/*
    Copyright (C) 2010 George Kiagiadakis <kiagiadakis.george@gmail.com>
    Copyright (C) 2010 Collabora Ltd.
      @author George Kiagiadakis <george.kiagiadakis@collabora.co.uk>

    This library is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published
    by the Free Software Foundation; either version 2.1 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "generator.h"
#include <cstdio>
#include <cstdlib>
#include <QtCore/QCoreApplication>
#include <QtCore/QFile>

extern int yylineno;
int yyparse(CodeGen *codegen);
void yyrestart(FILE *file);

QHash<QByteArray, QList<QByteArray> > CodeGen::s_wrapperDefinitions;

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QTextStream outStream(stdout);
    outStream
        << "// Autogenerated by the QtGStreamer helper code generator - DO NOT EDIT" << endl
        << "/*" << endl
        << "    Copyright (C) 2010 George Kiagiadakis <kiagiadakis.george@gmail.com>" << endl
        << "    Copyright (C) 2010 Collabora Ltd." << endl
        << "      @author George Kiagiadakis <george.kiagiadakis@collabora.co.uk>" << endl
        << endl
        << "    This library is free software; you can redistribute it and/or modify" << endl
        << "    it under the terms of the GNU Lesser General Public License as published" << endl
        << "    by the Free Software Foundation; either version 2.1 of the License, or" << endl
        << "    (at your option) any later version." << endl
        << endl
        << "    This program is distributed in the hope that it will be useful," << endl
        << "    but WITHOUT ANY WARRANTY; without even the implied warranty of" << endl
        << "    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the" << endl
        << "    GNU Lesser General Public License for more details." << endl
        << endl
        << "    You should have received a copy of the GNU Lesser General Public License" << endl
        << "    along with this program.  If not, see <http://www.gnu.org/licenses/>." << endl
        << "*/" << endl
        << endl
        << "#define INCLUDED_FROM_CODEGEN" << endl
        << "#include <boost/static_assert.hpp>" << endl
        << endl
        << "#define REGISTER_TYPE_IMPLEMENTATION(T, GTYPE) \\" << endl
        << "    namespace QGlib { \\" << endl
        << "        GetTypeImpl<T>::operator Type() { return (GTYPE); } \\" << endl
        << "    }" << endl
        << endl;

    for (int i=1; i<argc; ++i) {
        QString fileName(QFile::decodeName(argv[i]));
        if (fileName.startsWith("-I")) {
            outStream << "#include <" << fileName.remove(0, 2) << ">" << endl;
        } else if (fileName.endsWith(".h") && QFile::exists(fileName)) {
            CodeGen::parse(fileName, outStream);
        } else {
            QTextStream(stderr) << "Skipping " << fileName << ": Not an existing header" << endl;
        }
    }

    CodeGen::printGlobalWrapperDefinitions(outStream);

    return 0;
}

void CodeGen::parse(const QString & fileName, QTextStream & outStream)
{
    CodeGen codegen(fileName);

    FILE *fp = std::fopen(QFile::encodeName(fileName), "r");
    if (!fp) {
        std::perror("fopen");
        QTextStream(stderr) << "Could not open " << fileName << endl;
        return;
    }

    yylineno = 1;
    yyrestart(fp);
    yyparse(&codegen);
    std::fclose(fp);

    codegen.generateOutput(outStream);
}

void CodeGen::generateOutput(QTextStream & outStream)
{
    outStream << "#include \"" << m_fileName << "\"" << endl << endl;

    foreach(const QByteArrayHash & typeReg, m_typeRegistrations) {
        printTypeRegistration(outStream, typeReg);
        outStream << endl;
    }

    foreach(const QByteArrayHash & def, m_wrapperDefinitions) {
        printWrapperDefinition(outStream, def);
        outStream << endl;
    }

    foreach(const Enum & enumDef, m_enums) {
        if (!enumDef.options.contains("skip")) {
            printEnumAssertions(outStream, enumDef);
        }
        outStream << endl;
    }
}

void CodeGen::printTypeRegistration(QTextStream & outStream, const QByteArrayHash & typeReg)
{
    outStream << "REGISTER_TYPE_IMPLEMENTATION(";

    outStream << typeReg["namespace"] << "::" << typeReg["class"];
    if (!typeReg["enum"].isEmpty()) {
        outStream << "::" << typeReg["enum"];
    }

    outStream << ',';

    if (typeReg.contains("GType")) {
        outStream << typeReg["GType"];
    } else {
        outStream << namespaceToGstStyle(typeReg["namespace"]) << "_TYPE_";
        outStream << toGstStyle(typeReg["enum"].isEmpty() ? typeReg["class"] : typeReg["enum"]);
    }
    outStream << ")" << endl;
}

void CodeGen::printEnumAssertions(QTextStream& outStream, const Enum & enumDef)
{
    outStream << "namespace " << enumDef.options["namespace"] << " {" << endl;

    foreach(const QByteArray & value, enumDef.values) {
        outStream << "    BOOST_STATIC_ASSERT(static_cast<int>(";
        if (enumDef.options.contains("class") && !enumDef.options["class"].isEmpty()) {
            outStream << enumDef.options["class"] << "::";
        }
        outStream << value;
        outStream << ") == static_cast<int>(";

        if (enumDef.options.contains("prefix")) {
            outStream << enumDef.options["prefix"];
        } else {
            outStream << namespaceToGstStyle(enumDef.options["namespace"]) << "_";
            if (enumDef.options.contains("class") && !enumDef.options["class"].isEmpty()) {
                outStream << toGstStyle(enumDef.options["class"]) << "_";
            }
        }

        if (enumDef.options.contains(value)) {
            outStream << enumDef.options[value];
        } else {
            outStream << toGstStyle(value);
        }
        outStream << "));" << endl;
    }
    outStream << "}" << endl;
}

void CodeGen::printWrapperDefinition(QTextStream& outStream, const QByteArrayHash & def)
{
    //This function is not printed inside namespace Private because it needs to be friend
    //with the actual class and we cannot declare a friend from another namespace in the
    //class without a forward declaration.
    outStream << "namespace " << def["namespace"] << " {" << endl;
    outStream << "  QGlib::RefCountedObject *" << def["class"] << "_new(void *instance)" << endl;
    outStream << "  {" << endl;

    QByteArrayPair index = qMakePair(def["namespace"], def["class"]);
    if (m_wrapperSubclasses.contains(index)) {
        outStream << "    "<< def["namespace"] << "::" << def["class"] << " *cppClass = NULL;" << endl;
        outStream << "    switch(" << namespaceToGstStyle(def["namespace"])
                                   << "_" << toGstStyle(def["class"]) << "_"
                                   << "TYPE(instance)) {" << endl;

        Q_FOREACH(const QByteArrayHash & subclass, m_wrapperSubclasses[index]) {
            outStream << "    case " << def["namespace"] << "::"
                                     << def["class"] << subclass["prefix"] << ":" << endl;
            outStream << "      cppClass = new " << def["namespace"] << "::"
                                             << subclass["prefix"] << def["class"] << ";" << endl;
            outStream << "      break;" << endl;
        }

        outStream << "    default:" << endl;
        outStream << "      cppClass = new " << def["namespace"] << "::" << def["class"] << ";" << endl;
        outStream << "      break;" << endl;
        outStream << "    }" << endl;
    } else {
        outStream << "    " << def["namespace"] << "::" << def["class"] << " *cppClass = new "
                            << def["namespace"] << "::" << def["class"] << ";" << endl;
    }

    outStream << "    cppClass->m_object = instance;" << endl;
    outStream << "    return cppClass;" << endl;
    outStream << "  }" << endl;
    outStream << "} //namespace " << def["namespace"] << endl;

    s_wrapperDefinitions[def["namespace"]].append(def["class"]);
}

void CodeGen::printGlobalWrapperDefinitions(QTextStream & outStream)
{
    QHashIterator<QByteArray, QList<QByteArray> > it(s_wrapperDefinitions);
    while (it.hasNext()) {
        it.next();
        outStream << "namespace " << it.key() << " {" << endl;
        outStream << "namespace Private {" << endl;
        outStream << "  void registerWrapperConstructors()" << endl;
        outStream << "  {" << endl;
        outStream << "    QGlib::Quark q = g_quark_from_static_string(\"QGlib__wrapper_constructor\");" << endl;

        Q_FOREACH(const QByteArray & classId, it.value()) {
            outStream << "    QGlib::GetType<" << classId << ">()"
                      << ".setQuarkData(q, reinterpret_cast<void*>(&" << classId << "_new));" << endl;
        }
        outStream << "  }" << endl;
        outStream << "} //namespace Private" << endl;
        outStream << "} //namespace " << it.key() << endl << endl;
    }
    s_wrapperDefinitions.clear();
}

QByteArray CodeGen::toGstStyle(const QByteArray & str)
{
    QByteArray output;
    foreach(const char currentChar, str) {
        if (isupper(currentChar)) {
            if (!output.isEmpty()) { //if this is not the first char
                output.append('_');
            }
            output.append(currentChar);
        } else {
            output.append(toupper(currentChar));
        }
    }
    return output;
}

QByteArray CodeGen::namespaceToGstStyle(const QByteArray & ns)
{
    return ns == "QGst" ? "GST" : "G";
}

void CodeGen::addEnum(const QList<QByteArray> & values, const QByteArrayHash & options)
{
    Enum e;
    e.values = values;
    e.options = options;
    e.options["namespace"] = m_currentNamespace;
    e.options["class"] = m_currentClass;
    m_enums.append(e);
}

void CodeGen::addTypeRegistration(const QByteArray& namespaceId, const QByteArray& classId,
                                 const QByteArray& enumId, const QByteArrayHash & options)
{
    QByteArrayHash typeReg(options);
    typeReg["namespace"] = namespaceId;
    typeReg["class"] = classId;
    typeReg["enum"] = enumId;
    m_typeRegistrations.append(typeReg);
}

void CodeGen::addWrapperDefinition(const QByteArray & classId, const QByteArrayHash & options)
{
    QByteArrayHash def(options);
    def["namespace"] = m_currentNamespace;
    def["class"] = classId;
    m_wrapperDefinitions.append(def);
}

void CodeGen::addWrapperFakeSubclass(const QByteArray & prefix, const QByteArray & classId,
                                     const QByteArrayHash & options)
{
    QByteArrayHash sub(options);
    sub["prefix"] = prefix;
    m_wrapperSubclasses[qMakePair(m_currentNamespace, classId)].append(sub);
}

//called by yyerror()
void CodeGen::fatalError(const char* msg)
{
    QTextStream(stderr) << "codegen: " << m_fileName << ":" << yylineno << ": error: " << msg << endl;
    std::exit(1);
}