// The contacts section of the Android Sync page, on the Android application
// only (docs/MESHBAY_DESIGN.md §9.13). Loaded on demand: no other client has it.

import { html, useState, useEffect, useCallback } from './vendor/htm-preact.js';
import { t } from './i18n.js';
import { ask } from './ask.js';
import {
  KINDS, subscribe, runDocSync, privateGroups, probeWritable, failureText,
} from './phone-sync.js';

// What each kind says in its own words; everything else is shared.
const TEXT = {
  contacts: {
    intro: 'contactsync.intro',
    permission: 'contactsync.permission_needed',
    confirm: 'contactsync.confirm',
  },
};

function stateLine(st, status) {
  switch (st.phase) {
    case 'connecting': return t('photosync.state_connecting');
    case 'sending': return t('phonesync.state_sending');
    case 'offline': return t('photosync.state_offline');
    case 'interrupted': return t('photosync.state_interrupted');
    case 'up_to_date': return t('photosync.state_up_to_date');
    default: return status && status.lastCompleted ? t('photosync.state_up_to_date') : '';
  }
}

export function DocSyncSection({ kind, user, groups }) {
  const { sync, heading } = KINDS[kind];
  const [status, setStatus] = useState(null);
  const [run, setRun] = useState({ phase: 'idle' });
  const [editing, setEditing] = useState(false);
  const [error, setError] = useState('');

  const refresh = useCallback(() => sync.status().then(setStatus).catch(() => {}), [sync]);
  useEffect(() => { refresh(); }, [refresh]);
  useEffect(() => subscribe(kind, (st) => {
    setRun(st);
    if (st.phase !== 'sending' && st.phase !== 'connecting') refresh();
  }), [kind, refresh]);

  if (!status) return null;
  const cfg = status.config;
  const busy = run.phase === 'sending' || run.phase === 'connecting';

  const backUpNow = async () => {
    setError('');
    try { await runDocSync(kind, { force: true }); } catch (e) { setError(e.message); }
  };

  const turnOff = async () => {
    setError('');
    try { setStatus(await sync.configure(null)); } catch (e) { setError(e.message); }
  };

  return html`
    <div class="settings-section">
      <h3 class="settings-heading">${t(heading)}</h3>
      ${!cfg && !editing && html`
        <p class="settings-hint">${t(TEXT[kind].intro)}</p>
        <button class="admin-btn" onClick=${() => setEditing(true)}>${t('photosync.setup')}</button>
      `}
      ${cfg && !editing && html`
        <div class="settings-row">
          <span class="settings-label settings-name">
            ${t('phonesync.summary', { group: cfg.groupName, dir: status.dir })}
          </span>
        </div>
        ${cfg.account !== user.username && html`
          <p class="settings-hint">${t('photosync.other_account', { account: cfg.account })}</p>`}
        <p class="settings-hint">
          ${t('phonesync.copies_sent', { n: status.sent })}
          ${' · '}
          ${status.lastCompleted
            ? t('photosync.last_run', { when: new Date(status.lastCompleted).toLocaleString() })
            : t('photosync.never')}
        </p>
        ${status.lastSent && html`
          <p class="settings-hint settings-name">${t('phonesync.last_file', { name: status.lastSent })}</p>`}
        ${status.failure
          ? html`<p class="error-msg">${failureText(status.failure)}</p>`
          : stateLine(run, status) && html`<p class="settings-hint">${stateLine(run, status)}</p>`}
        <div class="settings-row" style="gap:8px; justify-content:flex-start; flex-wrap:wrap">
          <button class="admin-btn" disabled=${busy} onClick=${backUpNow}>${t('photosync.now')}</button>
          <button class="btn-secondary" onClick=${() => setEditing(true)}>${t('photosync.change')}</button>
          <button class="btn-secondary" onClick=${turnOff}>${t('photosync.turn_off')}</button>
        </div>
      `}
      ${editing && html`
        <${Setup} kind=${kind} user=${user} groups=${groups} status=${status}
          onPermission=${setStatus}
          onDone=${(next) => { setEditing(false); if (next) { setStatus(next); runDocSync(kind); } }} />`}
      ${error && html`<p class="error-msg">${error}</p>`}
    </div>
  `;
}

function Setup({ kind, user, groups, status, onPermission, onDone }) {
  const { sync, suffix } = KINDS[kind];
  const cfg = status.config && status.config.account === user.username ? status.config : null;
  const [candidates, setCandidates] = useState(null);  // null while the hub is asked
  const [groupId, setGroupId] = useState(cfg ? cfg.groupId : '');
  const [folders, setFolders] = useState(null);
  const [probe, setProbe] = useState('');              // '', 'checking', 'offline'
  const [folder, setFolder] = useState(cfg ? cfg.folder : '');
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState('');
  const permitted = status.permission === 'granted';

  // Only groups this account is alone in: what is sent is readable by every
  // member, and an address book or a conversation is not the group's.
  useEffect(() => {
    let gone = false;
    privateGroups(groups).then((list) => {
      if (gone) return;
      setCandidates(list);
      setGroupId((g) => (list.some((x) => x.id === g) ? g : ''));
    });
    return () => { gone = true; };
  }, [groups]);

  useEffect(() => {
    setFolders(null);
    if (!groupId) return undefined;
    let gone = false;
    setProbe('checking');
    probeWritable(groupId).then((r) => {
      if (gone) return;
      setProbe('');
      setFolders(r.folders);
      setFolder((f) => (r.folders.includes(f) ? f : (r.folders[0] || '')));
    }).catch(() => { if (!gone) setProbe('offline'); });
    return () => { gone = true; };
  }, [groupId]);

  const allow = async () => {
    setError('');
    try { onPermission(await sync.permit()); } catch (e) { setError(e.message); }
  };

  const dir = folder ? `${folder}/${user.username}-${suffix}` : '';

  const start = async () => {
    const group = (candidates || []).find((g) => g.id === groupId);
    if (!group || !folder) return;
    setBusy(true);
    setError('');
    try {
      if (!cfg || cfg.groupId !== groupId || cfg.folder !== folder) {
        const yes = await ask(t(TEXT[kind].confirm, { group: group.name, dir }));
        if (!yes) { setBusy(false); return; }
      }
      onDone(await sync.configure({
        account: user.username, groupId, groupName: group.name,
        owner: group.owner_username || '', folder,
      }));
    } catch (e) {
      setError(e.message);
      setBusy(false);
    }
  };

  return html`
    <div>
      ${!permitted && html`
        <p class="settings-hint">${t(TEXT[kind].permission)}</p>
        <div class="settings-row" style="gap:8px; justify-content:flex-start">
          <button class="admin-btn" onClick=${allow}>${t('photosync.permission_allow')}</button>
          <button class="btn-secondary" onClick=${() => onDone(null)}>${t('dialog.cancel')}</button>
        </div>
      `}
      ${permitted && html`
        ${candidates === null && html`<p class="settings-hint">${t('phonesync.checking_groups')}</p>`}
        ${candidates && !candidates.length && html`
          <p class="settings-hint">${t('phonesync.no_private_group')}</p>`}
        ${candidates && candidates.length > 0 && html`
          <div class="settings-row">
            <span class="settings-label">${t('photosync.group')}</span>
            <select class="settings-select" value=${groupId}
              onChange=${(e) => setGroupId(e.target.value)}>
              <option value="">${t('photosync.choose_group')}</option>
              ${candidates.map((g) => html`<option key=${g.id} value=${g.id}>${g.name}</option>`)}
            </select>
          </div>
        `}
        ${probe === 'checking' && html`<p class="settings-hint">${t('photosync.checking_group')}</p>`}
        ${probe === 'offline' && html`<p class="settings-hint">${t('photosync.group_offline')}</p>`}
        ${folders && !folders.length && html`<p class="settings-hint">${t('phonesync.no_folder')}</p>`}
        ${folders && folders.length > 0 && html`
          <div class="settings-row">
            <span class="settings-label">${t('photosync.folder')}</span>
            <select class="settings-select" value=${folder} onChange=${(e) => setFolder(e.target.value)}>
              ${folders.map((f) => html`<option key=${f} value=${f}>${f}</option>`)}
            </select>
          </div>
          <p class="settings-hint settings-name">${t('phonesync.destination', { dir })}</p>
        `}
        <div class="settings-row" style="gap:8px; justify-content:flex-start">
          <button class="admin-btn" onClick=${start}
            disabled=${busy || !groupId || !folder}>${t('photosync.start')}</button>
          <button class="btn-secondary" onClick=${() => onDone(null)}>${t('dialog.cancel')}</button>
        </div>
      `}
      ${error && html`<p class="error-msg">${error}</p>`}
    </div>
  `;
}