import { initializeAddInstanceFlow } from "./add_instance_flow.mjs";
import { findButtonOrFail, findDialogOrFail, findFormOrFail, findInputOrFail, findParagraphOrFail, findPreOrFail } from "./dom.mjs";
import knownSoftware from "./known_software.mjs";
import storageManager from "./storage_manager.mjs";

const radioButtonName = "instanceSelect";

const mainDialog = findDialogOrFail(document.body, "#mainDialog");
const showAddInstanceDialogButton = findButtonOrFail(document.body, "#showAddInstanceDialog");
const detailsDialog = findDialogOrFail(document.body, "#instanceDetails");
const addDialog = findDialogOrFail(document.body, "#addInstance");
const instanceSelectForm = findFormOrFail(document.body, "#instanceSelectForm");
const redirectButton = findButtonOrFail(document.body, "#redirect");
const redirectAlwaysButton = findButtonOrFail(document.body, "#redirectAlways");
const pathText = findPreOrFail(document.body, "#path");

showAddInstanceDialogButton.addEventListener("click", e => showAddInstanceDialog());

redirectButton.addEventListener("click", e => {
    // Can be assumed to not fail because the button is disabled if there are no options and the first one is selected by default
    redirect(getSelectedOption()!);
});

redirectAlwaysButton.addEventListener("click", e => {
    // Can be assumed to not fail because the button is disabled if there are no options and the first one is selected by default
    const option = getSelectedOption()!;
    setAutoRedirect(option);
    redirect(option);
});

let showAddInstanceDialog = () => { };
let hideAddInstanceDialog = () => { };

// Don't bother initializing if we're performing autoredirect
if (!autoRedirect()) {
    createInstanceSelectOptions();
    storageManager.addSaveCallback(createInstanceSelectOptions);
    updateNoInstanceHint();
    storageManager.addSaveCallback(updateNoInstanceHint);

    pathText.innerText = getTargetPath();

    ({
        showAddInstanceDialog,
        hideAddInstanceDialog
    } = initializeAddInstanceFlow(detailsDialog, addDialog));

    mainDialog.show();
};

function updateNoInstanceHint() {
    findParagraphOrFail(document.body, "#no-instance").style.display =
        storageManager.storage.instances.length > 0
            ? "none"
            : "";
}

function createInstanceSelectOptions() {
    instanceSelectForm.replaceChildren(); // Erase all child nodes
    for (const instance of storageManager.storage.instances) {
        const div = document.createElement("div");
        div.setAttribute("x-option", instance.origin);
        const radio = document.createElement("input");
        radio.id = instance.origin;
        radio.value = instance.origin;
        radio.type = "radio";
        radio.name = radioButtonName;
        const label = document.createElement("label");
        label.htmlFor = instance.origin;
        label.innerText = instance.name + " ";
        if (instance.iconURL) {
            const img = new Image();
            img.src = instance.iconURL;
            img.alt = `${instance.name} icon`;
            img.className = "inlineIcon medium-height";
            label.append(img, " ");
        }
        const small = document.createElement("small");
        const softwareName = knownSoftware.software[instance.software].name;
        small.innerText = `(${softwareName})`;
        label.appendChild(small);
        div.appendChild(radio);
        div.appendChild(label);
        instanceSelectForm.appendChild(div);
    }
    const firstInput = instanceSelectForm.querySelector("input");
    if (firstInput) firstInput.checked = true;
    setRedirectButtonState(firstInput !== null);
}

function setRedirectButtonState(enabled: boolean) {
    redirectButton.disabled = !enabled;
    redirectAlwaysButton.disabled = !enabled;
}

function getTargetSoftwareOrGroup(): string {
    const currentURL = URL.parse(location.href)!;
    const target = currentURL.pathname.match(/\/+([^\/]*)\/?/)?.[1];
    if (target == null) throw new Error("Crossroad was served on an invalid path (likely a backend routing mistake)");
    const softwareName = Object.entries(knownSoftware.software).find(([name, software]) => software.aliases.includes(target))?.[0];
    if (softwareName) return softwareName;
    const groupName = Object.entries(knownSoftware.groups).find(([name, group]) => group.aliases.includes(target))?.[0];
    if (groupName) return groupName;
    throw new Error("Could not identify target software or group");
}

function getTargetPath(): string {
    const currentURL = URL.parse(location.href)!;
    return currentURL.pathname.replace(/\/+[^\/]*\/?/, "/");
}

function getSelectedOption(): string | null {
    try {
        return findInputOrFail(instanceSelectForm, `input[name="${radioButtonName}"]:checked`).value;
    } catch {
        return null;
    }
}

function autoRedirect(): boolean {
    const targetSoftware = getTargetSoftwareOrGroup();
    const preferredFor = storageManager.storage.instances.find(instance => instance.preferredFor?.includes(targetSoftware));
    if (preferredFor) {
        redirect(preferredFor.origin);
        return true;
    }
    return false;
}

function setAutoRedirect(option: string) {
    const instance = storageManager.storage.instances.find(e => e.origin === option);
    if (!instance) throw new Error("Invalid argument");
    instance.preferredFor ??= [];
    instance.preferredFor.push(getTargetSoftwareOrGroup());
    storageManager.save();
}

function redirect(to: string) {
    const url = URL.parse(to);
    if (url === null) throw new Error("Couldn't parse destination");
    url.pathname = getTargetPath();
    location.href = url.toString();
}