"use client";

import {
  createBudgetAction,
  updateBudgetAction,
} from "@/app/(dashboard)/orcamentos/actions";
import { CategoryIcon } from "@/components/categorias/category-icon";
import { Button } from "@/components/ui/button";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from "@/components/ui/dialog";
import { CurrencyInput } from "@/components/ui/currency-input";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import { Label } from "@/components/ui/label";
import { useControlledState } from "@/hooks/use-controlled-state";
import { useFormState } from "@/hooks/use-form-state";
import {
  useCallback,
  useEffect,
  useMemo,
  useState,
  useTransition,
} from "react";
import { toast } from "sonner";

import type { Budget, BudgetCategory, BudgetFormValues } from "./types";

interface BudgetDialogProps {
  mode: "create" | "update";
  trigger?: React.ReactNode;
  budget?: Budget;
  categories: BudgetCategory[];
  defaultPeriod: string;
  open?: boolean;
  onOpenChange?: (open: boolean) => void;
}

type SelectOption = {
  value: string;
  label: string;
};

const monthFormatter = new Intl.DateTimeFormat("pt-BR", {
  month: "long",
  year: "numeric",
});

const formatPeriodLabel = (period: string) => {
  const [year, month] = period.split("-").map(Number);
  if (!year || !month) {
    return period;
  }
  const date = new Date(year, month - 1, 1);
  if (Number.isNaN(date.getTime())) {
    return period;
  }
  const label = monthFormatter.format(date);
  return label.charAt(0).toUpperCase() + label.slice(1);
};

const buildPeriodOptions = (currentValue?: string): SelectOption[] => {
  const now = new Date();
  const options: SelectOption[] = [];

  for (let offset = -3; offset <= 3; offset += 1) {
    const date = new Date(now.getFullYear(), now.getMonth() + offset, 1);
    const value = `${date.getFullYear()}-${String(date.getMonth() + 1).padStart(
      2,
      "0"
    )}`;
    options.push({ value, label: formatPeriodLabel(value) });
  }

  if (
    currentValue &&
    !options.some((option) => option.value === currentValue)
  ) {
    options.push({
      value: currentValue,
      label: formatPeriodLabel(currentValue),
    });
  }

  return options
    .sort((a, b) => a.value.localeCompare(b.value))
    .map((option) => ({
      value: option.value,
      label: option.label,
    }));
};

const buildInitialValues = ({
  budget,
  defaultPeriod,
}: {
  budget?: Budget;
  defaultPeriod: string;
}): BudgetFormValues => ({
  categoriaId: budget?.category?.id ?? "",
  period: budget?.period ?? defaultPeriod,
  amount: budget ? (Math.round(budget.amount * 100) / 100).toFixed(2) : "",
});

export function BudgetDialog({
  mode,
  trigger,
  budget,
  categories,
  defaultPeriod,
  open,
  onOpenChange,
}: BudgetDialogProps) {
  const [errorMessage, setErrorMessage] = useState<string | null>(null);
  const [isPending, startTransition] = useTransition();

  // Use controlled state hook for dialog open state
  const [dialogOpen, setDialogOpen] = useControlledState(
    open,
    false,
    onOpenChange
  );

  const initialState = useMemo(
    () =>
      buildInitialValues({
        budget,
        defaultPeriod,
      }),
    [budget, defaultPeriod]
  );

  // Use form state hook for form management
  const { formState, updateField, setFormState } =
    useFormState<BudgetFormValues>(initialState);

  // Reset form when dialog opens
  useEffect(() => {
    if (dialogOpen) {
      setFormState(initialState);
      setErrorMessage(null);
    }
  }, [dialogOpen, initialState, setFormState]);

  // Clear error when dialog closes
  useEffect(() => {
    if (!dialogOpen) {
      setErrorMessage(null);
    }
  }, [dialogOpen]);

  const periodOptions = useMemo(
    () => buildPeriodOptions(formState.period),
    [formState.period]
  );

  const handleSubmit = useCallback(
    (event: React.FormEvent<HTMLFormElement>) => {
      event.preventDefault();
      setErrorMessage(null);

      if (mode === "update" && !budget?.id) {
        const message = "Orçamento inválido.";
        setErrorMessage(message);
        toast.error(message);
        return;
      }

      if (formState.categoriaId.length === 0) {
        const message = "Selecione uma categoria.";
        setErrorMessage(message);
        toast.error(message);
        return;
      }

      if (formState.period.length === 0) {
        const message = "Informe o período.";
        setErrorMessage(message);
        toast.error(message);
        return;
      }

      if (formState.amount.length === 0) {
        const message = "Informe o valor limite.";
        setErrorMessage(message);
        toast.error(message);
        return;
      }

      const payload = {
        categoriaId: formState.categoriaId,
        period: formState.period,
        amount: formState.amount,
      };

      startTransition(async () => {
        const result =
          mode === "create"
            ? await createBudgetAction(payload)
            : await updateBudgetAction({
                id: budget?.id ?? "",
                ...payload,
              });

        if (result.success) {
          toast.success(result.message);
          setDialogOpen(false);
          setFormState(initialState);
          return;
        }

        setErrorMessage(result.error);
        toast.error(result.error);
      });
    },
    [budget?.id, formState, initialState, mode, setDialogOpen, setFormState]
  );

  const title = mode === "create" ? "Novo orçamento" : "Editar orçamento";
  const description =
    mode === "create"
      ? "Defina um limite de gastos para acompanhar suas despesas."
      : "Atualize os detalhes do orçamento selecionado.";
  const submitLabel =
    mode === "create" ? "Salvar orçamento" : "Atualizar orçamento";
  const disabled = categories.length === 0;

  return (
    <Dialog open={dialogOpen} onOpenChange={setDialogOpen}>
      {trigger ? <DialogTrigger asChild>{trigger}</DialogTrigger> : null}
      <DialogContent>
        <DialogHeader>
          <DialogTitle>{title}</DialogTitle>
          <DialogDescription>{description}</DialogDescription>
        </DialogHeader>

        {disabled ? (
          <div className="space-y-4">
            <div className="rounded-lg border border-dashed bg-muted/10 p-4 text-sm text-muted-foreground">
              Cadastre pelo menos uma categoria de despesa para criar um
              orçamento.
            </div>
            <DialogFooter className="gap-3">
              <Button
                type="button"
                variant="outline"
                onClick={() => setDialogOpen(false)}
              >
                Fechar
              </Button>
            </DialogFooter>
          </div>
        ) : (
          <form className="space-y-4" onSubmit={handleSubmit}>
            <div className="space-y-2">
              <Label htmlFor="budget-category">Categoria</Label>
              <Select
                value={formState.categoriaId}
                onValueChange={(value) => updateField("categoriaId", value)}
              >
                <SelectTrigger id="budget-category" className="w-full">
                  <SelectValue placeholder="Selecione uma categoria" />
                </SelectTrigger>
                <SelectContent>
                  {categories.map((category) => (
                    <SelectItem key={category.id} value={category.id}>
                      <CategoryIcon
                        name={category.icon ?? undefined}
                        className="size-4"
                      />
                      <span>{category.name}</span>
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>

            <div className="grid gap-4 sm:grid-cols-2">
              <div className="space-y-2">
                <Label htmlFor="budget-period">Período</Label>
                <Select
                  value={formState.period}
                  onValueChange={(value) => updateField("period", value)}
                >
                  <SelectTrigger id="budget-period" className="w-full">
                    <SelectValue placeholder="Selecione o período" />
                  </SelectTrigger>
                  <SelectContent className="max-h-64">
                    {periodOptions.map((option) => (
                      <SelectItem key={option.value} value={option.value}>
                        {option.label}
                      </SelectItem>
                    ))}
                  </SelectContent>
                </Select>
              </div>

              <div className="space-y-2">
                <Label htmlFor="budget-amount">Valor limite</Label>
                <CurrencyInput
                  id="budget-amount"
                  placeholder="R$ 0,00"
                  value={formState.amount}
                  onValueChange={(value) => updateField("amount", value)}
                />
              </div>
            </div>

            {errorMessage ? (
              <p className="text-sm font-medium text-destructive">
                {errorMessage}
              </p>
            ) : null}

            <DialogFooter className="gap-3">
              <Button
                type="button"
                variant="outline"
                onClick={() => setDialogOpen(false)}
                disabled={isPending}
              >
                Cancelar
              </Button>
              <Button type="submit" disabled={isPending}>
                {isPending ? "Salvando..." : submitLabel}
              </Button>
            </DialogFooter>
          </form>
        )}
      </DialogContent>
    </Dialog>
  );
}