using Adw;
using Gtk;

namespace Publicate {

    public class PpubEditor : Box {

        private Adw.HeaderBar header;
        private WindowTitle header_title;

        private Leaflet leaflet;

        private File publication_file;
        private ViewerWindow window;

        private FileExplorer file_explorer;
        private Box tab_box;
        private TabView tab_view;
        private TabBar tab_bar;

        private Button save_tab_button;
        private Button remove_file_button;

        private SaveProgress progress_window;

        private Gee.HashMap<string, Editors.EditorWidget> open_editors = new Gee.HashMap<string, Editors.EditorWidget>();

        public PpubEditor(ViewerWindow win) {
            window = win;

            progress_window = new SaveProgress(window);

            orientation = Orientation.VERTICAL;
            header = new Adw.HeaderBar();
            append(header);

            header_title = new WindowTitle("Untitled Publication", "");
            header.title_widget = header_title;

            var file_box = new Box(Orientation.VERTICAL, 0);
            file_box.vexpand = true;
            file_explorer = new FileExplorer();
            file_explorer.asset_selected.connect(open_asset);
            file_explorer.vexpand = true;
            file_box.append(file_explorer);
            
            var file_buttons = new Box(Orientation.HORIZONTAL, 0);
            file_buttons.add_css_class("linked");
            file_buttons.halign = Align.END;
            file_buttons.margin_end = 8;
            file_buttons.margin_bottom = 8;
            file_buttons.margin_start = 8;
            file_buttons.margin_top = 8;
            file_box.append(file_buttons);
            
            var new_file_button = new Button.from_icon_name("document-new-symbolic");
            file_buttons.append(new_file_button);
            new_file_button.sensitive = false; // Not yet implemented...

            var add_file_button = new Button.from_icon_name("list-add-symbolic");
            file_buttons.append(add_file_button);
            add_file_button.clicked.connect(import_file);

            remove_file_button = new Button.from_icon_name("user-trash-symbolic");
            file_buttons.append(remove_file_button);
            remove_file_button.clicked.connect(delete_file_clicked);
            remove_file_button.sensitive = false;
            
            leaflet = new Leaflet();
            leaflet.vexpand = true;
            leaflet.append(file_box);
            
            tab_view = new TabView();
            tab_bar = new TabBar();
            tab_box = new Box(Orientation.VERTICAL, 0);
            tab_bar.autohide = false;
            tab_bar.set_view(tab_view);
            tab_box.append(tab_bar);
            tab_box.append(tab_view);
            leaflet.append(tab_box);

            tab_view.close_page.connect(editor_closing);

            save_tab_button = new Button.from_icon_name("document-save-symbolic");
            save_tab_button.clicked.connect(save_tab);
            header.pack_end(save_tab_button);

            tab_view.notify["selected-page"].connect(() => select_file_from_tab());
            window.close_request.connect(app_close_request);

            append(leaflet);
        }

        public async void load_ppub(File file) throws Error {

            window.publication = new Ppub.Publication(file.get_path());
            publication_file = file;

            header_title.title = window.publication.metadata.title ?? "Untitled PPUB";
            header_title.subtitle = window.publication.metadata.author_name ?? "";
            window.title = header_title.title + " - Publicate!";

            file_explorer.set_assets(window.publication.assets);

        }

        public async void open_asset(Ppub.Asset? asset) {

            update_deletable();
            if(asset == null) {
                return;
            }

            if(open_editors.has_key(asset.name)) {
                tab_view.selected_page = open_editors[asset.name].tab_page;
                return;
            }
            
            if(asset.mimetype == "text/markdown") {
                var editor = new Editors.MarkdownEditor(window, tab_view);
                add_editor(editor, asset);
            }
            else if(asset.mimetype.has_prefix("text/")) {
                var editor = new Editors.PlainTextEditor(window, tab_view);
                add_editor(editor, asset);
            }
            else if(asset.mimetype == "application/x-ppub-metadata") {
                var editor = new Editors.MetadataEditor(window, tab_view);
                add_editor(editor, asset);
            }
            if(asset.mimetype == "application/x-ppvm") {
                var editor = new Editors.VideoManifestEditor(window, tab_view);
                add_editor(editor, asset);
            }

        }

        private bool editor_closing(TabPage page) {
            var editor = (Editors.EditorWidget)page.child;
            if(editor.has_unsaved_changes && open_editors.has_key(editor.asset_name)) {
                var prompt = new Adw.MessageDialog(window, "Save Changes?", "This editor has unsaved changes, would you like to save them before closing?");
                prompt.add_response("cancel", "Cancel");
                prompt.add_response("discard", "Discard");
                prompt.add_response("save", "Save");
                prompt.response.connect(r => {
                    if(r == "save") {
                        save_and_close_tab_page.begin(page);
                    }
                    else if(r == "discard") {
                        open_editors.unset(editor.asset_name);
                        tab_view.close_page(page);
                        tab_view.close_page_finish(page, true);
                    }
                    else {
                        tab_view.close_page_finish(page, false);
                    }
                });

                prompt.present();
                return Gdk.EVENT_STOP;
            }

            open_editors.unset(editor.asset_name);
            tab_view.close_page_finish(page, true);
            return Gdk.EVENT_STOP;
        }

        private void add_editor(Editors.EditorWidget editor, Ppub.Asset asset) {
            editor.load_asset(window.publication, asset);
            open_editors.set(asset.name, editor);
            tab_view.selected_page = editor.tab_page;
        }

        private async void save(Invercargill.Enumerable<Savable> to_save) {
            progress_window.display_progress("Saving…", 0.0);
            yield do_save(to_save);
            progress_window.complete();
        }

        private async void do_save(Invercargill.Enumerable<Savable> to_save) {

            SourceFunc callback = do_save.callback;
            
            ThreadFunc<bool> run = () => {
                var items = to_save.count();
                var count = 0;
                var builder = new Ppub.Builder();
                foreach (var item in to_save) {
                    count++;
                    item.save_asset(builder);
                    Idle.add(() => {
                        progress_window.display_progress("Processing Assets…", (double)count / (double)items);
                        return false;
                    });
                }
    
                Idle.add(() => {
                    progress_window.display_progress("Writing PPUB…", 1.0);
                    return false;
                });

                var temp_file = File.new_for_path(publication_file.get_path() + ".tmp");
                var stream = temp_file.replace(null, false, FileCreateFlags.REPLACE_DESTINATION);
    
                builder.write(stream);
                stream.close();
                
                temp_file.move(publication_file, FileCopyFlags.OVERWRITE);

                Idle.add(() => {
                    load_ppub.begin(publication_file, () => {
                        select_file_from_tab();
                        callback();
                    });
                    return false;
                });
                return true;
            };
            new Thread<bool>("saver thread", run);
            yield;

        }

        public async void save_tab() {
            var current_editor = (Editors.EditorWidget)tab_view.selected_page.child;
            var to_save = window.publication.assets.select<Savable>(a => a.name == current_editor.asset_name ? (Savable)current_editor : new SavableAsset(window.publication, a));
            yield save(to_save);
        }

        private async void save_all() {
            var to_save = window.publication.assets.select<Savable>(get_savable_editor_or_asset);
            yield save(to_save);
        }

        private Savable get_savable_editor_or_asset(Ppub.Asset asset) {
            if(open_editors.has_key(asset.name)) {
                var editor = open_editors[asset.name];
                if(editor.has_unsaved_changes) {
                    return (Savable)editor;
                }
            }
            return new SavableAsset(window.publication, asset);
        }

        private async void save_and_close_tab_page(TabPage page) {
            var editor = (Editors.EditorWidget)page.child;
            var to_save = window.publication.assets.select<Savable>(a => a.name == editor.asset_name ? (Savable)editor : new SavableAsset(window.publication, a));
            yield save(to_save);
            open_editors.unset(editor.asset_name);
            tab_view.close_page_finish(page, true);
        }


        private void select_file_from_tab() {
            var editor = (Editors.EditorWidget)tab_view.selected_page.child;
            file_explorer.set_selected_item(editor.asset_name);
        }

        public async void add_asset (string name, string mimetype, GLib.InputStream stream, Ppub.CompressionInfo compression) {

            var to_save = window.publication.assets.select<Savable>(a => new SavableAsset(window.publication, a)).to_sequence();
            to_save.add(new SavableNewAsset(name, mimetype, stream, compression));
            yield save(to_save);
            
        }

        public async void import_file() {

            var dialog = new FileDialog();
            var file = yield dialog.open(window, null);

            if(file == null) {
                return;
            }
            
            var stream = yield file.read_async(Priority.DEFAULT, null);
            var compression = new Ppub.CompressionInfo(stream, false);
            stream.seek(0, SeekType.SET, null);
            var sample = new uint8[2048];
            size_t sample_size;
            yield stream.read_all_async(sample, Priority.DEFAULT, null, out sample_size);
            stream.seek(0, SeekType.SET, null);

            var mimetype = Ppub.guess_mimetype(file.get_basename(), sample);
            yield add_asset(file.get_basename(), mimetype, stream, compression);
        }

        private bool app_close_request() {
            if(Invercargill.gte(open_editors.values).any(e => e.has_unsaved_changes)) {
                var prompt = new Adw.MessageDialog(window, "Save Changes?", "There are editors with unsaved changes, would you like to save them before closing?");
                prompt.add_response("cancel", "Cancel");
                prompt.add_response("discard", "Discard");
                prompt.add_response("save", "Save All");
                prompt.response.connect(r => {
                    if(r == "save") {
                        save_all_and_close.begin();
                    }
                    else if(r == "discard") {
                        open_editors.clear();
                        window.close();
                    }
                });
                prompt.present();
                return Gdk.EVENT_STOP;
            }

            return Gdk.EVENT_PROPAGATE;
        }

        private async void save_all_and_close() {
            yield save_all();
            window.close();
        }

        private void update_deletable() {
            // Inhibit deletion of default document or metadata.
            var asset = file_explorer.selected_asset;
            remove_file_button.sensitive = (asset != null && asset.name != "metadata" && window.publication.get_default_asset().name != asset.name);
        }

        private void delete_file_clicked() {
            var asset = file_explorer.selected_asset;
            if(asset == null) {
                return;
            }

            var prompt = new Adw.MessageDialog(window, "Delete File?", @"Are you sure you want to delete the file\"<i>$(asset.name)</i>\"? This cannot be undone.");
            prompt.body_use_markup = true;
            prompt.add_response("cancel", "Cancel");
            prompt.add_response("delete", "Delete");
            prompt.response.connect(r => {
                if(r == "delete") {
                    delete_file.begin(asset);
                }
            });
            prompt.present();
        }

        private async void delete_file(Ppub.Asset asset) {
            var to_save = window.publication.assets
                .where(a => a.name != asset.name)
                .select<Savable>(a => new SavableAsset(window.publication, a)).to_sequence();

            if(open_editors.has_key(asset.name)) {
                Editors.EditorWidget editor;
                open_editors.unset(asset.name, out editor);
                tab_view.close_page(editor.tab_page);
            }
            yield save(to_save);
        }

        
    }
}