/*
 * 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, HighlightRulesListPtr highlightRules, bool mucMode)
	: emoticons_(emoticons), highlightRules_(highlightRules), mucMode_(mucMode)
	{
	}

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

	ChatWindow::ChatMessage ChatMessageParser::parseMessageBody(const std::string& body, bool senderIsSelf) {
		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));
					}
				}
			}
		}

		/* do emoticon substitution */
		parsedMessage = emoticonHighlight(parsedMessage);

		if (!senderIsSelf) { /* do not highlight our own messsages */
			/* do word-based color highlighting */
			parsedMessage = splitHighlight(parsedMessage);
		}

		return parsedMessage;
	}

	ChatWindow::ChatMessage ChatMessageParser::emoticonHighlight(const ChatWindow::ChatMessage& message)
	{
		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()) {
			return message;
		}

		regexString += ")";
		boost::regex emoticonRegex(regexString);

		ChatWindow::ChatMessage newMessage;
		foreach (boost::shared_ptr<ChatWindow::ChatMessagePart> part, message.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);
			}
		}

		return newMessage;
	}

	ChatWindow::ChatMessage ChatMessageParser::splitHighlight(const ChatWindow::ChatMessage& message)
	{
		ChatWindow::ChatMessage parsedMessage = message;

		for (size_t i = 0; i < highlightRules_->getSize(); ++i) {
			const HighlightRule& rule = highlightRules_->getRule(i);
			if (rule.getMatchMUC() && !mucMode_) {
				continue; /* this rule only applies to MUC's, and this is a CHAT */
			} else if (rule.getMatchChat() && mucMode_) {
				continue; /* this rule only applies to CHAT's, and this is a MUC */
			}
			foreach(const boost::regex &regex, rule.getKeywordRegex()) {
				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, regex)) {
								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::ChatHighlightingMessagePart> highlightPart = boost::make_shared<ChatWindow::ChatHighlightingMessagePart>();
								highlightPart->text = match.str();
								highlightPart->foregroundColor = rule.getAction().getTextColor();
								highlightPart->backgroundColor = rule.getAction().getTextBackground();
								newMessage.append(highlightPart);
								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;
	}
}