// This file is part of RSS Guard.
//
// Copyright (C) 2011-2017 by Martin Rotter <rotter.martinos@gmail.com>
//
// RSS Guard 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.
//
// RSS Guard 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 RSS Guard. If not, see <http://www.gnu.org/licenses/>.

#include "core/messagesmodelsqllayer.h"

#include "definitions/definitions.h"
#include "miscellaneous/application.h"


MessagesModelSqlLayer::MessagesModelSqlLayer()
	: m_filter(QSL(DEFAULT_SQL_MESSAGES_FILTER)), m_fieldNames(QMap<int, QString>()),
	  m_sortColumns(QList<int>()), m_sortOrders(QList<Qt::SortOrder>()) {
	m_db = qApp->database()->connection(QSL("MessagesModel"), DatabaseFactory::FromSettings);
	m_fieldNames[MSG_DB_ID_INDEX] = "Messages.id";
	m_fieldNames[MSG_DB_READ_INDEX] = "Messages.is_read";
	m_fieldNames[MSG_DB_DELETED_INDEX] = "Messages.is_deleted";
	m_fieldNames[MSG_DB_IMPORTANT_INDEX] = "Messages.is_important";
	m_fieldNames[MSG_DB_FEED_TITLE_INDEX] = "Feeds.title";
	m_fieldNames[MSG_DB_TITLE_INDEX] = "Messages.title";
	m_fieldNames[MSG_DB_URL_INDEX] = "Messages.url";
	m_fieldNames[MSG_DB_AUTHOR_INDEX] = "Messages.author";
	m_fieldNames[MSG_DB_DCREATED_INDEX] = "Messages.date_created";
	m_fieldNames[MSG_DB_CONTENTS_INDEX] = "Messages.contents";
	m_fieldNames[MSG_DB_PDELETED_INDEX] = "Messages.is_pdeleted";
	m_fieldNames[MSG_DB_ENCLOSURES_INDEX] = "Messages.enclosures";
	m_fieldNames[MSG_DB_ACCOUNT_ID_INDEX] = "Messages.account_id";
	m_fieldNames[MSG_DB_CUSTOM_ID_INDEX]  = "Messages.custom_id";
	m_fieldNames[MSG_DB_CUSTOM_HASH_INDEX] = "Messages.custom_hash";
	m_fieldNames[MSG_DB_FEED_CUSTOM_ID_INDEX] = "Messages.feed";
}

void MessagesModelSqlLayer::addSortState(int column, Qt::SortOrder order) {
	int existing = m_sortColumns.indexOf(column);
	bool is_ctrl_pressed = (QApplication::queryKeyboardModifiers() & Qt::ControlModifier) == Qt::ControlModifier;

	if (existing >= 0) {
		m_sortColumns.removeAt(existing);
		m_sortOrders.removeAt(existing);
	}

	if (m_sortColumns.size() > MAX_MULTICOLUMN_SORT_STATES) {
		// We support only limited number of sort states
		// due to DB performance.
		m_sortColumns.removeAt(0);
		m_sortOrders.removeAt(0);
	}

	if (is_ctrl_pressed) {
		// User is activating the multicolumn sort mode.
		m_sortColumns.append(column);
		m_sortOrders.append(order);
	}
	else {
		m_sortColumns.prepend(column);
		m_sortOrders.prepend(order);
	}

	qDebug("Added sort state, select statement is now:\n'%s'", qPrintable(selectStatement()));
}

void MessagesModelSqlLayer::setFilter(const QString& filter) {
	m_filter = filter;
}

QString MessagesModelSqlLayer::formatFields() const {
	return m_fieldNames.values().join(QSL(", "));
}

QString MessagesModelSqlLayer::selectStatement() const {
	return QL1S("SELECT ") + formatFields() +
	       QSL(" FROM Messages LEFT JOIN Feeds ON Messages.feed = Feeds.custom_id AND Messages.account_id = Feeds.account_id WHERE ") +
	       m_filter + orderByClause() + QL1C(';');
}

QString MessagesModelSqlLayer::orderByClause() const {
	if (m_sortColumns.isEmpty()) {
		return QString();
	}
	else {
		QStringList sorts;

		for (int i = 0; i < m_sortColumns.size(); i++) {
			QString field_name(m_fieldNames[m_sortColumns[i]]);
			sorts.append(field_name + (m_sortOrders[i] == Qt::AscendingOrder ? QSL(" ASC") : QSL(" DESC")));
		}

		return QL1S(" ORDER BY ") + sorts.join(QSL(", "));
	}
}