/***

  Oak - Non-Linear Video Editor
  Copyright (C) 2026 Oak Team

  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, either version 3 of the License, or
  (at your option) any later version.

  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 for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.

***/

// Pure C ABI test for the liboakengine export facade. Codec probing and the
// argument/error paths require no GL; the actual export is GL-gated the same
// way as oakengine_renderer_test (dynamic backend probe + worker binary,
// SKIP with exit 0 when unavailable). The GL part builds a solid-color
// sequence through the engine C++ API (engine-internal test), exports one
// second of H.264 MP4 and validates it with ffprobe, and checks the
// progress callback.

#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#if defined(_WIN32)
#include <direct.h>
#include <windows.h>
#else
#include <unistd.h>
#endif

#include <QCoreApplication>
#include <QDir>
#include <QFileInfo>
#include <QString>

#include "config/config.h"
#include "node/generator/solid/solid.h"
#include "node/node.h"
#include "node/output/viewer/viewer.h"
#include "node/project.h"
#include "node/project/sequence/sequence.h"

#ifdef OAK_ENABLE_DYNAMIC_RENDER_BACKEND
#include "render/backend/dynamicrenderer.h"
#include "render/backend/renderbackend_c.h"
#endif

#include "oakengine/exporter.h"
#include "oakengine/footage.h"
#include "oakengine/init.h"
#include "oakengine/project.h"
#include "oakengine/timeline.h"

#ifndef OAK_TEST_SOURCE_DIR
#define OAK_TEST_SOURCE_DIR "."
#endif

static char g_tmpdir[4096];

static void make_tmpdir(void)
{
#if defined(_WIN32)
	char base[MAX_PATH];
	const DWORD len = GetTempPathA(MAX_PATH, base);
	assert(len > 0 && len < MAX_PATH);
	snprintf(g_tmpdir, sizeof(g_tmpdir), "%soakengine_export_test_%lu", base,
			 (unsigned long)GetCurrentProcessId());
	assert(_mkdir(g_tmpdir) == 0);
#else
	strcpy(g_tmpdir, "/tmp/oakengine_export_test_XXXXXX");
	assert(mkdtemp(g_tmpdir) != NULL);
#endif
}

// Same probe as tests/gtest/render_worker_footage_test.cpp.
static bool is_render_backend_available(const QString &backend)
{
#ifdef OAK_ENABLE_DYNAMIC_RENDER_BACKEND
	olive::DynamicRenderer renderer(backend);
	if (!renderer.load()) {
		return false;
	}

	OakRenderBackendInfo info = {};
	if (!renderer.get_backend_info(&info)) {
		return false;
	}

	if (backend == QStringLiteral("opengl") &&
		info.kind != oak_render_backend_opengl) {
		return false;
	}

	return renderer.init();
#else
	Q_UNUSED(backend)
	return false;
#endif
}

static bool worker_binary_exists()
{
	QDir dir(QCoreApplication::applicationDirPath());
	dir.cd(QStringLiteral("../worker"));
#if defined(_WIN32)
	return QFileInfo::exists(dir.filePath(QStringLiteral("oak-render-worker.exe")));
#else
	return QFileInfo::exists(dir.filePath(QStringLiteral("oak-render-worker")));
#endif
}

// ---- Progress callback state ----------------------------------------------
static int g_progress_calls = 0;
static double g_progress_last = -1.0;
static int g_progress_monotonic = 1;

static void progress_cb(double fraction, void *userdata)
{
	(void)userdata;
	g_progress_calls++;
	if (fraction < g_progress_last - 1e-9) {
		g_progress_monotonic = 0;
	}
	g_progress_last = fraction;
}

// ---- No-GL part -------------------------------------------------------------
static void test_codecs_and_validation(OakEngineSequence *seq)
{
	// Codec probing needs no RENDER bit and no GL.
	assert(oakengine_export_has_video_codec(OAKENGINE_EXPORT_VIDEO_H264) ==
		   1);
	assert(oakengine_export_has_video_codec(OAKENGINE_EXPORT_VIDEO_H265) ==
		   1);
	assert(oakengine_export_has_video_codec(
			   OAKENGINE_EXPORT_VIDEO_PNG_SEQUENCE) == 1);
	assert(oakengine_export_has_video_codec(-2) == 0);
	assert(oakengine_export_has_video_codec(99) == 0);
	assert(oakengine_export_has_audio_codec(OAKENGINE_EXPORT_AUDIO_AAC) == 1);
	assert(oakengine_export_has_audio_codec(OAKENGINE_EXPORT_AUDIO_PCM) == 1);
	assert(oakengine_export_has_audio_codec(
			   OAKENGINE_EXPORT_AUDIO_NONE) == 0);
	assert(oakengine_export_has_audio_codec(99) == 0);

	// Argument validation (engine has no RENDER bit yet either).
	char path[4096];
	snprintf(path, sizeof(path), "%s/out.mp4", g_tmpdir);
	assert(oakengine_export_render(NULL, path, 0, 30, 320, 180, NULL) ==
		   OAKENGINE_E_INVALID);
	assert(oakengine_export_render(seq, NULL, 0, 30, 320, 180, NULL) ==
		   OAKENGINE_E_INVALID);
	assert(oakengine_export_render(seq, path, -1, 30, 320, 180, NULL) ==
		   OAKENGINE_E_INVALID);
	assert(oakengine_export_render(seq, path, 30, 30, 320, 180, NULL) ==
		   OAKENGINE_E_INVALID);
	assert(oakengine_export_render(seq, path, 40, 30, 320, 180, NULL) ==
		   OAKENGINE_E_INVALID);

	// Without OAKENGINE_INIT_RENDER the export is refused with E_STATE.
	assert(oakengine_export_render(seq, path, 0, 30, 320, 180, NULL) ==
		   OAKENGINE_E_STATE);
	char err[256];
	assert(oakengine_export_last_error(err, sizeof(err)) > 0);
}

// Generate a loud test tone (440 Hz stereo sine, 2 s) with the ffmpeg
// CLI -- the demo file's own audio track is essentially silent, so a real
// tone is needed to exercise "audio content present" assertions.
static void make_tone(const char *path)
{
	char cmd[4608];
	snprintf(cmd, sizeof(cmd),
			 "ffmpeg -v error -y -f lavfi -i "
			 "\"sine=frequency=440:duration=2\" -ar 48000 -ac 2 \"%s\"",
			 path);
	assert(system(cmd) == 0);
	FILE *f = fopen(path, "rb");
	assert(f != NULL);
	fclose(f);
}

// Probe a media file with ffprobe/ffmpeg and assert the output contains a
// string (used for codec/dimension and loudness checks).
static void assert_probe_matches(const char *cmd, const char *needle)
{
	FILE *probe = popen(cmd, "r");
	assert(probe != NULL);
	char out[2048] = { 0 };
	const size_t len = fread(out, 1, sizeof(out) - 1, probe);
	(void)len;
	assert(pclose(probe) == 0);
	assert(strstr(out, needle) != NULL);
}

int main(void)
{
	make_tmpdir();

	// Sandbox the config/cache/data locations (see oakengine_init_test).
#if !defined(_WIN32)
	assert(setenv("XDG_CONFIG_HOME", g_tmpdir, 1) == 0);
	assert(setenv("XDG_CACHE_HOME", g_tmpdir, 1) == 0);
	assert(setenv("XDG_DATA_HOME", g_tmpdir, 1) == 0);
#endif

	assert(oakengine_init(OAKENGINE_INIT_HEADLESS) == OAKENGINE_OK);

	OakEngineProject *project = oakengine_project_create();
	assert(project != NULL);
	assert(oakengine_project_new(project) == OAKENGINE_OK);
	OakEngineSequence *seq = oakengine_sequence_new(project, "Export");
	assert(seq != NULL);

	test_codecs_and_validation(seq);

	// ---- GL-gated part ------------------------------------------------------
	if (!is_render_backend_available(QStringLiteral("opengl"))) {
		printf("oakengine_export_test: SKIP: OpenGL render backend not "
			   "available, export assertions skipped\n");
		oakengine_project_free(project);
		oakengine_shutdown();
		return 0;
	}
	if (!worker_binary_exists()) {
		printf("oakengine_export_test: SKIP: oak-render-worker binary not "
			   "found, export assertions skipped\n");
		oakengine_project_free(project);
		oakengine_shutdown();
		return 0;
	}

	olive::Config::current()[QStringLiteral("GraphicsBackend")] =
		QStringLiteral("opengl");
	assert(oakengine_init(OAKENGINE_INIT_HEADLESS | OAKENGINE_INIT_RENDER) ==
		   OAKENGINE_OK);

	// Solid red generator -> texture input (engine C++ API, internal test).
	auto *proj = reinterpret_cast<olive::Project *>(project);
	auto *sequence = reinterpret_cast<olive::Sequence *>(seq);
	auto *solid = new olive::SolidGenerator();
	solid->setParent(proj);
	olive::Node::connect_edge(
		solid, olive::NodeInput(sequence, olive::ViewerOutput::k_texture_input));

	// Export one second (30 frames at the default 30000/1001) of H.264.
	char out[4096];
	snprintf(out, sizeof(out), "%s/export.mp4", g_tmpdir);
	oak_export_options opts;
	memset(&opts, 0, sizeof(opts));
	opts.video_codec = OAKENGINE_EXPORT_VIDEO_H264;
	opts.audio_codec = OAKENGINE_EXPORT_AUDIO_NONE; // no audio content here

	oakengine_export_set_progress_callback(progress_cb, NULL);
	char err[512];
	int rc = oakengine_export_render(seq, out, 0, 30, 320, 180, &opts);
	if (rc != OAKENGINE_OK) {
		fprintf(stderr, "export failed (%d): %s\n", rc,
				oakengine_export_last_error(err, sizeof(err)) > 0 ?
					err :
					"(no error)");
	}
	assert(rc == OAKENGINE_OK);
	oakengine_export_set_progress_callback(NULL, NULL);

	// Progress was reported, monotonically, and completed.
	assert(g_progress_calls > 0);
	assert(g_progress_monotonic == 1);
	assert(fabs(g_progress_last - 1.0) < 1e-6);

	// Validate the MP4 with ffprobe: h264 video, 320x180, ~1 second.
	assert(access(out, F_OK) == 0);
	char cmd[4608];
	snprintf(cmd, sizeof(cmd),
			 "ffprobe -v error -select_streams v:0 -show_entries "
			 "stream=codec_name,width,height,duration -of csv=p=0 \"%s\"",
			 out);
	FILE *probe = popen(cmd, "r");
	assert(probe != NULL);
	char probe_out[512] = { 0 };
	const size_t probe_len = fread(probe_out, 1, sizeof(probe_out) - 1, probe);
	(void)probe_len;
	assert(pclose(probe) == 0);
	assert(strstr(probe_out, "h264") != NULL);
	assert(strstr(probe_out, "320,180") != NULL);
	// Duration is the last csv field; 30 frames at 30000/1001 ~= 1.001 s.
	const char *comma = strrchr(probe_out, ',');
	assert(comma != NULL);
	const double duration = atof(comma + 1);
	assert(fabs(duration - 1.001) < 0.15);

	// ---- First-conform audio export ---------------------------------------
	// The sandboxed cache guarantees no conform exists yet: this is the
	// exact first-time-export path that used to come out silent. Lay a loud
	// tone clip on an audio track and export with AAC audio; the exported
	// audio must actually contain the tone.
	{
		char tone_path[4096];
		snprintf(tone_path, sizeof(tone_path), "%s/tone.wav", g_tmpdir);
		make_tone(tone_path);

		// Import through the facade and place through the timeline editing
		// primitives.
		OakEngineFootage *tone =
			oakengine_project_import_footage(project, tone_path);
		assert(tone != NULL);
		assert(oakengine_sequence_add_track(seq, OAKENGINE_TRACK_TYPE_AUDIO) ==
			   0);
		assert(oakengine_sequence_add_footage_clip(
				   seq, tone, OAKENGINE_TRACK_TYPE_AUDIO, 0, 0, 30, 0) !=
			   NULL);

		char out2[4096];
		snprintf(out2, sizeof(out2), "%s/export_audio.mp4", g_tmpdir);
		oak_export_options opts2;
		memset(&opts2, 0, sizeof(opts2));
		opts2.video_codec = OAKENGINE_EXPORT_VIDEO_H264;
		opts2.audio_codec = OAKENGINE_EXPORT_AUDIO_AAC;
		opts2.audio_sample_rate = 48000;
		opts2.audio_channel_count = 2;
		rc = oakengine_export_render(seq, out2, 0, 30, 320, 180, &opts2);
		if (rc != OAKENGINE_OK) {
			fprintf(stderr, "audio export failed (%d): %s\n", rc,
					oakengine_export_last_error(err, sizeof(err)) > 0 ?
						err :
						"(no error)");
		}
		assert(rc == OAKENGINE_OK);
		assert(access(out2, F_OK) == 0);

		// The MP4 carries an AAC audio stream...
		snprintf(cmd, sizeof(cmd),
				 "ffprobe -v error -select_streams a:0 -show_entries "
				 "stream=codec_name -of csv=p=0 \"%s\"",
				 out2);
		assert_probe_matches(cmd, "aac");

		// ...and the tone is really in there (sine is ~-24 dB; silence
		// would read ~-91 dB).
		snprintf(cmd, sizeof(cmd),
				 "ffmpeg -v info -i \"%s\" -map a:0 -af volumedetect -f "
				 "null - 2>&1 | grep mean_volume",
				 out2);
		FILE *vol = popen(cmd, "r");
		assert(vol != NULL);
		char vol_out[512] = { 0 };
		const size_t vol_len = fread(vol_out, 1, sizeof(vol_out) - 1, vol);
		(void)vol_len;
		assert(pclose(vol) == 0);
		const char *db = strstr(vol_out, "mean_volume:");
		assert(db != NULL);
		const double mean_db = atof(db + strlen("mean_volume:"));
		assert(mean_db > -60.0);

		oakengine_footage_free(tone);
	}

	oakengine_project_free(project);
	assert(oakengine_shutdown() == OAKENGINE_OK);

	printf("oakengine_export_test: all assertions passed\n");
	return 0;
}