import { useEffect, useState } from 'react';
import { useNavigate } from 'react-router-dom';
import { Plus, Save, Trash2, RotateCcw, ArrowLeft } from 'lucide-react';
import { useUi } from '../../context/ui-context.jsx';
import { useAuth } from '../../context/auth-context.jsx';
import { useAsync, useAction } from '../../hooks/useAsync.js';
import { useDebouncedValue } from '../../hooks/useDebouncedValue.js';
import { listProjects, createProject, deleteProject, restoreProject, permanentlyDeleteProject } from '../../services/projects.js';
import { listUsers } from '../../services/users.js';
import { search as searchApi } from '../../services/search.js';
import { listCatalog } from '../../services/catalogs.js';
import { listDepartments } from '../../services/departments.js';
import { ListView } from '../../components/ListView.jsx';
import { SearchInput } from '../../components/SearchInput.jsx';
import { SearchResultsDropdown } from '../../components/SearchResultsDropdown.jsx';
import { Button } from '../../components/Button.jsx';
import { Field, FieldRow } from '../../components/Field.jsx';
import { ComboBox } from '../../components/ComboBox.jsx';
import { StatusBadge, ProgressBar } from '../../components/StatusBadge.jsx';
import { Badge } from '../../components/Badge.jsx';
import { DetailPopup } from '../../components/DetailPopup.jsx';
import { DraftNotice } from '../../components/DraftNotice.jsx';
import { DraftMark, useGuardedClose } from '../../components/NavigationGuard.jsx';
import { useDraftForm, useUserDrafts, hasDraftFor } from '../../hooks/useDraftForm.js';
import { SharedWithIcon } from '../../components/SharedWithIcon.jsx';

const CAN_DELETE_ROLES = ['superadmin', 'admin', 'it_manager', 'project_lead'];
const PROGRESS_FILTER_KEY = 'plc_projects_progress_filter';
const LEGACY_HIDE_COMPLETED_KEY = 'plc_projects_hide_completed';

function flatten(nodes, acc = []) {
  for (const n of nodes) { acc.push(n); if (n.children?.length) flatten(n.children, acc); }
  return acc;
}

const RISK_COLOR = { low: 'success', medium: 'warning', high: 'danger' };
const EMPTY_FORM = {
  name: '', description: '', objective: '', projectTypeId: '', priorityId: '', statusId: '',
  requestingDepartmentId: '', responsibleDepartmentId: '', startDate: '', estimatedEndDate: '',
  riskLevel: 'low', notes: '',
};

export default function ProyectosPage() {
  const { t, pushToast, openDialog } = useUi();
  const { user: currentUser } = useAuth();
  const navigate = useNavigate();
  const runAction = useAction();

  const [showTrash, setShowTrash] = useState(false);
  const isSuperadmin = currentUser?.roleCode === 'superadmin';
  const canDelete = CAN_DELETE_ROLES.includes(currentUser?.roleCode);

  const [filterStatusId, setFilterStatusId] = useState('');
  const [filterPriorityId, setFilterPriorityId] = useState('');
  const [filterDueSoon, setFilterDueSoon] = useState(false);
  const [page, setPage] = useState(1);
  const [pageSize, setPageSize] = useState(20);
  // '' = todos, 'hide' = ocultar 100%, 'only' = solo 100%. Persistido en el navegador (sobrevive
  // al cierre de sesion). Respeta el checkbox anterior "Ocultar 100%" (clave vieja) si existia.
  const [progressFilter, setProgressFilter] = useState(() => {
    try {
      const saved = localStorage.getItem(PROGRESS_FILTER_KEY);
      if (saved !== null) return saved;
      return localStorage.getItem(LEGACY_HIDE_COMPLETED_KEY) === '1' ? 'hide' : '';
    } catch { return ''; }
  });
  function changeProgressFilter(value) {
    setProgressFilter(value);
    try { localStorage.setItem(PROGRESS_FILTER_KEY, value); } catch { /* sin storage: solo en memoria */ }
  }
  const [filterOwnerUserId, setFilterOwnerUserId] = useState('');
  // Prueba exploratoria: filtro "ver todos / por usuario" solo para roles que ya ven todos los
  // proyectos hoy (superadmin/admin/it_manager) -- backend ya soporta ownerUserId, sin cambios.
  const canFilterByUser = ['superadmin', 'admin', 'it_manager'].includes(currentUser?.roleCode);
  const [search, setSearch] = useState('');
  const debouncedSearch = useDebouncedValue(search, 300);

  const { data: projectPage, reload } = useAsync(
    () => listProjects(showTrash ? { trash: true, page, pageSize, q: debouncedSearch } : {
      statusId: filterStatusId, priorityId: filterPriorityId, ownerUserId: filterOwnerUserId || undefined,
      dueSoon: filterDueSoon, progress: progressFilter, q: debouncedSearch, page, pageSize,
    }),
    [showTrash, filterStatusId, filterPriorityId, filterOwnerUserId, filterDueSoon, progressFilter, debouncedSearch, page, pageSize]
  );
  const projects = projectPage?.items;
  const { data: allUsers } = useAsync(listUsers, []);
  const { data: priorities } = useAsync(() => listCatalog('priorities'), []);
  const { data: statuses } = useAsync(() => listCatalog('project-statuses'), []);
  const { data: types } = useAsync(() => listCatalog('project-types'), []);
  const { data: deptTree } = useAsync(listDepartments, []);

  useEffect(() => { setPage(1); }, [showTrash, filterStatusId, filterPriorityId, filterOwnerUserId, filterDueSoon, progressFilter, search, pageSize]);
  const [creating, setCreating] = useState(false);
  // "Nuevo proyecto" con borrador: si se sale a medio llenar, al volver se reabre el popup.
  const draft = useDraftForm({ formId: 'project-new', entityId: null, initial: EMPTY_FORM, label: t('project_new'), enabled: creating });
  const form = draft.values;
  const setForm = draft.setValues;
  const guardedClose = useGuardedClose();
  const pendingNew = hasDraftFor(useUserDrafts(), 'project-new', null);
  useEffect(() => { if (pendingNew) setCreating(true); }, []); // eslint-disable-line react-hooks/exhaustive-deps

  // Busca tambien en actividades y tareas de CUALQUIER proyecto (no solo el nombre del proyecto,
  // que ya filtra la tabla mas abajo via getSearchHaystack) — resultados con su ruta completa
  // "Proyecto - Actividad - Tarea" en un panel flotante bajo el buscador.
  const searchQuery = debouncedSearch.trim();
  const { data: searchResults } = useAsync(
    () => (searchQuery.length >= 2 ? searchApi(searchQuery) : Promise.resolve(null)),
    [searchQuery]
  );
  const searchItems = searchResults ? [
    ...searchResults.projects.map((p) => ({
      key: `p-${p.id}`,
      breadcrumb: [`${p.code} — ${p.name}`],
      onClick: () => { setSearch(''); navigate(`/proyectos/${p.id}`); },
    })),
    ...searchResults.activities.map((a) => ({
      key: `a-${a.id}`,
      breadcrumb: [`${a.project_code} — ${a.project_name}`, `${a.code} — ${a.name}`],
      onClick: () => { setSearch(''); navigate(`/proyectos/${a.project_id}?tab=activities&activity=${a.id}`); },
    })),
    ...searchResults.tasks.map((tk) => ({
      key: `t-${tk.id}`,
      breadcrumb: [`${tk.project_code} — ${tk.project_name}`, `${tk.activity_code} — ${tk.activity_name}`, tk.name],
      onClick: () => { setSearch(''); navigate(`/proyectos/${tk.project_id}?tab=activities&activity=${tk.activity_id}&activityTab=tasks`); },
    })),
  ] : null;

  const deptOptions = deptTree ? flatten(deptTree).map((d) => ({ value: d.id, label: d.name })) : [];
  const priorityOptions = (priorities || []).map((p) => ({ value: p.id, label: p.name }));
  const statusOptions = (statuses || []).map((s) => ({ value: s.id, label: s.name }));
  const typeOptions = (types || []).map((tp) => ({ value: tp.id, label: tp.name }));

  async function save() {
    if (!form.name.trim() || !form.priorityId || !form.statusId) return;
    await runAction(async () => {
      const project = await createProject({
        ...form,
        projectTypeId: form.projectTypeId || null,
        requestingDepartmentId: form.requestingDepartmentId || null,
        responsibleDepartmentId: form.responsibleDepartmentId || null,
        startDate: form.startDate || null,
        estimatedEndDate: form.estimatedEndDate || null,
      });
      draft.clear();
      setCreating(false);
      pushToast({ tone: 'success', message: t('common_saved') });
      navigate(`/proyectos/${project.id}`);
    });
  }

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

  function confirmPurge(project) {
    openDialog({
      tone: 'error',
      title: t('project_delete_permanent'),
      message: t('project_delete_permanent_confirm_msg'),
      actions: [
        { label: t('common_cancel'), variant: 'standard' },
        {
          label: t('project_delete_permanent'), variant: 'danger',
          onClick: () => runAction(async () => {
            await permanentlyDeleteProject(project.id);
            await reload();
            pushToast({ tone: 'success', message: t('common_saved') });
          }),
        },
      ],
    });
  }

  function restore(project) {
    runAction(async () => {
      await restoreProject(project.id);
      await reload();
      pushToast({ tone: 'success', message: t('common_saved') });
    });
  }

  const columns = [
    { key: 'code', label: t('project_code') },
    { key: 'name', label: t('common_name') },
    { key: 'status_name', label: t('common_status'), render: (r) => <StatusBadge name={r.status_name} color={r.status_color} /> },
    { key: 'priority_name', label: t('common_priority'), sortValue: (r) => r.priority_level, render: (r) => <StatusBadge name={r.priority_name} color={r.priority_color} /> },
    { key: 'owner_name', label: t('project_owner') },
    { key: 'progress_pct', label: t('project_progress'), render: (r) => <div style={{ width: 90 }}><ProgressBar value={Number(r.progress_pct)} /></div> },
    { key: 'shared', label: '', sortable: false, render: (r) => <SharedWithIcon projectId={r.id} count={r.shared_count} /> },
    { key: 'risk_level', label: t('project_risk'), render: (r) => <Badge color={RISK_COLOR[r.risk_level]}>{t(`risk_${r.risk_level}`)}</Badge> },
    { key: 'updated_at', label: t('project_updated_at'), render: (r) => String(r.updated_at).slice(0, 16) },
    ...(showTrash ? [{ key: 'deleted_at', label: t('project_deleted_at'), render: (r) => String(r.deleted_at).slice(0, 10) }] : []),
  ];

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

  const visibleProjects = projects;

  return (
    <div>
      <div className="toolbar">
        <div className="toolbar-left">
          <h2 className="page-title mt-0">{showTrash ? t('project_trash_title') : t('projects_title')}</h2>
        </div>
        {showTrash ? (
          <Button variant="standard" icon={ArrowLeft} onClick={() => setShowTrash(false)}>{t('project_trash_back')}</Button>
        ) : (
          <div style={{ display: 'flex', gap: 8 }}>
            {isSuperadmin && (
              <Button variant="standard" icon={Trash2} onClick={() => setShowTrash(true)}>{t('project_trash')}</Button>
            )}
            <Button variant="accent" icon={Plus} onClick={() => setCreating(true)}>{t('project_new')}{pendingNew && !creating && <DraftMark />}</Button>
          </div>
        )}
      </div>

      {showTrash && <div className="text-muted" style={{ fontSize: '.8rem', marginBottom: 8 }}>{t('project_trash_empty_hint')}</div>}

      <div className="toolbar">
        <div style={{ position: 'relative' }}>
          <SearchInput value={search} onChange={setSearch} />
          {searchQuery.length >= 2 && searchItems && (
            <SearchResultsDropdown items={searchItems} emptyLabel={t('common_search_no_results')} />
          )}
        </div>
        {!showTrash && (
          <>
            <div style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
              <span className="text-muted" style={{ fontSize: '.72rem', whiteSpace: 'nowrap' }}>{t('common_status')}</span>
              <div style={{ width: 160 }}>
                <ComboBox options={[{ value: '', label: t('common_all') }, ...statusOptions]} value={filterStatusId} onChange={setFilterStatusId} placeholder={t('common_status')} />
              </div>
            </div>
            <div style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
              <span className="text-muted" style={{ fontSize: '.72rem', whiteSpace: 'nowrap' }}>{t('common_priority')}</span>
              <div style={{ width: 160 }}>
                <ComboBox options={[{ value: '', label: t('common_all') }, ...priorityOptions]} value={filterPriorityId} onChange={setFilterPriorityId} placeholder={t('common_priority')} />
              </div>
            </div>
            <div style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
              <span className="text-muted" style={{ fontSize: '.72rem', whiteSpace: 'nowrap' }}>{t('project_filter_progress')}</span>
              <div style={{ width: 160 }}>
                <ComboBox
                  options={[
                    { value: '', label: t('common_all') },
                    { value: 'hide', label: t('project_filter_progress_hide') },
                    { value: 'only', label: t('project_filter_progress_only') },
                  ]}
                  value={progressFilter}
                  onChange={changeProgressFilter}
                  placeholder={t('project_filter_progress')}
                />
              </div>
            </div>
            {canFilterByUser && (
              <div style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
                <span className="text-muted" style={{ fontSize: '.72rem', whiteSpace: 'nowrap' }}>Usuario</span>
                <div style={{ width: 200 }}>
                  <ComboBox
                    options={[{ value: '', label: t('common_all') }, ...(allUsers || []).map((u) => ({ value: u.id, label: u.name }))]}
                    value={filterOwnerUserId}
                    onChange={setFilterOwnerUserId}
                    placeholder="Usuario"
                  />
                </div>
              </div>
            )}
            <label className="checkbox-row">
              <input type="checkbox" checked={filterDueSoon} onChange={(e) => setFilterDueSoon(e.target.checked)} />
              {t('project_filter_due_soon')}
            </label>
          </>
        )}
      </div>

      <ListView
        columns={columns}
        rows={visibleProjects}
        searchValue=""
        getSearchHaystack={(p) => `${p.code} ${p.name} ${p.owner_name} ${p.status_name}`}
        getRowKey={(p) => p.id}
        onRowClick={showTrash ? undefined : (p) => navigate(`/proyectos/${p.id}`)}
        initialSort={{ key: 'updated_at', dir: -1 }}
        rowActions={
          showTrash
            ? (p) => [
                { label: t('project_restore'), icon: RotateCcw, onClick: () => restore(p) },
                { label: t('project_delete_permanent'), icon: Trash2, danger: true, onClick: () => confirmPurge(p) },
              ]
            : canDelete
              ? (p) => [{ label: t('common_delete'), icon: Trash2, danger: true, onClick: () => confirmDelete(p) }]
              : undefined
        }
      />

      <div className="toolbar" style={{ justifyContent: 'flex-end', marginTop: 8 }}>
        <span className="text-muted">{t('project_page_range')} {projectPage.total ? (page - 1) * pageSize + 1 : 0}–{Math.min(page * pageSize, projectPage.total)} {t('project_page_of')} {projectPage.total}</span>
        <ComboBox options={[10, 20, 50, 100].map((n) => ({ value: n, label: String(n) }))} value={pageSize} onChange={setPageSize} />
        <Button variant="standard" disabled={page <= 1} onClick={() => setPage((p) => p - 1)}>{t('project_page_previous')}</Button>
        <Button variant="standard" disabled={page * pageSize >= projectPage.total} onClick={() => setPage((p) => p + 1)}>{t('project_page_next')}</Button>
      </div>

      <DetailPopup open={creating} title={t('project_new')} onClose={() => guardedClose(draft, () => setCreating(false))} width={720} height={720}>
          <DraftNotice draft={draft} />
          <Field label={t('common_name')} dirty={draft.isFieldDirty('name')}>
            <input className="input" value={form.name} onChange={(e) => setForm((f) => ({ ...f, name: e.target.value }))} autoFocus />
          </Field>
          <Field label={t('common_description')} dirty={draft.isFieldDirty('description')}>
            <textarea className="textarea" value={form.description} onChange={(e) => setForm((f) => ({ ...f, description: e.target.value }))} />
          </Field>
          <Field label={t('project_objective')} dirty={draft.isFieldDirty('objective')}>
            <textarea className="textarea" value={form.objective} onChange={(e) => setForm((f) => ({ ...f, objective: e.target.value }))} />
          </Field>
          <FieldRow>
            <Field label={t('project_type')} dirty={draft.isFieldDirty('projectTypeId')}>
              <ComboBox options={[{ value: '', label: '—' }, ...typeOptions]} value={form.projectTypeId} onChange={(v) => setForm((f) => ({ ...f, projectTypeId: v }))} />
            </Field>
            <Field label={t('common_priority')} dirty={draft.isFieldDirty('priorityId')}>
              <ComboBox options={priorityOptions} value={form.priorityId} onChange={(v) => setForm((f) => ({ ...f, priorityId: v }))} />
            </Field>
            <Field label={t('common_status')} dirty={draft.isFieldDirty('statusId')}>
              <ComboBox options={statusOptions} value={form.statusId} onChange={(v) => setForm((f) => ({ ...f, statusId: v }))} />
            </Field>
          </FieldRow>
          <FieldRow>
            <Field label={t('project_requesting_department')} dirty={draft.isFieldDirty('requestingDepartmentId')}>
              <ComboBox options={[{ value: '', label: '—' }, ...deptOptions]} value={form.requestingDepartmentId} onChange={(v) => setForm((f) => ({ ...f, requestingDepartmentId: v }))} />
            </Field>
            <Field label={t('project_responsible_department')} dirty={draft.isFieldDirty('responsibleDepartmentId')}>
              <ComboBox options={[{ value: '', label: '—' }, ...deptOptions]} value={form.responsibleDepartmentId} onChange={(v) => setForm((f) => ({ ...f, responsibleDepartmentId: v }))} />
            </Field>
            <Field label={t('project_risk')} dirty={draft.isFieldDirty('riskLevel')}>
              <ComboBox options={['low', 'medium', 'high'].map((r) => ({ value: r, label: t(`risk_${r}`) }))} value={form.riskLevel} onChange={(v) => setForm((f) => ({ ...f, riskLevel: v }))} />
            </Field>
          </FieldRow>
          <FieldRow>
            <Field label={t('project_start_date')} dirty={draft.isFieldDirty('startDate')}>
              <input className="input" type="date" value={form.startDate} onChange={(e) => setForm((f) => ({ ...f, startDate: e.target.value }))} />
            </Field>
            <Field label={t('project_estimated_end_date')} dirty={draft.isFieldDirty('estimatedEndDate')}>
              <input className="input" type="date" value={form.estimatedEndDate} onChange={(e) => setForm((f) => ({ ...f, estimatedEndDate: e.target.value }))} />
            </Field>
          </FieldRow>
          <Field label={t('project_notes')} dirty={draft.isFieldDirty('notes')}>
            <textarea className="textarea" value={form.notes} onChange={(e) => setForm((f) => ({ ...f, notes: e.target.value }))} />
          </Field>
          <div style={{ display: 'flex', gap: 8 }}>
            <Button variant="accent" icon={Save} onClick={save}>{t('common_save')}</Button>
            <Button variant="standard" onClick={() => { draft.discard(); setCreating(false); }}>{t('common_cancel')}</Button>
          </div>
      </DetailPopup>
    </div>
  );
}