/*
    Copyright (C) 2016 Volker Krause <vkrause@kde.org>
    Copyright (C) 2018 Dominik Haumann <dhaumann@kde.org>
    Copyright (C) 2018 Christoph Cullmann <cullmann@kde.org>

    Permission is hereby granted, free of charge, to any person obtaining
    a copy of this software and associated documentation files (the
    "Software"), to deal in the Software without restriction, including
    without limitation the rights to use, copy, modify, merge, publish,
    distribute, sublicense, and/or sell copies of the Software, and to
    permit persons to whom the Software is furnished to do so, subject to
    the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/


#include "definition.h"
#include "definition_p.h"
#include "definitionref_p.h"

#include "context_p.h"
#include "format.h"
#include "format_p.h"
#include "repository.h"
#include "repository_p.h"
#include "rule_p.h"
#include "ksyntaxhighlighting_logging.h"
#include "ksyntaxhighlighting_version.h"
#include "xml_p.h"

#include <QCoreApplication>
#include <QDebug>
#include <QFile>
#include <QHash>
#include <QJsonObject>
#include <QStringList>
#include <QVector>
#include <QXmlStreamReader>

#include <algorithm>

using namespace KSyntaxHighlighting;

DefinitionData::DefinitionData()
    : wordDelimiters(QStringLiteral("\t !%&()*+,-./:;<=>?[\\]^{|}~")) // must be sorted!
    , wordWrapDelimiters(wordDelimiters)
{
}

DefinitionData::~DefinitionData()
{
    qDeleteAll(contexts);
}

DefinitionData* DefinitionData::get(const Definition &def)
{
    return def.d.get();
}

Definition::Definition() :
    d(new DefinitionData)
{
}

Definition::Definition(const Definition &other) :
    d(other.d)
{
    d->q = *this;
}

Definition::Definition(const std::shared_ptr<DefinitionData> &dd) :
    d(dd)
{
}

Definition::~Definition()
{
}

Definition& Definition::operator=(const Definition &rhs)
{
    d = rhs.d;
    return *this;
}

bool Definition::operator==(const Definition &other) const
{
    return d->fileName == other.d->fileName;
}

bool Definition::operator!=(const Definition& other) const
{
    return d->fileName != other.d->fileName;
}

bool Definition::isValid() const
{
    return d->repo && !d->fileName.isEmpty() && !d->name.isEmpty();
}

QString Definition::filePath() const
{
    return d->fileName;
}

QString Definition::name() const
{
    return d->name;
}

QString Definition::translatedName() const
{
    return QCoreApplication::instance()->translate("Language", d->name.toUtf8().constData());
}

QString Definition::section() const
{
    return d->section;
}

QString Definition::translatedSection() const
{
    return QCoreApplication::instance()->translate("Language Section", d->section.toUtf8().constData());
}

QVector<QString> Definition::mimeTypes() const
{
    return d->mimetypes;
}

QVector<QString> Definition::extensions() const
{
    return d->extensions;
}

int Definition::version() const
{
    return d->version;
}

int Definition::priority() const
{
    return d->priority;
}

bool Definition::isHidden() const
{
    return d->hidden;
}

QString Definition::style() const
{
    return d->style;
}

QString Definition::indenter() const
{
    return d->indenter;
}

QString Definition::author() const
{
    return d->author;
}

QString Definition::license() const
{
    return d->license;
}

bool Definition::isWordDelimiter(QChar c) const
{
    d->load();
    return d->isWordDelimiter(c);
}

bool Definition::isWordWrapDelimiter(QChar c) const
{
    d->load();
    return std::binary_search(d->wordWrapDelimiters.constBegin(), d->wordWrapDelimiters.constEnd(), c);
}

bool Definition::foldingEnabled() const
{
    d->load();
    if (d->hasFoldingRegions || indentationBasedFoldingEnabled()) {
        return true;
    }

    // check included definitions
    const auto defs = includedDefinitions();
    for (const auto &def : defs) {
        if (def.foldingEnabled()) {
            d->hasFoldingRegions = true;
            break;
        }
    }

    return d->hasFoldingRegions;
}

bool Definition::indentationBasedFoldingEnabled() const
{
    d->load();
    return d->indentationBasedFolding;
}

QStringList Definition::foldingIgnoreList() const
{
    d->load();
    return d->foldingIgnoreList;
}

QStringList Definition::keywordLists() const
{
    d->load(DefinitionData::OnlyKeywords(true));
    return d->keywordLists.keys();
}

QStringList Definition::keywordList(const QString& name) const
{
    d->load(DefinitionData::OnlyKeywords(true));
    const auto list = d->keywordList(name);
    return list ? list->keywords() : QStringList();
}

QVector<Format> Definition::formats() const
{
    d->load();

    // sort formats so that the order matches the order of the itemDatas in the xml files.
    auto formatList = QVector<Format>::fromList(d->formats.values());
    std::sort(formatList.begin(), formatList.end(), [](const KSyntaxHighlighting::Format & lhs, const KSyntaxHighlighting::Format & rhs){
        return lhs.id() < rhs.id();
    });

    return formatList;
}

QVector<Definition> Definition::includedDefinitions() const
{
    d->load();

    // init worklist and result used as guard with this definition
    QVector<Definition> queue{*this};
    QVector<Definition> definitions{*this};
    while (!queue.isEmpty()) {
        // Iterate all context rules to find associated Definitions. This will
        // automatically catch other Definitions referenced with IncludeRuldes or ContextSwitch.
        const auto definition = queue.takeLast();
        for (const auto & context : qAsConst(definition.d->contexts)) {
            // handle context switch attributes of this context itself
            for (const auto switchContext : {context->lineEndContext().context(), context->lineEmptyContext().context(), context->fallthroughContext().context()}) {
                if (switchContext) {
                    if (!definitions.contains(switchContext->definition())) {
                        queue.push_back(switchContext->definition());
                        definitions.push_back(switchContext->definition());
                    }
                }
            }

            // handle the embedded rules
            for (const auto &rule : context->rules()) {
                // handle include rules like inclusion
                if (!definitions.contains(rule->definition())) {
                    queue.push_back(rule->definition());
                    definitions.push_back(rule->definition());
                }

                // handle context switch context inclusion
                if (auto switchContext = rule->context().context()) {
                    if (!definitions.contains(switchContext->definition())) {
                        queue.push_back(switchContext->definition());
                        definitions.push_back(switchContext->definition());
                    }
                }
            }
        }
    }

    // remove the 1st entry, since it is this Definition
    definitions.pop_front();

    return definitions;
}

QString Definition::singleLineCommentMarker() const
{
    d->load();
    return d->singleLineCommentMarker;
}

CommentPosition Definition::singleLineCommentPosition() const
{
    d->load();
    return d->singleLineCommentPosition;
}

QPair<QString, QString> Definition::multiLineCommentMarker() const
{
    d->load();
    return { d->multiLineCommentStartMarker, d->multiLineCommentEndMarker };
}

QVector<QPair<QChar, QString>> Definition::characterEncodings() const
{
    d->load();
    return d->characterEncodings;
}

Context* DefinitionData::initialContext() const
{
    Q_ASSERT(!contexts.isEmpty());
    return contexts.first();
}

Context* DefinitionData::contextByName(const QString& name) const
{
    foreach (auto context, contexts) {
        if (context->name() == name)
            return context;
    }
    return nullptr;
}

KeywordList *DefinitionData::keywordList(const QString& name)
{
    auto it = keywordLists.find(name);
    return (it == keywordLists.end()) ? nullptr : &it.value();
}

bool DefinitionData::isWordDelimiter(QChar c) const
{
    return std::binary_search(wordDelimiters.constBegin(), wordDelimiters.constEnd(), c);
}

Format DefinitionData::formatByName(const QString& name) const
{
    const auto it = formats.constFind(name);
    if (it != formats.constEnd())
        return it.value();

    return Format();
}

bool DefinitionData::isLoaded() const
{
    return !contexts.isEmpty();
}

bool DefinitionData::load(OnlyKeywords onlyKeywords)
{
    if (fileName.isEmpty())
        return false;

    if (isLoaded())
        return true;

    if (bool(onlyKeywords) && keywordIsLoaded)
        return true;

    QFile file(fileName);
    if (!file.open(QFile::ReadOnly))
        return false;

    QXmlStreamReader reader(&file);
    while (!reader.atEnd()) {
        const auto token = reader.readNext();
        if (token != QXmlStreamReader::StartElement)
            continue;

        if (reader.name() == QLatin1String("highlighting")) {
            loadHighlighting(reader, onlyKeywords);
            if (bool(onlyKeywords)) {
                return true;
            }
        }

        else if (reader.name() == QLatin1String("general"))
            loadGeneral(reader);
    }

    for (auto it = keywordLists.begin(); it != keywordLists.end(); ++it) {
        it->setCaseSensitivity(caseSensitive);
    }

    foreach (auto context, contexts) {
        context->resolveContexts();
        context->resolveIncludes();
        context->resolveAttributeFormat();
    }

    Q_ASSERT(std::is_sorted(wordDelimiters.constBegin(), wordDelimiters.constEnd()));
    return true;
}

void DefinitionData::clear()
{
    // keep only name and repo, so we can re-lookup to make references persist over repo reloads
    keywordLists.clear();
    qDeleteAll(contexts);
    contexts.clear();
    formats.clear();

    fileName.clear();
    section.clear();
    style.clear();
    indenter.clear();
    author.clear();
    license.clear();
    mimetypes.clear();
    extensions.clear();
    wordDelimiters = QStringLiteral("\t !%&()*+,-./:;<=>?[\\]^{|}~"); // must be sorted!
    wordWrapDelimiters = wordDelimiters;
    caseSensitive = Qt::CaseSensitive;
    version = 0.0f;
    priority = 0;
    hidden = false;
}

bool DefinitionData::loadMetaData(const QString& definitionFileName)
{
    fileName = definitionFileName;

    QFile file(definitionFileName);
    if (!file.open(QFile::ReadOnly))
        return false;

    QXmlStreamReader reader(&file);
    while (!reader.atEnd()) {
        const auto token = reader.readNext();
        if (token != QXmlStreamReader::StartElement)
            continue;
        if (reader.name() == QLatin1String("language")) {
            return loadLanguage(reader);
        }
    }

    return false;
}

bool DefinitionData::loadMetaData(const QString &file, const QJsonObject &obj)
{
    name     = obj.value(QLatin1String("name")).toString();
    section  = obj.value(QLatin1String("section")).toString();
    version  = obj.value(QLatin1String("version")).toInt();
    priority = obj.value(QLatin1String("priority")).toInt();
    style    = obj.value(QLatin1String("style")).toString();
    author   = obj.value(QLatin1String("author")).toString();
    license  = obj.value(QLatin1String("license")).toString();
    indenter = obj.value(QLatin1String("indenter")).toString();
    hidden   = obj.value(QLatin1String("hidden")).toBool();
    fileName = file;

    const auto exts = obj.value(QLatin1String("extensions")).toString();
    foreach (const auto &ext, exts.split(QLatin1Char(';'), QString::SkipEmptyParts))
        extensions.push_back(ext);
    const auto mts = obj.value(QLatin1String("mimetype")).toString();
    foreach (const auto &mt, mts.split(QLatin1Char(';'), QString::SkipEmptyParts))
        mimetypes.push_back(mt);

    return true;
}

bool DefinitionData::loadLanguage(QXmlStreamReader &reader)
{
    Q_ASSERT(reader.name() == QLatin1String("language"));
    Q_ASSERT(reader.tokenType() == QXmlStreamReader::StartElement);

    if (!checkKateVersion(reader.attributes().value(QStringLiteral("kateversion"))))
        return false;

    name = reader.attributes().value(QStringLiteral("name")).toString();
    section = reader.attributes().value(QStringLiteral("section")).toString();
    // toFloat instead of toInt for backward compatibility with old Kate files
    version = reader.attributes().value(QStringLiteral("version")).toFloat();
    priority = reader.attributes().value(QStringLiteral("priority")).toInt();
    hidden = Xml::attrToBool(reader.attributes().value(QStringLiteral("hidden")));
    style = reader.attributes().value(QStringLiteral("style")).toString();
    indenter = reader.attributes().value(QStringLiteral("indenter")).toString();
    author = reader.attributes().value(QStringLiteral("author")).toString();
    license = reader.attributes().value(QStringLiteral("license")).toString();
    const auto exts = reader.attributes().value(QStringLiteral("extensions")).toString();
    foreach (const auto &ext, exts.split(QLatin1Char(';'), QString::SkipEmptyParts))
        extensions.push_back(ext);
    const auto mts = reader.attributes().value(QStringLiteral("mimetype")).toString();
    foreach (const auto &mt, mts.split(QLatin1Char(';'), QString::SkipEmptyParts))
        mimetypes.push_back(mt);
    if (reader.attributes().hasAttribute(QStringLiteral("casesensitive")))
        caseSensitive = Xml::attrToBool(reader.attributes().value(QStringLiteral("casesensitive"))) ? Qt::CaseSensitive : Qt::CaseInsensitive;
    return true;
}

void DefinitionData::loadHighlighting(QXmlStreamReader& reader, OnlyKeywords onlyKeywords)
{
    Q_ASSERT(reader.name() == QLatin1String("highlighting"));
    Q_ASSERT(reader.tokenType() == QXmlStreamReader::StartElement);

    // skip highlighting
    reader.readNext();

    while (!reader.atEnd()) {
        switch (reader.tokenType()) {
            case QXmlStreamReader::StartElement:
                if (reader.name() == QLatin1String("list")) {
                    if (!keywordIsLoaded) {
                        KeywordList keywords;
                        keywords.load(reader);
                        keywordLists.insert(keywords.name(), keywords);
                    }
                    else {
                        reader.skipCurrentElement();
                        reader.readNext(); // Skip </list>
                    }
                } else if (bool(onlyKeywords)) {
                    resolveIncludeKeywords();
                    return;
                } else if (reader.name() == QLatin1String("contexts")) {
                    resolveIncludeKeywords();
                    loadContexts(reader);
                    reader.readNext();
                } else if (reader.name() == QLatin1String("itemDatas")) {
                    loadItemData(reader);
                } else {
                    reader.readNext();
                }
                break;
            case QXmlStreamReader::EndElement:
                return;
            default:
                reader.readNext();
                break;
        }
    }
}

void DefinitionData::resolveIncludeKeywords()
{
    if (keywordIsLoaded) {
        return;
    }

    keywordIsLoaded = true;

    for (auto it = keywordLists.begin(); it != keywordLists.end(); ++it) {
        it->resolveIncludeKeywords(*this);
    }
}

void DefinitionData::loadContexts(QXmlStreamReader& reader)
{
    Q_ASSERT(reader.name() == QLatin1String("contexts"));
    Q_ASSERT(reader.tokenType() == QXmlStreamReader::StartElement);

    while (!reader.atEnd()) {
        switch (reader.tokenType()) {
            case QXmlStreamReader::StartElement:
                if (reader.name() == QLatin1String("context")) {
                    auto context = new Context;
                    context->setDefinition(q);
                    context->load(reader);
                    contexts.push_back(context);
                }
                reader.readNext();
                break;
            case QXmlStreamReader::EndElement:
                return;
            default:
                reader.readNext();
                break;
        }
    }
}

void DefinitionData::loadItemData(QXmlStreamReader& reader)
{
    Q_ASSERT(reader.name() == QLatin1String("itemDatas"));
    Q_ASSERT(reader.tokenType() == QXmlStreamReader::StartElement);

    while (!reader.atEnd()) {
        switch (reader.tokenType()) {
            case QXmlStreamReader::StartElement:
                if (reader.name() == QLatin1String("itemData")) {
                    Format f;
                    auto formatData = FormatPrivate::detachAndGet(f);
                    formatData->definition = q;
                    formatData->load(reader);
                    formatData->id = RepositoryPrivate::get(repo)->nextFormatId();
                    formats.insert(f.name(), f);
                    reader.readNext();
                }
                reader.readNext();
                break;
            case QXmlStreamReader::EndElement:
                return;
            default:
                reader.readNext();
                break;
        }
    }
}

void DefinitionData::loadGeneral(QXmlStreamReader& reader)
{
    Q_ASSERT(reader.name() == QLatin1String("general"));
    Q_ASSERT(reader.tokenType() == QXmlStreamReader::StartElement);
    reader.readNext();

    // reference counter to count XML child elements, to not return too early
    int elementRefCounter = 1;

    while (!reader.atEnd()) {
        switch (reader.tokenType()) {
            case QXmlStreamReader::StartElement:
                ++elementRefCounter;

                if (reader.name() == QLatin1String("keywords")) {
                    if (reader.attributes().hasAttribute(QStringLiteral("casesensitive")))
                        caseSensitive = Xml::attrToBool(reader.attributes().value(QStringLiteral("casesensitive"))) ? Qt::CaseSensitive : Qt::CaseInsensitive;

                    // adapt sorted wordDelimiters
                    wordDelimiters += reader.attributes().value(QStringLiteral("additionalDeliminator"));
                    std::sort(wordDelimiters.begin(), wordDelimiters.end());
                    auto it = std::unique(wordDelimiters.begin(), wordDelimiters.end());
                    wordDelimiters.truncate(std::distance(wordDelimiters.begin(), it));
                    foreach (const auto c, reader.attributes().value(QLatin1String("weakDeliminator")))
                        wordDelimiters.remove(c);

                    // adaptWordWrapDelimiters, and sort
                    wordWrapDelimiters = reader.attributes().value(QStringLiteral("wordWrapDeliminator")).toString();
                    std::sort(wordWrapDelimiters.begin(), wordWrapDelimiters.end());
                    if (wordWrapDelimiters.isEmpty())
                        wordWrapDelimiters = wordDelimiters;
                } else if (reader.name() == QLatin1String("folding")) {
                    if (reader.attributes().hasAttribute(QStringLiteral("indentationsensitive")))
                        indentationBasedFolding = Xml::attrToBool(reader.attributes().value(QStringLiteral("indentationsensitive")));
                } else if (reader.name() == QLatin1String("emptyLines")) {
                    loadFoldingIgnoreList(reader);
                } else if (reader.name() == QLatin1String("comments")) {
                    loadComments(reader);
                } else if (reader.name() == QLatin1String("spellchecking")) {
                    loadSpellchecking(reader);
                } else {
                    reader.skipCurrentElement();
                }
                reader.readNext();
                break;
            case QXmlStreamReader::EndElement:
                --elementRefCounter;
                if (elementRefCounter == 0)
                    return;
                reader.readNext();
                break;
            default:
                reader.readNext();
                break;
        }
    }
}

void DefinitionData::loadComments(QXmlStreamReader &reader)
{
    Q_ASSERT(reader.name() == QLatin1String("comments"));
    Q_ASSERT(reader.tokenType() == QXmlStreamReader::StartElement);
    reader.readNext();

    // reference counter to count XML child elements, to not return too early
    int elementRefCounter = 1;

    while (!reader.atEnd()) {
        switch (reader.tokenType()) {
            case QXmlStreamReader::StartElement:
                ++elementRefCounter;
                if (reader.name() == QLatin1String("comment")) {
                    const bool isSingleLine = reader.attributes().value(QStringLiteral("name")) == QStringLiteral("singleLine");
                    if (isSingleLine) {
                        singleLineCommentMarker = reader.attributes().value(QStringLiteral("start")).toString();
                        const bool afterWhiteSpace = reader.attributes().value(QStringLiteral("position")).toString() == QStringLiteral("afterwhitespace");
                        singleLineCommentPosition = afterWhiteSpace ? CommentPosition::AfterWhitespace : CommentPosition::StartOfLine;
                    } else {
                        multiLineCommentStartMarker = reader.attributes().value(QStringLiteral("start")).toString();
                        multiLineCommentEndMarker = reader.attributes().value(QStringLiteral("end")).toString();
                    }
                }
                reader.readNext();
                break;
            case QXmlStreamReader::EndElement:
                --elementRefCounter;
                if (elementRefCounter == 0)
                    return;
                reader.readNext();
                break;
            default:
                reader.readNext();
                break;
        }
    }
}

void DefinitionData::loadFoldingIgnoreList(QXmlStreamReader& reader)
{
    Q_ASSERT(reader.name() == QLatin1String("emptyLines"));
    Q_ASSERT(reader.tokenType() == QXmlStreamReader::StartElement);
    reader.readNext();

    // reference counter to count XML child elements, to not return too early
    int elementRefCounter = 1;

    while (!reader.atEnd()) {
        switch (reader.tokenType()) {
            case QXmlStreamReader::StartElement:
                ++elementRefCounter;
                if (reader.name() == QLatin1String("emptyLine")) {
                    foldingIgnoreList << reader.attributes().value(QStringLiteral("regexpr")).toString();
                }
                reader.readNext();
                break;
            case QXmlStreamReader::EndElement:
                --elementRefCounter;
                if (elementRefCounter == 0)
                    return;
                reader.readNext();
                break;
            default:
                reader.readNext();
                break;
        }
    }
}

void DefinitionData::loadSpellchecking(QXmlStreamReader &reader)
{
    Q_ASSERT(reader.name() == QLatin1String("spellchecking"));
    Q_ASSERT(reader.tokenType() == QXmlStreamReader::StartElement);
    reader.readNext();

    // reference counter to count XML child elements, to not return too early
    int elementRefCounter = 1;

    while (!reader.atEnd()) {
        switch (reader.tokenType()) {
            case QXmlStreamReader::StartElement:
                ++elementRefCounter;
                if (reader.name() == QLatin1String("encoding")) {
                    const auto charRef = reader.attributes().value(QStringLiteral("char"));
                    if (!charRef.isEmpty()) {
                        const auto str = reader.attributes().value(QStringLiteral("string")).toString();
                        characterEncodings.push_back({ charRef[0], str });
                    }
                }
                reader.readNext();
                break;
            case QXmlStreamReader::EndElement:
                --elementRefCounter;
                if (elementRefCounter == 0)
                    return;
                reader.readNext();
                break;
            default:
                reader.readNext();
                break;
        }
    }
}

bool DefinitionData::checkKateVersion(const QStringRef& verStr)
{
    const auto idx = verStr.indexOf(QLatin1Char('.'));
    if (idx <= 0) {
        qCWarning(Log) << "Skipping" << fileName << "due to having no valid kateversion attribute:" << verStr;
        return false;
    }
    const auto major = verStr.left(idx).toInt();
    const auto minor = verStr.mid(idx + 1).toInt();

    if (major > SyntaxHighlighting_VERSION_MAJOR || (major == SyntaxHighlighting_VERSION_MAJOR && minor > SyntaxHighlighting_VERSION_MINOR)) {
        qCWarning(Log) << "Skipping" << fileName << "due to being too new, version:" << verStr;
        return false;
    }

    return true;
}

quint16 DefinitionData::foldingRegionId(const QString &foldName)
{
    hasFoldingRegions = true;
    return RepositoryPrivate::get(repo)->foldingRegionId(name, foldName);
}

DefinitionRef::DefinitionRef()
{
}

DefinitionRef::DefinitionRef(const Definition &def) :
    d(def.d)
{
}

DefinitionRef::~DefinitionRef()
{
}

DefinitionRef& DefinitionRef::operator=(const Definition &def)
{
    d = def.d;
    return *this;
}

Definition DefinitionRef::definition() const
{
    if (!d.expired())
        return Definition(d.lock());
    return Definition();
}

bool DefinitionRef::operator==(const DefinitionRef &other) const
{
    if (d.expired() != other.d.expired()) {
        return false;
    }

    return d.expired() || d.lock().get() == other.d.lock().get();
}
