import { ROUTES } from "@config/config_frontend";
import { hasMinLength, isBlank, isValidEmail } from "@util/common_util_validate";
import {
  createButton,
  createInputField,
  hideLoadingOverlay,
  showLoadingOverlay,
  showToast,
} from "@ui/ui_template_elements";
import { currentLanguageIndex, ui_locales } from "@ui/ui_template_locale";
import { navigateTo } from "../A00_Common/router";
import { requestRegistration, verifyRegistration } from "./A07_Register_Api_Fetch";
import "./A07_Register_UI_Style.css";

const L = (key: keyof typeof ui_locales): string => ui_locales[key][currentLanguageIndex];

interface AgreementField {
  root: HTMLElement;
  input: HTMLInputElement;
}

function checkboxWithAccordion(label: string, contentText: string): AgreementField {
  const container = document.createElement("div");
  container.className = "a07-register__agreement";

  const summary = document.createElement("div");
  summary.className = "a07-register__agreement-summary";

  const input = document.createElement("input");
  input.type = "checkbox";

  const labelSpan = document.createElement("span");
  labelSpan.className = "a07-register__agreement-label";
  labelSpan.textContent = label;

  summary.append(input, labelSpan);

  const details = document.createElement("details");
  details.className = "a07-register__agreement-details";

  const detailsContent = document.createElement("div");
  detailsContent.className = "a07-register__agreement-content";
  detailsContent.textContent = contentText;

  details.appendChild(detailsContent);

  summary.addEventListener("click", (e) => {
    if (e.target !== input) {
      details.open = !details.open;
    }
  });

  container.append(summary, details);

  return { root: container, input };
}

async function loadAgreementText(filename: string): Promise<string> {
  const filePath = `resources/legal/${filename}`;
  const response = await fetch(filePath);
  if (!response.ok) {
    console.warn(`Failed to load ${filename}`);
    return `[${filename}을 불러올 수 없습니다]`;
  }
  return await response.text();
}

export function renderA07Register(root: HTMLElement): void {
  const page = document.createElement("div");
  page.className = "a07-register";
  const card = document.createElement("div");
  card.className = "a07-register__card";
  const title = document.createElement("h1");
  title.className = "a07-register__title";
  title.textContent = L("A07_Register_Title");

  const name = createInputField({ label: L("A07_Register_Field_Name"), type: "text" });
  const position = createInputField({
    label: L("A07_Register_Field_Position"),
    type: "text",
  });
  const email = createInputField({ label: L("A07_Register_Field_Email"), type: "email" });
  const phone = createInputField({ label: L("A07_Register_Field_Phone"), type: "tel" });
  const password = createInputField({ label: L("A07_Register_Field_Password"), type: "password" });
  const passwordConfirm = createInputField({
    label: L("A07_Register_Field_PasswordConfirm"),
    type: "password",
  });

  const terms: AgreementField = {
    root: document.createElement("div"),
    input: document.createElement("input"),
  };
  const privacy: AgreementField = {
    root: document.createElement("div"),
    input: document.createElement("input"),
  };
  const marketing: AgreementField = {
    root: document.createElement("div"),
    input: document.createElement("input"),
  };

  const otp = createInputField({ label: L("A07_Register_Field_Otp"), type: "text" });
  otp.root.hidden = true;
  const submit = createButton({ label: L("A07_Register_Submit"), type: "submit" });
  const form = document.createElement("form");
  form.className = "a07-register__form";
  let verifyStep = false;
  let termsText = "";
  let privacyText = "";
  let marketingText = "";

  async function loadAgreementTexts(): Promise<void> {
    termsText = await loadAgreementText("terms_of_service.txt");
    privacyText = await loadAgreementText("privacy_policy.txt");
    marketingText = await loadAgreementText("marketing_consent.txt");

    const termsField = checkboxWithAccordion(L("A07_Register_Terms"), termsText);
    terms.root = termsField.root;
    terms.input = termsField.input;

    const privacyField = checkboxWithAccordion(L("A07_Register_Privacy"), privacyText);
    privacy.root = privacyField.root;
    privacy.input = privacyField.input;

    const marketingField = checkboxWithAccordion(L("A07_Register_Marketing"), marketingText);
    marketing.root = marketingField.root;
    marketing.input = marketingField.input;

    form.innerHTML = "";
    form.append(
      name.root,
      position.root,
      email.root,
      phone.root,
      password.root,
      passwordConfirm.root,
      terms.root,
      privacy.root,
      marketing.root,
      otp.root,
      submit,
    );
  }

  async function onA07_Register_Submit_Click(event: Event): Promise<void> {
    event.preventDefault();
    showLoadingOverlay();
    try {
      if (verifyStep) {
        await verifyRegistration(email.input.value.trim(), otp.input.value);
        showToast(L("A07_Register_Success"), "success");
        navigateTo(ROUTES.A06_LOGIN);
        return;
      }
      if (
        [name, email, password, passwordConfirm].some((field) => isBlank(field.input.value)) ||
        !isValidEmail(email.input.value)
      ) {
        throw new Error(L("A07_Register_Error_Required"));
      }
      if (!hasMinLength(password.input.value, 8)) throw new Error(L("A07_Register_Error_Password"));
      if (password.input.value !== passwordConfirm.input.value)
        throw new Error(L("A07_Register_Error_PasswordMismatch"));
      if (!terms.input.checked || !privacy.input.checked)
        throw new Error(L("A07_Register_Error_Terms"));
      await requestRegistration({
        email: email.input.value.trim(),
        password: password.input.value,
        password_confirm: passwordConfirm.input.value,
        name: name.input.value.trim(),
        position: position.input.value.trim() || null,
        phone: phone.input.value.trim() || null,
        terms_version: "1.0",
        terms_agreed: true,
        privacy_agreed: true,
        marketing_agreed: marketing.input.checked,
      });
      verifyStep = true;
      Array.from(form.children).forEach((child) => {
        if (child !== otp.root && child !== submit) {
          (child as HTMLElement).hidden = true;
        }
      });
      otp.root.hidden = false;
      submit.hidden = false;
      submit.querySelector(".ui-btn__label")!.textContent = L("A07_Register_Verify");
      showToast(L("A07_Register_OtpSent"), "info");
    } catch (error) {
      showToast(error instanceof Error ? error.message : L("A07_Register_Error_Request"), "error");
    } finally {
      hideLoadingOverlay();
    }
  }

  form.addEventListener("submit", onA07_Register_Submit_Click);
  loadAgreementTexts().then(() => {
    const login = createButton({
      label: L("A07_Register_ToLogin"),
      variant: "ghost",
      onClick: () => navigateTo(ROUTES.A06_LOGIN),
    });
    card.append(title, form, login);
    page.append(card);
    root.append(page);
  });
}