/*
 * Copyright (c) 2013 Kevin Smith
 * Licensed under the GNU General Public License v3.
 * See Documentation/Licenses/GPLv3.txt for more information.
 */

#include <Swift/Controllers/Chat/ChatMessageParser.h>

#include <vector>
#include <utility>

#include <boost/smart_ptr/make_shared.hpp>
#include <boost/algorithm/string.hpp>

#include <Swiften/Base/Regex.h>
#include <Swiften/Base/foreach.h>

#include <SwifTools/Linkify.h>


namespace Swift {

	ChatMessageParser::ChatMessageParser(const std::map<std::string, std::string>& emoticons) : emoticons_(emoticons) {

	}

	typedef std::pair<std::string, std::string> StringPair;

	ChatWindow::ChatMessage ChatMessageParser::parseMessageBody(const std::string& body) {
		ChatWindow::ChatMessage parsedMessage;
		std::string remaining = body;
		/* Parse one, URLs */
		while (!remaining.empty()) {
			bool found = false;
			std::pair<std::vector<std::string>, size_t> links = Linkify::splitLink(remaining);
			remaining = "";
			for (size_t i = 0; i < links.first.size(); i++) {
				const std::string& part = links.first[i];
				if (found) {
					// Must be on the last part, then
					remaining = part;
				}
				else {
					if (i == links.second) {
						found = true;
						parsedMessage.append(boost::make_shared<ChatWindow::ChatURIMessagePart>(part));
					}
					else {
						parsedMessage.append(boost::make_shared<ChatWindow::ChatTextMessagePart>(part));
					}
				}
			}
		}
		


		std::string regexString;
		/* Parse two, emoticons */
		foreach (StringPair emoticon, emoticons_) {
			/* Construct a regexp that finds an instance of any of the emoticons inside a group */
			regexString += regexString.empty() ? "(" : "|";
			regexString += Regex::escape(emoticon.first);
		}
		if (!regexString.empty()) {
			regexString += ")";
			boost::regex emoticonRegex(regexString);

			ChatWindow::ChatMessage newMessage;
			foreach (boost::shared_ptr<ChatWindow::ChatMessagePart> part, parsedMessage.getParts()) {
				boost::shared_ptr<ChatWindow::ChatTextMessagePart> textPart;
				if ((textPart = boost::dynamic_pointer_cast<ChatWindow::ChatTextMessagePart>(part))) {
					try {
						boost::match_results<std::string::const_iterator> match;
						const std::string& text = textPart->text;
						std::string::const_iterator start = text.begin();
						while (regex_search(start, text.end(), match, emoticonRegex)) {
							std::string::const_iterator matchStart = match[0].first;
							std::string::const_iterator matchEnd = match[0].second;
							if (start != matchStart) {
								/* If we're skipping over plain text since the previous emoticon, record it as plain text */
								newMessage.append(boost::make_shared<ChatWindow::ChatTextMessagePart>(std::string(start, matchStart)));
							}
							boost::shared_ptr<ChatWindow::ChatEmoticonMessagePart> emoticonPart = boost::make_shared<ChatWindow::ChatEmoticonMessagePart>();
							std::map<std::string, std::string>::const_iterator emoticonIterator = emoticons_.find(match.str());
							assert (emoticonIterator != emoticons_.end());
							const StringPair& emoticon = *emoticonIterator;
							emoticonPart->imagePath = emoticon.second;
							emoticonPart->alternativeText = emoticon.first;
							newMessage.append(emoticonPart);
							start = matchEnd;
						}
						if (start != text.end()) {
							/* If there's plain text after the last emoticon, record it */
							newMessage.append(boost::make_shared<ChatWindow::ChatTextMessagePart>(std::string(start, text.end())));
						}

					}
					catch (std::runtime_error) {
						/* Basically too expensive to compute the regex results and it gave up, so pass through as text */
						newMessage.append(part);
					}
				}
				else {
					newMessage.append(part);
				}
			}
			parsedMessage = newMessage;

		}
		return parsedMessage;
	}
}