#include "LogModel.h"

LogModel::LogModel(QObject *parent):QAbstractListModel(parent)
{
	m_content.resize(m_maxLines);
}

int LogModel::rowCount(const QModelIndex &parent) const
{
	if (parent.isValid())
		return 0;

	return m_numLines;
}

QVariant LogModel::data(const QModelIndex &index, int role) const
{
	if (index.row() < 0 || index.row() >= m_numLines)
		return QVariant();

	auto row = index.row();
	auto realRow = (row + m_firstLine) % m_maxLines;
	if (role == Qt::DisplayRole || role == Qt::EditRole)
	{
		return m_content[realRow].line;
	}
	if(role == LevelRole)
	{
		return m_content[realRow].level;
	}

	return QVariant();
}

void LogModel::append(MessageLevel::Enum level, QString line)
{
	if(m_suspended)
	{
		return;
	}
	int lineNum = (m_firstLine + m_numLines) % m_maxLines;
	// overflow
	if(m_numLines == m_maxLines)
	{
		if(m_stopOnOverflow)
		{
			// nothing more to do, the buffer is full
			return;
		}
		beginRemoveRows(QModelIndex(), 0, 0);
		m_firstLine = (m_firstLine + 1) % m_maxLines;
		m_numLines --;
		endRemoveRows();
	}
	else if (m_numLines == m_maxLines - 1 && m_stopOnOverflow)
	{
		level = MessageLevel::Fatal;
		line = m_overflowMessage;
	}
	beginInsertRows(QModelIndex(), m_numLines, m_numLines);
	m_numLines ++;
	m_content[lineNum].level = level;
	m_content[lineNum].line = line;
	endInsertRows();
}

void LogModel::suspend(bool suspend)
{
	m_suspended = suspend;
}

void LogModel::clear()
{
	beginResetModel();
	m_firstLine = 0;
	m_numLines = 0;
	endResetModel();
}

QString LogModel::toPlainText()
{
	QString out;
	out.reserve(m_numLines * 80);
	for(int i = 0; i < m_numLines; i++)
	{
		QString & line = m_content[(m_firstLine + i) % m_maxLines].line;
		out.append(line + '\n');
	}
	out.squeeze();
	return out;
}

void LogModel::setMaxLines(int maxLines)
{
	// no-op
	if(maxLines == m_maxLines)
	{
		return;
	}
	// if it all still fits in the buffer, just resize it
	if(m_firstLine + m_numLines < maxLines)
	{
		m_maxLines = maxLines;
		m_content.resize(maxLines);
		return;
	}
	// otherwise, we need to reorganize the data because it crosses the wrap boundary
	QVector<entry> newContent;
	newContent.resize(maxLines);
	if(m_numLines <= maxLines)
	{
		// if it all fits in the new buffer, just copy it over
		for(int i = 0; i < m_numLines; i++)
		{
			newContent[i] = m_content[(m_firstLine + i) % m_maxLines];
		}
		m_content.swap(newContent);
	}
	else
	{
		// if it doesn't fit, part of the data needs to be thrown away (the oldest log messages)
		int lead = m_numLines - maxLines;
		beginRemoveRows(QModelIndex(), 0, lead - 1);
		for(int i = 0; i < maxLines; i++)
		{
			newContent[i] = m_content[(m_firstLine + lead + i) % m_maxLines];
		}
		m_numLines = m_maxLines;
		m_content.swap(newContent);
		endRemoveRows();
	}
	m_firstLine = 0;
	m_maxLines = maxLines;
}

void LogModel::setStopOnOverflow(bool stop)
{
	m_stopOnOverflow = stop;
}

void LogModel::setOverflowMessage(const QString& overflowMessage)
{
	m_overflowMessage = overflowMessage;
}