int res, n_params;

	pw_init(&argc, &argv);

	/* create a main loop */
	data.loop = pw_main_loop_new(NULL);

	pw_loop_add_signal(pw_main_loop_get_loop(data.loop), SIGINT, do_quit, &data);
	pw_loop_add_signal(pw_main_loop_get_loop(data.loop), SIGTERM, do_quit, &data);

	/* the timer to pull in data */
	data.timer = pw_loop_add_timer(pw_main_loop_get_loop(data.loop), on_timeout, &data);

	/* create a simple stream, the simple stream manages to core and remote
	 * objects for you if you don't need to deal with them
	 *
	 * If you plan to autoconnect your stream, you need to provide at least
	 * media, category and role properties
	 *
	 * Pass your events and a user_data pointer as the last arguments. This
	 * will inform you about the stream state. The most important event
	 * you need to listen to is the process event where you need to consume
	 * the data provided to you.
	 */
	props = pw_properties_new(PW_KEY_MEDIA_TYPE, "Video",
			PW_KEY_MEDIA_CATEGORY, "Capture",
			PW_KEY_MEDIA_ROLE, "Camera",
			PW_KEY_NODE_SUPPORTS_LAZY, "1",
			PW_KEY_NODE_SUPPORTS_REQUEST, "1",
			NULL),
	data.path = argc > 1 ? argv[1] : NULL;
	if (data.path)
		/* Set stream target if given on command line */
		pw_properties_set(props, PW_KEY_TARGET_OBJECT, data.path);

	data.stream = pw_stream_new_simple(
			pw_main_loop_get_loop(data.loop),
			"video-play",
			props,
			&stream_events,
			&data);

	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
		fprintf(stderr, "can't initialize SDL: %s\n", SDL_GetError());
		return -1;
	}

	if (SDL_CreateWindowAndRenderer
	    (WIDTH, HEIGHT, SDL_WINDOW_RESIZABLE, &data.window, &data.renderer)) {
		fprintf(stderr, "can't create window: %s\n", SDL_GetError());
		return -1;
	}

	/* build the extra parameters to connect with. To connect, we can provide
	 * a list of supported formats.  We use a builder that writes the param
	 * object to the stack. */
	n_params = build_format(&data, &b, params);

	/* now connect the stream, we need a direction (input/output),
	 * an optional target node to connect to, some flags and parameters
	 */
	if ((res = pw_stream_connect(data.stream,
			  PW_DIRECTION_INPUT,
			  PW_ID_ANY,
			  PW_STREAM_FLAG_DRIVER |	/* we're driver, we pull */
			  PW_STREAM_FLAG_AUTOCONNECT |	/* try to automatically connect this stream */
			  PW_STREAM_FLAG_MAP_BUFFERS,	/* mmap the buffer data for us */
			  params, n_params))		/* extra parameters, see above */ < 0) {
		fprintf(stderr, "can't connect: %s\n", spa_strerror(res));
		return -1;
	}

	/* do things until we quit the mainloop */
	pw_main_loop_run(data.loop);

	pw_stream_destroy(data.stream);
	pw_main_loop_destroy(data.loop);

	SDL_DestroyTexture(data.texture);
	if (data.cursor)
		SDL_DestroyTexture(data.cursor);
	SDL_DestroyRenderer(data.renderer);
	SDL_DestroyWindow(data.window);
	pw_deinit();

	return 0;
}