/*export function h(el: any, attrs: any, content: any) {
    const node = document.createElement(el);

    Object.entries(attrs || {}).forEach(([name, value]) => {
        node.setAttribute(name, value);
    });

    if (typeof content === "string") {
        content = document.createTextNode(content);
    }

    node.appendChild(content);

    return node;
}*/

interface entityMapData {
    [key: string]: string;
}
export const entityMap: entityMapData = {
    "&": "amp",
    "<": "lt",
    ">": "gt",
    '"': "quot",
    "'": "#39",
    "/": "#x2F",
};

export const escapeHtml = (str: object[] | string) =>
    String(str).replace(/[&<>"'\/\\]/g, (s) => `&${entityMap[s]};`);

// To keep some consistency with React DOM, lets use a mapper
// https://reactjs.org/docs/dom-elements.html
export const AttributeMapper = (val: string) =>
    ({
        tabIndex: "tabindex",
        className: "class",
        readOnly: "readonly",
    }[val] || val);

// tslint:disable-next-line:no-default-export
export function DOMcreateElement(
    tag: Function | string,
    attrs?: { [key: string]: any },
    ...children: (HTMLElement | string)[]
): HTMLElement {
    attrs = attrs || {};
    const stack: any[] = [...children];

    // Support for components(ish)
    if (typeof tag === "function") {
        attrs.children = stack;
        return tag(attrs);
    }

    const elm = document.createElement(tag);

    // Add attributes
    for (let [name, val] of Object.entries(attrs)) {
        name = escapeHtml(AttributeMapper(name));
        if (name.startsWith("on") && name.toLowerCase() in window) {
            elm.addEventListener(name.toLowerCase().substr(2), val);
        } else if (name === "ref") {
            val(elm);
        } else if (name === "style") {
            Object.assign(elm.style, val);
        } else if (val === true) {
            elm.setAttribute(name, name);
        } else if (val !== false && val != null) {
            elm.setAttribute(name, escapeHtml(val));
        } else if (val === false) {
            elm.removeAttribute(name);
        }
    }

    // Append children
    while (stack.length) {
        const child = stack.shift();

        // Is child a leaf?
        if (!Array.isArray(child)) {
            elm.appendChild(
                (child as HTMLElement).nodeType == null
                    ? document.createTextNode(child.toString())
                    : child
            );
        } else {
            stack.push(...child);
        }
    }

    return elm;
}

export const DOMcreateFragment = (
    _attrs?: { [key: string]: any },
    ...children: (HTMLElement | string)[]
): (HTMLElement | string)[] => {
    return children;
};