import { GefestElement } from "./element";

// For protecting the set of elements from direct access
const elements: Set<GefestElement> = new Set();
const elementsMapping: Record<string, GefestElement> = {};
export class GefestEngine {
    static register (element: GefestElement) : string {
        elements.add(element);
        // Generate GefestID for the element
        let gefestId : string;
        do {
            gefestId = `gefest-${Math.random().toString(36).substr(2, 9)}`;
        } while(!!elementsMapping[gefestId]);
        elementsMapping[gefestId] = element;

        return gefestId;
    }

    static async activateOnClick(): Promise<void> {
        for (let element of elements) {
            const elementHTML = document.querySelectorAll(`[data-gefest-id="${element.gefestId}"]`);
            if (elementHTML.length > 0) {
                const htmlElement = elementHTML[0] as HTMLElement;
                htmlElement.onclick = element.onClick;
            }
        }
    }

    static async main(main : () => Promise<void>): Promise<void> {
        await main();
        await GefestEngine.activateOnClick();
    }

    static render (gefestId: string | string[] | null = null) {
        let gefestElements : string[] | null = null;
        if (typeof gefestId === "string")
            gefestId = [gefestId];
        else if (gefestId === null) {
            gefestId = Object.keys(elementsMapping);
            gefestElements = gefestId;
        }
        //const gefestElement = elementsMapping.get(gefestId);
        if (!gefestElements)
            gefestElements = gefestId.filter(gid => !!elementsMapping[gid]);
        if (gefestElements.length === 0) return;
        const elementHTML = document.querySelectorAll('[data-gefest-id]');

        if (elementHTML.length > 0) {
            for (let htmlElement of elementHTML) {
                const gid = htmlElement.getAttribute("data-gefest-id");
                if (!gid || !elementsMapping[gid])
                    continue;

                htmlElement.outerHTML = elementsMapping[gid].build();
            }
            GefestEngine.activateOnClick();
        }
    }
}