/*
 * Copyright (c) 2010 Remko Tronçon
 * Licensed under the GNU General Public License v3.
 * See Documentation/Licenses/GPLv3.txt for more information.
 */

#include <iostream>
#include <boost/lexical_cast.hpp>

#include <sqlite3.h>
#include <Swiften/History/SQLiteHistoryManager.h>
#include <boost/date_time/gregorian/gregorian.hpp>

inline std::string getEscapedString(const std::string& s) {
	std::string result(s);

	size_t pos = result.find('\'');
	while (pos != std::string::npos) {
		result.insert(pos, "'");
		pos = result.find('\'', pos + 2);
	}
	return result;
}

namespace Swift {

SQLiteHistoryManager::SQLiteHistoryManager(const std::string& file) : db_(0) {
	sqlite3_open(file.c_str(), &db_);
	if (!db_) {
		std::cerr << "Error opening database " << file << std::endl; // FIXME
	}

	char* errorMessage;
	int result = sqlite3_exec(db_, "CREATE TABLE IF NOT EXISTS messages('message' STRING, 'fromBare' INTEGER, 'fromResource' STRING, 'toBare' INTEGER, 'toResource' STRING, 'type' INTEGER, 'time' INTEGER, 'offset' INTEGER)", 0, 0, &errorMessage);
	if (result != SQLITE_OK) {
		std::cerr << "SQL Error: " << errorMessage << std::endl;
		sqlite3_free(errorMessage);
	}

	result = sqlite3_exec(db_, "CREATE TABLE IF NOT EXISTS jids('id' INTEGER PRIMARY KEY ASC AUTOINCREMENT, 'jid' STRING UNIQUE NOT NULL)", 0, 0, &errorMessage);
	if (result != SQLITE_OK) {
		std::cerr << "SQL Error: " << errorMessage << std::endl;
		sqlite3_free(errorMessage);
	}
}

SQLiteHistoryManager::~SQLiteHistoryManager() {
	sqlite3_close(db_);
}

void SQLiteHistoryManager::addMessage(const HistoryMessage& message) {
	int secondsSinceEpoch = (message.getTime() - boost::posix_time::ptime(boost::gregorian::date(1970, 1, 1))).total_seconds();

	std::string statement = std::string("INSERT INTO messages('message', 'fromBare', 'fromResource', 'toBare', 'toResource', 'type', 'time', 'offset') VALUES(") +
					"'" + getEscapedString(message.getMessage()) + "', " +
					boost::lexical_cast<std::string>(getIDForJID(message.getFromJID().toBare())) + ", '" +
					getEscapedString(message.getFromJID().getResource()) + "', " +
					boost::lexical_cast<std::string>(getIDForJID(message.getToJID().toBare())) + ", '" +
					getEscapedString(message.getToJID().getResource()) + "', " +
					boost::lexical_cast<std::string>(message.getType()) + ", " +
					boost::lexical_cast<std::string>(secondsSinceEpoch) + ", " +
					boost::lexical_cast<std::string>(message.getOffset()) + ")";
	char* errorMessage;
	int result = sqlite3_exec(db_, statement.c_str(), 0, 0, &errorMessage);
	if (result != SQLITE_OK) {
		std::cerr << "SQL Error: " << errorMessage << std::endl;
		sqlite3_free(errorMessage);
	}
}

std::vector<HistoryMessage> SQLiteHistoryManager::getMessagesFromDate(const JID& selfJID, const JID& contactJID, HistoryMessage::Type type, const boost::gregorian::date& date) const {
	sqlite3_stmt* selectStatement;

	boost::optional<int> selfID = getIDFromJID(selfJID.toBare());
	boost::optional<int> contactID = getIDFromJID(contactJID.toBare());

	if (!selfID || !contactID) {
		// JIDs missing from the database
		return std::vector<HistoryMessage>();
	}

	std::string selectQuery = "SELECT * FROM messages WHERE (type=" + boost::lexical_cast<std::string>(type);
	if (contactJID.isBare()) {
		// match only bare jid
		selectQuery += " AND ((fromBare=" + boost::lexical_cast<std::string>(*selfID) + " AND toBare=" +
				boost::lexical_cast<std::string>(*contactID) + ") OR (fromBare=" +
				boost::lexical_cast<std::string>(*contactID) + " AND toBare=" + boost::lexical_cast<std::string>(*selfID) + ")))";
	}
	else {
		// match resource too
		selectQuery += " AND ((fromBare=" + boost::lexical_cast<std::string>(*selfID) + " AND (toBare=" +
				boost::lexical_cast<std::string>(*contactID) +" AND toResource='" +
				getEscapedString(contactJID.getResource()) + "')) OR ((fromBare=" +
				boost::lexical_cast<std::string>(*contactID) + " AND fromResource='" +
				getEscapedString(contactJID.getResource()) + "') AND toBare=" +
				boost::lexical_cast<std::string>(*selfID) + ")))";
	}

	if (!date.is_not_a_date()) {
		int lowerBound = (boost::posix_time::ptime(date) - boost::posix_time::ptime(boost::gregorian::date(1970, 1, 1))).total_seconds();
		int upperBound = lowerBound + 86400;

		selectQuery += " AND (time>=" + boost::lexical_cast<std::string>(lowerBound) +
				" AND time<" + boost::lexical_cast<std::string>(upperBound) + ")";
	}

	int r = sqlite3_prepare(db_, selectQuery.c_str(), selectQuery.size(), &selectStatement, NULL);
	if (r != SQLITE_OK) {
		std::cout << "Error: " << sqlite3_errmsg(db_) << std::endl;
	}
	r = sqlite3_step(selectStatement);

	// Retrieve result
	std::vector<HistoryMessage> result;
	while (r == SQLITE_ROW) {
		std::string message(reinterpret_cast<const char*>(sqlite3_column_text(selectStatement, 0)));

		// fromJID
		boost::optional<JID> fromJID(getJIDFromID(sqlite3_column_int(selectStatement, 1)));
		std::string fromResource(reinterpret_cast<const char*>(sqlite3_column_text(selectStatement, 2)));
		if (fromJID) {
			fromJID = boost::optional<JID>(JID(fromJID->getNode(), fromJID->getDomain(), fromResource));
		}

		// toJID
		boost::optional<JID> toJID(getJIDFromID(sqlite3_column_int(selectStatement, 3)));
		std::string toResource(reinterpret_cast<const char*>(sqlite3_column_text(selectStatement, 4)));
		if (toJID) {
			toJID = boost::optional<JID>(JID(toJID->getNode(), toJID->getDomain(), toResource));
		}

		// message type
		HistoryMessage::Type type = static_cast<HistoryMessage::Type>(sqlite3_column_int(selectStatement, 5));

		// timestamp
		int secondsSinceEpoch(sqlite3_column_int(selectStatement, 6));
		boost::posix_time::ptime time(boost::gregorian::date(1970, 1, 1), boost::posix_time::seconds(secondsSinceEpoch));

		// offset from utc
		int offset = sqlite3_column_int(selectStatement, 7);

		result.push_back(HistoryMessage(message, (fromJID ? *fromJID : JID()), (toJID ? *toJID : JID()), type, time, offset));
		r = sqlite3_step(selectStatement);
	}
	if (r != SQLITE_DONE) {
		std::cout << "Error: " << sqlite3_errmsg(db_) << std::endl;
	}
	sqlite3_finalize(selectStatement);

	return result;
}

int SQLiteHistoryManager::getIDForJID(const JID& jid) {
	boost::optional<int> id = getIDFromJID(jid);
	if (id) {
		return *id;
	}
	else {
		return addJID(jid);
	}
}

int SQLiteHistoryManager::addJID(const JID& jid) {
	std::string statement = std::string("INSERT INTO jids('jid') VALUES('") + getEscapedString(jid.toString()) + "')";
	char* errorMessage;
	int result = sqlite3_exec(db_, statement.c_str(), 0, 0, &errorMessage);
	if (result != SQLITE_OK) {
		std::cerr << "SQL Error: " << errorMessage << std::endl;
		sqlite3_free(errorMessage);
	}
	return sqlite3_last_insert_rowid(db_);
}

boost::optional<JID> SQLiteHistoryManager::getJIDFromID(int id) const {
	boost::optional<JID> result;
	sqlite3_stmt* selectStatement;
	std::string selectQuery("SELECT jid FROM jids WHERE id=" + boost::lexical_cast<std::string>(id));
	int r = sqlite3_prepare(db_, selectQuery.c_str(), selectQuery.size(), &selectStatement, NULL);
	if (r != SQLITE_OK) {
		std::cout << "Error: " << sqlite3_errmsg(db_) << std::endl;
	}
	r = sqlite3_step(selectStatement);
	if (r == SQLITE_ROW) {
		result = boost::optional<JID>(reinterpret_cast<const char*>(sqlite3_column_text(selectStatement, 0)));
	}
	sqlite3_finalize(selectStatement);
	return result;
}

boost::optional<int> SQLiteHistoryManager::getIDFromJID(const JID& jid) const {
	boost::optional<int> result;
	sqlite3_stmt* selectStatement;
	std::string selectQuery("SELECT id FROM jids WHERE jid='" + jid.toString() + "'");
	int r = sqlite3_prepare(db_, selectQuery.c_str(), selectQuery.size(), &selectStatement, NULL);
	if (r != SQLITE_OK) {
		std::cout << "Error: " << sqlite3_errmsg(db_) << std::endl;
	}
	r = sqlite3_step(selectStatement);
	if (r == SQLITE_ROW) {
		result = boost::optional<int>(sqlite3_column_int(selectStatement, 0));
	}
	sqlite3_finalize(selectStatement);
	return result;
}

ContactsMap SQLiteHistoryManager::getContacts(const JID& selfJID, HistoryMessage::Type type, const std::string& keyword) const {
	ContactsMap result;
	sqlite3_stmt* selectStatement;

	// get id
	boost::optional<int> id = getIDFromJID(selfJID);
	if (!id) {
		return result;
	}

	// get contacts
	std::string query = "SELECT DISTINCT messages.'fromBare', messages.'fromResource', messages.'toBare', messages.'toResource', messages.'time' "
		"FROM messages WHERE (type="
		+ boost::lexical_cast<std::string>(type) + " AND (toBare="
		+ boost::lexical_cast<std::string>(*id) + " OR fromBare=" + boost::lexical_cast<std::string>(*id) + "))";

	// match keyword
	if (getEscapedString(keyword).length()) {
		query += " AND message LIKE '%" + getEscapedString(keyword) + "%'";
	}

	int r = sqlite3_prepare(db_, query.c_str(), query.size(), &selectStatement, NULL);
	if (r != SQLITE_OK) {
		std::cout << "Error: " << sqlite3_errmsg(db_) << std::endl;
	}

	r = sqlite3_step(selectStatement);
	while (r == SQLITE_ROW) {
		int fromBareID = sqlite3_column_int(selectStatement, 0);
		std::string fromResource(reinterpret_cast<const char*>(sqlite3_column_text(selectStatement, 1)));
		int toBareID = sqlite3_column_int(selectStatement, 2);
		std::string toResource(reinterpret_cast<const char*>(sqlite3_column_text(selectStatement, 3)));
		std::string resource;

		int secondsSinceEpoch(sqlite3_column_int(selectStatement, 4));
		boost::posix_time::ptime time(boost::gregorian::date(1970, 1, 1), boost::posix_time::seconds(secondsSinceEpoch));

		boost::optional<JID> contactJID;

		if (fromBareID == *id) {
			contactJID = getJIDFromID(toBareID);
			resource = toResource;
		}
		else {
			contactJID = getJIDFromID(fromBareID);
			resource = fromResource;
		}

		// check if it is a MUC contact (from a private conversation)
		if (type == HistoryMessage::PrivateMessage) {
			contactJID = boost::optional<JID>(JID(contactJID->getNode(), contactJID->getDomain(), resource));
		}

		if (contactJID) {
			result[*contactJID].insert(time.date());
		}

		r = sqlite3_step(selectStatement);
	}

	if (r != SQLITE_DONE) {
		std::cout << "Error: " << sqlite3_errmsg(db_) << std::endl;
	}
	sqlite3_finalize(selectStatement);

	return result;
}

boost::gregorian::date SQLiteHistoryManager::getNextDateWithLogs(const JID& selfJID, const JID& contactJID, HistoryMessage::Type type, const boost::gregorian::date& date, bool reverseOrder) const {
	sqlite3_stmt* selectStatement;
	boost::optional<int> selfID = getIDFromJID(selfJID.toBare());
	boost::optional<int> contactID = getIDFromJID(contactJID.toBare());

	if (!selfID || !contactID) {
		// JIDs missing from the database
		return boost::gregorian::date(boost::gregorian::not_a_date_time);
	}

	std::string selectQuery = "SELECT time FROM messages WHERE (type=" + boost::lexical_cast<std::string>(type);
	if (contactJID.isBare()) {
		// match only bare jid
		selectQuery += " AND ((fromBare=" + boost::lexical_cast<std::string>(*selfID) + " AND toBare=" +
				boost::lexical_cast<std::string>(*contactID) + ") OR (fromBare=" +
				boost::lexical_cast<std::string>(*contactID) + " AND toBare=" + boost::lexical_cast<std::string>(*selfID) + ")))";
	}
	else {
		// match resource too
		selectQuery += " AND ((fromBare=" + boost::lexical_cast<std::string>(*selfID) + " AND (toBare=" +
				boost::lexical_cast<std::string>(*contactID) +" AND toResource='" +
				getEscapedString(contactJID.getResource()) + "')) OR ((fromBare=" +
				boost::lexical_cast<std::string>(*contactID) + " AND fromResource='" +
				getEscapedString(contactJID.getResource()) + "') AND toBare=" +
				boost::lexical_cast<std::string>(*selfID) + ")))";
	}

	int timeStamp = (boost::posix_time::ptime(date) - boost::posix_time::ptime(boost::gregorian::date(1970, 1, 1))).total_seconds() + (reverseOrder ? 0 : 86400);

	selectQuery += " AND time" + (reverseOrder ? std::string("<") : std::string(">")) + boost::lexical_cast<std::string>(timeStamp);
	selectQuery += " ORDER BY time " + (reverseOrder ? std::string("DESC") : std::string("ASC")) + " LIMIT 1";

	int r = sqlite3_prepare(db_, selectQuery.c_str(), selectQuery.size(), &selectStatement, NULL);
	if (r != SQLITE_OK) {
		std::cout << "Error: " << sqlite3_errmsg(db_) << std::endl;
	}

	r = sqlite3_step(selectStatement);
	if (r == SQLITE_ROW) {
		int secondsSinceEpoch(sqlite3_column_int(selectStatement, 0));
		boost::posix_time::ptime time(boost::gregorian::date(1970, 1, 1), boost::posix_time::seconds(secondsSinceEpoch));
		std::cout << "next day is: " << time.date() << "\n";
		return time.date();
	}

	return boost::gregorian::date(boost::gregorian::not_a_date_time);
}

std::vector<HistoryMessage> SQLiteHistoryManager::getMessagesFromNextDate(const JID& selfJID, const JID& contactJID, HistoryMessage::Type type, const boost::gregorian::date& date) const {
	boost::gregorian::date nextDate = getNextDateWithLogs(selfJID, contactJID, type, date, false);

	if (nextDate.is_not_a_date()) {
		return std::vector<HistoryMessage>();
	}

	return getMessagesFromDate(selfJID, contactJID, type, nextDate);
}

std::vector<HistoryMessage> SQLiteHistoryManager::getMessagesFromPreviousDate(const JID& selfJID, const JID& contactJID, HistoryMessage::Type type, const boost::gregorian::date& date) const {
	boost::gregorian::date previousDate = getNextDateWithLogs(selfJID, contactJID, type, date, true);

	if (previousDate.is_not_a_date()) {
		return std::vector<HistoryMessage>();
	}

	return getMessagesFromDate(selfJID, contactJID, type, previousDate);
}

boost::posix_time::ptime SQLiteHistoryManager::getLastTimeStampFromMUC(const JID& selfJID, const JID& mucJID) const {
	boost::optional<int> selfID = getIDFromJID(selfJID.toBare());
	boost::optional<int> mucID = getIDFromJID(mucJID.toBare());

	if (!selfID || !mucID) {
		// JIDs missing from the database
		return boost::posix_time::ptime(boost::posix_time::not_a_date_time);
	}


	sqlite3_stmt* selectStatement;
	std::string selectQuery = "SELECT messages.'time', messages.'offset' from messages WHERE type=1 AND (toBare=" +
				boost::lexical_cast<std::string>(*selfID) + " AND fromBare=" +
				boost::lexical_cast<std::string>(*mucID) + ") ORDER BY time DESC LIMIT 1";

	int r = sqlite3_prepare(db_, selectQuery.c_str(), selectQuery.size(), &selectStatement, NULL);
	if (r != SQLITE_OK) {
		std::cout << "Error: " << sqlite3_errmsg(db_) << std::endl;
	}

	r = sqlite3_step(selectStatement);
	if (r == SQLITE_ROW) {
		int secondsSinceEpoch(sqlite3_column_int(selectStatement, 0));
		boost::posix_time::ptime time(boost::gregorian::date(1970, 1, 1), boost::posix_time::seconds(secondsSinceEpoch));
		int offset = sqlite3_column_int(selectStatement, 1);

		return time - boost::posix_time::hours(offset);
	}

	return boost::posix_time::ptime(boost::posix_time::not_a_date_time);
}

}