#include "xmlpatch.h"

XmlPatch::XmlPatch(QString patchFilesWildcard, QString forceTargetFilesWildcard, bool noBackups)
{
    this->patchFilesToProcess=UtilXmlTools::getAllPatchFilesByWildcard(patchFilesWildcard);
    this->forceTargetFilesWildcard=forceTargetFilesWildcard;
    this->backupsEnabled=!noBackups;

    if(forceTargetFilesWildcard!=""){
        std::cout << "User forced patch in the target file(s): " << forceTargetFilesWildcard.toLatin1().constData() << std::endl;
    }

    if(this->patchFilesToProcess.isEmpty()){
        UtilXmlTools::displayErrorMessage("Loading patch files","No .patch or .oni-patch files were found for the wildcard: "+patchFilesWildcard);
    }

}

void XmlPatch::readAndProcessPatchFile(){

    // Process all PatchFiles
    for(int i=0; i<this->patchFilesToProcess.size(); i++){

        QFile inputFile(this->patchFilesToProcess[i]);

        if (inputFile.open(QIODevice::ReadOnly))
        {

            QTextStream fileStream(&inputFile);

            checkPatchVersion(this->patchFilesToProcess[i], fileStream);
            checkAndProcessValidCommands(fileStream);

            inputFile.close();
        }
        else{
            UtilXmlTools::displayErrorMessage("Read patch file", "Error opening patch file: '" + this->patchFilesToProcess[i] + "'.\n" + inputFile.errorString());
        }

    }

    UtilXmlTools::displaySuccessMessage(this->patchFilesToProcess.size(),"Patch File(s)");

}

void XmlPatch::insertNodesOperation(const QString &xmlString, XmlFilter &filters, const QString &xPathExpression, const QString &filesWildcard){

    QStringList filesToProcess;
    QList<pugi::xml_node> nodesToInsertion;
    pugi::xml_document newNode;
    pugi::xml_parse_result result;

    filesToProcess=UtilXmlTools::getAllXmlFilesByWildcard(filesWildcard);

    if(filesToProcess.isEmpty()){
        UtilXmlTools::displayErrorMessage("@ADD_INSIDE_NODES","No XML files were found for the wildcard: "+filesWildcard);
    }

    result=newNode.load(xmlString.toLatin1().constData()); // load xml to insert

    if(result.status!=pugi::status_ok){
        UtilXmlTools::displayErrorMessage("@ADD_INSIDE_NODES", "The xml node to insert is invalid.\n" + Util::toQString(result.description()));
    }

    // Process all XmlFiles
    for(int i=0; i<filesToProcess.size(); i++){

        UtilXmlTools::loadXmlFile(filesToProcess[i],this->document,this->rootNode,this->backupsEnabled,"@ADD_INSIDE_NODES");

        // Check how the element will be fetched via element name or xpath expression
        if(xPathExpression.isEmpty()){
            UtilXmlTools::getAllNamedElements(this->rootNode,nodesToInsertion,filters);
        }
        else{
            UtilXmlTools::getAllXpathElements(xPathExpression,this->document,nodesToInsertion);
        }

        if(nodesToInsertion[0].type()==pugi::node_null){

            QString errMessage;

            if(xPathExpression.isEmpty()){
                errMessage = "It wasn't found any node with a ElementName: '" + filters.getElementName() + "'";
                if(filters.getParentElementName()!=""){
                    errMessage += " and a ParentElementName: '" + filters.getParentElementName() + "'";
                }
                if(filters.getAttributeName()!=""){
                    errMessage += " and an AttributeName: '" + filters.getAttributeName() + "' and an AttributeValue: '" + filters.getAttributeValue() + "'";
                }
            }
            else{
                errMessage = "It wasn't found any node with a XPathExpression: '" + xPathExpression + "'";
            }

            UtilXmlTools::displayErrorMessage("@ADD_INSIDE_NODES",errMessage);
        }

        for(int j=0; j<nodesToInsertion.size(); j++){
            nodesToInsertion[j].prepend_copy(newNode.first_child()); // append the new node
        }


        UtilXmlTools::saveXmlFile(filesToProcess[i],this->document, "@ADD_INSIDE_NODES");
    }

    UtilXmlTools::displaySuccessMessage(filesToProcess.size(),"@ADD_INSIDE_NODES");
}

void XmlPatch::removeNodesOperation(XmlFilter &filters, const QString &xPathExpression, const QString &filesWildcard){

    QStringList filesToProcess;

    QList<pugi::xml_node> nodesToDeletion;

    filesToProcess=UtilXmlTools::getAllXmlFilesByWildcard(filesWildcard);

    if(filesToProcess.isEmpty()){
        UtilXmlTools::displayErrorMessage("@REMOVE_NODES","No XML files were found for the wildcard: "+filesWildcard);
    }

    // Process all XmlFiles
    for(int i=0; i<filesToProcess.size(); i++){

        UtilXmlTools::loadXmlFile(filesToProcess[i],this->document,this->rootNode,this->backupsEnabled,"@REMOVE_NODES");

        // Check how the element will be fetched via element name or xpath expression
        if(xPathExpression.isEmpty()){
            UtilXmlTools::getAllNamedElements(this->rootNode,nodesToDeletion,filters);
        }
        else{
            UtilXmlTools::getAllXpathElements(xPathExpression,this->document,nodesToDeletion);
        }

        if(nodesToDeletion[0].type()==pugi::node_null){

            QString errMessage;

            if(xPathExpression.isEmpty()){
                errMessage = "It wasn't found any node with a ElementName: '" + filters.getElementName() + "'";
                if(filters.getParentElementName()!=""){
                    errMessage += " and a ParentElementName: '" + filters.getParentElementName() + "'";
                }
                if(filters.getAttributeName()!=""){
                    errMessage += " and an AttributeName: '" + filters.getAttributeName() + "' and an AttributeValue: '" + filters.getAttributeValue() + "'";
                }
            }
            else{
                errMessage = "It wasn't found any node with a XPathExpression: '" + xPathExpression + "'";
            }

            UtilXmlTools::displayErrorMessage("@REMOVE_NODES",errMessage);
        }

        // Delete all the specified nodes
        for(int j=0; j<nodesToDeletion.size(); j++){
            if(!nodesToDeletion[j].parent().remove_child(nodesToDeletion[j])){  // remove the node

                QString errMessage;
                if(xPathExpression.isEmpty()){
                    errMessage = "Couldn't remove the node with Element '" + filters.getElementName() + "'";

                    if(filters.getParentElementName()!=""){
                        errMessage += " and a ParentElement: '" + filters.getParentElementName() + "'";
                    }
                }
                else{
                    errMessage = "Couldn't remove the node with the XPathExpression '" + xPathExpression + "'";
                }

                UtilXmlTools::displayErrorMessage("@REMOVE_NODES",errMessage);
            }
        }

        UtilXmlTools::saveXmlFile(filesToProcess[i],this->document, "@REMOVE_NODES");
    }

    UtilXmlTools::displaySuccessMessage(filesToProcess.size(), "@REMOVE_NODES");
}

void XmlPatch::executeCommandOperation(const QString &commandString){

    QProcess newXmlToolsInstance;
    QString resultOutput;

    // Avoid infinite fork loops
    if(commandString.contains(" -p ") || commandString.contains(" --patch-files ")){
        UtilXmlTools::displayErrorMessage("@COMMAND","Use of --patch-files option is not allowed inside a patch file");
    }

    newXmlToolsInstance.start(GlobalVars::AppExecutable + " " + commandString);
    newXmlToolsInstance.waitForFinished(-1); // wait for new instance to finish

    resultOutput=newXmlToolsInstance.readAll();

    if(newXmlToolsInstance.exitCode()!=0){
        UtilXmlTools::displayErrorMessage("@COMMAND", "An error ocurred:\n" + resultOutput);
        exit(1);
    }

    std::cout << "@COMMAND patch operation output:\n"
              << "########################################################################\n"
              << resultOutput.toLatin1().constData()
              << "########################################################################"
              << std::endl;

    UtilXmlTools::displaySuccessMessage(1,"@COMMAND");
}

void XmlPatch::executeCustomCommandOperation(const QString &jsString, const QString &filesWildcard){

    QStringList filesToProcess;
#ifdef _USE_OLD_JS_ENGINE
    QScriptEngine engine;
    QScriptValue engineResult; // variable to check for js_errors
#else
    QJSEngine engine;
    QJSValue engineResult; // variable to check for js_errors
#endif

    QString rexmlString, jsxmlString, currXmlFileString;


    QFile rexmlfile(":/resources/libs/rexml.js");
    QFile jsxmlfile(":/resources/libs/jsxml.js");

    filesToProcess=UtilXmlTools::getAllXmlFilesByWildcard(filesWildcard);

    if(filesToProcess.isEmpty()){
        UtilXmlTools::displayErrorMessage("@CUSTOM_CODE","No XML files were found for the wildcard: "+filesWildcard);
    }

    rexmlfile.open(QFile::ReadOnly | QFile::Text);
    jsxmlfile.open(QFile::ReadOnly | QFile::Text);

    rexmlString=QTextStream(&rexmlfile).readAll();
    jsxmlString=QTextStream(&jsxmlfile).readAll();

    engine.evaluate(rexmlString); // load js libraries
    engine.evaluate(jsxmlString);

    // Process all XmlFiles
    for(int i=0; i<filesToProcess.size(); i++){

        if(this->backupsEnabled){
            UtilXmlTools::backupFile(filesToProcess[i]);
        }

        QFile currXmlFile(filesToProcess[i]);

        if(!currXmlFile.open(QFile::ReadOnly | QFile::Text)){
            UtilXmlTools::displayErrorMessage("@CUSTOM_CODE","Error loading '" + filesToProcess[i] + "' file for read operation.");
        }

        currXmlFileString=QTextStream(&currXmlFile).readAll();

        currXmlFile.close(); // close reading

        engine.globalObject().setProperty("$xmlData",currXmlFileString);

        engineResult=engine.evaluate(jsString);

#ifdef _USE_OLD_JS_ENGINE
        if (engine.hasUncaughtException()) {
            displayJsException(engine,engineResult);
        }
#else
        checkForJsException(engineResult);
#endif

        if(!currXmlFile.open(QFile::WriteOnly | QFile::Text | QIODevice::Truncate)){
            UtilXmlTools::displayErrorMessage("@CUSTOM_CODE","Error loading '" + filesToProcess[i] + "' file for @CUSTOM_CODE write operation.");
        }

        engineResult=engine.globalObject().property("$xmlData");

#ifdef _USE_OLD_JS_ENGINE
        if (engine.hasUncaughtException()) {
            displayJsException(engine,engineResult);
        }
#else
        checkForJsException(engineResult);
#endif

        QTextStream(&currXmlFile) << engineResult.toString(); // retreive the modified xml by javascript and save it to the file
    }

    UtilXmlTools::displaySuccessMessage(filesToProcess.size(), "@CUSTOM_CODE");
}

void XmlPatch::checkPatchVersion(const QString &file, QTextStream &fileStream){

    QString line, patchVersion="";

    // First get the patch version and check it validity
    while ( !fileStream.atEnd() ){
        line = fileStream.readLine();

        if(line.startsWith('#')){ // Ignore comments
            continue;
        }
        else if(line.startsWith("@XML_TOOLS")){

            patchVersion=getPatchParameterValue(line,"Version");

            if(!patchVersion.startsWith("2.0")){
                QString errMessage;

                errMessage = "The current patch version is incompatible with this XmlTools version:\n";
                errMessage += "Patch file name: '" + file + "'\n";
                errMessage += "XmlTools version:  " + GlobalVars::AppVersion + "\n" + "CurrPatch version: " + patchVersion + "";
                UtilXmlTools::displayErrorMessage("@XML_TOOLS",errMessage);
            }
            break; // We have got what we wanted
        }
    }

    if(patchVersion==""){
        UtilXmlTools::displayErrorMessage("@XML_TOOLS","Patch version not found.");
    }

}

void XmlPatch::checkAndProcessValidCommands(QTextStream &fileStream){

    QString line, filesWildcard;
    QString xmlToInsert, command, jsCode;
    QString xPathExpression;
    XmlFilter filters;

    // Process the rest of the commands in patch file
    while ( !fileStream.atEnd() ){
        line = fileStream.readLine();

        if(line.startsWith('#')){ // Ignore comments
            continue;
        }
        else if(line.startsWith("@ADD_INSIDE_NODES")){
            xPathExpression=getPatchParameterValue(line,"XPathExpression");
            filters.setElementName(getPatchParameterValue(line,"ElementName"));
            filters.setParentElementName(getPatchParameterValue(line,"ParentElementName"));
            filters.setAttributeName(getPatchParameterValue(line,"AttributeName"));
            filters.setAttributeValue(getPatchParameterValue(line,"AttributeValue"));

            if(this->forceTargetFilesWildcard!=""){
                filesWildcard=this->forceTargetFilesWildcard;
            }
            else{
                filesWildcard=getPatchParameterValue(line,"Files");
            }

            // Check options
            if(xPathExpression.isEmpty() && filters.getElementName().isEmpty()){
                UtilXmlTools::displayErrorMessage("@ADD_INSIDE_NODES","ElementName option or XPathExpression option is required.");
            }
            else if(!xPathExpression.isEmpty() && !filters.getElementName().isEmpty()){
                UtilXmlTools::displayErrorMessage("@ADD_INSIDE_NODES","ElementName option and XPathExpression options cannot be used simultaneously.");
            }
            if(filters.getAttributeName()!="" && filters.getAttributeValue()==""){
                UtilXmlTools::displayErrorMessage("@ADD_INSIDE_NODES","AttributeValue option is required if using AttributeName option.");
            }

            if(filters.getAttributeValue()!="" && filters.getAttributeName()==""){
                UtilXmlTools::displayErrorMessage("@ADD_INSIDE_NODES","AttributeName option is required if using AttributeValue option.");
            }

            while ( !fileStream.atEnd() && !line.startsWith("</xml>")){
                line = fileStream.readLine();

                if(!line.startsWith("<xml>") && !line.startsWith("</xml>")){
                    xmlToInsert += line + "\n";
                }
            }

            insertNodesOperation(xmlToInsert,filters,xPathExpression,filesWildcard);

            xmlToInsert.clear();
            filters.clear();
            xPathExpression.clear();
            filesWildcard.clear();
        }
        else if(line.startsWith("@REMOVE_NODES")){

            xPathExpression=getPatchParameterValue(line,"XPathExpression");
            filters.setElementName(getPatchParameterValue(line,"ElementName"));
            filters.setParentElementName(getPatchParameterValue(line,"ParentElementName"));
            filters.setAttributeName(getPatchParameterValue(line,"AttributeName"));
            filters.setAttributeValue(getPatchParameterValue(line,"AttributeValue"));

            if(this->forceTargetFilesWildcard!=""){
                filesWildcard=this->forceTargetFilesWildcard;
            }
            else{
                filesWildcard=getPatchParameterValue(line,"Files");
            }

            // Check options
            if(xPathExpression.isEmpty() && filters.getElementName().isEmpty()){
                UtilXmlTools::displayErrorMessage("@REMOVE_NODES","ElementName option or XPathExpression option is required.");
            }
            else if(!xPathExpression.isEmpty() && !filters.getElementName().isEmpty()){
                UtilXmlTools::displayErrorMessage("@REMOVE_NODES","ElementName option and XPathExpression options cannot be used simultaneously.");
            }

            if(filters.getAttributeName()!="" && filters.getAttributeValue()==""){
                UtilXmlTools::displayErrorMessage("@REMOVE_NODES","AttributeValue option is required if using AttributeName option.");
            }

            if(filters.getAttributeValue()!="" && filters.getAttributeName()==""){
                UtilXmlTools::displayErrorMessage("@REMOVE_NODES","AttributeName option is required if using AttributeValue option.");
            }

            removeNodesOperation(filters,xPathExpression,filesWildcard);

            filters.clear();
            xPathExpression.clear();
            filesWildcard.clear();
        }
        else if(line.startsWith("@COMMAND")){

            command=getPatchParameterValue(line,"Arguments");

            command.replace("'","\""); //replace apostrophe by quotes, to avoid problems

            executeCommandOperation(command);

            command.clear();
        }
        else if(line.startsWith("@CUSTOM_CODE")){

            if(this->forceTargetFilesWildcard!=""){
                filesWildcard=this->forceTargetFilesWildcard;
            }
            else{
                filesWildcard=getPatchParameterValue(line,"Files");
            }

            while ( !fileStream.atEnd() && !line.startsWith("</code>")){

                line = fileStream.readLine();

                if(!line.startsWith("<code>") && !line.startsWith("</code>")){
                    jsCode += line + "\n";
                }
            }

            executeCustomCommandOperation(jsCode,filesWildcard);

            jsCode.clear();
            filesWildcard.clear();
        }
    }
}

QString XmlPatch::getPatchParameterValue(const QString& line, QString parameter){

    int startValueIdx, endValueIdx;

    parameter=" "+parameter+" "; // Parameters include a space before and after it's value.

    if(!line.contains(parameter)){
        if(parameter==" ParentElementName " || parameter==" AttributeName " || parameter==" AttributeValue "
                || parameter==" ElementName " || parameter==" XPathExpression "){
            return ""; // not mandatory
        }
        parameter.remove(" "); // just remove the space added so it doesn't look weird when outputted to the user

        UtilXmlTools::displayErrorMessage("Read patch file parameter","Couldn't retreive '" + parameter + "' parameter.");
    }

    startValueIdx=line.indexOf(parameter); // get the position where parameter is defined
    endValueIdx=line.indexOf("\"",startValueIdx)+1; // get the position where parameter value begins (+1 to ignore mandotory quote)

    startValueIdx=endValueIdx;
    endValueIdx=line.indexOf("\"",startValueIdx); // get the last mandatory quote of the value

    return line.mid(startValueIdx,endValueIdx-startValueIdx); // return the value of the parameter (is in the middle of the mandatory quotes)
}

#ifdef _USE_OLD_JS_ENGINE
void XmlPatch::displayJsException(QScriptEngine &engine, QScriptValue &engineResult){
    if (engine.hasUncaughtException()) {
        UtilXmlTools::displayErrorMessage("@CUSTOM_CODE","Uncaught js exception (user code) at line " +QString::number(engine.uncaughtExceptionLineNumber()) + ":\n" + engineResult.toString());
    }
}
#else
void XmlPatch::checkForJsException(QJSValue &engineResult){
    if (engineResult.isError()) {
        UtilXmlTools::displayErrorMessage("@CUSTOM_CODE","Uncaught js exception (user code):\n" + engineResult.toString());
    }
}
#endif