// Copyright 2005-2020 The Mumble Developers. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file at the root of the
// Mumble source tree or at <https://www.mumble.info/LICENSE>.

#include "XMLTools.h"

#include <QXmlStreamReader>
#include <QXmlStreamWriter>
#include <QStringList>

void XMLTools::recurseParse(QXmlStreamReader &reader,
							QXmlStreamWriter &writer,
							int &paragraphs,
							const QMap<QString, QString> &opstyle,
							const int close,
							bool ignore) {
	while (! reader.atEnd()) {
		QXmlStreamReader::TokenType tt = reader.readNext();

		QXmlStreamAttributes a = reader.attributes();
		QMap<QString, QString> style;
		QMap<QString, QString> pstyle = opstyle;

		QStringRef styleref = a.value(QLatin1String("style"));
		if (!styleref.isNull()) {
			QString stylestring = styleref.toString();
			QStringList styles = stylestring.split(QLatin1String(";"), QString::SkipEmptyParts);
			foreach(QString s, styles) {
				s = s.simplified();
				int idx = s.indexOf(QLatin1Char(':'));
				QString key = (idx > 0) ? s.left(idx).simplified() : s;
				QString val = (idx > 0) ? s.mid(idx+1).simplified() : QString();

				if (! pstyle.contains(key) || (pstyle.value(key) != val)) {
					style.insert(key,val);
					pstyle.insert(key,val);
				}
			}
		}

		switch (tt) {
			case QXmlStreamReader::StartElement: {
					QString name = reader.name().toString();
					int rclose = 1;
					if (name == QLatin1String("body")) {
						rclose = 0;
						ignore = false;
					} else if (name == QLatin1String("span")) {
						// Substitute style with <b>, <i> and <u>

						rclose = 0;
						if (style.value(QLatin1String("font-weight")) == QLatin1String("600")) {
							writer.writeStartElement(QLatin1String("b"));
							rclose++;
							style.remove(QLatin1String("font-weight"));
						}
						if (style.value(QLatin1String("font-style")) == QLatin1String("italic")) {
							writer.writeStartElement(QLatin1String("i"));
							rclose++;
							style.remove(QLatin1String("font-style"));
						}
						if (style.value(QLatin1String("text-decoration")) == QLatin1String("underline")) {
							writer.writeStartElement(QLatin1String("u"));
							rclose++;
							style.remove(QLatin1String("text-decoration"));
						}
						if (! style.isEmpty()) {
							rclose++;
							writer.writeStartElement(name);

							QStringList qsl;
							QMap<QString, QString>::const_iterator i;
							for (i=style.constBegin(); i != style.constEnd(); ++i) {
								if (! i.value().isEmpty())
									qsl << QString::fromLatin1("%1:%2").arg(i.key(), i.value());
								else
									qsl << i.key();
							}

							writer.writeAttribute(QLatin1String("style"), qsl.join(QLatin1String("; ")));
						}
					} else if (name == QLatin1String("p")) {
						paragraphs++;
						if (paragraphs == 1) {
							// Ignore first paragraph. If it is styled empty drop its contents (e.g. <br />) too.
							if (style.value(QLatin1String("-qt-paragraph-type")) == QLatin1String("empty")) {
								reader.skipCurrentElement();
								continue;
							}
							rclose = 0;
						}
						else {
							rclose = 1;
							writer.writeStartElement(name);

							if (! style.isEmpty()) {
								QStringList qsl;
								QMap<QString, QString>::const_iterator i;
								for (i=style.constBegin(); i != style.constEnd(); ++i) {
									if (! i.value().isEmpty())
										qsl << QString::fromLatin1("%1:%2").arg(i.key(), i.value());
									else
										qsl << i.key();
								}

								writer.writeAttribute(QLatin1String("style"), qsl.join(QLatin1String("; ")));
							}
						}
					} else if (name == QLatin1String("a")) {
						// Set pstyle to include implicit blue underline.
						rclose = 1;
						writer.writeCurrentToken(reader);
						pstyle.insert(QLatin1String("text-decoration"), QLatin1String("underline"));
						pstyle.insert(QLatin1String("color"), QLatin1String("#0000ff"));
					} else if (! ignore) {
						rclose = 1;
						writer.writeCurrentToken(reader);
					}

					recurseParse(reader, writer, paragraphs, pstyle, rclose, ignore);
					break;
				}
			case QXmlStreamReader::EndElement:
				if (!ignore)
					for (int i=0;i<close;++i)
						writer.writeEndElement();
				return;
			case QXmlStreamReader::Characters:
				if (! ignore)
					writer.writeCharacters(reader.text().toString());
				break;
			default:
				break;
		}
	}
}

bool XMLTools::unduplicateTags(QXmlStreamReader &reader, QXmlStreamWriter &writer) {
	bool changed = false;
	bool needclose = false;

	QStringList qslConcat;
	qslConcat << QLatin1String("b");
	qslConcat << QLatin1String("i");
	qslConcat << QLatin1String("u");
	qslConcat << QLatin1String("a");

	QList<QString> qlNames;
	QList<QXmlStreamAttributes> qlAttributes;

	while (! reader.atEnd()) {
		QXmlStreamReader::TokenType tt = reader.readNext();
		QString name = reader.name().toString();
		switch (tt) {
			case QXmlStreamReader::StartDocument:
			case QXmlStreamReader::EndDocument:
				break;
			case QXmlStreamReader::StartElement: {
					QXmlStreamAttributes a = reader.attributes();

					if (name == QLatin1String("unduplicate"))
						break;

					if (needclose) {
						needclose = false;

						if ((a == qlAttributes.last()) && (name == qlNames.last()) && (qslConcat.contains(name))) {
							changed = true;
							break;
						}
						qlNames.takeLast();
						qlAttributes.takeLast();
						writer.writeEndElement();
					}
					writer.writeCurrentToken(reader);
					qlNames.append(name);
					qlAttributes.append(a);
				}
				break;
			case QXmlStreamReader::EndElement: {
					if (name == QLatin1String("unduplicate"))
						break;
					if (needclose) {
						qlNames.takeLast();
						qlAttributes.takeLast();
						writer.writeCurrentToken(reader);
					}
					needclose = true;
				}
				break;
			default:
				if (needclose) {
					writer.writeEndElement();
					needclose = false;
				}
				writer.writeCurrentToken(reader);
		}
	}
	if (needclose)
		writer.writeEndElement();
	return changed;
}