#include <QtCore/QDir>
#include <QtCore/QFileInfo>
#include <QtCore/QDebug>
#include <QtSql/QSqlQuery>
#include <QtSql/QSqlError>

#include "global.h"
#include "action.h"
#include "fetchconfigaction.h"
#include "fetchforumsaction.h"
#include "loginaction.h"
#include "newtopicaction.h"
#include "newpostaction.h"
#include "xmlrpcinterface.h"
#include "board.h"

const QLatin1String Board::CURRENT_DB_VERSION("testing1");

Board::Board(QObject *parent) :
	QObject(parent)
{
}

Board::Board(const QUrl& url, const QString& username, const QString& password, QObject *parent) :
	QObject(parent), _url(url), _slug(createSlug(url)),
	_db(QSqlDatabase::addDatabase("QSQLITE", _slug)),
	_iface(new XmlRpcInterface(QUrl(_url), this))
{
	_db.setDatabaseName(QDir::toNativeSeparators(getDbPathFor(_slug)));
	qDebug() << "Opening database file" << _db.databaseName() << "for" << _url;
	if (!_db.open()) {
		qWarning() << "Could not open database file" << _db.databaseName() << ":"
		           << _db.lastError().text();
		_db.setDatabaseName(QDir::toNativeSeparators(getTempDbPathFor(_slug)));
		if (!_db.open()) {
			qWarning() << "Could not open temp database file"
			           << _db.databaseName() << ":" << _db.lastError().text();
			return; // Give up
		}
	}
	if (!checkCompatibleDb()) {
		qDebug() << "Database version incompatible, reinitializing";
		eraseDb();
		initializeDb();
	}
	fetchConfigIfOutdated();
	if (!username.isEmpty()) {
		login(username, password);
	}
	fetchForumsIfOutdated();
	initializeBbCode(); // TODO This might depend on board config
	initializeSmilies();
}

Board::~Board()
{
	disconnect(this, SLOT(handleActionFinished(Action*)));
	if (!_slug.isEmpty()) {
		qDebug() << "Cleaning cache database";
		cleanDb();
		QSqlDatabase::removeDatabase(_slug);
	}
}

void Board::enqueueAction(Action *action)
{
	// Let's find if a duplicate action is in there already.
	qDebug() << "Enqueing" << action;

	foreach (Action *a, _queue) {
		if (a->isSupersetOf(action)) {
			qDebug() << "Action superseded, ignoring";
			delete action;
			return;
		}
	}

	// Otherwise, enqueue the action
	connect(action, SIGNAL(finished(Action*)), SLOT(handleActionFinished(Action*)));
	connect(action, SIGNAL(error(Action*,QString)), SLOT(handleActionError(Action*,QString)));

	_queue.enqueue(action);

	if (_queue.size() == 1) {
		// There were no actions queued, so start by executing this one.
		executeActionFromQueue();
		emit busyChanged();
	}
}

QString Board::getConfig(const QString &key) const
{
	// Try config cache first
	QHash<QString, QString>::const_iterator i = _config.find(key);
	if (i != _config.end()) {
		// Cache hit
		return i.value();
	}

	// Try database
	QSqlQuery query(_db);
	query.prepare("SELECT key, value FROM config WHERE key = :key");
	query.bindValue(":key", key);
	if (!query.exec()) {
		qWarning() << "Could not get configuration key:" << key;
		return QString();
	}
	if (query.next()) {
		QString value = query.value(1).toString();
		_config[key] = value; // Store in cache
		return value;
	}
	return QString();
}

void Board::setConfig(const QString &key, const QString &value)
{
	// Try config cache first
	QHash<QString, QString>::const_iterator i = _config.find(key);
	if (i != _config.end()) {
		QString old_value = i.value();
		if (old_value == value) {
			// It's in the cache, and it's the same value: don't change.
			return;
		}
	}

	// Update value in DB
	QSqlQuery query(_db);
	query.prepare("INSERT OR REPLACE INTO config (key, value) VALUES (:key, :value)");
	query.bindValue(":key", key);
	query.bindValue(":value", value);
	if (!query.exec()) {
		qWarning() << "Could not set configuration key" << key << ":" << query.lastError().text();
	}
	_config.insert(key, value);
	notifyConfigChanged(key);
}

QVariant Board::getLoginInfo(const QString &key) const
{
	return _loginInfo[key];
}

void Board::login(const QString &username, const QString &password)
{
	enqueueAction(new LoginAction(username, password, this));
}

void Board::logout()
{
	// TODO
}

int Board::getTopicForumId(int topicId)
{
	QSqlQuery q(_db);
	q.prepare("SELECT forum_id FROM topics WHERE topic_id = ?");
	q.bindValue(0, topicId);
	if (q.exec()) {
		if (q.next()) {
			return q.value(0).toInt();
		} else {
			qWarning() << "Could not get forum of topic";
		}
	} else {
		qWarning() << "Could not get forum of topic:" << q.lastError().text();
	}

	return -1;
}

void Board::newTopic(int forumId, const QString &subject, const QString &text)
{
	enqueueAction(new NewTopicAction(forumId, subject, text, this));
}

void Board::replyToTopic(int topicId, const QString &text)
{
	enqueueAction(new NewPostAction(topicId, text, this));
}

QString Board::removeHtml(QString text) const
{
	static const QRegExp regexp("<[a-zA-Z\\/][^>]*>");
	text.replace(regexp, "");
	return text;
}

QString Board::removeBbcode(QString text) const
{
	static const QRegExp regexp("\\[[a-zA-Z\\/][^]]*\\]");
	text.replace(regexp, "");
	return text;
}

QString Board::bbcodeToRichText(QString text) const
{
	typedef QPair<QRegExp, QString> Pair; // Workaround for ',' in Q_FOREACH
	foreach (const Pair& pair, _bbcodes) {
		text.replace(pair.first, pair.second);
	}

	return text;
}

QString Board::parseSmilies(QString text) const
{
	int pos = 0;
	text.append(' '); // So that the regexp matches a smilie at the end.
	while ((pos = _smilieRegexp.indexIn(text, pos)) != -1) {
		const int len = _smilieRegexp.matchedLength();
		QString smilie = _smilieRegexp.cap(1);
		const int smilie_pos = _smilieRegexp.pos(1);
		const int smilie_len = smilie.length();
		QHash<QString,QString>::const_iterator i = _smilies.find(smilie);
		if (i != _smilies.end()) {
			QString replacement = "<img src=\"" + i.value() + "\" />";
			text.replace(smilie_pos, smilie_len, replacement);
			pos += replacement.size();
		} else {
			pos += len - 1;
		}
	}
	text.remove(text.length() - 1, 1);
	return text;
}

QString Board::formatDateTime(const QDateTime &dateTime, DateTimePrecisionOptions precision) const
{
	const QDateTime now = QDateTime::currentDateTime();
	const QDateTime ldt = dateTime.toLocalTime();
	const int secs = ldt.secsTo(now);
	const int days = ldt.daysTo(now);

	if (precision & RelativeTime) {
		if (secs < 1) {
			return tr("Just now");
		} else if (secs < 60) {
			return tr("%n second(s) ago", 0, secs);
		} else if (secs < 3600) {
			int mins = (secs + 10) / 60; // + 10 to round a bit
			return tr("%n minute(s) ago", 0, mins);
		}
		// Fall through
	}
	if (precision & (TodayYesterday | RelativeDate)) {
		if (precision & ShowTime) {
			const QString time = ldt.time().toString(Qt::DefaultLocaleShortDate);
			if (days == 0) {
				return tr("Today %1").arg(time);
			} else if (days == 1) {
				return tr("Yesterday %1").arg(time);
			}
		} else {
			if (days == 0) {
				return tr("Today");
			} else if (days == 1) {
				return tr("Yesterday");
			}
		}
	}
	if (precision & RelativeDate) {
		if (days < 7) {
			const int dayOfWeek = ldt.date().dayOfWeek();
			QString name = QDate::longDayName(dayOfWeek, QDate::StandaloneFormat);
			name[0] = name[0].toUpper();
			return name;
		} else if (days < 30) {
			return tr("%n week(s) ago", 0, days / 7);
		} else if (days < 365) {
			return tr("%n month(s) ago", 0, days / 30);
		} else {
			return tr("%n year(s) ago", 0, days / 365);
		}
	}
	if (precision & ShowTime) {
		return ldt.toString(Qt::DefaultLocaleShortDate);
	} else {
		return ldt.date().toString(Qt::DefaultLocaleShortDate);
	}
}

void Board::cancelAllActions()
{
	if (!_queue.isEmpty()) {
		disconnect(this, SLOT(handleActionFinished(Action*)));
		while (!_queue.isEmpty()) {
			Action *action = _queue.dequeue();
			delete action;
		}
		emit busyChanged();
	}
}

void Board::notifyConfigChanged(const QString& key)
{
	if (!key.isEmpty()) {
		_config.remove(key);
	} else {
		// Must assume all keys were changed
		_config.clear();
	}
	emit configChanged(key);
}

void Board::notifyForumsChanged()
{
	emit forumsChanged();
}

void Board::notifyForumChanged(int forumId)
{
	emit forumChanged(forumId);
}

void Board::notifyForumTopicsChanged(int forumId, TopicType type, int start, int end)
{
	qDebug() << "ForumTopics changed" << forumId << type << start << end;
	emit forumTopicsChanged(forumId, type, start, end);
}

void Board::notifyForumTopicChanged(int forumId, int topicId)
{
	qDebug() << "ForumTopic changed" << forumId << topicId;
	emit forumTopicChanged(forumId, topicId);
}

void Board::notifyTopicPostsChanged(int topicId, int start, int end)
{
	qDebug() << "TopicPosts changed" << topicId << start << end;
	emit topicPostsChanged(topicId, start, end);
}

void Board::notifyTopicPostsUnread(int topicId, int position)
{
	qDebug() << "TopicPosts unread" << topicId << position;
	emit topicPostsUnread(topicId, position);
}

void Board::notifyLogin(const QMap<QString, QVariant> &info)
{
	if (_loginInfo.empty()) {
		_loginInfo = info;
		qDebug() << "Now logged in as" << _loginInfo["username"].toString();
		emit loggedInChanged();
		if (getConfig("last_forums_fetch_logged_in") != "1") {
			// Forum list is probably outdated, because we fetched it while
			// we were logged out.
			if (_iface->isAccessible()) {
				qDebug() << "Fetching forums because of login";
				enqueueAction(new FetchForumsAction(this));
			}
		}
	} else {
		// Double login?
		_loginInfo = info;
	}
}

void Board::notifyLogout()
{
	if (!_loginInfo.empty()) {
		_loginInfo.clear();
		emit loggedInChanged();
	}
}

void Board::markTopicAsRead(int topicId)
{
	QSqlQuery q(_db);
	q.prepare("UPDATE topics SET new_post = 0 WHERE topic_id = ? AND new_post = 1");
	q.bindValue(0, topicId);
	if (q.exec()) {
		if (q.numRowsAffected() > 0) {
			int forum_id = getTopicForumId(topicId);
			if (forum_id >= 0) {
				notifyForumTopicChanged(forum_id, topicId);
				updateForumReadState(forum_id);
			}
		}
	} else {
		qWarning() << "Could not mark topic as read:" << q.lastError().text();
	}
}

QString Board::createSlug(const QUrl& url)
{
	static const QRegExp regexp("[^a-z0-9]+");
	static const QString mobiquo_default_endpoint("/mobiquo.php");
	QString slug = url.toString(QUrl::RemoveScheme | QUrl::RemoveUserInfo | QUrl::StripTrailingSlash);
	slug = slug.toLower();
	if (slug.startsWith("//")) {
		slug.remove(0, 2);
	}
	if (slug.endsWith(mobiquo_default_endpoint)) {
		slug.chop(mobiquo_default_endpoint.size());
	}
	slug.replace(regexp, "_");
	return slug;
}

QString Board::getDbPathFor(const QString &slug)
{
	return board_manager->getCachePath() + "/" + slug + ".sqlite";
}

QString Board::getTempDbPathFor(const QString& slug)
{
	return QDir::tempPath() + "/" + slug + ".sqlite";
}

int Board::dbSize() const
{
	QFileInfo info(getDbPathFor(_slug));
	return info.size();
}

bool Board::checkCompatibleDb()
{
	QString version = getConfig("tapasboard_db_version");
	return version == CURRENT_DB_VERSION;
}

bool Board::initializeDb()
{
	QSqlQuery q(_db);

	if (!q.exec("PRAGMA synchronous = OFF")) {
		qWarning() << "Could not disable synchronous flag:" << q.lastError().text();
		// Not fatal
	}

	if (!q.exec("CREATE TABLE IF NOT EXISTS config (key TEXT PRIMARY KEY, value TEXT)")) {
		qWarning() << "Could not create config table:" << q.lastError().text();
		return false;
	}

	if (!q.exec("CREATE TABLE IF NOT EXISTS forums (forum_id INTEGER PRIMARY KEY, forum_name TEXT, description TEXT, parent_id INTEGER, logo_url TEXT, new_post BOOL, is_protected BOOL, is_subscribed BOOL, can_subscribe BOOL, url TEXT, sub_only BOOL, position INT)")) {
		qWarning() << "Could not create forums table:" << q.lastError().text();
		return false;
	}
	if (!q.exec("CREATE INDEX IF NOT EXISTS forums_parent ON forums (parent_id)")) {
		qWarning() << "Could not create forums_parent index:" << q.lastError().text();
		return false;
	}
	if (!q.exec("CREATE UNIQUE INDEX IF NOT EXISTS forums_order ON forums (position ASC)")) {
		qWarning() << "Could not create forums_order index:" << q.lastError().text();
		return false;
	}

	if (!q.exec("CREATE TABLE IF NOT EXISTS topics (forum_id INTEGER, topic_id INTEGER PRIMARY KEY, topic_type INT, topic_title TEXT, topic_author_id INTEGER, topic_author_name TEXT, is_subscribed BOOL, is_closed BOOL, icon_url TEXT, last_reply_time TEXT, reply_number INT, new_post BOOL, position INT, last_update_time TEXT)")) {
		qWarning() << "Could not create topics table:" << q.lastError().text();
		return false;
	}
	if (!q.exec("CREATE INDEX IF NOT EXISTS topics_forum ON topics (forum_id)")) {
		qWarning() << "Could not create topics_forum index:" << q.lastError().text();
		return false;
	}
	if (!q.exec("CREATE INDEX IF NOT EXISTS topics_time ON topics (last_reply_time)")) {
		qWarning() << "Could not create topics_time index:" << q.lastError().text();
		return false;
	}
	if (!q.exec("CREATE INDEX IF NOT EXISTS topics_order ON topics (forum_id, topic_type DESC, position ASC)")) {
		qWarning() << "Could not create topics_order index:" << q.lastError().text();
		return false;
	}

	if (!q.exec("CREATE TABLE IF NOT EXISTS posts (forum_id INTEGER, topic_id INTEGER, post_id INTEGER PRIMARY KEY, post_title TEXT, post_content TEXT, post_author_id INTEGER, post_author_name TEXT, can_edit BOOL, icon_url TEXT, post_time TEXT, position INT, last_update_time TEXT)")) {
		qWarning() << "Could not create posts table:" << q.lastError().text();
		return false;
	}
	if (!q.exec("CREATE INDEX IF NOT EXISTS posts_topic ON posts (topic_id)")) {
		qWarning() << "Could not create posts_topic index:" << q.lastError().text();
		return false;
	}
	if (!q.exec("CREATE INDEX IF NOT EXISTS posts_time ON posts (post_time)")) {
		qWarning() << "Could not create posts_time index:" << q.lastError().text();
		return false;
	}
	if (!q.exec("CREATE INDEX IF NOT EXISTS posts_order ON posts (topic_id, position ASC)")) {
		qWarning() << "Could not create posts_order index:" << q.lastError().text();
		return false;
	}

	return true;
}

bool Board::eraseDb()
{
	QSqlQuery q(_db);

	if (!q.exec("DROP TABLE IF EXISTS config")) {
		qWarning() << "Could not drop config table:" << q.lastError().text();
		return false;
	}
	if (!q.exec("DROP TABLE IF EXISTS forums")) {
		qWarning() << "Could not drop forums table:" << q.lastError().text();
		return false;
	}
	if (!q.exec("DROP TABLE IF EXISTS topics")) {
		qWarning() << "Could not drop topics table:" << q.lastError().text();
		return false;
	}
	if (!q.exec("DROP TABLE IF EXISTS posts")) {
		qWarning() << "Could not drop posts table:" << q.lastError().text();
		return false;
	}
	if (!q.exec("VACUUM")) {
		qWarning() << "Could not vacuum database:" << q.lastError().text();
		return false;
	}

	return true;
}

bool Board::cleanDb()
{
	QSqlQuery q(_db);

	int total_rows = 0;

	q.prepare("DELETE FROM topics WHERE last_update_time < ?");
	q.bindValue(0, QDateTime::currentDateTimeUtc().addDays(-FORUM_TOPICS_CACHE));
	if (q.exec()) {
		total_rows += q.numRowsAffected();
	} else {
		qWarning() << "Could not clean old topics:" << q.lastError().text();
	}


	q.prepare("DELETE FROM posts WHERE last_update_time < ?");
	q.bindValue(0, QDateTime::currentDateTimeUtc().addDays(-TOPIC_POSTS_CACHE));
	if (q.exec()) {
		total_rows += q.numRowsAffected();
	} else {
		qWarning() << "Could not clean old posts:" << q.lastError().text();
	}

	if (q.exec("DELETE FROM topics WHERE forum_id NOT IN (SELECT forum_id FROM forums)")) {
		total_rows += q.numRowsAffected();
	} else {
		qWarning() << "Could not clean unreferenced topics:" << q.lastError().text();
	}
	if (q.exec("DELETE FROM posts WHERE topic_id NOT IN (SELECT topic_id FROM topics)")) {
		total_rows += q.numRowsAffected();
	} else {
		qWarning() << "Could not clean unreferenced posts:" << q.lastError().text();
	}

	if (total_rows > 100) {
		qDebug() << "Vacuuming database";
		if (q.exec("VACUUM")) {
			qWarning() << "Could not vacuum database:" << q.lastError().text();
		}
	}

	return true;
}

bool Board::removeFromActionQueue(Action *action)
{
	if (_queue.isEmpty()) return false;
	Action *head = _queue.head();
	if (_queue.removeOne(action)) {
		if (!_queue.isEmpty() && head != _queue.head()) {
			// The head action was removed; advance the queue.
			qDebug() << "Now running" << _queue.head();
			executeActionFromQueue();
		}
		action->deleteLater();
		// Don't use delete here because this might be called in response to
		// error() or finished() QNetworkReply signals.
		if (_queue.isEmpty()) {
			emit busyChanged();
		}
		return true;
	}
	return false;
}

void Board::executeActionFromQueue()
{
	if (!_queue.empty()) {
		Action *head = _queue.head();
		head->execute();
	}
}

void Board::initializeBbCode()
{
	_bbcodes.clear();
	_bbcodes << qMakePair(QRegExp("\\[(/?[bius])\\]", Qt::CaseInsensitive), QString("<\\1>"));

	_bbcodes << qMakePair(QRegExp("\\[(/?)quote\\]", Qt::CaseInsensitive), QString("<\\1blockquote>"));

	_bbcodes << qMakePair(QRegExp("\\[url\\]([^[]*)\\[/url\\]", Qt::CaseInsensitive), QString("<a href=\"\\1\">\\1</a>"));
	_bbcodes << qMakePair(QRegExp("\\[url=([^]]*)\\]", Qt::CaseInsensitive), QString("<a href=\"\\1\">"));
	_bbcodes << qMakePair(QRegExp("\\[/url\\]", Qt::CaseInsensitive), QString("</a>"));

	_bbcodes << qMakePair(QRegExp("\\[img\\]([^[]*)\\[/img\\]", Qt::CaseInsensitive), QString("<img src=\"\\1\" />"));

	_bbcodes << qMakePair(QRegExp("\\[hr\\]", Qt::CaseInsensitive), QString("<hr>"));

	_bbcodes << qMakePair(QRegExp("\n"), QString("<br>"));
}

void Board::initializeSmilies()
{
	_smilies[":)"] = "image://theme/icon-s-messaging-smiley-happy";
	_smilies["=)"] = "image://theme/icon-s-messaging-smiley-happy";
	_smilies[":("] = "image://theme/icon-s-messaging-smiley-sad";
	_smilies[":D"] = "image://theme/icon-s-messaging-smiley-very-happy";
	_smilies["XD"] = "image://theme/icon-s-messaging-smiley-very-happy";
	_smilies["=D>"] = "image://theme/icon-s-messaging-smiley-very-happy";
	_smilies[":lol:"] = "image://theme/icon-s-messaging-smiley-very-happy";
	_smilies[";)"] = "image://theme/icon-s-messaging-smiley-wink";
	_smilies[";D"] = "image://theme/icon-s-messaging-smiley-wink";
	_smilies[":wink:"] = "image://theme/icon-s-messaging-smiley-wink";
	_smilies[":P"] = "image://theme/icon-s-messaging-smiley-tongue";
	_smilies[":p"] = "image://theme/icon-s-messaging-smiley-tongue";
	_smilies[":mrgreen:"] = "image://theme/icon-s-messaging-smiley-grin";
	_smilies[":roll:"] = "image://theme/icon-s-messaging-smiley-grin";
	_smilies[":O"] = "image://theme/icon-s-messaging-smiley-surprised";
	_smilies["O_O"] = "image://theme/icon-s-messaging-smiley-surprised";
	_smilies["O_o"] = "image://theme/icon-s-messaging-smiley-surprised";
	_smilies[":shock:"] = "image://theme/icon-s-messaging-smiley-surprised";
	_smilies[":evil:"] = "image://theme/icon-s-messaging-smiley-evil";

	// Let's construct a single regular expression that will cover all smilies
	QString regexp("[^A-Za-z](");
	for (QHash<QString, QString>::const_iterator i = _smilies.begin();
	     i != _smilies.end();
	     i++) {
		if (i != _smilies.begin()) {
			regexp += "|";
		}
		regexp += QRegExp::escape(i.key());
	}
	regexp += ")[^A-Za-z]";
	_smilieRegexp = QRegExp(regexp);
	Q_ASSERT(_smilieRegexp.isValid());
}

void Board::fetchConfigIfOutdated()
{
	if (_iface->isAccessible()) {
		// Only fetch if network is accessible and data is >48h old.
		QDateTime last_fetch = QDateTime::fromString(
		            getConfig("last_config_fetch"), Qt::ISODate);
		if (!last_fetch.isValid() || last_fetch.daysTo(QDateTime::currentDateTimeUtc()) >= BOARD_CONFIG_TTL) {
			enqueueAction(new FetchConfigAction(this));
		}
	}

}

void Board::fetchForumsIfOutdated()
{
	if (_iface->isAccessible()) {
		// Only fetch if network is accessible and data is >48h old.
		QDateTime last_fetch = QDateTime::fromString(
		            getConfig("last_forums_fetch"), Qt::ISODate);
		if (!last_fetch.isValid() || last_fetch.daysTo(QDateTime::currentDateTimeUtc()) >= BOARD_LIST_TTL) {
			enqueueAction(new FetchForumsAction(this));
		}
	}
}

void Board::updateForumReadState(int forumId)
{
	QSqlQuery q(_db);

	q.prepare("SELECT COUNT() FROM topics WHERE forum_id = ? AND new_post = 1");
	q.bindValue(0, forumId);
	if (!q.exec()) {
		qWarning() << "Could not select unread topics from forum:" << q.lastError().text();
		return;
	}

	int unread_topics = 0;
	if (q.next()) {
		unread_topics = q.value(0).toInt();
	}

	int new_post = (unread_topics > 0) ? 1 : 0;

	q.prepare("UPDATE forums SET new_post = :new_post WHERE forum_id = :forum_id AND new_post != :cur_new_post");
	q.bindValue(":new_post", new_post);
	q.bindValue(":forum_id", forumId);
	q.bindValue(":cur_new_post", new_post);

	if (!q.exec()) {
		qWarning() << "Could not update forum read status:" << q.lastError().text();
		return;
	}

	if (q.numRowsAffected() > 0) {
		notifyForumChanged(forumId);
	}
}

void Board::handleActionFinished(Action *action)
{
	qDebug() << action << "finished";
	bool ok = removeFromActionQueue(action);
	if (!ok) {
		qWarning() << "Finished action not in queue";
	}
}

void Board::handleActionError(Action *action, const QString& message)
{
	qWarning() << "Action failed:" << message;
	removeFromActionQueue(action);
}