Form

npx chandra-asri-ui add form

"use client";

import { Label } from "@/app/components/ui/label";
import { cn } from "@/lib/utils";
import { Slot } from "@radix-ui/react-slot";
import * as React from "react";
import {
  Controller,
  FormProvider,
  useFormContext,
  useFormState,
  type ControllerProps,
  type FieldPath,
  type FieldValues,
} from "react-hook-form";

/**
 * Wraps react-hook-form so every field gets a consistent id/label/error
 * pattern — this is the only source of visual error state across forms in
 * the source bundle: Input/Textarea never change border color on error,
 * only FormLabel (turns red) and FormMessage (renders the error text) do.
 * Uses this project's own danger scale (`text-danger-70`) instead of the
 * source's theme-token `text-destructive`, matching how the rest of this
 * bundle sources color from the brand scale.
 */
export const Form = FormProvider;

type FormFieldContextValue<
  TFieldValues extends FieldValues = FieldValues,
  TName extends FieldPath<TFieldValues> = FieldPath<TFieldValues>,
> = {
  name: TName;
};

const FormFieldContext = React.createContext<FormFieldContextValue>(
  {} as FormFieldContextValue,
);

export function FormField<
  TFieldValues extends FieldValues = FieldValues,
  TName extends FieldPath<TFieldValues> = FieldPath<TFieldValues>,
>(props: ControllerProps<TFieldValues, TName>) {
  return (
    <FormFieldContext.Provider value={{ name: props.name }}>
      <Controller {...props} />
    </FormFieldContext.Provider>
  );
}

type FormItemContextValue = {
  id: string;
};

const FormItemContext = React.createContext<FormItemContextValue>(
  {} as FormItemContextValue,
);

export function useFormField() {
  const fieldContext = React.useContext(FormFieldContext);
  const itemContext = React.useContext(FormItemContext);
  const { getFieldState } = useFormContext();
  const formState = useFormState({ name: fieldContext.name });
  const fieldState = getFieldState(fieldContext.name, formState);

  if (!fieldContext) {
    throw new Error("useFormField should be used within <FormField>");
  }

  const { id } = itemContext;

  return {
    id,
    name: fieldContext.name,
    formItemId: `${id}-form-item`,
    formDescriptionId: `${id}-form-item-description`,
    formMessageId: `${id}-form-item-message`,
    ...fieldState,
  };
}

export const FormItem = React.forwardRef<
  HTMLDivElement,
  React.HTMLAttributes<HTMLDivElement>
>(({ className, ...props }, ref) => {
  const id = React.useId();
  return (
    <FormItemContext.Provider value={{ id }}>
      <div ref={ref} className={cn("space-y-2", className)} {...props} />
    </FormItemContext.Provider>
  );
});
FormItem.displayName = "FormItem";

export const FormLabel = React.forwardRef<
  React.ComponentRef<typeof Label>,
  React.ComponentPropsWithoutRef<typeof Label>
>(({ className, ...props }, ref) => {
  const { error, formItemId } = useFormField();
  return (
    <Label
      ref={ref}
      className={cn(error && "text-danger-70", className)}
      htmlFor={formItemId}
      {...props}
    />
  );
});
FormLabel.displayName = "FormLabel";

export const FormControl = React.forwardRef<
  HTMLElement,
  React.HTMLAttributes<HTMLElement>
>(({ ...props }, ref) => {
  const { error, formItemId, formDescriptionId, formMessageId } =
    useFormField();
  return (
    <Slot
      ref={ref}
      id={formItemId}
      aria-describedby={
        !error ? formDescriptionId : `${formDescriptionId} ${formMessageId}`
      }
      aria-invalid={!!error}
      {...props}
    />
  );
});
FormControl.displayName = "FormControl";

export const FormDescription = React.forwardRef<
  HTMLParagraphElement,
  React.HTMLAttributes<HTMLParagraphElement>
>(({ className, ...props }, ref) => {
  const { formDescriptionId } = useFormField();
  return (
    <p
      ref={ref}
      id={formDescriptionId}
      className={cn("text-muted text-[0.8rem]", className)}
      {...props}
    />
  );
});
FormDescription.displayName = "FormDescription";

export const FormMessage = React.forwardRef<
  HTMLParagraphElement,
  React.HTMLAttributes<HTMLParagraphElement>
>(({ className, children, ...props }, ref) => {
  const { error, formMessageId } = useFormField();
  const body = error ? String(error?.message ?? "") : children;

  if (!body) return null;

  return (
    <p
      ref={ref}
      id={formMessageId}
      className={cn("text-danger-70 text-[0.8rem] font-medium", className)}
      {...props}
    >
      {body}
    </p>
  );
});
FormMessage.displayName = "FormMessage";