// This file Copyright © Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.

#include "FileList.h"

#include "GtkCompat.h"
#include "HigWorkarea.h" // GUI_PAD, GUI_PAD_BIG
#include "IconCache.h"
#include "PrefsDialog.h"
#include "Session.h"
#include "Utils.h"

#include <libtransmission/utils.h>

#include <giomm/icon.h>
#include <glibmm/fileutils.h>
#include <glibmm/i18n.h>
#include <glibmm/main.h>
#include <glibmm/markup.h>
#include <glibmm/miscutils.h>
#include <glibmm/nodetree.h>
#include <gtkmm/cellrendererpixbuf.h>
#include <gtkmm/cellrendererprogress.h>
#include <gtkmm/cellrenderertext.h>
#include <gtkmm/cellrenderertoggle.h>
#include <gtkmm/messagedialog.h>
#include <gtkmm/treemodel.h>
#include <gtkmm/treemodelcolumn.h>
#include <gtkmm/treeselection.h>
#include <gtkmm/treestore.h>
#include <gtkmm/treeview.h>

#include <fmt/core.h>

#include <algorithm>
#include <cstddef>
#include <list>
#include <memory>
#include <queue>
#include <stack>
#include <string>
#include <string_view>
#include <unordered_map>
#include <utility>

using namespace std::literals;

namespace
{

enum
{
    /* these two fields could be any number at all so long as they're not
     * TR_PRI_LOW, TR_PRI_NORMAL, TR_PRI_HIGH, true, or false */
    NOT_SET = 1000,
    MIXED = 1001
};

class FileModelColumns : public Gtk::TreeModelColumnRecord
{
public:
    FileModelColumns() noexcept
    {
        add(icon);
        add(label);
        add(label_esc);
        add(prog);
        add(prog_str);
        add(index);
        add(size);
        add(size_str);
        add(have);
        add(priority);
        add(enabled);
    }

    Gtk::TreeModelColumn<Glib::RefPtr<Gio::Icon>> icon;
    Gtk::TreeModelColumn<Glib::ustring> label;
    Gtk::TreeModelColumn<Glib::ustring> label_esc;
    Gtk::TreeModelColumn<int> prog;
    Gtk::TreeModelColumn<Glib::ustring> prog_str;
    Gtk::TreeModelColumn<unsigned int> index;
    Gtk::TreeModelColumn<uint64_t> size;
    Gtk::TreeModelColumn<Glib::ustring> size_str;
    Gtk::TreeModelColumn<uint64_t> have;
    Gtk::TreeModelColumn<int> priority;
    Gtk::TreeModelColumn<int> enabled;
};

FileModelColumns const file_cols;

} // namespace

class FileList::Impl
{
public:
    Impl(
        FileList& widget,
        Glib::RefPtr<Gtk::Builder> const& builder,
        Glib::ustring const& view_name,
        Glib::RefPtr<Session> const& core,
        tr_torrent_id_t torrent_id);
    ~Impl();

    TR_DISABLE_COPY_MOVE(Impl)

    void set_torrent(tr_torrent_id_t torrent_id);
    void reset_torrent();

private:
    void clearData();
    void refresh();

    bool getAndSelectEventPath(double view_x, double view_y, Gtk::TreeViewColumn*& col, Gtk::TreeModel::Path& path);

    [[nodiscard]] std::vector<tr_file_index_t> getActiveFilesForPath(Gtk::TreeModel::Path const& path) const;
    [[nodiscard]] std::vector<tr_file_index_t> getSelectedFilesAndDescendants() const;
    [[nodiscard]] std::vector<tr_file_index_t> getSubtree(Gtk::TreeModel::Path const& path) const;

    bool onViewButtonPressed(guint button, TrGdkModifierType state, double view_x, double view_y);
    bool onViewPathToggled(Gtk::TreeViewColumn* col, Gtk::TreeModel::Path const& path);
    void onRowActivated(Gtk::TreeModel::Path const& path, Gtk::TreeViewColumn* col);
    void cell_edited_callback(Glib::ustring const& path_string, Glib::ustring const& newname);
    void on_rename_done(Glib::ustring const& path_string, Glib::ustring const& newname, int error);
    void on_rename_done_idle(Glib::ustring const& path_string, Glib::ustring const& newname, int error);

private:
    FileList& widget_;

    Glib::RefPtr<Session> const core_;
    // GtkWidget* top_ = nullptr; // == widget_
    Gtk::TreeView* view_ = nullptr;
    Glib::RefPtr<Gtk::TreeStore> store_;
    tr_torrent_id_t torrent_id_ = {};
    sigc::connection timeout_tag_;
    std::queue<sigc::connection> rename_done_tags_;
};

void FileList::Impl::clearData()
{
    torrent_id_ = -1;

    timeout_tag_.disconnect();
}

FileList::Impl::~Impl()
{
    while (!rename_done_tags_.empty())
    {
        rename_done_tags_.front().disconnect();
        rename_done_tags_.pop();
    }

    clearData();
}

/***
****
***/

namespace
{

struct RefreshData
{
    int sort_column_id;
    bool resort_needed;
    tr_torrent* tor;
};

bool refreshFilesForeach(
    Glib::RefPtr<Gtk::TreeStore> const& store,
    Gtk::TreeModel::iterator const& iter,
    RefreshData& refresh_data)
{
    bool const is_file = iter->children().empty();

    auto const old_enabled = iter->get_value(file_cols.enabled);
    auto const old_have = iter->get_value(file_cols.have);
    auto const old_priority = iter->get_value(file_cols.priority);
    auto const old_progress = iter->get_value(file_cols.prog);
    auto const old_size = iter->get_value(file_cols.size);

    auto new_enabled = int{};
    auto new_have = decltype(old_have){};
    auto new_priority = int{};
    auto new_progress = int{};
    auto new_size = decltype(old_size){};

    if (is_file)
    {
        auto const index = iter->get_value(file_cols.index);
        auto const file = tr_torrentFile(refresh_data.tor, index);

        new_enabled = static_cast<int>(file.wanted);
        new_priority = int{ file.priority };
        new_have = file.have;
        new_size = file.length;
        new_progress = static_cast<int>(100 * file.progress);
    }
    else
    {
        new_enabled = NOT_SET;
        new_priority = NOT_SET;

        /* since gtk_tree_model_foreach() is depth-first, we can
         * get the `sub' info by walking the immediate children */

        for (auto const& child : iter->children())
        {
            auto const child_size = child[file_cols.size];
            auto const child_have = child[file_cols.have];
            auto const child_priority = child[file_cols.priority];
            auto const child_enabled = child[file_cols.enabled];

            if (child_enabled != static_cast<int>(false) && (child_enabled != NOT_SET))
            {
                new_size += child_size;
                new_have += child_have;
            }

            if (new_enabled == NOT_SET)
            {
                new_enabled = child_enabled;
            }
            else if (new_enabled != child_enabled)
            {
                new_enabled = MIXED;
            }

            if (new_priority == NOT_SET)
            {
                new_priority = child_priority;
            }
            else if (new_priority != child_priority)
            {
                new_priority = MIXED;
            }
        }

        new_progress = new_size != 0 ? static_cast<int>(100.0 * new_have / new_size) : 1;
    }

    new_progress = std::clamp(new_progress, 0, 100);

    if (new_priority != old_priority || new_enabled != old_enabled)
    {
        /* Changing a value in the sort column can trigger a resort
         * which breaks this foreach () call. (See #3529)
         * As a workaround: if that's about to happen, temporarily disable
         * sorting until we finish walking the tree. */
        if (!refresh_data.resort_needed &&
            (((refresh_data.sort_column_id == file_cols.priority.index()) && (new_priority != old_priority)) ||
             ((refresh_data.sort_column_id == file_cols.enabled.index()) && (new_enabled != old_enabled))))
        {
            refresh_data.resort_needed = true;

            store->set_sort_column(GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID, TR_GTK_SORT_TYPE(ASCENDING));
        }
    }

    if (new_enabled != old_enabled)
    {
        (*iter)[file_cols.enabled] = new_enabled;
    }

    if (new_priority != old_priority)
    {
        (*iter)[file_cols.priority] = new_priority;
    }

    if (new_size != old_size)
    {
        (*iter)[file_cols.size] = new_size;
        (*iter)[file_cols.size_str] = tr_strlsize(new_size);
    }

    if (new_have != old_have)
    {
        (*iter)[file_cols.have] = new_have;
    }

    if (new_progress != old_progress)
    {
        (*iter)[file_cols.prog] = new_progress;
        (*iter)[file_cols.prog_str] = fmt::format(FMT_STRING("{:d}%"), new_progress);
    }

    return false; /* keep walking */
}

void gtr_tree_model_foreach_postorder(Glib::RefPtr<Gtk::TreeModel> const& model, Gtk::TreeModel::SlotForeachIter const& func)
{
    auto items = std::stack<Gtk::TreeModel::iterator>();
    if (auto const root_child_it = model->children().begin(); root_child_it)
    {
        items.push(root_child_it);
    }

    while (!items.empty())
    {
        while (items.top())
        {
            if (auto const child_it = items.top()->children().begin(); child_it)
            {
                items.push(child_it);
            }
            else
            {
                func(items.top()++);
            }
        }

        items.pop();

        if (!items.empty())
        {
            func(items.top()++);
        }
    }
}

} // namespace

void FileList::Impl::refresh()
{
    if (tr_torrent* tor = core_->find_torrent(torrent_id_); tor == nullptr)
    {
        widget_.clear();
    }
    else
    {
        Gtk::SortType order = TR_GTK_SORT_TYPE(ASCENDING);
        int sort_column_id = 0;
        store_->get_sort_column_id(sort_column_id, order);

        RefreshData refresh_data{ sort_column_id, false, tor };
        gtr_tree_model_foreach_postorder(
            store_,
            [this, &refresh_data](Gtk::TreeModel::iterator const& iter)
            { return refreshFilesForeach(store_, iter, refresh_data); });

        if (refresh_data.resort_needed)
        {
            store_->set_sort_column(sort_column_id, order);
        }
    }
}

/***
****
***/

namespace
{

bool getSelectedFilesForeach(
    Gtk::TreeModel::iterator const& iter,
    Glib::RefPtr<Gtk::TreeSelection> const& sel,
    std::vector<tr_file_index_t>& indexBuf)
{
    if (bool const is_file = iter->children().empty(); is_file)
    {
        /* active means: if it's selected or any ancestor is selected */
        bool is_active = sel->is_selected(iter);

        if (!is_active)
        {
            for (auto walk = iter->parent(); !is_active && walk; walk = walk->parent())
            {
                is_active = sel->is_selected(walk);
            }
        }

        if (is_active)
        {
            indexBuf.push_back(iter->get_value(file_cols.index));
        }
    }

    return false; /* keep walking */
}

} // namespace

std::vector<tr_file_index_t> FileList::Impl::getSelectedFilesAndDescendants() const
{
    auto const sel = view_->get_selection();
    std::vector<tr_file_index_t> indexBuf;
    store_->foreach_iter([&sel, &indexBuf](Gtk::TreeModel::iterator const& iter)
                         { return getSelectedFilesForeach(iter, sel, indexBuf); });
    return indexBuf;
}

namespace
{

bool getSubtreeForeach(
    Gtk::TreeModel::Path const& path,
    Gtk::TreeModel::iterator const& iter,
    Gtk::TreeModel::Path const& subtree_path,
    std::vector<tr_file_index_t>& indexBuf)
{
    if (bool const is_file = iter->children().empty(); is_file)
    {
        if (path == subtree_path || path.is_descendant(subtree_path))
        {
            indexBuf.push_back(iter->get_value(file_cols.index));
        }
    }

    return false; /* keep walking */
}

} // namespace

std::vector<tr_file_index_t> FileList::Impl::getSubtree(Gtk::TreeModel::Path const& subtree_path) const
{
    std::vector<tr_file_index_t> indexBuf;
    store_->foreach ([&subtree_path, &indexBuf](Gtk::TreeModel::Path const& path, Gtk::TreeModel::iterator const& iter)
                     { return getSubtreeForeach(path, iter, subtree_path, indexBuf); });
    return indexBuf;
}

/* if `path' is a selected row, all selected rows are returned.
 * otherwise, only the row indicated by `path' is returned.
 * this is for toggling all the selected rows' states in a batch.
 *
 * indexBuf should be large enough to hold tr_inf.fileCount files.
 */
std::vector<tr_file_index_t> FileList::Impl::getActiveFilesForPath(Gtk::TreeModel::Path const& path) const
{
    if (view_->get_selection()->is_selected(path))
    {
        /* clicked in a selected row... use the current selection */
        return getSelectedFilesAndDescendants();
    }

    /* clicked OUTSIDE of the selected row... just use the clicked row */
    return getSubtree(path);
}

/***
****
***/

void FileList::clear()
{
    impl_->reset_torrent();
}

namespace
{

struct build_data
{
    Gtk::Widget* w = nullptr;
    tr_torrent* tor = nullptr;
    Gtk::TreeStore::iterator iter;
    Glib::RefPtr<Gtk::TreeStore> store;
};

struct row_struct
{
    uint64_t length = 0;
    Glib::ustring name;
    int index = 0;
};

using FileRowNode = Glib::NodeTree<row_struct>;

void buildTree(FileRowNode& node, build_data& build)
{
    auto const& child_data = node.data();
    bool const isLeaf = node.child_count() == 0;

    auto const mime_type = isLeaf ? tr_get_mime_type_for_filename(child_data.name.raw()) : DirectoryMimeType;
    auto const icon = gtr_get_mime_type_icon(mime_type);
    auto const file = isLeaf ? tr_torrentFile(build.tor, child_data.index) : tr_file_view{};
    int const priority = isLeaf ? file.priority : 0;
    bool const enabled = isLeaf ? file.wanted : true;
    auto name_esc = Glib::Markup::escape_text(child_data.name);

    auto const child_iter = build.store->prepend(build.iter->children());
    (*child_iter)[file_cols.index] = child_data.index;
    (*child_iter)[file_cols.label] = child_data.name;
    (*child_iter)[file_cols.label_esc] = name_esc;
    (*child_iter)[file_cols.size] = child_data.length;
    (*child_iter)[file_cols.size_str] = tr_strlsize(child_data.length);
    (*child_iter)[file_cols.icon] = icon;
    (*child_iter)[file_cols.priority] = priority;
    (*child_iter)[file_cols.enabled] = static_cast<int>(enabled);

    if (!isLeaf)
    {
        build_data b = build;
        b.iter = child_iter;
        node.foreach ([&b](auto& child_node) { buildTree(child_node, b); }, TR_GLIB_NODE_TREE_TRAVERSE_FLAGS(FileRowNode, ALL));
    }
}

} // namespace

void FileList::set_torrent(tr_torrent_id_t torrent_id)
{
    impl_->set_torrent(torrent_id);
}

struct PairHash
{
    template<typename T1, typename T2>
    auto operator()(std::pair<T1, T2> const& pair) const
    {
        return std::hash<T1>{}(pair.first) ^ std::hash<T2>{}(pair.second);
    }
};

void FileList::Impl::set_torrent(tr_torrent_id_t torrent_id)
{
    if (torrent_id_ == torrent_id && store_ != nullptr && !store_->children().empty())
    {
        return;
    }

    /* unset the old fields */
    clearData();

    /* instantiate the model */
    store_ = Gtk::TreeStore::create(file_cols);
    torrent_id_ = torrent_id;

    /* populate the model */
    if (torrent_id_ > 0)
    {
        if (auto* const tor = core_->find_torrent(torrent_id_); tor != nullptr)
        {
            // build a GNode tree of the files
            auto root = FileRowNode{};
            auto& root_data = root.data();
            root_data.name = tr_torrentName(tor);
            root_data.index = -1;
            root_data.length = 0;

            auto nodes = std::unordered_map<std::pair<FileRowNode* /*parent*/, std::string_view>, FileRowNode*, PairHash>{};

            for (tr_file_index_t i = 0, n_files = tr_torrentFileCount(tor); i < n_files; ++i)
            {
                auto* parent = &root;
                auto const file = tr_torrentFile(tor, i);

                auto path = std::string_view{ file.name };
                auto token = std::string_view{};
                while (tr_strv_sep(&path, &token, '/'))
                {
                    auto*& node = nodes[std::make_pair(parent, token)];

                    if (node == nullptr)
                    {
                        auto const is_leaf = std::empty(path);

                        node = parent->prepend_data({});
                        auto& node_data = node->data();
                        node_data.name = std::string{ token };
                        node_data.index = is_leaf ? (int)i : -1;
                        node_data.length = is_leaf ? file.length : 0;
                    }

                    parent = node;
                }
            }

            // now, add them to the model
            struct build_data build;
            build.w = &widget_;
            build.tor = tor;
            build.store = store_;
            root.foreach (
                [&build](auto& child_node) { buildTree(child_node, build); },
                TR_GLIB_NODE_TREE_TRAVERSE_FLAGS(FileRowNode, ALL));
        }

        refresh();
        timeout_tag_ = Glib::signal_timeout().connect_seconds(
            [this]() { return refresh(), true; },
            SECONDARY_WINDOW_REFRESH_INTERVAL_SECONDS);
    }

    view_->set_model(store_);

    /* set default sort by label */
    store_->set_sort_column(file_cols.label, TR_GTK_SORT_TYPE(ASCENDING));

    view_->expand_row(Gtk::TreeModel::Path("0"), false);
    // view_->expand_all();
}

void FileList::Impl::reset_torrent()
{
    clearData();

    store_ = Gtk::TreeStore::create(file_cols);
    view_->set_model(store_);
}

/***
****
***/

namespace
{

void renderDownload(Gtk::CellRenderer* renderer, Gtk::TreeModel::const_iterator const& iter)
{
    auto* const toggle_renderer = dynamic_cast<Gtk::CellRendererToggle*>(renderer);
    g_assert(toggle_renderer != nullptr);
    if (toggle_renderer == nullptr)
    {
        return;
    }

    auto const enabled = iter->get_value(file_cols.enabled);
    toggle_renderer->property_inconsistent() = enabled == MIXED;
    toggle_renderer->property_active() = enabled == static_cast<int>(true);
}

void renderPriority(Gtk::CellRenderer* renderer, Gtk::TreeModel::const_iterator const& iter)
{
    auto* const text_renderer = dynamic_cast<Gtk::CellRendererText*>(renderer);
    g_assert(text_renderer != nullptr);
    if (text_renderer == nullptr)
    {
        return;
    }

    Glib::ustring text;

    switch (auto const priority = iter->get_value(file_cols.priority); priority)
    {
    case TR_PRI_HIGH:
        text = _("High");
        break;

    case TR_PRI_NORMAL:
        text = _("Normal");
        break;

    case TR_PRI_LOW:
        text = _("Low");
        break;

    default:
        text = _("Mixed");
        break;
    }

    text_renderer->property_text() = text;
}

/* build a filename from tr_torrentGetCurrentDir() + the model's FC_LABELs */
std::string buildFilename(tr_torrent const* tor, Gtk::TreeModel::iterator const& iter)
{
    std::vector<std::string> tokens;
    for (auto child = iter; child; child = child->parent())
    {
        tokens.push_back(child->get_value(file_cols.label));
    }

    tokens.emplace_back(tr_torrentGetCurrentDir(tor));
    std::reverse(tokens.begin(), tokens.end());
    return Glib::build_filename(tokens);
}

} // namespace

void FileList::Impl::onRowActivated(Gtk::TreeModel::Path const& path, Gtk::TreeViewColumn* /*col*/)
{
    bool handled = false;

    if (auto const* tor = core_->find_torrent(torrent_id_); tor != nullptr)
    {
        if (auto const iter = store_->get_iter(path); iter)
        {
            auto filename = buildFilename(tor, iter);
            auto const prog = iter->get_value(file_cols.prog);

            /* if the file's not done, walk up the directory tree until we find
             * an ancestor that exists, and open that instead */
            if (!filename.empty() && (prog < 100 || !Glib::file_test(filename, TR_GLIB_FILE_TEST(EXISTS))))
            {
                do
                {
                    filename = Glib::path_get_dirname(filename);
                } while (!filename.empty() && !Glib::file_test(filename, TR_GLIB_FILE_TEST(EXISTS)));
            }

            if (handled = !filename.empty(); handled)
            {
                gtr_open_file(filename);
            }
        }
    }

    // return handled;
}

bool FileList::Impl::onViewPathToggled(Gtk::TreeViewColumn* col, Gtk::TreeModel::Path const& path)
{
    if (col == nullptr || path.empty())
    {
        return false;
    }

    bool handled = false;

    auto const cid = col->get_sort_column_id();
    auto* tor = core_->find_torrent(torrent_id_);

    if (tor != nullptr && (cid == file_cols.priority.index() || cid == file_cols.enabled.index()))
    {
        auto const indexBuf = getActiveFilesForPath(path);

        auto const iter = store_->get_iter(path);

        if (cid == file_cols.priority.index())
        {
            auto priority = iter->get_value(file_cols.priority);

            switch (priority)
            {
            case TR_PRI_NORMAL:
                priority = TR_PRI_HIGH;
                break;

            case TR_PRI_HIGH:
                priority = TR_PRI_LOW;
                break;

            default:
                priority = TR_PRI_NORMAL;
                break;
            }

            tr_torrentSetFilePriorities(tor, indexBuf.data(), indexBuf.size(), priority);
        }
        else
        {
            auto const enabled = iter->get_value(file_cols.enabled);
            tr_torrentSetFileDLs(tor, indexBuf.data(), indexBuf.size(), enabled == static_cast<int>(false));
        }

        refresh();
        handled = true;
    }

    return handled;
}

/**
 * @note 'col' and 'path' are assumed not to be nullptr.
 */
bool FileList::Impl::getAndSelectEventPath(double view_x, double view_y, Gtk::TreeViewColumn*& col, Gtk::TreeModel::Path& path)
{
    int cell_x = 0;
    int cell_y = 0;

    if (view_->get_path_at_pos(view_x, view_y, path, col, cell_x, cell_y))
    {
        if (auto const sel = view_->get_selection(); !sel->is_selected(path))
        {
            sel->unselect_all();
            sel->select(path);
        }

        return true;
    }

    return false;
}

bool FileList::Impl::onViewButtonPressed(guint button, TrGdkModifierType state, double view_x, double view_y)
{
    Gtk::TreeViewColumn* col = nullptr;
    Gtk::TreeModel::Path path;
    bool handled = false;

    if (button == GDK_BUTTON_PRIMARY &&
        (state & (TR_GDK_MODIFIED_TYPE(SHIFT_MASK) | TR_GDK_MODIFIED_TYPE(CONTROL_MASK))) == TrGdkModifierType{} &&
        getAndSelectEventPath(view_x, view_y, col, path))
    {
        handled = onViewPathToggled(col, path);
    }

    return handled;
}

struct rename_data
{
    Glib::ustring newname;
    Glib::ustring path_string;
    gpointer impl = nullptr;
};

void FileList::Impl::on_rename_done(Glib::ustring const& path_string, Glib::ustring const& newname, int error)
{
    rename_done_tags_.push(Glib::signal_idle().connect(
        [this, path_string, newname, error]()
        {
            rename_done_tags_.pop();
            on_rename_done_idle(path_string, newname, error);
            return false;
        }));
}

void FileList::Impl::on_rename_done_idle(Glib::ustring const& path_string, Glib::ustring const& newname, int error)
{
    if (error == 0)
    {
        if (auto const iter = store_->get_iter(path_string); iter)
        {
            bool const isLeaf = iter->children().empty();
            auto const mime_type = isLeaf ? tr_get_mime_type_for_filename(newname.raw()) : DirectoryMimeType;
            auto const icon = gtr_get_mime_type_icon(mime_type);

            (*iter)[file_cols.label] = newname;
            (*iter)[file_cols.icon] = icon;

            if (!iter->parent())
            {
                core_->torrent_changed(torrent_id_);
            }
        }
    }
    else
    {
        auto w = std::make_shared<Gtk::MessageDialog>(
            gtr_widget_get_window(widget_),
            fmt::format(
                _("Couldn't rename '{old_path}' as '{path}': {error} ({error_code})"),
                fmt::arg("old_path", path_string),
                fmt::arg("path", newname),
                fmt::arg("error", tr_strerror(error)),
                fmt::arg("error_code", error)),
            false,
            TR_GTK_MESSAGE_TYPE(ERROR),
            TR_GTK_BUTTONS_TYPE(CLOSE),
            true);
        w->set_secondary_text(_("Please correct the errors and try again."));
        w->signal_response().connect([w](int /*response*/) mutable { w.reset(); });
        w->show();
    }
}

void FileList::Impl::cell_edited_callback(Glib::ustring const& path_string, Glib::ustring const& newname)
{
    tr_torrent* const tor = core_->find_torrent(torrent_id_);

    if (tor == nullptr)
    {
        return;
    }

    auto iter = store_->get_iter(path_string);
    if (!iter)
    {
        return;
    }

    /* build oldpath */
    Glib::ustring oldpath;

    for (;;)
    {
        oldpath.insert(0, iter->get_value(file_cols.label));

        iter = iter->parent();
        if (!iter)
        {
            break;
        }

        oldpath.insert(0, 1, G_DIR_SEPARATOR);
    }

    /* do the renaming */
    auto rename_data = std::make_unique<struct rename_data>();
    rename_data->newname = newname;
    rename_data->impl = this;
    rename_data->path_string = path_string;
    tr_torrentRenamePath(
        tor,
        oldpath.c_str(),
        newname.c_str(),
        static_cast<tr_torrent_rename_done_func>(
            [](tr_torrent* /*tor*/, char const* /*oldpath*/, char const* /*newname*/, int error, gpointer data)
            {
                auto const data_grave = std::unique_ptr<struct rename_data>(static_cast<struct rename_data*>(data));
                static_cast<Impl*>(data_grave->impl)->on_rename_done(data_grave->path_string, data_grave->newname, error);
            }),
        rename_data.release());
}

FileList::FileList(
    BaseObjectType* cast_item,
    Glib::RefPtr<Gtk::Builder> const& builder,
    Glib::ustring const& view_name,
    Glib::RefPtr<Session> const& core,
    tr_torrent_id_t torrent_id)
    : Gtk::ScrolledWindow(cast_item)
    , impl_(std::make_unique<Impl>(*this, builder, view_name, core, torrent_id))
{
}

FileList::Impl::Impl(
    FileList& widget,
    Glib::RefPtr<Gtk::Builder> const& builder,
    Glib::ustring const& view_name,
    Glib::RefPtr<Session> const& core,
    tr_torrent_id_t torrent_id)
    : widget_(widget)
    , core_(core)
    , view_(gtr_get_widget<Gtk::TreeView>(builder, view_name))
{
    /* create the view */
    view_->signal_row_activated().connect(sigc::mem_fun(*this, &Impl::onRowActivated));
    setup_item_view_button_event_handling(
        *view_,
        [this](guint button, TrGdkModifierType state, double view_x, double view_y, bool /*context_menu_requested*/)
        { return onViewButtonPressed(button, state, view_x, view_y); },
        [this](double view_x, double view_y) { return on_item_view_button_released(*view_, view_x, view_y); });

    auto pango_font_description = view_->create_pango_context()->get_font_description();
    if (auto const new_size = pango_font_description.get_size() * 0.8; pango_font_description.get_size_is_absolute())
    {
        pango_font_description.set_absolute_size(new_size);
    }
    else
    {
        pango_font_description.set_size(new_size);
    }

    /* set up view */
    auto const sel = view_->get_selection();
    sel->set_mode(TR_GTK_SELECTION_MODE(MULTIPLE));
    view_->expand_all();
    view_->set_search_column(file_cols.label);

    {
        /* add file column */
        auto* col = Gtk::make_managed<Gtk::TreeViewColumn>();
        col->set_expand(true);
        col->set_title(_("Name"));
        col->set_resizable(true);
        auto* icon_rend = Gtk::make_managed<Gtk::CellRendererPixbuf>();
        col->pack_start(*icon_rend, false);
        col->add_attribute(icon_rend->property_gicon(), file_cols.icon);
#if GTKMM_CHECK_VERSION(4, 0, 0)
        icon_rend->property_icon_size() = Gtk::IconSize::NORMAL;
#else
        icon_rend->property_stock_size() = Gtk::ICON_SIZE_MENU;
#endif
        /* add text renderer */
        auto* text_rend = Gtk::make_managed<Gtk::CellRendererText>();
        text_rend->property_editable() = true;
        text_rend->property_ellipsize() = TR_PANGO_ELLIPSIZE_MODE(END);
        text_rend->property_font_desc() = pango_font_description;
        text_rend->signal_edited().connect(sigc::mem_fun(*this, &Impl::cell_edited_callback));
        col->pack_start(*text_rend, true);
        col->add_attribute(text_rend->property_text(), file_cols.label);
        col->set_sort_column(file_cols.label);
        view_->append_column(*col);
    }

    {
        /* add "size" column */
        auto* rend = Gtk::make_managed<Gtk::CellRendererText>();
        rend->property_alignment() = TR_PANGO_ALIGNMENT(RIGHT);
        rend->property_font_desc() = pango_font_description;
        rend->property_xpad() = GUI_PAD;
        rend->property_xalign() = 1.0F;
        rend->property_yalign() = 0.5F;
        auto* col = Gtk::make_managed<Gtk::TreeViewColumn>(_("Size"), *rend);
        col->set_sizing(TR_GTK_TREE_VIEW_COLUMN_SIZING(GROW_ONLY));
        col->set_sort_column(file_cols.size);
        col->add_attribute(rend->property_text(), file_cols.size_str);
        view_->append_column(*col);
    }

    {
        /* add "progress" column */
        auto const* title = _("Have");
        int width = 0;
        int height = 0;
        view_->create_pango_layout(title)->get_pixel_size(width, height);
        width += 30; /* room for the sort indicator */
        auto* rend = Gtk::make_managed<Gtk::CellRendererProgress>();
        auto* col = Gtk::make_managed<Gtk::TreeViewColumn>(title, *rend);
        col->add_attribute(rend->property_text(), file_cols.prog_str);
        col->add_attribute(rend->property_value(), file_cols.prog);
        col->set_fixed_width(width);
        col->set_sizing(TR_GTK_TREE_VIEW_COLUMN_SIZING(FIXED));
        col->set_sort_column(file_cols.prog);
        view_->append_column(*col);
    }

    {
        /* add "enabled" column */
        auto const* title = _("Download");
        int width = 0;
        int height = 0;
        view_->create_pango_layout(title)->get_pixel_size(width, height);
        width += 30; /* room for the sort indicator */
        auto* rend = Gtk::make_managed<Gtk::CellRendererToggle>();
        auto* col = Gtk::make_managed<Gtk::TreeViewColumn>(title, *rend);
        col->set_fixed_width(width);
        col->set_sizing(TR_GTK_TREE_VIEW_COLUMN_SIZING(FIXED));
        col->set_cell_data_func(*rend, sigc::ptr_fun(&renderDownload));
        col->set_sort_column(file_cols.enabled);
        view_->append_column(*col);
    }

    {
        /* add priority column */
        auto const* title = _("Priority");
        int width = 0;
        int height = 0;
        view_->create_pango_layout(title)->get_pixel_size(width, height);
        width += 30; /* room for the sort indicator */
        auto* rend = Gtk::make_managed<Gtk::CellRendererText>();
        rend->property_xalign() = 0.5F;
        rend->property_yalign() = 0.5F;
        auto* col = Gtk::make_managed<Gtk::TreeViewColumn>(title, *rend);
        col->set_fixed_width(width);
        col->set_sizing(TR_GTK_TREE_VIEW_COLUMN_SIZING(FIXED));
        col->set_sort_column(file_cols.priority);
        col->set_cell_data_func(*rend, sigc::ptr_fun(&renderPriority));
        view_->append_column(*col);
    }

    /* add tooltip to tree */
    view_->set_tooltip_column(file_cols.label_esc.index());

    set_torrent(torrent_id);
}

FileList::~FileList() = default;