// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include "dynamicqmetaobject.h"
#include "pysideqobject.h"
#include "pysidesignal.h"
#include "pysidesignal_p.h"
#include "pysideproperty.h"
#include "pysideproperty_p.h"
#include "pysideslot_p.h"
#include "pysideqenum.h"
#include "pyside_p.h"
#include "pysidestaticstrings.h"

#include <shiboken.h>

#include <QtCore/QByteArray>
#include <QtCore/QObject>
#include <QtCore/QStringList>
#include <QtCore/QTextStream>
#include <QtCore/QList>
#include <private/qmetaobjectbuilder_p.h>

#include <cstring>
#include <vector>

using namespace Qt::StringLiterals;

using namespace PySide;

// MetaObjectBuilder: Provides the QMetaObject's returned by
// QObject::metaObject() for PySide6 objects. There are several
// scenarios to consider:
// 1) A plain Qt class (say QTimer) is instantiated. In that case,
// return the base meta object until a modification is made by
// adding methods, properties or class info (cf qmetaobject_test.py).
// In that case, instantiate a QMetaObjectBuilder inheriting the
// base meta meta object, add the method and return the result
// of QMetaObjectBuilder::toMetaObject() (with dirty handling should
// further modifications be made).
// 2) A Python class inheriting a Qt class is instantiated. For this,
// instantiate a QMetaObjectBuilder and add the methods/properties
// found by inspecting the Python class.

class MetaObjectBuilderPrivate
{
public:
    using MetaObjects = std::vector<const QMetaObject *>;

    QMetaObjectBuilder *ensureBuilder();
    void parsePythonType(PyTypeObject *type);
    int indexOfMethod(QMetaMethod::MethodType mtype,
                      const QByteArray &signature) const;
    int indexOfProperty(const QByteArray &name) const;
    int addSlot(const QByteArray &signature);
    int addSlot(const QByteArray &signature, const QByteArray &type,
                const QByteArray &tag = {});
    int addSignal(const QByteArray &signature);
    void removeMethod(QMetaMethod::MethodType mtype, int index);
    int getPropertyNotifyId(PySideProperty *property) const;
    int addProperty(const QByteArray &property, PyObject *data);
    void addInfo(const QByteArray &key, const  QByteArray &value);
    void addInfo(const QMap<QByteArray, QByteArray> &info);
    void addEnumerator(const char *name, bool flag, bool scoped,
                       const MetaObjectBuilder::EnumValues &entries);
    void removeProperty(int index);
    const QMetaObject *update();

    QMetaObjectBuilder *m_builder = nullptr;

    const QMetaObject *m_baseObject = nullptr;
    MetaObjects m_cachedMetaObjects;
    bool m_dirty = true;

private:
    QMetaPropertyBuilder
        createProperty(PySideProperty *property, const QByteArray &propertyName);
};

QMetaObjectBuilder *MetaObjectBuilderPrivate::ensureBuilder()
{
    if (!m_builder) {
        m_builder = new QMetaObjectBuilder();
        m_builder->setClassName(m_baseObject->className());
        m_builder->setSuperClass(m_baseObject);
    }
    return m_builder;
}

MetaObjectBuilder::MetaObjectBuilder(const char *className, const QMetaObject *metaObject) :
    m_d(new MetaObjectBuilderPrivate)
{
    m_d->m_baseObject = metaObject;
    m_d->m_builder = new QMetaObjectBuilder();
    m_d->m_builder->setClassName(className);
    m_d->m_builder->setSuperClass(metaObject);
    m_d->m_builder->setClassName(className);
}

MetaObjectBuilder::MetaObjectBuilder(PyTypeObject *type, const QMetaObject *metaObject)
    : m_d(new MetaObjectBuilderPrivate)
{
    m_d->m_baseObject = metaObject;
    const char *className = type->tp_name;
    if (const char *lastDot = strrchr(type->tp_name, '.'))
        className = lastDot + 1;
    // Different names indicate a Python class inheriting a Qt class.
    // Parse the type.
    if (strcmp(className, metaObject->className()) != 0) {
        m_d->m_builder = new QMetaObjectBuilder();
        m_d->m_builder->setClassName(className);
        m_d->m_builder->setSuperClass(metaObject);
        m_d->parsePythonType(type);
    }
}

MetaObjectBuilder::~MetaObjectBuilder()
{
    for (auto *metaObject : m_d->m_cachedMetaObjects)
        free(const_cast<QMetaObject*>(metaObject));
    delete m_d->m_builder;
    delete m_d;
}

int MetaObjectBuilderPrivate::indexOfMethod(QMetaMethod::MethodType mtype,
                                            const QByteArray &signature) const
{
    int result = -1;
    if (m_builder) {
        switch (mtype) {
        case QMetaMethod::Signal:
            result = m_builder->indexOfSignal(signature);
            break;
        case QMetaMethod::Slot:
            result = m_builder->indexOfSlot(signature);
            break;
        case QMetaMethod::Constructor:
            result = m_builder->indexOfConstructor(signature);
            break;
        case QMetaMethod::Method:
            result = m_builder->indexOfMethod(signature);
            break;
        }
        if (result >= 0)
            return result + m_baseObject->methodCount();
    }
    switch (mtype) {
    case QMetaMethod::Signal:
        result = m_baseObject->indexOfSignal(signature);
        break;
    case QMetaMethod::Slot:
        result = m_baseObject->indexOfSlot(signature);
        break;
    case QMetaMethod::Constructor:
        result = m_baseObject->indexOfConstructor(signature);
        break;
    case QMetaMethod::Method:
        result = m_baseObject->indexOfMethod(signature);
        break;
    }
    return result;
}

int MetaObjectBuilder::indexOfMethod(QMetaMethod::MethodType mtype,
                                     const QByteArray &signature) const
{
    return m_d->indexOfMethod(mtype, signature);
}

int MetaObjectBuilderPrivate::indexOfProperty(const QByteArray &name) const
{
    if (m_builder) {
        const int result = m_builder->indexOfProperty(name);
        if (result >= 0)
            return m_baseObject->propertyCount() + result;
    }
    return m_baseObject->indexOfProperty(name);
}

int MetaObjectBuilder::indexOfProperty(const QByteArray &name) const
{
    return m_d->indexOfProperty(name);
}

static bool checkMethodSignature(const QByteArray &signature)
{
    // Common mistake not to add parentheses to the signature.
    const auto openParen = signature.indexOf('(');
    const auto closingParen = signature.lastIndexOf(')');
    const bool ok = openParen != -1 && closingParen != -1 && openParen < closingParen;
    if (!ok) {
         const QByteArray message =
             "MetaObjectBuilder::addMethod: Invalid method signature provided for \""
                 + signature + '"';
         PyErr_WarnEx(PyExc_RuntimeWarning, message.constData(), 0);
    }
    return ok;
}

int MetaObjectBuilderPrivate::addSlot(const QByteArray &signature)
{
    if (!checkMethodSignature(signature))
        return -1;
    m_dirty = true;
    return m_baseObject->methodCount()
        + ensureBuilder()->addSlot(signature).index();
}

int MetaObjectBuilder::addSlot(const char *signature)
{
    return m_d->addSlot(signature);
}

int MetaObjectBuilderPrivate::addSlot(const QByteArray &signature,
                                      const QByteArray &type,
                                      const QByteArray &tag)
{
    if (!checkMethodSignature(signature))
        return -1;
    m_dirty = true;
    QMetaMethodBuilder methodBuilder = ensureBuilder()->addSlot(signature);
    if (!type.isEmpty() && type != "void"_ba)
        methodBuilder.setReturnType(type);
    if (!tag.isEmpty())
        methodBuilder.setTag(tag);
    return m_baseObject->methodCount() + methodBuilder.index();
}

int MetaObjectBuilder::addSlot(const char *signature, const char *type)
{
    return m_d->addSlot(signature, type);
}

int MetaObjectBuilderPrivate::addSignal(const QByteArray &signature)
{
    if (!checkMethodSignature(signature))
        return -1;
    m_dirty = true;
    return m_baseObject->methodCount()
        + ensureBuilder()->addSignal(signature).index();
}

int MetaObjectBuilder::addSignal(const char *signature)
{
    return m_d->addSignal(signature);
}

void MetaObjectBuilderPrivate::removeMethod(QMetaMethod::MethodType mtype,
                                            int index)
{
    index -= m_baseObject->methodCount();
    auto builder = ensureBuilder();
    Q_ASSERT(index >= 0 && index < builder->methodCount());
    switch (mtype) {
    case QMetaMethod::Constructor:
        builder->removeConstructor(index);
        break;
    default:
        builder->removeMethod(index);
        break;
    }
    m_dirty = true;
}

void MetaObjectBuilder::removeMethod(QMetaMethod::MethodType mtype, int index)
{
    m_d->removeMethod(mtype, index);
}

int MetaObjectBuilderPrivate::getPropertyNotifyId(PySideProperty *property) const
{
    int notifyId = -1;
    if (property->d->notify) {
        if (const char *signalNotify = PySide::Property::getNotifyName(property))
            notifyId = indexOfMethod(QMetaMethod::Signal, signalNotify);
    }
    return notifyId;
}

QMetaPropertyBuilder
    MetaObjectBuilderPrivate::createProperty(PySideProperty *property,
                                             const QByteArray &propertyName)
{
    int propertyNotifyId = getPropertyNotifyId(property);
    if (propertyNotifyId >= 0)
        propertyNotifyId -= m_baseObject->methodCount();

    // For QObject-derived Python types, retrieve the meta type registered
    // by name from the qmlRegisterType, if there is one. This is required for
    // grouped QML properties to work.
    auto *builder = ensureBuilder();
    auto *typeObject = Property::getTypeObject(property);
    if (typeObject != nullptr && PyType_Check(typeObject)) {
        auto *pyTypeObject = reinterpret_cast<PyTypeObject *>(typeObject);
        if (qstrncmp(pyTypeObject->tp_name, "PySide", 6) != 0
            && PySide::isQObjectDerived(pyTypeObject, false)) {
            const QByteArray pyType(pyTypeObject->tp_name);
            const auto metaType = QMetaType::fromName(pyType + '*');
            if (metaType.isValid()) {
                return builder->addProperty(propertyName, pyType,
                                            metaType, propertyNotifyId);
            }
        }
    }
    return builder->addProperty(propertyName, property->d->typeName,
                                propertyNotifyId);
}

int MetaObjectBuilderPrivate::addProperty(const QByteArray &propertyName,
                                          PyObject *data)
{
    int index = indexOfProperty(propertyName);
    if (index != -1)
        return index;

    auto *property = reinterpret_cast<PySideProperty *>(data);
    auto newProperty = createProperty(property, propertyName);

    // Adding property attributes
    newProperty.setReadable(PySide::Property::isReadable(property));
    newProperty.setWritable(PySide::Property::isWritable(property));
    newProperty.setResettable(PySide::Property::hasReset(property));
    newProperty.setDesignable(PySide::Property::isDesignable(property));
    newProperty.setScriptable(PySide::Property::isScriptable(property));
    newProperty.setStored(PySide::Property::isStored(property));
    newProperty.setUser(PySide::Property::isUser(property));
    newProperty.setConstant(PySide::Property::isConstant(property));
    newProperty.setFinal(PySide::Property::isFinal(property));

    index = newProperty.index() + m_baseObject->propertyCount();
    m_dirty = true;
    return index;
}

int MetaObjectBuilder::addProperty(const char *property, PyObject *data)
{
    return m_d->addProperty(property, data);
}

void MetaObjectBuilderPrivate::addInfo(const QByteArray &key,
                                       const QByteArray &value)
{
    ensureBuilder()->addClassInfo(key, value);
    m_dirty = true;
}

void MetaObjectBuilder::addInfo(const char *key, const char *value)
{
    m_d->addInfo(key, value);
}

void MetaObjectBuilderPrivate::addInfo(const QMap<QByteArray, QByteArray> &info)
{
    auto builder = ensureBuilder();
    for (auto i = info.constBegin(), end = info.constEnd(); i != end; ++i)
        builder->addClassInfo(i.key(), i.value());
    m_dirty = true;
}

void MetaObjectBuilder::addInfo(const QMap<QByteArray, QByteArray> &info)
{
    m_d->addInfo(info);
}

void MetaObjectBuilder::addEnumerator(const char *name, bool flag, bool scoped,
                                      const EnumValues &entries)
{
    m_d->addEnumerator(name, flag, scoped, entries);
}

void MetaObjectBuilderPrivate::addEnumerator(const char *name, bool flag, bool scoped,
                                             const MetaObjectBuilder::EnumValues &entries)
{
    auto builder = ensureBuilder();
    int have_already = builder->indexOfEnumerator(name);
    if (have_already >= 0)
        builder->removeEnumerator(have_already);
    auto enumbuilder = builder->addEnumerator(name);
    enumbuilder.setIsFlag(flag);
    enumbuilder.setIsScoped(scoped);

    for (const auto &item : entries)
        enumbuilder.addKey(item.first, item.second);
    m_dirty = true;
}

void MetaObjectBuilderPrivate::removeProperty(int index)
{
    index -= m_baseObject->propertyCount();
    auto builder = ensureBuilder();
    Q_ASSERT(index >= 0 && index < builder->propertyCount());
    builder->removeProperty(index);
    m_dirty = true;
}

void MetaObjectBuilder::removeProperty(int index)
{
    m_d->removeProperty(index);
}

// PYSIDE-315: Instead of sorting the items and maybe breaking indices, we
// ensure that the signals and slots are sorted by the improved
// parsePythonType() (signals must go before slots). The order can only
// become distorted if the class is modified after creation. In that
// case, we give a warning.

static QString msgMethodSortOrder(const QMetaObject *mo, int offendingIndex)
{
    QString result;
    QTextStream str(&result);
    str << "\n\n*** Sort Warning ***\nSignals and slots in QMetaObject '"
        << mo->className()
        << "' are not ordered correctly, this may lead to issues.\n";
    const int methodOffset = mo->methodOffset();
    for (int m = methodOffset, methodCount = mo->methodCount(); m < methodCount; ++m) {
        const auto method = mo->method(m);
        str << (m - methodOffset + 1) << (m > offendingIndex ? '!' : ' ')
            << (method.methodType() == QMetaMethod::Signal ? " Signal " : " Slot   ")
            << method.methodSignature() << '\n';
    }
    return result;
}

static void checkMethodOrder(const QMetaObject *metaObject)
{
    const int lastMethod = metaObject->methodCount() - 1;
    for (int m = metaObject->methodOffset(); m < lastMethod; ++m)  {
        if (metaObject->method(m).methodType() == QMetaMethod::Slot
            && metaObject->method(m + 1).methodType() == QMetaMethod::Signal) {
            const auto message = msgMethodSortOrder(metaObject, m);
            PyErr_WarnEx(PyExc_RuntimeWarning, qPrintable(message), 0);
            // Prevent a warning from being turned into an error. We cannot easily unwind.
            PyErr_Clear();
            break;
        }
    }
}

const QMetaObject *MetaObjectBuilderPrivate::update()
{
    if (!m_builder)
        return m_baseObject;
    if (m_cachedMetaObjects.empty() || m_dirty) {
        // PYSIDE-803: The dirty branch needs to be protected by the GIL.
        // This was moved from SignalManager::retrieveMetaObject to here,
        // which is only the update in "return builder->update()".
        Shiboken::GilState gil;
        m_cachedMetaObjects.push_back(m_builder->toMetaObject());
        checkMethodOrder(m_cachedMetaObjects.back());
        m_dirty = false;
    }
    return m_cachedMetaObjects.back();
}

const QMetaObject *MetaObjectBuilder::update()
{
    return m_d->update();
}

static void formatEnum(QTextStream &str, const QMetaEnum &e)
{
    str << '"' << e.name() << "\" {";
    for (int k = 0, cnt = e.keyCount(); k < cnt; ++k) {
        if (k)
            str << ", ";
        str << e.key(k);
    }
    str << "}";
}

static void formatProperty(QTextStream &str, const QMetaProperty &p)
{
    str << '"' << p.name() << "\", " << p.typeName();
    if (p.isWritable())
        str << " [writeable]";
    if (p.isResettable())
        str << " [resettable]";
    if (p.isConstant())
        str << " [constant]";
    if (p.isFinal())
        str << " [final]";
    if (p.isDesignable())
        str << " [designable]";
    auto sig = p.notifySignal();
    if (sig.isValid())
        str << ", notify=" << sig.name();
}

static void formatMethod(QTextStream &str, const QMetaMethod &m)
{
    str << "type=";
    switch (m.methodType()) {
    case QMetaMethod::Method:
        str << "Method";
        break;
    case QMetaMethod::Signal:
        str << "Signal";
        break;
    case QMetaMethod::Slot:
        str << "Slot";
        break;
    case QMetaMethod::Constructor:
        str << "Constructor";
        break;
    }

    str << ", signature="
      << m.methodSignature();
    const QByteArrayList parms = m.parameterTypes();
    if (!parms.isEmpty())
        str << ", parameters=" << parms.join(", ");
}

QString MetaObjectBuilder::formatMetaObject(const QMetaObject *metaObject)
{
    QString result;
    QTextStream str(&result);
    str << "PySide" << QT_VERSION_MAJOR << ".QtCore.QMetaObject(\""
        << metaObject->className() << '"';
    if (auto *s = metaObject->superClass())
        str << " inherits \"" << s->className() << '"';
    str << ":\n";

    int offset = metaObject->enumeratorOffset();
    int count = metaObject->enumeratorCount();
    if (offset < count) {
        str << "Enumerators:\n";
        for (int e = offset; e < count; ++e) {
            str << "  #" << e << ' ';
            formatEnum(str, metaObject->enumerator(e));
            str << '\n';
        }
    }

    offset = metaObject->propertyOffset();
    count = metaObject->propertyCount();
    if (offset < count) {
        str << "Properties:\n";
        for (int p = offset; p < count; ++p) {
            str << "  #" << p << ' ';
            formatProperty(str, metaObject->property(p));
            str << '\n';
        }
    }

    offset = metaObject->methodOffset();
    count = metaObject->methodCount();
    if (offset < count) {
        str << "Methods:\n";
        for (int m = offset; m < count; ++m) {
            str << "  #" << m << ' ';
            formatMethod(str, metaObject->method(m));
            str << '\n';
        }
    }

    str << ')';
    return result;
}

using namespace Shiboken;

void MetaObjectBuilderPrivate::parsePythonType(PyTypeObject *type)
{
    // Get all non-QObject-derived base types in method resolution order, filtering out the types
    // that can't have signals, slots or properties.
    // This enforces registering of all signals and slots at type parsing time, and not later at
    // signal connection time, thus making sure no method indices change which would break
    // existing connections.
    const PyObject *mro = type->tp_mro;
    const Py_ssize_t basesCount = PyTuple_GET_SIZE(mro);

    std::vector<PyTypeObject *> basesToCheck;
    // Prepend the actual type that we are parsing.
    basesToCheck.reserve(1u + basesCount);
    basesToCheck.push_back(type);

    auto sbkObjTypeF = SbkObject_TypeF();
    auto baseObjType = reinterpret_cast<PyTypeObject *>(&PyBaseObject_Type);
    for (Py_ssize_t i = 0; i < basesCount; ++i) {
        auto baseType = reinterpret_cast<PyTypeObject *>(PyTuple_GET_ITEM(mro, i));
        if (baseType != sbkObjTypeF && baseType != baseObjType
            && !PySide::isQObjectDerived(baseType, false)) {
            basesToCheck.push_back(baseType);
        }
    }

    // PYSIDE-315: Handle all signals first, in all involved types.
    // Leave the properties to be registered after signals because they may depend on
    // notify signals.
    for (PyTypeObject *baseType : basesToCheck) {
        AutoDecRef tpDict(PepType_GetDict(baseType));
        PyObject *attrs = tpDict.object();
        PyObject *key = nullptr;
        PyObject *value = nullptr;
        Py_ssize_t pos = 0;

        while (PyDict_Next(attrs, &pos, &key, &value)) {
            if (Signal::checkType(value)) {
                // Register signals.
                auto *data = reinterpret_cast<PySideSignal *>(value)->data;
                if (data->signalName.isEmpty())
                    data->signalName = String::toCString(key);
                for (const auto &s : data->signatures) {
                    const auto sig = data->signalName + '(' + s.signature + ')';
                    if (m_baseObject->indexOfSignal(sig) == -1) {
                        // Registering the parameterNames to the QMetaObject (PYSIDE-634)
                        // from:
                        //     Signal(..., arguments=['...', ...]
                        // the arguments are now on data-data->signalArguments
                        auto builder = m_builder->addSignal(sig);
                        if (!data->signalArguments.isEmpty())
                            builder.setParameterNames(data->signalArguments);
                    }
                }
            }
        }
    }

    PyObject *slotAttrName = PySide::PySideMagicName::slot_list_attr();
    // PYSIDE-315: Now take care of the rest.
    // Signals and slots should be separated, unless the types are modified, later.
    // We check for this using "is_sorted()". Sorting no longer happens at all.
    for (PyTypeObject *baseType : basesToCheck) {
        AutoDecRef tpDict(PepType_GetDict(baseType));
        PyObject *attrs = tpDict.object();
        PyObject *key = nullptr;
        PyObject *value = nullptr;
        Py_ssize_t pos = 0;

        while (PyDict_Next(attrs, &pos, &key, &value)) {
            if (Property::checkType(value)) {
                const QByteArray name = String::toCString(key);
                const int index = m_baseObject->indexOfProperty(name);
                if (index == -1)
                    addProperty(name, value);
            } else if (PepType_GetSlot(Py_TYPE(value), Py_tp_call) != nullptr) {
                // PYSIDE-198: PyFunction_Check does not work with Nuitka.
                // Register slots.
                if (PyObject_HasAttr(value, slotAttrName)) {
                    auto *capsule = PyObject_GetAttr(value, slotAttrName);
                    const auto *entryList = PySide::Slot::dataListFromCapsule(capsule);
                    for (const auto &e : *entryList) {
                        if (m_baseObject->indexOfSlot(e.signature) == -1)
                            addSlot(e.signature, e.resultType, e.tag);
                    }
                }
            }
        }
    }
    // PYSIDE-957: Collect the delayed QEnums
    auto collectedEnums = PySide::QEnum::resolveDelayedQEnums(type);
    for (PyObject *obEnumType : collectedEnums) {
        bool isFlag = PySide::QEnum::isFlag(obEnumType);
        AutoDecRef obName(PyObject_GetAttr(obEnumType, PyMagicName::name()));
        // Everything has been checked already in resolveDelayedQEnums.
        // Therefore, we don't need to error-check here again.
        auto name = String::toCString(obName);
        AutoDecRef members(PyObject_GetAttr(obEnumType, PyMagicName::members()));
        AutoDecRef items(PyMapping_Items(members));
        Py_ssize_t nr_items = PySequence_Length(items);

        QList<std::pair<QByteArray, int> > entries;
        for (Py_ssize_t idx = 0; idx < nr_items; ++idx) {
            AutoDecRef item(PySequence_GetItem(items, idx));
            AutoDecRef key(PySequence_GetItem(item, 0));
            AutoDecRef member(PySequence_GetItem(item, 1));
            AutoDecRef value(PyObject_GetAttr(member, Shiboken::PyName::value()));
            auto ckey = String::toCString(key);
            auto ivalue = PyLong_AsSsize_t(value);
            entries.push_back(std::make_pair(ckey, int(ivalue)));
        }
        addEnumerator(name, isFlag, true, entries);
    }
}