#include <AK/QuickSort.h>
#include <LibGUI/GAbstractView.h>
#include <LibGUI/GSortingProxyModel.h>
#include <stdio.h>
#include <stdlib.h>

GSortingProxyModel::GSortingProxyModel(NonnullRefPtr<GModel>&& target)
    : m_target(move(target))
    , m_key_column(-1)
{
    m_target->on_update = [this] {
        resort();
    };
}

GSortingProxyModel::~GSortingProxyModel()
{
}

int GSortingProxyModel::row_count(const GModelIndex& index) const
{
    return target().row_count(index);
}

int GSortingProxyModel::column_count(const GModelIndex& index) const
{
    return target().column_count(index);
}

GModelIndex GSortingProxyModel::map_to_target(const GModelIndex& index) const
{
    if (!index.is_valid())
        return {};
    if (index.row() >= m_row_mappings.size() || index.column() >= column_count())
        return {};
    return target().index(m_row_mappings[index.row()], index.column());
}

String GSortingProxyModel::row_name(int index) const
{
    return target().row_name(index);
}

String GSortingProxyModel::column_name(int index) const
{
    return target().column_name(index);
}

GModel::ColumnMetadata GSortingProxyModel::column_metadata(int index) const
{
    return target().column_metadata(index);
}

GVariant GSortingProxyModel::data(const GModelIndex& index, Role role) const
{
    return target().data(map_to_target(index), role);
}

void GSortingProxyModel::update()
{
    target().update();
}

void GSortingProxyModel::set_key_column_and_sort_order(int column, GSortOrder sort_order)
{
    if (column == m_key_column && sort_order == m_sort_order)
        return;

    ASSERT(column >= 0 && column < column_count());
    m_key_column = column;
    m_sort_order = sort_order;
    resort();
}

void GSortingProxyModel::resort()
{
    auto old_row_mappings = m_row_mappings;
    int row_count = target().row_count();
    m_row_mappings.resize(row_count);
    for (int i = 0; i < row_count; ++i)
        m_row_mappings[i] = i;
    if (m_key_column == -1) {
        did_update();
        return;
    }
    quick_sort(m_row_mappings.begin(), m_row_mappings.end(), [&](auto row1, auto row2) -> bool {
        auto data1 = target().data(target().index(row1, m_key_column), GModel::Role::Sort);
        auto data2 = target().data(target().index(row2, m_key_column), GModel::Role::Sort);
        if (data1 == data2)
            return 0;
        bool is_less_than;
        if (data1.is_string() && data2.is_string() && !m_sorting_case_sensitive)
            is_less_than = data1.as_string().to_lowercase() < data2.as_string().to_lowercase();
        else
            is_less_than = data1 < data2;
        return m_sort_order == GSortOrder::Ascending ? is_less_than : !is_less_than;
    });
    did_update();
    for_each_view([&](GAbstractView& view) {
        auto& selection = view.selection();
        Vector<GModelIndex> selected_indexes_in_target;
        selection.for_each_index([&](const GModelIndex& index) {
            selected_indexes_in_target.append(target().index(old_row_mappings[index.row()], index.column()));
        });

        selection.clear();
        for (auto& index : selected_indexes_in_target) {
            for (int i = 0; i < m_row_mappings.size(); ++i) {
                if (m_row_mappings[i] == index.row()) {
                    selection.add(this->index(i, index.column()));
                    continue;
                }
            }
        }
    });
}