/*
 * helper.cpp, part of VCMI engine
 *
 * Authors: listed in file AUTHORS in main folder
 *
 * License: GNU General Public License v2.0 or later
 * Full text of license available in license.txt file, in main folder
 *
 */
#include "StdInc.h"
#include "helper.h"

#include "mainwindow_moc.h"
#include "settingsView/csettingsview_moc.h"
#include "modManager/cmodlistview_moc.h"

#include "../lib/CConfigHandler.h"

#include <QObject>
#include <QScroller>

#ifdef VCMI_ANDROID
#include <QAndroidJniObject>
#include <QtAndroid>
#include <QAndroidJniEnvironment>
#include <QAndroidActivityResultReceiver>
#endif

#ifdef VCMI_IOS
#include "ios/revealdirectoryinfiles.h"
#include "ios/selectdirectory.h"
#include "iOS_utils.h"
#endif

#ifdef VCMI_MOBILE
static QScrollerProperties generateScrollerProperties()
{
	QScrollerProperties result;

	result.setScrollMetric(QScrollerProperties::OvershootDragResistanceFactor, 0.25);
	result.setScrollMetric(QScrollerProperties::OvershootDragDistanceFactor, 0.25);
	result.setScrollMetric(QScrollerProperties::HorizontalOvershootPolicy, QScrollerProperties::OvershootAlwaysOff);

	return result;
}
#endif

#ifdef VCMI_ANDROID
static QString safeEncode(QString uri)
{
	// %-encode unencoded parts of string.
	// This is needed because Qt returns a mixed content url with %-encoded and unencoded parts. On Android >= 13 this causes problems reading these files, when using spaces and unicode characters in folder or filename.
	// Only these should be encoded (other typically %-encoded chars should not be encoded because this leads to errors).
	// Related, but seems not completly fixed (at least in our setup): https://bugreports.qt.io/browse/QTBUG-114435
	if (!uri.startsWith("content://", Qt::CaseInsensitive))
		return uri;
	return QString::fromUtf8(QUrl::toPercentEncoding(uri, "!#$&'()*+,/:;=?@[]<>{}\"`^~%"));
}
#endif

namespace Helper
{
void loadSettings()
{
	settings.init("config/settings.json", "vcmi:settings");
	persistentStorage.init("config/persistentStorage.json", "");
}

void reLoadSettings()
{
	loadSettings();
	for(const auto widget : qApp->allWidgets())
		if(auto settingsView = qobject_cast<CSettingsView *>(widget))
		{
			settingsView->loadSettings();
			break;
		}
	getMainWindow()->updateTranslation();
	getMainWindow()->getModView()->reload();
}

void enableScrollBySwiping(QObject * scrollTarget)
{
#ifdef VCMI_MOBILE
	QScroller::grabGesture(scrollTarget, QScroller::LeftMouseButtonGesture);
	QScroller * scroller = QScroller::scroller(scrollTarget);
	scroller->setScrollerProperties(generateScrollerProperties());
#endif
}

QString getRealPath(QString path)
{
#ifdef VCMI_ANDROID
	if(path.contains("content://", Qt::CaseInsensitive))
	{
		auto str = QAndroidJniObject::fromString(safeEncode(path));
		return QAndroidJniObject::callStaticObjectMethod("eu/vcmi/vcmi/util/FileUtil", "getFilenameFromUri", "(Ljava/lang/String;Landroid/content/Context;)Ljava/lang/String;", str.object<jstring>(), QtAndroid::androidContext().object()).toString();
	}
	return path;
#else
	return path;
#endif
}

bool performNativeCopy(QString src, QString dst)
{
#ifdef VCMI_ANDROID
	const bool srcIsContent = src.startsWith("content://", Qt::CaseInsensitive);
	const bool dstIsContent = dst.startsWith("content://", Qt::CaseInsensitive);

	if(srcIsContent || dstIsContent)
	{
		const QAndroidJniObject jSrc = QAndroidJniObject::fromString(srcIsContent ? safeEncode(src) : src);
		const QAndroidJniObject jDst = QAndroidJniObject::fromString(dstIsContent ? safeEncode(dst) : dst);
		QAndroidJniObject::callStaticMethod<void>("eu/vcmi/vcmi/util/FileUtil", "copyFileFromUri", "(Ljava/lang/String;Ljava/lang/String;Landroid/content/Context;)V", jSrc.object<jstring>(), jDst.object<jstring>(), QtAndroid::androidContext().object());
		return QFileInfo(dst).exists();
	}
#endif

	// Pure filesystem -> use Qt copy
	QFile::remove(dst);
	return QFile::copy(src, dst);
}

void revealDirectoryInFileBrowser(QString path)
{
	const auto dirUrl = QUrl::fromLocalFile(QFileInfo{path}.absoluteFilePath());
#ifdef VCMI_IOS
	iOS_utils::revealDirectoryInFiles(dirUrl);
#else
	QDesktopServices::openUrl(dirUrl);
#endif
}

MainWindow * getMainWindow()
{
	foreach(QWidget *w, qApp->allWidgets())
		if(auto mainWin = qobject_cast<MainWindow*>(w))
			return mainWin;
	return nullptr;
}

void keepScreenOn(bool isEnabled)
{
#if defined(VCMI_ANDROID)
	QtAndroid::runOnAndroidThread([isEnabled]
	{
		QtAndroid::androidActivity().callMethod<void>("keepScreenOn", "(Z)V", isEnabled);
	});
#elif defined(VCMI_IOS)
	iOS_utils::keepScreenOn(isEnabled);
#endif
}

bool canUseFolderPicker()
{
#if defined(VCMI_ANDROID)
	// Folder picker is available on API >= 21.
	// Android/Google TV usually lacks DocumentsUI — hide this option.

	QAndroidJniObject context = QtAndroid::androidContext();
	QAndroidJniObject uiModeMgr = context.callObjectMethod("getSystemService", "(Ljava/lang/String;)Ljava/lang/Object;", QAndroidJniObject::fromString("uimode").object<jstring>());

	if(uiModeMgr.isValid())
	{
		jint mode = uiModeMgr.callMethod<jint>("getCurrentModeType", "()I");
		jint TV = QAndroidJniObject::getStaticField<jint>("android/content/res/Configuration", "UI_MODE_TYPE_TELEVISION");
		if(mode == TV)
			return false;
	}

	return true;
#elif defined(VCMI_IOS)
	// selecting directory through UIDocumentPickerViewController is available only since iOS 13
	return iOS_utils::isOsVersionAtLeast(13);
#else
	return true;
#endif
}

#ifdef VCMI_ANDROID
// Request code for Android folder picker (ACTION_OPEN_DOCUMENT_TREE).
// Value is arbitrary, used only to match activity result callback.
static constexpr int  kFolderPickerReqCode = 4242;

static jint intentFlags()
{
	const jint fRead	= QAndroidJniObject::getStaticField<jint>("android/content/Intent", "FLAG_GRANT_READ_URI_PERMISSION");
	const jint fWrite   = QAndroidJniObject::getStaticField<jint>("android/content/Intent", "FLAG_GRANT_WRITE_URI_PERMISSION");
	const jint fPersist = QAndroidJniObject::getStaticField<jint>("android/content/Intent", "FLAG_GRANT_PERSISTABLE_URI_PERMISSION");
	const jint fPrefix  = QAndroidJniObject::getStaticField<jint>("android/content/Intent", "FLAG_GRANT_PREFIX_URI_PERMISSION");

	return fRead | fWrite | fPersist | fPrefix;
}

class FolderPickReceiver final : public QAndroidActivityResultReceiver
{
public:
	std::function<void(QString)> onDone;

	// One-shot result handler for ACTION_OPEN_DOCUMENT_TREE
	void handleActivityResult(int req, int res, const QAndroidJniObject &data) override
	{
		auto cb = std::exchange(onDone, {}); // guarantee single-use
		if(!cb)
			return;

		if(req != kFolderPickerReqCode || res != -1 /*RESULT_OK*/ || !data.isValid())
		{
			QMetaObject::invokeMethod(qApp, [cb]{ if (cb) cb({}); }, Qt::QueuedConnection);
			return;
		}

		// Always return content:// tree URI
		const QAndroidJniObject uri = data.callObjectMethod("getData","()Landroid/net/Uri;");
		const QAndroidJniObject us  = uri.callObjectMethod("toString","()Ljava/lang/String;");
		const QString pickedTree	= us.toString();

		// Persist read+write permission
		const QAndroidJniObject ctx = QtAndroid::androidContext();
		const QAndroidJniObject cr  = ctx.callObjectMethod("getContentResolver","()Landroid/content/ContentResolver;");
		cr.callMethod<void>("takePersistableUriPermission", "(Landroid/net/Uri;I)V", uri.object<jobject>(), jint(1 | 2));

		// Bounce back to Qt thread
		QMetaObject::invokeMethod(qApp, [cb, pickedTree]{ if (cb) cb(pickedTree); }, Qt::QueuedConnection);
	}
};

static FolderPickReceiver g_receiver;
#endif

void nativeFolderPicker(QWidget *parent, std::function<void(QString)>&& cb)
{
	if(!cb)
		return;

#if defined(VCMI_ANDROID)
	Q_UNUSED(parent);
	g_receiver.onDone = std::move(cb);

	QAndroidJniObject intent("android/content/Intent","()V");
	intent.callObjectMethod("setAction", "(Ljava/lang/String;)Landroid/content/Intent;", QAndroidJniObject::fromString("android.intent.action.OPEN_DOCUMENT_TREE").object<jstring>());
	intent.callObjectMethod("addFlags", "(I)Landroid/content/Intent;", intentFlags());

	QtAndroid::startActivity(intent, kFolderPickerReqCode, &g_receiver);

#elif defined(VCMI_IOS)
	SelectDirectory iosDirectorySelector;
	const QString dir = iosDirectorySelector.getExistingDirectory();
	cb(dir);

#else
	const QString dir = QFileDialog::getExistingDirectory(parent, {}, {}, QFileDialog::ShowDirsOnly | QFileDialog::DontResolveSymlinks);
	cb(dir);
#endif
}

static inline QString classifyTargetByExt(const QString &baseName)
{
	// Case-insensitive suffix checks without making a lowercase copy
	auto ends = [&](const char *s){ return baseName.endsWith(QLatin1String(s), Qt::CaseInsensitive); };

	if(ends(".lod") || ends(".snd") || ends(".vid") || ends(".pak"))
		return QStringLiteral("Data");

	if(ends(".h3m"))
		return QStringLiteral("Maps");

	if(ends(".mp3"))
		return QStringLiteral("Mp3");

	return {};
}

static void addIfExists(QVector<QDir> &scan, const QDir &base, const char *child)
{
	QDir dir(base.filePath(QLatin1String(child)));
	if(dir.exists())
		scan << dir;
}

QStringList findFilesForCopy(const QString &path)
{
#ifdef VCMI_ANDROID
	if(path.startsWith(QLatin1String("content://"), Qt::CaseInsensitive))
	{
		const QAndroidJniObject jUri = QAndroidJniObject::fromString(safeEncode(path));
		const QAndroidJniObject jArr = QAndroidJniObject::callStaticObjectMethod("eu/vcmi/vcmi/util/FileUtil", "findFilesForCopy", "(Ljava/lang/String;Landroid/content/Context;)[Ljava/lang/String;", jUri.object<jstring>(), QtAndroid::androidContext().object());

		QStringList out;
		if(!jArr.isValid())
			return out;

		QAndroidJniEnvironment env;
		const jobjectArray arr = static_cast<jobjectArray>(jArr.object<jobject>());
		const jsize n = env->GetArrayLength(arr);
		out.reserve(n);

		for(jsize i = 0; i < n; ++i)
		{
			QAndroidJniObject s((jstring)env->GetObjectArrayElement(arr, i));
			out.push_back(s.toString());																// "src \t Target \t Name"
		}

		return out;
	}
#endif

	// Non-Android, or Android with real FS path
	QStringList out;
	QDir root(path);
	if(!root.exists())
		return out;

	// Build list of directories to scan
	QVector<QDir> scan;
	scan << root;

	// If user picked "Data", also scan ../Maps and ../Mp3 (if present)
	if(root.dirName().compare(QLatin1String("Data"), Qt::CaseInsensitive) == 0)
	{
		QDir parent = root;
		if(parent.cdUp())
		{
			addIfExists(scan, parent, "Maps");
			addIfExists(scan, parent, "Mp3");
		}
	}

	// Depth-first traversal on each directory; classify by extension
	for(const QDir &dir : scan)
	{
		QDirIterator it(dir.absolutePath(), QDir::Files | QDir::Readable | QDir::NoSymLinks, QDirIterator::Subdirectories);

		while(it.hasNext())
		{
			const QString filePath = it.next();
			const QFileInfo file(filePath);
			const QString target = classifyTargetByExt(file.fileName());
			if(target.isEmpty())
				continue;

			out.push_back(filePath + QLatin1Char('\t') + target + QLatin1Char('\t') + file.fileName());	// "src \t Target \t Name"
		}
	}

	return out;
}

void sendFileToApp(QString path)
{
#if defined(VCMI_ANDROID)
	// delegate to Android activity which will copy to cache and share via FileProvider
	auto jstr = QAndroidJniObject::fromString(path);
	QtAndroid::runOnAndroidThread([jstr]() mutable {
		QtAndroid::androidActivity().callMethod<void>("shareFile", "(Ljava/lang/String;)V", jstr.object<jstring>());
	});
#elif defined(VCMI_IOS)
	// use iOS share sheet
	iOS_utils::shareFile(path.toStdString());
#else
	Q_UNUSED(path);
#endif
}

}