import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { useState } from 'react';
import { usuariosApi } from '@/api/usuarios';
import { rolesApi } from '@/api/roles';
import type { ActualizarUsuarioBody, Usuario } from '@/types';
import { PageHeader } from '@/components/PageHeader';
import { DataTable, type Column } from '@/components/DataTable';
import { Modal } from '@/components/Modal';
import { ConfirmDialog } from '@/components/ConfirmDialog';
import { ErrorAlert } from '@/components/ErrorAlert';
import {
  Field,
  Input,
  Select,
  Checkbox,
  btnPrimary,
  btnSecondary,
  btnDanger,
} from '@/components/form/Field';

export function UsersPage() {
  const qc = useQueryClient();
  const [editUser, setEditUser] = useState<Usuario | null>(null);
  const [deleteId, setDeleteId] = useState<number | null>(null);
  const [formError, setFormError] = useState('');

  const usuarios = useQuery({ queryKey: ['usuarios'], queryFn: usuariosApi.list });
  const pendientes = useQuery({
    queryKey: ['usuarios-pendientes'],
    queryFn: usuariosApi.pendientes,
  });
  const roles = useQuery({ queryKey: ['roles'], queryFn: rolesApi.list });

  const aceptar = useMutation({
    mutationFn: (id: number) => usuariosApi.aceptar(id),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: ['usuarios'] });
      qc.invalidateQueries({ queryKey: ['usuarios-pendientes'] });
      qc.invalidateQueries({ queryKey: ['dashboard-stats'] });
    },
  });

  const update = useMutation({
    mutationFn: ({ id, body }: { id: number; body: ActualizarUsuarioBody }) =>
      usuariosApi.update(id, body),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: ['usuarios'] });
      qc.invalidateQueries({ queryKey: ['usuarios-pendientes'] });
      setEditUser(null);
    },
    onError: (e: Error) => setFormError(e.message),
  });

  const remove = useMutation({
    mutationFn: (id: number) => usuariosApi.delete(id),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: ['usuarios'] });
      setDeleteId(null);
    },
  });

  const columns: Column<Usuario>[] = [
    { key: 'id', header: 'ID', render: (u) => u.id },
    { key: 'email', header: 'Email', render: (u) => u.username },
    { key: 'nombre', header: 'Nombre', render: (u) => u.nombre },
    {
      key: 'rol',
      header: 'Rol',
      render: (u) => u.rol?.name ?? u.roles ?? '—',
    },
    {
      key: 'aprobado',
      header: 'Aprobado',
      render: (u) => (u.aprobado ? 'Sí' : 'No'),
    },
    {
      key: 'visible',
      header: 'Visible',
      render: (u) => (u.visible ? 'Sí' : 'No'),
    },
    {
      key: 'actions',
      header: '',
      render: (u) => (
        <div className="flex gap-2">
          <button type="button" className={btnSecondary} onClick={() => setEditUser(u)}>
            Editar
          </button>
          <button type="button" className={btnDanger} onClick={() => setDeleteId(u.id)}>
            Eliminar
          </button>
        </div>
      ),
    },
  ];

  return (
    <div>
      <PageHeader
        title="Usuarios"
        description="Gestión de cuentas y aprobaciones"
      />

      {pendientes.data && pendientes.data.length > 0 && (
        <section className="mb-8 rounded-xl border border-amber-500/30 bg-amber-950/20 p-5">
          <h2 className="mb-3 font-semibold text-amber-200">
            Pendientes de aprobación ({pendientes.data.length})
          </h2>
          <ul className="space-y-2">
            {pendientes.data.map((u) => (
              <li
                key={u.id}
                className="flex flex-wrap items-center justify-between gap-2 rounded-lg bg-surface-raised/80 px-4 py-3"
              >
                <span>
                  <strong>{u.nombre}</strong> — {u.username}
                </span>
                <button
                  type="button"
                  className={btnPrimary}
                  disabled={aceptar.isPending}
                  onClick={() => aceptar.mutate(u.id)}
                >
                  Aprobar
                </button>
              </li>
            ))}
          </ul>
        </section>
      )}

      <DataTable
        columns={columns}
        data={usuarios.data ?? []}
        keyExtractor={(u) => u.id}
        loading={usuarios.isLoading}
      />

      {editUser && (
        <UserFormModal
          user={editUser}
          roles={roles.data ?? []}
          error={formError}
          loading={update.isPending}
          onClose={() => {
            setEditUser(null);
            setFormError('');
          }}
          onSave={(body) => update.mutate({ id: editUser.id, body })}
        />
      )}

      <ConfirmDialog
        open={deleteId != null}
        title="Eliminar usuario"
        message="¿Confirma eliminar este usuario? Esta acción no se puede deshacer."
        onConfirm={() => deleteId != null && remove.mutate(deleteId)}
        onCancel={() => setDeleteId(null)}
        loading={remove.isPending}
      />
    </div>
  );
}

function UserFormModal({
  user,
  roles,
  error,
  loading,
  onClose,
  onSave,
}: {
  user: Usuario;
  roles: { id: number; name: string }[];
  error: string;
  loading: boolean;
  onClose: () => void;
  onSave: (body: ActualizarUsuarioBody) => void;
}) {
  const [nombre, setNombre] = useState(user.nombre);
  const [ci, setCi] = useState(String(user.ci));
  const [celular, setCelular] = useState(String(user.celular));
  const [aprobado, setAprobado] = useState(user.aprobado);
  const [visible, setVisible] = useState(user.visible);
  const [rolId, setRolId] = useState(String(user.rol?.id ?? ''));
  const [password, setPassword] = useState('');

  return (
    <Modal open title={`Editar: ${user.username}`} onClose={onClose}>
      {error && <div className="mb-4"><ErrorAlert message={error} /></div>}
      <form
        className="space-y-4"
        onSubmit={(e) => {
          e.preventDefault();
          const body: ActualizarUsuarioBody = {
            nombre,
            ci: Number(ci),
            celular: Number(celular),
            aprobado,
            visible,
            rol: rolId ? Number(rolId) : undefined,
          };
          if (password) body.password = password;
          onSave(body);
        }}
      >
        <Field label="Nombre">
          <Input value={nombre} onChange={(e) => setNombre(e.target.value)} required />
        </Field>
        <Field label="CI">
          <Input type="number" value={ci} onChange={(e) => setCi(e.target.value)} required />
        </Field>
        <Field label="Celular">
          <Input
            type="number"
            value={celular}
            onChange={(e) => setCelular(e.target.value)}
            required
          />
        </Field>
        <Field label="Rol (tabla roles)">
          <Select value={rolId} onChange={(e) => setRolId(e.target.value)}>
            <option value="">— Sin cambio —</option>
            {roles.map((r) => (
              <option key={r.id} value={r.id}>
                {r.name}
              </option>
            ))}
          </Select>
        </Field>
        <Field label="Nueva contraseña (opcional)">
          <Input
            type="password"
            value={password}
            onChange={(e) => setPassword(e.target.value)}
            autoComplete="new-password"
          />
        </Field>
        <Checkbox label="Aprobado" checked={aprobado} onChange={(e) => setAprobado(e.target.checked)} />
        <Checkbox label="Visible" checked={visible} onChange={(e) => setVisible(e.target.checked)} />
        <div className="flex justify-end gap-3 pt-2">
          <button type="button" className={btnSecondary} onClick={onClose}>
            Cancelar
          </button>
          <button type="submit" className={btnPrimary} disabled={loading}>
            Guardar
          </button>
        </div>
      </form>
    </Modal>
  );
}