#include <QtCore/QDebug>
#include <QtSql/QSqlError>

#include "global.h"
#include "board.h"
#include "boardmodel.h"

BoardModel::BoardModel(QObject *parent) :
    QAbstractListModel(parent),
    _rootForumId(0)
{
	QHash<int, QByteArray> roles = roleNames();
	roles[NameRole] = QByteArray("title");
	roles[LogoRole] = QByteArray("logo");
	roles[DescriptionRole] = QByteArray("description");
	roles[ForumIdRole] = QByteArray("forumId");
	roles[SubOnlyRole] = QByteArray("subOnly");
	roles[CategoryRole] = QByteArray("category");
	setRoleNames(roles);
}

QString BoardModel::boardUrl() const
{
	return _boardUrl;
}

void BoardModel::setBoardUrl(const QString &url)
{
	if (_boardUrl != url) {
		disconnect(this, SLOT(reload()));
		_boardUrl = url;
		reload();
		emit boardUrlChanged();
	}
}

int BoardModel::rootForumId() const
{
	return _rootForumId;
}

void BoardModel::setRootForumId(const int id)
{
	if (_rootForumId != id) {
		_rootForumId = id;
		reload();
		emit rootForumIdChanged();
	}
}

int BoardModel::rowCount(const QModelIndex &parent) const
{
	return parent.isValid() ? 0 : _records;
}

QVariant BoardModel::data(const QModelIndex &index, int role) const
{
	if (!index.isValid()) return QVariant();
	if (!_query.seek(index.row())) {
		qWarning() << "Could not seek to" << index.row();
		return QVariant();
	}

	switch (role) {
	case ForumIdRole:
		return _query.value(0);
	case NameRole:
		return _query.value(1);
	case LogoRole:
		return _query.value(2);
	case DescriptionRole:
		return _query.value(3);
	case SubOnlyRole:
		return _query.value(4);
	case CategoryRole:
		return _query.value(5);
	}

	return QVariant();
}

bool BoardModel::canFetchMore(const QModelIndex &parent) const
{
	return parent.isValid() || !_query.isValid() ? false : !_eof;
}

void BoardModel::fetchMore(const QModelIndex &parent)
{
	if (parent.isValid()) return;
	if (_eof) return;

	const int prefetch_count = 20;
	int new_num_records;
	if (_query.seek(_records + prefetch_count)) {
		new_num_records = _query.at() + 1;
	} else if (_query.previous()) {
		// We hit the last record and just went back
		new_num_records = _query.at() + 1;
		_eof = true;
	} else {
		// There are no records or other error
		new_num_records = 0;
		_eof = true;
	}


	if (new_num_records <= 0) {
		return; // No records!
	} else if (new_num_records > _records) {
		beginInsertRows(QModelIndex(), _records, new_num_records - 1);
		_records = new_num_records;
		endInsertRows();
	}
}

void BoardModel::reload()
{
	beginResetModel();
	_eof = false;
	_records = 0;
	_query.clear();

	if (!_boardUrl.isEmpty()) {
		Board *board = board_manager->getBoard(_boardUrl);
		connect(board, SIGNAL(forumsChanged()), SLOT(reload()));
		_query = QSqlQuery(board->database());
		_query.prepare("SELECT f1.forum_id,f1.forum_name,f1.logo_url,f1.description,f1.sub_only,f2.forum_name AS cat_name FROM forums f1 "
					   "LEFT JOIN forums f2 ON f2.forum_id = f1.parent_id "
					   "WHERE (f1.parent_id=:parent_id_1 AND f1.sub_only = 0) OR f1.parent_id IN "
					   "(SELECT forum_id from forums WHERE parent_id=:parent_id_2 AND sub_only=1) "
					   "ORDER by f1.sort_index ASC;");
		_query.bindValue(0, _rootForumId);
		_query.bindValue(1, _rootForumId);
		if (!_query.exec()) {
			qWarning() << "Coult not select forums: " << _query.lastError().text();
		}
	}

	endResetModel();
	fetchMore();
}