'use client';

import * as React from 'react';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { useForm } from 'react-hook-form';
import { zodResolver } from '@hookform/resolvers/zod';
import { Plus } from 'lucide-react';

import { createPlano, deletePlano, listPlanos, updatePlano, type Plano } from '@/lib/api/planos';
import { planoSchema, type PlanoFormValues } from '@/lib/validators/planos';
import { ApiError } from '@/lib/api/client';
import { formatCurrency } from '@/lib/format';
import { toast } from '@/lib/toast';

import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import { DataTable, type DataTableColumn } from '@/components/ui/data-table';
import { FormField } from '@/components/ui/form-field';
import { Input } from '@/components/ui/input';
import { ResponsiveDialog } from '@/components/ui/responsive-dialog';
import { Textarea } from '@/components/ui/textarea';
import { ConfirmDialog } from '@/components/domain/confirm-dialog';

/** `<input type="number">` vazio deve virar `undefined` (ilimitado), não `NaN`/`0`. */
function toOptionalInt(value: string): number | undefined {
  return value === '' ? undefined : Number(value);
}

export default function PlanosPage() {
  const queryClient = useQueryClient();
  const { data: planos, isLoading } = useQuery({
    queryKey: ['master', 'planos'],
    queryFn: () => listPlanos(),
  });

  const [editing, setEditing] = React.useState<Plano | null>(null);
  const [formOpen, setFormOpen] = React.useState(false);
  const [deleting, setDeleting] = React.useState<Plano | null>(null);

  const form = useForm<PlanoFormValues>({ resolver: zodResolver(planoSchema) });

  function openCreate() {
    setEditing(null);
    form.reset({
      nome: '',
      descricao: '',
      valor_mensal: 0,
      limite_customers: undefined,
      limite_usuarios: undefined,
      limite_instancias_whatsapp: undefined,
    });
    setFormOpen(true);
  }

  function openEdit(plano: Plano) {
    setEditing(plano);
    form.reset({
      nome: plano.nome,
      descricao: plano.descricao ?? '',
      valor_mensal: Number(plano.valor_mensal),
      limite_customers: plano.limite_customers ?? undefined,
      limite_usuarios: plano.limite_usuarios ?? undefined,
      limite_instancias_whatsapp: plano.limite_instancias_whatsapp,
    });
    setFormOpen(true);
  }

  const saveMutation = useMutation({
    mutationFn: (values: PlanoFormValues) =>
      editing ? updatePlano(editing.id, values) : createPlano(values),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['master', 'planos'] });
      toast.success(editing ? 'Plano atualizado.' : 'Plano criado.');
      setFormOpen(false);
    },
    onError: (err) => {
      toast.error(err instanceof ApiError ? err.message : 'Não foi possível salvar o plano.');
    },
  });

  const deleteMutation = useMutation({
    mutationFn: (id: string) => deletePlano(id),
    onSuccess: (result) => {
      queryClient.invalidateQueries({ queryKey: ['master', 'planos'] });
      toast.success(
        result.deletado ? 'Plano excluído.' : 'Plano em uso por tenant(s) — desativado em vez de excluído.',
      );
      setDeleting(null);
    },
    onError: (err) => {
      toast.error(err instanceof ApiError ? err.message : 'Não foi possível excluir o plano.');
      setDeleting(null);
    },
  });

  const columns: DataTableColumn<Plano>[] = [
    { id: 'nome', header: 'Plano', primary: true, cell: (row) => row.nome },
    {
      id: 'valor',
      header: 'Valor mensal',
      cell: (row) => formatCurrency(row.valor_mensal),
    },
    {
      id: 'limites',
      header: 'Limites',
      cell: (row) => (
        <span className="text-muted-foreground">
          {row.limite_customers ?? '∞'} clientes · {row.limite_usuarios ?? '∞'} usuários ·{' '}
          {row.limite_instancias_whatsapp} WhatsApp
        </span>
      ),
    },
    {
      id: 'status',
      header: 'Status',
      primary: true,
      cell: (row) => (
        <Badge variant={row.ativo ? 'default' : 'outline'}>{row.ativo ? 'Ativo' : 'Inativo'}</Badge>
      ),
    },
  ];

  return (
    <div className="flex flex-col gap-6">
      <div className="flex flex-wrap items-center justify-between gap-4">
        <div>
          <h1 className="text-xl font-semibold text-foreground">Planos</h1>
          <p className="text-sm text-muted-foreground">Planos de assinatura oferecidos aos tenants</p>
        </div>
        <Button onClick={openCreate}>
          <Plus /> Novo plano
        </Button>
      </div>

      <DataTable
        columns={columns}
        data={planos ?? []}
        keyField={(row) => row.id}
        loading={isLoading}
        emptyTitle="Nenhum plano cadastrado"
        emptyDescription="Crie o primeiro plano para poder cadastrar tenants."
        emptyAction={
          <Button size="sm" onClick={openCreate}>
            Novo plano
          </Button>
        }
        rowActions={(row) => (
          <>
            <Button variant="ghost" size="sm" onClick={() => openEdit(row)}>
              Editar
            </Button>
            <Button variant="ghost" size="sm" onClick={() => setDeleting(row)}>
              Excluir
            </Button>
          </>
        )}
      />

      <ResponsiveDialog
        open={formOpen}
        onOpenChange={setFormOpen}
        title={editing ? 'Editar plano' : 'Novo plano'}
        footer={
          <>
            <Button variant="outline" onClick={() => setFormOpen(false)}>
              Cancelar
            </Button>
            <Button
              loading={saveMutation.isPending}
              onClick={form.handleSubmit((values) => saveMutation.mutate(values))}
            >
              Salvar
            </Button>
          </>
        }
      >
        <form
          className="flex flex-col gap-4 px-4 pb-4 sm:px-0 sm:pb-0"
          onSubmit={form.handleSubmit((values) => saveMutation.mutate(values))}
        >
          <FormField label="Nome" error={form.formState.errors.nome?.message} required>
            <Input {...form.register('nome')} />
          </FormField>
          <FormField label="Descrição" error={form.formState.errors.descricao?.message}>
            <Textarea rows={2} {...form.register('descricao')} />
          </FormField>
          <FormField
            label="Valor mensal (R$)"
            error={form.formState.errors.valor_mensal?.message}
            required
          >
            <Input
              type="number"
              step="0.01"
              min="0"
              {...form.register('valor_mensal', { valueAsNumber: true })}
            />
          </FormField>
          <div className="grid grid-cols-1 gap-4 sm:grid-cols-3">
            <FormField
              label="Limite de clientes"
              helpText="Vazio = ilimitado"
              error={form.formState.errors.limite_customers?.message}
            >
              <Input
                type="number"
                min="1"
                {...form.register('limite_customers', { setValueAs: toOptionalInt })}
              />
            </FormField>
            <FormField
              label="Limite de usuários"
              helpText="Vazio = ilimitado"
              error={form.formState.errors.limite_usuarios?.message}
            >
              <Input
                type="number"
                min="1"
                {...form.register('limite_usuarios', { setValueAs: toOptionalInt })}
              />
            </FormField>
            <FormField
              label="Instâncias WhatsApp"
              error={form.formState.errors.limite_instancias_whatsapp?.message}
            >
              <Input
                type="number"
                min="1"
                {...form.register('limite_instancias_whatsapp', { setValueAs: toOptionalInt })}
              />
            </FormField>
          </div>
        </form>
      </ResponsiveDialog>

      <ConfirmDialog
        open={deleting !== null}
        onOpenChange={(open) => !open && setDeleting(null)}
        title={`Excluir "${deleting?.nome}"?`}
        description="Se este plano estiver em uso por algum tenant não cancelado, ele será desativado em vez de excluído."
        confirmLabel="Excluir"
        destructive
        loading={deleteMutation.isPending}
        onConfirm={() => deleting && deleteMutation.mutate(deleting.id)}
      />
    </div>
  );
}