import { useState } from 'react';
import { Plus, Save, Trash2, Share2, UserPlus, GripVertical } from 'lucide-react';
import { useUi } from '../../context/ui-context.jsx';
import { useAsync, useAction } from '../../hooks/useAsync.js';
import { useDragReorder } from '../../hooks/useDragReorder.js';
import {
  listNotes, createNote, updateNote, deleteNote, reorderNotes, listNoteShares, addNoteShare, removeNoteShare,
} from '../../services/notes.js';
import { listUsers } from '../../services/users.js';
import { Button } from '../../components/Button.jsx';
import { Field } from '../../components/Field.jsx';
import { ComboBox } from '../../components/ComboBox.jsx';
import { DetailPopup } from '../../components/DetailPopup.jsx';
import { SearchInput } from '../../components/SearchInput.jsx';

function formatDateTime(value) {
  return String(value).slice(0, 16).replace('T', ' ');
}

export default function NotasPage() {
  const { t, pushToast, openDialog } = useUi();
  const runAction = useAction();
  const { data: notes, reload } = useAsync(listNotes, []);
  const { data: users } = useAsync(listUsers, []);

  const [selected, setSelected] = useState(null); // nota abierta en el popup (null = cerrado)
  const [creating, setCreating] = useState(false);
  const [content, setContent] = useState('');
  const [shares, setShares] = useState([]);
  const [sharingWith, setSharingWith] = useState('');
  const [search, setSearch] = useState('');

  function openCreate() {
    setSelected(null);
    setCreating(true);
    setContent('');
    setShares([]);
    setSharingWith('');
  }

  async function openNote(note) {
    setSelected(note);
    setCreating(false);
    setContent(note.content);
    setSharingWith('');
    setShares(note.is_owner ? await listNoteShares(note.id) : []);
  }

  function closePopup() {
    setSelected(null);
    setCreating(false);
  }

  async function save() {
    if (!content.trim()) return;
    await runAction(async () => {
      if (creating) {
        await createNote(content);
      } else {
        await updateNote(selected.id, content);
      }
      closePopup();
      await reload();
    });
  }

  function confirmDelete() {
    openDialog({
      tone: 'warning',
      title: t('common_confirm_delete_title'),
      message: t('common_confirm_delete_msg'),
      actions: [
        { label: t('common_cancel'), variant: 'standard' },
        {
          label: t('common_delete'), variant: 'danger',
          onClick: () => runAction(async () => {
            await deleteNote(selected.id);
            closePopup();
            await reload();
            pushToast({ tone: 'success', message: t('common_saved') });
          }),
        },
      ],
    });
  }

  const userOptions = (users || [])
    .filter((u) => !shares.some((s) => s.user_id === u.id))
    .map((u) => ({ value: u.id, label: u.name }));

  async function addShare() {
    if (!sharingWith) return;
    await runAction(async () => {
      setShares(await addNoteShare(selected.id, Number(sharingWith)));
      setSharingWith('');
      await reload(); // el ícono de compartida de la tarjeta usa share_count de la lista principal
    });
  }

  function removeShare(userId) {
    runAction(async () => {
      setShares(await removeNoteShare(selected.id, userId));
      await reload();
    });
  }

  const query = search.trim().toLowerCase();
  const filteredNotes = query ? (notes || []).filter((n) => n.content.toLowerCase().includes(query)) : (notes || []);
  const ownNotes = filteredNotes.filter((n) => n.is_owner);
  const sharedNotes = filteredNotes.filter((n) => !n.is_owner);
  // Solo se puede arrastrar lo propio, y no mientras hay un filtro de busqueda activo (el orden
  // de un subconjunto filtrado no tiene un significado claro que persistir).
  const dragEnabled = !query;
  const { order: orderedOwnNotes, getHandleProps, getRowProps, isDragging } = useDragReorder(ownNotes, async (ids) => {
    await reorderNotes(ids);
    await reload();
  });
  const displayedOwnNotes = dragEnabled ? orderedOwnNotes : ownNotes;

  if (!notes) return <div className="text-muted">{t('common_loading')}</div>;

  return (
    <div>
      <div className="toolbar" style={{ marginBottom: 16 }}>
        <h2 className="page-title mt-0" style={{ marginBottom: 0 }}>{t('notes_title')}</h2>
        <SearchInput value={search} onChange={setSearch} />
      </div>

      <div className="notes-grid">
        <button type="button" className="notes-card notes-card-new" onClick={openCreate}>
          <Plus size={28} />
          <span>{t('notes_new')}</span>
        </button>
        {displayedOwnNotes.map((note) => (
          <div
            key={note.id}
            className={`notes-card ${dragEnabled && isDragging(note.id) ? 'dragging' : ''}`}
            onClick={() => openNote(note)}
            {...(dragEnabled ? getRowProps(note) : {})}
          >
            <div className="notes-card-corner">
              {note.share_count > 0 && (
                <span className="notes-card-corner-share" title={t('notes_share_title')}>
                  <Share2 size={13} strokeWidth={2.5} />
                </span>
              )}
              {dragEnabled && (
                <span className="notes-card-handle" onClick={(e) => e.stopPropagation()} {...getHandleProps(note)}>
                  <GripVertical size={14} />
                </span>
              )}
            </div>
            <div className="notes-card-preview">{note.content}</div>
            <div className="notes-card-meta">
              <span className="notes-card-meta-row">
                {note.created_at === note.updated_at
                  ? formatDateTime(note.created_at)
                  : `${t('notes_updated')} ${formatDateTime(note.updated_at)}`}
              </span>
            </div>
          </div>
        ))}
        {sharedNotes.map((note) => (
          <div key={note.id} className="notes-card" onClick={() => openNote(note)}>
            <div className="notes-card-corner">
              <span className="notes-card-corner-share" title={t('notes_share_title')}>
                <Share2 size={13} strokeWidth={2.5} />
              </span>
            </div>
            <div className="notes-card-preview">{note.content}</div>
            <div className="notes-card-meta">
              <span className="notes-card-meta-row">
                {note.created_at === note.updated_at
                  ? formatDateTime(note.created_at)
                  : `${t('notes_updated')} ${formatDateTime(note.updated_at)}`}
              </span>
              <span className="notes-card-shared">{t('notes_shared_by')} {note.owner_name}</span>
            </div>
          </div>
        ))}
      </div>

      {filteredNotes.length === 0 && (
        <div className="text-muted" style={{ marginTop: 12 }}>
          {query ? t('common_search_no_results') : t('notes_empty')}
        </div>
      )}

      <DetailPopup
        open={creating || !!selected}
        title={creating ? t('notes_new') : t('notes_title')}
        onClose={closePopup}
        width={560}
        height={creating || selected?.is_owner ? 620 : 420}
      >
        {creating || selected?.is_owner ? (
          <>
            <textarea
              className="textarea" rows={6} autoFocus
              placeholder={t('notes_placeholder')}
              value={content}
              onChange={(e) => setContent(e.target.value)}
            />
            <div style={{ display: 'flex', gap: 8, marginTop: 8, marginBottom: creating ? 0 : 20 }}>
              <Button variant="accent" icon={Save} onClick={save} disabled={!content.trim()}>{t('common_save')}</Button>
              <Button variant="standard" onClick={closePopup}>{t('common_cancel')}</Button>
              {!creating && <Button variant="danger" icon={Trash2} onClick={confirmDelete}>{t('common_delete')}</Button>}
            </div>

            {!creating && (
              <div>
                <h4 style={{ display: 'flex', alignItems: 'center', gap: 6 }}><Share2 size={15} /> {t('notes_share_title')}</h4>
                <Field label={t('notes_share_add')}>
                  <div style={{ display: 'flex', gap: 8 }}>
                    <div style={{ flex: 1 }}>
                      <ComboBox options={userOptions} value={sharingWith} onChange={setSharingWith} placeholder={t('notes_share_placeholder')} />
                    </div>
                    <Button variant="standard" icon={UserPlus} onClick={addShare} disabled={!sharingWith}>{t('notes_share_add')}</Button>
                  </div>
                </Field>
                {shares.length === 0 && <div className="text-muted" style={{ fontSize: '.78rem' }}>{t('notes_share_empty')}</div>}
                {shares.map((s) => (
                  <div key={s.user_id} style={{ display: 'flex', alignItems: 'center', gap: 10, padding: '6px 0' }}>
                    <span style={{ flex: 1, fontSize: '.82rem' }}>{s.name} <span className="text-muted">· {s.email}</span></span>
                    <button className="icon-btn" onClick={() => removeShare(s.user_id)}><Trash2 size={15} /></button>
                  </div>
                ))}
              </div>
            )}
          </>
        ) : (
          <>
            <div className="text-muted" style={{ fontSize: '.78rem', marginBottom: 10 }}>{t('notes_shared_by')} {selected?.owner_name}</div>
            <div style={{ fontSize: '.85rem', whiteSpace: 'pre-wrap' }}>{content}</div>
          </>
        )}
      </DetailPopup>
    </div>
  );
}