import htmx, {HtmxSettleInfo, HtmxSwapStyle} from "htmx.org";

function kebabEventName(str: string) {
    return str.replace(/([a-z0-9])([A-Z])/g, '$1-$2').toLowerCase()
}

const ignoredEvents = ['htmx:beforeProcessNode', 'htmx:afterProcessNode', 'htmx:beforeSwap', 'htmx:afterSwap', 'htmx:beforeOnLoad', 'htmx:afterOnLoad', 'htmx:configRequest', 'htmx:configResponse', 'htmx:responseError'];

function makeEvent(eventName: string, detail: any) {
    let evt
    if (window.CustomEvent && typeof window.CustomEvent === 'function') {
        // TODO: `composed: true` here is a hack to make global event handlers work with events in shadow DOM
        evt = new CustomEvent(eventName, { bubbles: false, cancelable: true, composed: true, detail })
    } else {
        evt = document.createEvent('CustomEvent')
        evt.initCustomEvent(eventName, true, true, detail)
    }
    return evt
}

function triggerChildren(target: HTMLElement, name: string, event: CustomEvent, triggered: Set<HTMLElement>) {
    if(ignoredEvents.includes(name)) {
        return
    }
    if (target && target.children) {
        Array.from(target.children).forEach((e) => {
            const kehab = kebabEventName(name);
            const eventName = kehab.replace("htmx:", "hx-on::")
            if (!triggered.has(e as HTMLElement)) {
                if(e.hasAttribute(eventName)) {
                    const newEvent = makeEvent(eventName.replace("hx-on::", "htmx:"), event.detail)
                    newEvent.detail.meta = 'trigger-children'
                    e.dispatchEvent(newEvent)
                    triggered.add(e as HTMLElement);
                }
                if (e.children) {
                    triggerChildren(e as HTMLElement, name, event, triggered);
                }
            }
        });
    }
}


htmx.defineExtension("trigger-children", {
    onEvent: (name, evt: Event | CustomEvent) => {
        if (!(evt instanceof CustomEvent)) {
            return false;
        }
        if(evt.detail.meta === 'trigger-children') {
            return false;
        }
        const triggered = new Set<HTMLElement>();
        const target = evt.target as HTMLElement || evt.detail.target as HTMLElement;
        triggerChildren(target, name, evt, triggered);
        return true;
    },
    init: function (api: any): void {
    },
    transformResponse: function (
        text: string,
        xhr: XMLHttpRequest,
        elt: Element,
    ): string {
        return text;
    },
    isInlineSwap: function (swapStyle: HtmxSwapStyle): boolean {
        return false;
    },
    handleSwap: function (
        swapStyle: HtmxSwapStyle,
        target: Node,
        fragment: Node,
        settleInfo: HtmxSettleInfo,
    ): boolean | Node[] {
        return false;
    },
    encodeParameters: function (
        xhr: XMLHttpRequest,
        parameters: FormData,
        elt: Node,
    ) {
    },
    getSelectors: function (): string[] | null {
        return null;
    },
});