#include <QSqlError>
#include <QDateTime>
#include <QtConcurrentMap>
#include <QProcess>
#include <functional>
#include "filesaver.h"
#include "processor.h"
#include "pdfprocessor.h"
#include "defaulttextprocessor.h"
#include "tagstripperprocessor.h"
#include "nothingprocessor.h"
#include "odtprocessor.h"
#include "odsprocessor.h"
#include "utils.h"
#include "logger.h"

FileSaver::FileSaver(SqliteDbService &dbService)
{
	this->dbService = &dbService;
}

SaveFileResult FileSaver::addFile(QString path)
{
	QFileInfo info(path);
	QString absPath = info.absoluteFilePath();

	auto mtime = info.lastModified().toSecsSinceEpoch();

	bool exists = false;
	if(this->fileSaverOptions.fillExistingContentless)
	{
		exists = this->dbService->fileExistsInDatabase(absPath, mtime, 'c');
	}
	else
	{
		exists = this->dbService->fileExistsInDatabase(absPath, mtime);
	}

	if(exists)
	{
		return SKIPPED;
	}

	return saveFile(info);
}

SaveFileResult FileSaver::updateFile(QString path)
{
	QFileInfo info(path);
	return saveFile(info);
}

int FileSaver::addFiles(const QVector<QString> paths)
{
	return processFiles(paths, std::bind(&FileSaver::addFile, this, std::placeholders::_1));
}

int FileSaver::updateFiles(const QVector<QString> paths)
{
	return processFiles(paths, std::bind(&FileSaver::updateFile, this, std::placeholders::_1));
}

int FileSaver::processFiles(const QVector<QString> paths, std::function<SaveFileResult(QString path)> saverFunc)
{
	std::atomic<bool> terminate{false};
	std::atomic<int> processedCount{0};
	QtConcurrent::blockingMap(paths,
							  [&](const QString &path)
							  {
								  if(terminate.load())
								  {
									  return;
								  }
								  if(this->fileSaverOptions.verbose)
								  {
									  Logger::info() << "Processing " << path << Qt::endl;
								  }
								  SaveFileResult result = saverFunc(path);
								  if(result == DBFAIL || result == PROCESSFAIL)
								  {
									  Logger::error() << "Failed to process " << path << Qt::endl;
									  if(!this->fileSaverOptions.keepGoing)
									  {
										  terminate = true;
									  }
								  }
								  else
								  {
									  ++processedCount;
									  if(this->fileSaverOptions.verbose)
									  {
										  if(result == SKIPPED)
										  {
											  Logger::info() << "Skipped" << path
															 << "as it already exists in the database" << Qt::endl;
										  }
										  else if(result == OK)
										  {
											  Logger::info() << "Saved" << path << Qt::endl;
										  }
										  else if(result == OK_WASEMPTY)
										  {
											  Logger::info() << "Saved (but content was empty)" << path << Qt::endl;
										  }
									  }
								  }
							  });
	return processedCount.load();
}

SaveFileResult FileSaver::saveFile(const QFileInfo &fileInfo)
{
	QVector<PageData> pageData;
	QString canonicalPath = fileInfo.canonicalFilePath();

	int processorReturnCode = -1;

	if(!fileInfo.isReadable())
	{
		return NOACCESS;
	}

	if(!fileInfo.exists())
	{
		return NOTFOUND;
	}

	if(fileInfo.isFile())
	{
		for(QString &excludedPath : this->excludedPaths)
		{
			if(canonicalPath.startsWith(excludedPath))
			{
				if(this->fileSaverOptions.verbose)
				{
					Logger::info() << "Skipped due to excluded path";
				}
				return SKIPPED;
			}
		}

		bool mustFillContent = this->fileSaverOptions.fillExistingContentless;
		if(!mustFillContent)
		{
			mustFillContent = !this->fileSaverOptions.metadataOnly;
			if(mustFillContent)
			{
				auto filetype = this->dbService->queryFileType(fileInfo.absolutePath());
				mustFillContent = !filetype.has_value() || filetype.value() == 'c';
			}
		}

		if(fileInfo.size() > 0 && mustFillContent)
		{
			QProcess process;
			QStringList args;
			args << "process" << canonicalPath;
			process.setProcessChannelMode(QProcess::ForwardedErrorChannel);
			process.start("/proc/self/exe", args);
			process.waitForStarted();
			process.waitForFinished();

			/* TODO: This is suboptimal as it eats lots of mem
			 * but avoids a weird QDataStream/QProcess behaviour
			 * where it thinks the process has ended when it has not...
			 *
			 * Also, there seem to be issues with reads not being blocked, so
			 * the only reliable way appears to be waiting until the process
			 * finishes.
			 */
			QDataStream in(process.readAllStandardOutput());
			while(!in.atEnd())
			{
				PageData pd;
				in >> pd;
				pageData.append(pd);
			}
			processorReturnCode = process.exitCode();
			if(processorReturnCode != OK && processorReturnCode != OK_WASEMPTY)
			{
				Logger::error() << "FileSaver::saveFile(): Error while processing" << canonicalPath << ":"
								<< "Exit code " << processorReturnCode << Qt::endl;

				return static_cast<SaveFileResult>(processorReturnCode);
			}
		}
	}
	SaveFileResult result = this->dbService->saveFile(fileInfo, pageData, this->fileSaverOptions.metadataOnly);
	if(result == OK && processorReturnCode == OK_WASEMPTY)
	{
		return OK_WASEMPTY;
	}
	return result;
}