import { djbase, djclass } from "../declare";
import _WidgetBase = require("dijit/_WidgetBase");
import _AttachMixin = require("dijit/_AttachMixin");
import { BuildContext, isNode, startupWidgets } from "./traits";
import registry = require("dijit/registry");

// type Handle = dojo.Handle;

export interface EventArgs {
    bubbles?: boolean;

    cancelable?: boolean;

    composed?: boolean;
}

export interface DjxWidgetBase<Attrs = any, Events extends { [name in keyof Events]: Event } = any> {
    set<K extends keyof Attrs & string>(key: K, value: Attrs[K]): this;
    set(props: Partial<Attrs>): this;
    get<K extends keyof Attrs & string>(key: K): Attrs[K];

    on<K extends keyof Events & string>(eventName: K, cb: (evt: Events[K]) => void): dojo.WatchHandle;

    emit<K extends keyof Events & string>(eventName: K, evt: Omit<Events[K], keyof Event> & EventArgs): void;
}

@djclass
export abstract class DjxWidgetBase<Attrs = any, Events = any> extends djbase(_WidgetBase, _AttachMixin) {

    buildRendering() {
        this.domNode = this.render().getDomNode();
        super.buildRendering();

        // now we should get assigned data-dojo-attach-points
        // place the contents of the original srcNode to the containerNode
        const src = this.srcNodeRef;
        const dest = this.containerNode;

        if (src && dest) {
            while (src.firstChild)
                dest.appendChild(src.firstChild);
        }
    }

    abstract render(): BuildContext<HTMLElement>;

    _processTemplateNode<T extends (Element | Node | _WidgetBase)>(
        baseNode: T,
        getAttrFunc: (baseNode: T, attr: string) => string,
        // tslint:disable-next-line: ban-types
        attachFunc: (node: T, type: string, func?: Function) => dojo.Handle
    ): boolean {
        if (isNode(baseNode)) {
            const w = registry.byNode(baseNode);
            if (w) {
                // from dijit/_WidgetsInTemplateMixin
                this._processTemplateNode(w,
                    (n, p) => n.get(p), // callback to get a property of a widget
                    (widget, type, callback) => {
                        if (!callback)
                            throw new Error("The callback must be specified");

                        // callback to do data-dojo-attach-event to a widget
                        if (type in widget) {
                            // back-compat, remove for 2.0
                            return widget.connect(widget, type, callback as EventListener);
                        } else {
                            // 1.x may never hit this branch, but it's the default for 2.0
                            return widget.on(type, callback);
                        }

                    });
                // don't process widgets internals
                return false;
            }
        }
        return super._processTemplateNode(baseNode, getAttrFunc, attachFunc);
    }

    /** Starts current widget and all its supporting widgets (placed outside
     * `containerNode`) and child widgets (placed inside `containerNode`)
     */
    startup() {
        // startup supporting widgets
        startupWidgets(this.domNode, this.containerNode);
        super.startup();
    }
}