Begin delete command implementation

cli/commanddelete.cpp

@@ -0,0 +1,96 @@
+#include <QCommandLineParser>
+#include <QFile>
+#include <QFileInfo>
+#include <QDebug>
+#include <QRegularExpression>
+#include <QSqlError>
+#include "commanddelete.h"
+
+int CommandDelete::handle(QStringList arguments)
+{
+	QCommandLineParser parser;
+	parser.addOptions({{{"v", "verbose"}, "Print path of the files while deleting them"},
+					   {"pattern", "Only delete files from index matching the pattern, e. g. */.git/*", "pattern"},
+					   {"deleted", "Delete all files from the index that don't exist anymore"}});
+
+	parser.addHelpOption();
+	parser.addPositionalArgument("delete", "Delete paths from the index", "delete [paths...]");
+
+	parser.process(arguments);
+	bool removeNonExistant = parser.isSet("deleted");
+	bool verbose = parser.isSet("verbose");
+	QString pattern = parser.value("pattern");
+
+	// TODO: port this to QRegularExpression once >5.12 gets more widespread because of this bug
+	// https://bugreports.qt.io/browse/QTBUG-72539?focusedCommentId=439053&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel
+
+	// QRegularExpression regexPattern = QRegularExpression::wildcardToRegularExpression(pattern);
+
+	bool usePattern = !pattern.isEmpty();
+	QRegExp regexPattern(pattern);
+	regexPattern.setPatternSyntax(QRegExp::PatternSyntax::WildcardUnix);
+
+	QSqlDatabase db = dbConnection();
+
+	if(removeNonExistant)
+	{
+		// TODO: try to translate pattern to SQL WHERE
+		QSqlQuery pathsQuery("SELECT path FROM file", db);
+		if(!pathsQuery.exec())
+		{
+			qDebug() << "Failed to query current paths";
+			return 1;
+		}
+
+		while(pathsQuery.next())
+		{
+			QString path = pathsQuery.value(0).toString();
+			if(usePattern && regexPattern.exactMatch(path))
+			{
+				QFile file(path);
+				if(!file.exists())
+				{
+					QSqlQuery query("DELETE FROM file WHERE path = ?", db);
+					query.addBindValue(path);
+					if(!query.exec())
+					{
+						qDebug() << "Failed to delete " << path << query.lastError();
+						return 1;
+					}
+					if(verbose)
+					{
+						qInfo() << "Deleted " << path;
+					}
+				}
+			}
+		}
+	}
+
+	QStringList files = parser.positionalArguments();
+	for(QString &file : files)
+	{
+		QFileInfo fileInfo(file);
+		QString absPath = fileInfo.absoluteFilePath();
+		if(fileExistsInDatabase(db, absPath))
+		{
+			QSqlQuery deletionQuery("DELETE FROM file WHERE path = ?", db);
+			deletionQuery.addBindValue(absPath);
+			if(deletionQuery.exec())
+			{
+				if(verbose)
+				{
+					qInfo() << "Deleted" << absPath;
+				}
+			}
+			else
+			{
+				qDebug() << "Failed to delete:" << absPath << deletionQuery.lastError();
+			}
+		}
+		else
+		{
+			qInfo() << "No such file in database:" << absPath;
+		}
+	}
+	return 0;
+}