uLib/app/gcompose/src/ContextModel.cpp

#include "ContextModel.h"
#include <QString>
#include <typeinfo>
#include <cxxabi.h>
#include <functional>
#include "Core/Object.h"

ContextModel::ContextModel(QObject* parent) 
    : QAbstractItemModel(parent), m_rootContext(nullptr) {}

ContextModel::~ContextModel() {}

void ContextModel::setContext(uLib::ObjectsContext* context) {
    beginResetModel();
    m_rootContext = context;
    if (m_rootContext) {
        uLib::Object::connect(m_rootContext, &uLib::Object::Updated, [this]() {
            this->beginResetModel();
            this->endResetModel();
        });
    }
    endResetModel();
}

QModelIndex ContextModel::index(int row, int column, const QModelIndex& parent) const {
    if (!hasIndex(row, column, parent) || !m_rootContext) {
        return QModelIndex();
    }

    if (!parent.isValid()) {
        if (row < m_rootContext->GetCount()) {
            return createIndex(row, column, m_rootContext->GetObject(row));
        }
    } else {
        uLib::Object* parentObj = static_cast<uLib::Object*>(parent.internalPointer());
        uLib::ObjectsContext* parentCtx = dynamic_cast<uLib::ObjectsContext*>(parentObj);
        if (parentCtx && row < parentCtx->GetCount()) {
            return createIndex(row, column, parentCtx->GetObject(row));
        }
    }
    return QModelIndex();
}

QModelIndex ContextModel::parent(const QModelIndex& child) const {
    if (!child.isValid() || !m_rootContext) {
        return QModelIndex();
    }

    uLib::Object* childObj = static_cast<uLib::Object*>(child.internalPointer());
    
    // Finding the parent of childObj is O(N) since there is no parent pointer.
    // We just do a recursive search starting from root context.
    std::function<uLib::ObjectsContext*(uLib::ObjectsContext*, uLib::Object*)> findParent = 
        [&findParent](uLib::ObjectsContext* ctx, uLib::Object* target) -> uLib::ObjectsContext* {
        for (const auto& obj : ctx->GetObjects()) {
            if (obj == target) return ctx;
            if (auto subCtx = dynamic_cast<uLib::ObjectsContext*>(obj)) {
                if (auto p = findParent(subCtx, target)) return p;
            }
        }
        return nullptr;
    };

    uLib::ObjectsContext* parentCtx = findParent(m_rootContext, childObj);
    if (!parentCtx || parentCtx == m_rootContext) {
        return QModelIndex(); // Root items have invalid parent index
    }

    // Now need to find the row of parentCtx in its own parent Context.
    uLib::ObjectsContext* grandParentCtx = findParent(m_rootContext, parentCtx);
    if (!grandParentCtx) grandParentCtx = m_rootContext;

    int row = -1;
    for (size_t i = 0; i < grandParentCtx->GetCount(); ++i) {
        if (grandParentCtx->GetObject(i) == parentCtx) {
            row = (int)i;
            break;
        }
    }

    if (row != -1) {
        return createIndex(row, 0, parentCtx);
    }
    return QModelIndex();
}

int ContextModel::rowCount(const QModelIndex& parent) const {
    if (!m_rootContext) return 0;

    if (!parent.isValid()) {
        return m_rootContext->GetCount();
    }

    uLib::Object* parentObj = static_cast<uLib::Object*>(parent.internalPointer());
    if (auto parentCtx = dynamic_cast<uLib::ObjectsContext*>(parentObj)) {
        return parentCtx->GetCount();
    }
    return 0; // leaf node
}

int ContextModel::columnCount(const QModelIndex& parent) const {
    return 1;
}

static QString getDemangledName(const std::type_info& info) {
    int status = -4;
    char* demangled = abi::__cxa_demangle(info.name(), nullptr, nullptr, &status);
    QString res = (status == 0 && demangled) ? QString::fromUtf8(demangled) : QString::fromUtf8(info.name());
    if (demangled) free(demangled);
    
    // Remove namespaces
    int lastColon = res.lastIndexOf("::");
    if (lastColon != -1) {
        res = res.mid(lastColon + 2);
    }
    
    // Remove "class " prefix if any
    if (res.startsWith("class ")) res = res.mid(6);
    return res;
}

QVariant ContextModel::data(const QModelIndex& index, int role) const {
    if (!index.isValid()) return QVariant();

    uLib::Object* obj = static_cast<uLib::Object*>(index.internalPointer());
    
    if (role == Qt::DisplayRole) {
        QString typeName = getDemangledName(typeid(*obj));
        std::string instName = obj->GetInstanceName();
        if (instName.empty()) return typeName;
        return QString("%1 (%2)").arg(QString::fromStdString(instName)).arg(typeName);
    }
    
    if (role == Qt::EditRole) {
        return QString::fromStdString(obj->GetInstanceName());
    }
    
    return QVariant();
}

QVariant ContextModel::headerData(int section, Qt::Orientation orientation, int role) const {
    if (orientation == Qt::Horizontal && role == Qt::DisplayRole && section == 0) {
        return "Object Context";
    }
    return QVariant();
}

Qt::ItemFlags ContextModel::flags(const QModelIndex& index) const {
    if (!index.isValid()) return Qt::NoItemFlags;
    return Qt::ItemIsEditable | Qt::ItemIsSelectable | Qt::ItemIsEnabled;
}

bool ContextModel::setData(const QModelIndex& index, const QVariant& value, int role) {
    if (index.isValid() && role == Qt::EditRole) {
        uLib::Object* obj = static_cast<uLib::Object*>(index.internalPointer());
        obj->SetInstanceName(value.toString().toStdString());
        emit dataChanged(index, index, {Qt::DisplayRole, Qt::EditRole});
        return true;
    }
    return false;
}