/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * Copyright (c) 2021, Mustafa Quraish <mustafa@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include "HexEditorWidget.h"
#include "FindDialog.h"
#include "GoToOffsetDialog.h"
#include "SearchResultsModel.h"
#include <AK/Optional.h>
#include <AK/StringBuilder.h>
#include <Applications/HexEditor/HexEditorWindowGML.h>
#include <LibConfig/Client.h>
#include <LibCore/File.h>
#include <LibFileSystemAccessClient/Client.h>
#include <LibGUI/Action.h>
#include <LibGUI/BoxLayout.h>
#include <LibGUI/Button.h>
#include <LibGUI/FilePicker.h>
#include <LibGUI/InputBox.h>
#include <LibGUI/Menu.h>
#include <LibGUI/Menubar.h>
#include <LibGUI/MessageBox.h>
#include <LibGUI/Model.h>
#include <LibGUI/Statusbar.h>
#include <LibGUI/TableView.h>
#include <LibGUI/TextBox.h>
#include <LibGUI/Toolbar.h>
#include <LibGUI/ToolbarContainer.h>
#include <string.h>

REGISTER_WIDGET(HexEditor, HexEditor);

HexEditorWidget::HexEditorWidget()
{
    load_from_gml(hex_editor_window_gml);

    m_toolbar = *find_descendant_of_type_named<GUI::Toolbar>("toolbar");
    m_toolbar_container = *find_descendant_of_type_named<GUI::ToolbarContainer>("toolbar_container");
    m_editor = *find_descendant_of_type_named<HexEditor>("editor");
    m_statusbar = *find_descendant_of_type_named<GUI::Statusbar>("statusbar");
    m_search_results = *find_descendant_of_type_named<GUI::TableView>("search_results");
    m_search_results_container = *find_descendant_of_type_named<GUI::Widget>("search_results_container");

    m_editor->on_status_change = [this](int position, HexEditor::EditMode edit_mode, int selection_start, int selection_end) {
        m_statusbar->set_text(0, String::formatted("Offset: {:#08X}", position));
        m_statusbar->set_text(1, String::formatted("Edit Mode: {}", edit_mode == HexEditor::EditMode::Hex ? "Hex" : "Text"));
        m_statusbar->set_text(2, String::formatted("Selection Start: {}", selection_start));
        m_statusbar->set_text(3, String::formatted("Selection End: {}", selection_end));
        m_statusbar->set_text(4, String::formatted("Selected Bytes: {}", m_editor->selection_size()));
    };

    m_editor->on_change = [this] {
        bool was_dirty = m_document_dirty;
        m_document_dirty = true;
        if (!was_dirty)
            update_title();
    };

    m_search_results->set_activates_on_selection(true);
    m_search_results->on_activation = [this](const GUI::ModelIndex& index) {
        if (!index.is_valid())
            return;
        auto offset = index.data(GUI::ModelRole::Custom).to_i32();
        m_last_found_index = offset;
        m_editor->set_position(offset);
        m_editor->update();
    };

    m_new_action = GUI::Action::create("New", { Mod_Ctrl, Key_N }, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/new.png").release_value_but_fixme_should_propagate_errors(), [this](const GUI::Action&) {
        String value;
        if (request_close() && GUI::InputBox::show(window(), value, "Enter new file size:", "New file size") == GUI::InputBox::ExecOK && !value.is_empty()) {
            auto file_size = value.to_int();
            if (file_size.has_value() && file_size.value() > 0) {
                m_document_dirty = false;
                auto buffer_result = ByteBuffer::create_zeroed(file_size.value());
                if (!buffer_result.has_value()) {
                    GUI::MessageBox::show(window(), "Entered file size is too large.", "Error", GUI::MessageBox::Type::Error);
                    return;
                }
                m_editor->set_buffer(buffer_result.release_value());
                set_path({});
                update_title();
            } else {
                GUI::MessageBox::show(window(), "Invalid file size entered.", "Error", GUI::MessageBox::Type::Error);
            }
        }
    });

    m_open_action = GUI::CommonActions::make_open_action([this](auto&) {
        auto response = FileSystemAccessClient::Client::the().open_file(window()->window_id());

        if (response.error != 0) {
            if (response.error != -1)
                GUI::MessageBox::show_error(window(), String::formatted("Opening \"{}\" failed: {}", *response.chosen_file, strerror(response.error)));
            return;
        }

        if (m_document_dirty) {
            auto save_document_first_result = GUI::MessageBox::show(window(), "Save changes to current document first?", "Warning", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel);
            if (save_document_first_result == GUI::Dialog::ExecResult::ExecYes)
                m_save_action->activate();
            if (save_document_first_result != GUI::Dialog::ExecResult::ExecNo && m_document_dirty)
                return;
        }

        open_file(*response.fd, *response.chosen_file);
    });

    m_save_action = GUI::CommonActions::make_save_action([&](auto&) {
        if (m_path.is_empty())
            return m_save_as_action->activate();

        auto response = FileSystemAccessClient::Client::the().request_file(window()->window_id(), m_path, Core::OpenMode::Truncate | Core::OpenMode::WriteOnly);

        if (response.error != 0) {
            if (response.error != -1)
                GUI::MessageBox::show_error(window(), String::formatted("Unable to save file: {}", strerror(response.error)));
            return;
        }

        if (!m_editor->write_to_file(*response.fd)) {
            GUI::MessageBox::show(window(), "Unable to save file.\n", "Error", GUI::MessageBox::Type::Error);
        } else {
            m_document_dirty = false;
            update_title();
        }
        return;
    });

    m_save_as_action = GUI::CommonActions::make_save_as_action([&](auto&) {
        auto response = FileSystemAccessClient::Client::the().save_file(window()->window_id(), m_name, m_extension);

        if (response.error != 0) {
            if (response.error != -1)
                GUI::MessageBox::show_error(window(), String::formatted("Saving \"{}\" failed: {}", *response.chosen_file, strerror(response.error)));
            return;
        }

        if (!m_editor->write_to_file(*response.fd)) {
            GUI::MessageBox::show(window(), "Unable to save file.\n", "Error", GUI::MessageBox::Type::Error);
            return;
        }

        m_document_dirty = false;
        set_path(*response.chosen_file);
        dbgln("Wrote document to {}", *response.chosen_file);
    });

    m_find_action = GUI::Action::create("&Find", { Mod_Ctrl, Key_F }, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/find.png").release_value_but_fixme_should_propagate_errors(), [&](const GUI::Action&) {
        auto old_buffer = m_search_buffer;
        bool find_all = false;
        if (FindDialog::show(window(), m_search_text, m_search_buffer, find_all) == GUI::InputBox::ExecOK) {
            if (find_all) {
                auto matches = m_editor->find_all(m_search_buffer, 0);
                m_search_results->set_model(*new SearchResultsModel(move(matches)));
                m_search_results->update();

                if (matches.is_empty()) {
                    GUI::MessageBox::show(window(), String::formatted("Pattern \"{}\" not found in this file", m_search_text), "Not found", GUI::MessageBox::Type::Warning);
                    return;
                }

                GUI::MessageBox::show(window(), String::formatted("Found {} matches for \"{}\" in this file", matches.size(), m_search_text), String::formatted("{} matches", matches.size()), GUI::MessageBox::Type::Warning);
                set_search_results_visible(true);
            } else {
                bool same_buffers = false;
                if (old_buffer.size() == m_search_buffer.size()) {
                    if (memcmp(old_buffer.data(), m_search_buffer.data(), old_buffer.size()) == 0)
                        same_buffers = true;
                }

                auto result = m_editor->find_and_highlight(m_search_buffer, same_buffers ? last_found_index() : 0);

                if (!result.has_value()) {
                    GUI::MessageBox::show(window(), String::formatted("Pattern \"{}\" not found in this file", m_search_text), "Not found", GUI::MessageBox::Type::Warning);
                    return;
                }

                m_last_found_index = result.value();
            }

            m_editor->update();
        }
    });

    m_goto_offset_action = GUI::Action::create("&Go to Offset ...", { Mod_Ctrl, Key_G }, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/go-to.png").release_value_but_fixme_should_propagate_errors(), [this](const GUI::Action&) {
        int new_offset;
        auto result = GoToOffsetDialog::show(
            window(),
            m_goto_history,
            new_offset,
            m_editor->selection_start_offset(),
            m_editor->buffer_size());
        if (result == GUI::InputBox::ExecOK) {
            m_editor->highlight(new_offset, new_offset);
            m_editor->update();
        }
    });

    m_layout_toolbar_action = GUI::Action::create_checkable("&Toolbar", [&](auto& action) {
        m_toolbar_container->set_visible(action.is_checked());
        Config::write_bool("HexEditor", "Layout", "ShowToolbar", action.is_checked());
    });

    m_layout_search_results_action = GUI::Action::create_checkable("&Search Results", [&](auto& action) {
        set_search_results_visible(action.is_checked());
    });

    m_toolbar->add_action(*m_new_action);
    m_toolbar->add_action(*m_open_action);
    m_toolbar->add_action(*m_save_action);
    m_toolbar->add_separator();
    m_toolbar->add_action(*m_find_action);
    m_toolbar->add_action(*m_goto_offset_action);

    m_editor->set_focus(true);
}

HexEditorWidget::~HexEditorWidget()
{
}

void HexEditorWidget::initialize_menubar(GUI::Window& window)
{
    auto& file_menu = window.add_menu("&File");
    file_menu.add_action(*m_new_action);
    file_menu.add_action(*m_open_action);
    file_menu.add_action(*m_save_action);
    file_menu.add_action(*m_save_as_action);
    file_menu.add_separator();
    file_menu.add_action(GUI::CommonActions::make_quit_action([this](auto&) {
        if (!request_close())
            return;
        GUI::Application::the()->quit();
    }));

    auto& edit_menu = window.add_menu("&Edit");
    edit_menu.add_action(GUI::CommonActions::make_select_all_action([this](auto&) {
        m_editor->select_all();
        m_editor->update();
    }));
    edit_menu.add_action(GUI::Action::create("Fill &Selection...", { Mod_Ctrl, Key_B }, [&](const GUI::Action&) {
        String value;
        if (GUI::InputBox::show(&window, value, "Fill byte (hex):", "Fill Selection") == GUI::InputBox::ExecOK && !value.is_empty()) {
            auto fill_byte = strtol(value.characters(), nullptr, 16);
            m_editor->fill_selection(fill_byte);
        }
    }));
    edit_menu.add_separator();
    edit_menu.add_action(GUI::Action::create("Copy &Hex", { Mod_Ctrl, Key_C }, [&](const GUI::Action&) {
        m_editor->copy_selected_hex_to_clipboard();
    }));
    edit_menu.add_action(GUI::Action::create("Copy &Text", { Mod_Ctrl | Mod_Shift, Key_C }, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/edit-copy.png").release_value_but_fixme_should_propagate_errors(), [&](const GUI::Action&) {
        m_editor->copy_selected_text_to_clipboard();
    }));
    edit_menu.add_action(GUI::Action::create("Copy as &C Code", { Mod_Alt | Mod_Shift, Key_C }, [&](const GUI::Action&) {
        m_editor->copy_selected_hex_to_clipboard_as_c_code();
    }));
    edit_menu.add_separator();
    edit_menu.add_action(*m_find_action);
    edit_menu.add_action(GUI::Action::create("Find &Next", { Mod_None, Key_F3 }, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/find-next.png").release_value_but_fixme_should_propagate_errors(), [&](const GUI::Action&) {
        if (m_search_text.is_empty() || m_search_buffer.is_empty()) {
            GUI::MessageBox::show(&window, "Nothing to search for", "Not found", GUI::MessageBox::Type::Warning);
            return;
        }

        auto result = m_editor->find_and_highlight(m_search_buffer, last_found_index());
        if (!result.has_value()) {
            GUI::MessageBox::show(&window, String::formatted("No more matches for \"{}\" found in this file", m_search_text), "Not found", GUI::MessageBox::Type::Warning);
            return;
        }
        m_editor->update();
        m_last_found_index = result.value();
    }));

    edit_menu.add_action(GUI::Action::create("Find All &Strings", { Mod_Ctrl | Mod_Shift, Key_S }, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/find.png").release_value_but_fixme_should_propagate_errors(), [&](const GUI::Action&) {
        int min_length = 4;
        auto matches = m_editor->find_all_strings(min_length);
        m_search_results->set_model(*new SearchResultsModel(move(matches)));
        m_search_results->update();

        if (matches.is_empty()) {
            GUI::MessageBox::show(&window, "No strings found in this file", "Not found", GUI::MessageBox::Type::Warning);
            return;
        }

        set_search_results_visible(true);
        m_editor->update();
    }));
    edit_menu.add_separator();
    edit_menu.add_action(*m_goto_offset_action);

    auto& view_menu = window.add_menu("&View");

    auto show_toolbar = Config::read_bool("HexEditor", "Layout", "ShowToolbar", true);
    m_layout_toolbar_action->set_checked(show_toolbar);
    m_toolbar_container->set_visible(show_toolbar);
    view_menu.add_action(*m_layout_toolbar_action);
    view_menu.add_action(*m_layout_search_results_action);
    view_menu.add_separator();

    auto bytes_per_row = Config::read_i32("HexEditor", "Layout", "BytesPerRow", 16);
    m_editor->set_bytes_per_row(bytes_per_row);
    m_editor->update();

    m_bytes_per_row_actions.set_exclusive(true);
    auto& bytes_per_row_menu = view_menu.add_submenu("Bytes per &Row");
    for (int i = 8; i <= 32; i += 8) {
        auto action = GUI::Action::create_checkable(String::number(i), [this, i](auto&) {
            m_editor->set_bytes_per_row(i);
            m_editor->update();
            Config::write_i32("HexEditor", "Layout", "BytesPerRow", i);
        });
        m_bytes_per_row_actions.add_action(action);
        bytes_per_row_menu.add_action(action);
        if (i == bytes_per_row)
            action->set_checked(true);
    }

    auto& help_menu = window.add_menu("&Help");
    help_menu.add_action(GUI::CommonActions::make_about_action("Hex Editor", GUI::Icon::default_icon("app-hex-editor"), &window));
}

void HexEditorWidget::set_path(StringView path)
{
    if (path.is_empty()) {
        m_path = {};
        m_name = {};
        m_extension = {};
    } else {
        auto lexical_path = LexicalPath(path);
        m_path = lexical_path.string();
        m_name = lexical_path.title();
        m_extension = lexical_path.extension();
    }
    update_title();
}

void HexEditorWidget::update_title()
{
    StringBuilder builder;
    if (m_path.is_empty())
        builder.append("Untitled");
    else
        builder.append(m_path);
    if (m_document_dirty)
        builder.append(" (*)");
    builder.append(" - Hex Editor");
    window()->set_title(builder.to_string());
}

void HexEditorWidget::open_file(int fd, String const& path)
{
    VERIFY(path.starts_with("/"sv));
    auto file = Core::File::construct();

    if (!file->open(fd, Core::OpenMode::ReadOnly, Core::File::ShouldCloseFileDescriptor::Yes) && file->error() != ENOENT) {
        GUI::MessageBox::show(window(), String::formatted("Opening \"{}\" failed: {}", path, strerror(errno)), "Error", GUI::MessageBox::Type::Error);
        return;
    }

    if (file->is_device()) {
        GUI::MessageBox::show(window(), String::formatted("Opening \"{}\" failed: Can't open device files", path), "Error", GUI::MessageBox::Type::Error);
        return;
    }

    if (file->is_directory()) {
        GUI::MessageBox::show(window(), String::formatted("Opening \"{}\" failed: Can't open directories", path), "Error", GUI::MessageBox::Type::Error);
        return;
    }

    m_document_dirty = false;
    m_editor->set_buffer(file->read_all()); // FIXME: On really huge files, this is never going to work. Should really create a framework to fetch data from the file on-demand.
    set_path(path);
}

bool HexEditorWidget::request_close()
{
    if (!m_document_dirty)
        return true;

    auto result = GUI::MessageBox::show(window(), "The file has been modified. Save before closing?", "Save changes", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel);
    if (result == GUI::MessageBox::ExecCancel)
        return false;
    if (result == GUI::MessageBox::ExecYes) {
        m_save_action->activate();
        return m_document_dirty == false;
    }
    return true;
}

void HexEditorWidget::set_search_results_visible(bool visible)
{
    m_layout_search_results_action->set_checked(visible);
    m_search_results_container->set_visible(visible);
}

void HexEditorWidget::drop_event(GUI::DropEvent& event)
{
    event.accept();

    if (event.mime_data().has_urls()) {
        auto urls = event.mime_data().urls();
        if (urls.is_empty())
            return;
        window()->move_to_front();

        // TODO: A drop event should be considered user consent for opening a file
        auto file_response = FileSystemAccessClient::Client::the().request_file(window()->window_id(), urls.first().path(), Core::OpenMode::ReadOnly);

        if (file_response.error != 0)
            return;

        open_file(*file_response.fd, urls.first().path());
    }
}