/*
 * Copyright (c) 2020, the SerenityOS developers.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <AK/StringBuilder.h>
#include <LibWeb/DOM/Position.h>
#include <LibWeb/DOM/Text.h>
#include <LibWeb/Layout/LayoutPosition.h>
#include <LibWeb/Page/Frame.h>

#include <LibWeb/DOM/Document.h>
#include <LibWeb/Dump.h>
#include <LibWeb/Layout/InitialContainingBlockBox.h>

#include "EditEventHandler.h"

namespace Web {

void EditEventHandler::handle_delete(DOM::Range range)
{
    // FIXME: Deleting nodes seems to mess up the layout tree. Not sure if this is not entirely
    //        my fault or not my fault at all.

    dump_tree(*m_frame.document());

    if (range.start().node() != range.end().node()) {
        if (range.start().node()->parent() == range.end().node()->parent()) {
            // Remove all intermediate nodes.
            auto* current = range.start().node()->next_sibling();
            while (current != range.end().node()) {
                auto* next = current->next_sibling();
                current->parent()->remove_child(*current);
                current = next;
            }

            // Join remaining text together.
            StringBuilder builder;
            builder.append(downcast<DOM::Text>(range.start().node())->data().substring_view(0, range.start().offset()));
            builder.append(downcast<DOM::Text>(range.end().node())->data().substring_view(range.end().offset()));

            range.start().node()->parent()->remove_child(*range.end().node());
            downcast<DOM::Text>(range.start().node())->set_data(builder.to_string());

            range.start().node()->invalidate_style();
        } else {
            TODO();
        }
    } else {
        if (is<DOM::Text>(*range.start().node())) {
            m_frame.document()->layout_node()->set_selection({});

            auto& node = downcast<DOM::Text>(*range.start().node());

            StringBuilder builder;
            builder.append(node.data().substring_view(0, range.start().offset()));
            builder.append(node.data().substring_view(range.end().offset()));
            node.set_data(builder.to_string());

            node.invalidate_style();
        }
    }

    // FIXME: We need to remove stale layout nodes when nodes are removed from the DOM. Currently,
    //        this is the only way to get these to disappear.
    m_frame.document()->force_layout();

    dump_tree(*m_frame.document());
}

void EditEventHandler::handle_insert(DOM::Position position, u32 code_point)
{
    if (is<DOM::Text>(*position.node())) {
        auto& node = downcast<DOM::Text>(*position.node());

        StringBuilder builder;
        builder.append(node.data().substring_view(0, position.offset()));
        builder.append_code_point(code_point);
        builder.append(node.data().substring_view(position.offset()));
        node.set_data(builder.to_string());

        node.invalidate_style();
    }

    // FIXME: We need to remove stale layout nodes when nodes are removed from the DOM. Currently,
    //        this is the only way to get these to disappear.
    m_frame.document()->force_layout();
}

}