// Login view — Mullvad-style account tokens (no username/password).
// Two panels: create a new account (one-time token reveal) or log in with an
// existing account number.
import { api } from '../api.js';
import { el, mount, toast } from '../dom.js';
import { groupCode, normalizeCode } from '../format.js';

export function renderAuth(container, ctx) {
  let mode = 'create'; // 'create' | 'login'

  function draw() {
    const card = el(
      'div',
      { class: 'auth-card card' },
      el(
        'div',
        { class: 'auth-head' },
        el('div', { class: 'brand-mark brand-mark-lg' }, '🧭'),
        el('h1', {}, 'Trip Plan'),
        el('p', { class: 'muted' }, 'Plan trips together, day by day.'),
      ),
      el(
        'div',
        { class: 'auth-tabs' },
        tab('Create account', mode === 'create', () => setMode('create')),
        tab('Log in', mode === 'login', () => setMode('login')),
      ),
      mode === 'create' ? createPanel() : loginPanel(),
    );
    mount(container, el('div', { class: 'auth-wrap' }, card));
  }

  function setMode(next) {
    if (mode !== next) {
      mode = next;
      draw();
    }
  }

  function tab(label, active, onClick) {
    return el('button', { class: `auth-tab${active ? ' active' : ''}`, type: 'button', onClick }, label);
  }

  // ----- Create account -----
  function createPanel() {
    const errorEl = el('p', { class: 'form-error' });
    const createBtn = el('button', { class: 'btn btn-primary btn-block', type: 'button' }, 'Create account');

    async function onCreate() {
      errorEl.textContent = '';
      createBtn.disabled = true;
      createBtn.textContent = 'Creating…';
      try {
        const data = await api.auth.createAccount();
        showToken(data.token, data.user);
      } catch (err) {
        errorEl.textContent = err.message;
        createBtn.disabled = false;
        createBtn.textContent = 'Create account';
      }
    }
    createBtn.addEventListener('click', onCreate);

    return el(
      'div',
      { class: 'auth-panel' },
      el('p', { class: 'auth-lead' }, 'No email, no password. We generate a private account number — it is your only key to your trips.'),
      errorEl,
      createBtn,
    );
  }

  function showToken(token, user) {
    const grouped = groupCode(token, 4);
    const copyBtn = el('button', { class: 'btn', type: 'button' }, '📋 Copy');
    copyBtn.addEventListener('click', async () => {
      try {
        await navigator.clipboard.writeText(grouped);
        toast('Account number copied', 'success');
      } catch {
        toast('Copy failed — select and copy it manually');
      }
    });

    const panel = el(
      'div',
      { class: 'auth-panel token-reveal' },
      el('div', { class: 'token-warning' },
        el('strong', {}, 'This is your only credential.'),
        ' Save it now — it will never be shown again. Anyone with it can access your trips.'),
      el('div', { class: 'token-box' }, grouped),
      el('div', { class: 'token-actions' }, copyBtn),
      el(
        'button',
        {
          class: 'btn btn-primary btn-block',
          type: 'button',
          onClick: () => {
            ctx.state.user = user;
            ctx.navigate('#/trips');
          },
        },
        "I've saved it — continue",
      ),
    );

    mount(container, el('div', { class: 'auth-wrap' }, el('div', { class: 'auth-card card' },
      el('div', { class: 'auth-head' },
        el('div', { class: 'brand-mark brand-mark-lg' }, '🎉'),
        el('h1', {}, 'Account created'),
        el('p', { class: 'muted' }, `You're ${user.display_name}. You can rename yourself later.`)),
      panel,
    )));
  }

  // ----- Log in -----
  function loginPanel() {
    const errorEl = el('p', { class: 'form-error' });
    const input = el('input', {
      class: 'input token-input',
      type: 'text',
      autocomplete: 'off',
      autocapitalize: 'characters',
      spellcheck: 'false',
      placeholder: 'XXXX-XXXX-XXXX-XXXX',
      'aria-label': 'Account number',
    });
    const submitBtn = el('button', { class: 'btn btn-primary btn-block', type: 'submit' }, 'Log in');

    async function onSubmit(e) {
      e.preventDefault();
      errorEl.textContent = '';
      const token = normalizeCode(input.value);
      if (token.length < 8) {
        errorEl.textContent = 'Enter your full account number.';
        return;
      }
      submitBtn.disabled = true;
      submitBtn.textContent = 'Signing in…';
      try {
        const data = await api.auth.login(token);
        ctx.state.user = data.user;
        ctx.navigate('#/trips');
      } catch (err) {
        errorEl.textContent = err.message;
        submitBtn.disabled = false;
        submitBtn.textContent = 'Log in';
      }
    }

    return el(
      'form',
      { class: 'auth-panel auth-form', onSubmit },
      el('label', { class: 'field' }, el('span', { class: 'field-label' }, 'Account number'), input),
      el('p', { class: 'hint muted' }, 'Dashes, spaces and letter case do not matter.'),
      errorEl,
      submitBtn,
    );
  }

  draw();
}