// This file handles the "Add an instance" dialog

import { FormDialog, ONCE } from "./dialog.mjs";
import { findButtonOrFail, findFormOrFail, findInputOrFail } from "./dom.mjs";

export function parseHost(host: string): { host: string, secure: boolean } | null {
    let parsedInstance = URL.parse(host);
    parsedInstance ??= URL.parse("https://" + host);
    if (!parsedInstance?.host) return null;
    if (!/https?:/.test(parsedInstance.protocol)) return null;
    return {
        host: parsedInstance.host,
        secure: parsedInstance.protocol === "https:"
    };
}

export type AddInstanceDialogData = {
    host: string,
    secure: boolean,
    autoQueryMetadata: boolean,
};

export class AddInstanceDialog extends FormDialog {
    protected instanceHost: HTMLInputElement;
    protected autoQueryMetadata: HTMLInputElement;
    protected closeButton: HTMLButtonElement;

    constructor(dialog: HTMLDialogElement, initializeDOM: boolean = true) {
        super(dialog, findFormOrFail(dialog, ".addInstanceForm"));

        this.instanceHost = findInputOrFail(this.form, "#instanceHost");
        this.autoQueryMetadata = findInputOrFail(this.form, "#autoQueryMetadata");
        this.closeButton = findButtonOrFail(this.form, ".close");

        if (initializeDOM) this.initializeDOM();
    }

    protected override initializeDOM() {
        super.initializeDOM();

        this.instanceHost.addEventListener("input", e => this.#getDataIfValid());
        this.closeButton.addEventListener("click", e => this.close());
    }

    #getDataIfValid(): AddInstanceDialogData | null {
        const parsedHost = parseHost(this.instanceHost.value);
        if (parsedHost === null) {
            this.instanceHost.setCustomValidity("Invalid instance hostname or URL");
            return null;
        }
        this.instanceHost.setCustomValidity("");
        return {
            host: parsedHost.host,
            secure: parsedHost.secure,
            autoQueryMetadata: this.autoQueryMetadata.checked
        };
    }

    #handleSubmit(resolve: (data: AddInstanceDialogData) => void) {
        this.form.addEventListener("submit", e => {
            const data = this.#getDataIfValid();
            if (data === null) {
                // Prevent the user from submitting the form if it's invalid and let them try again
                e.preventDefault();
                this.#handleSubmit(resolve);
                return;
            }
            resolve(data);
            this.close();
        }, ONCE);
    }

    async present(): Promise<AddInstanceDialogData> {
        return new Promise((resolve, reject) => {
            this.cancelOnceClosed(reject);
            this.#handleSubmit(resolve);
            this.open();
        });
    }
}