feat: complete stage 1 infrastructure

src/components/ui/form.tsx

@@ -0,0 +1,165 @@
+import * as React from "react";
+import * as LabelPrimitive from "@radix-ui/react-label";
+import { Slot } from "@radix-ui/react-slot";
+import {
+  Controller,
+  FormProvider,
+  useFormContext,
+  type ControllerProps,
+  type FieldPath,
+  type FieldValues,
+} from "react-hook-form";
+import { cn } from "@/lib/utils";
+
+const Form = FormProvider;
+
+type FormFieldContextValue<
+  TFieldValues extends FieldValues = FieldValues,
+  TName extends FieldPath<TFieldValues> = FieldPath<TFieldValues>
+> = {
+  name: TName;
+};
+
+const FormFieldContext = React.createContext<FormFieldContextValue>(
+  {} as FormFieldContextValue
+);
+
+const 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>
+  );
+};
+
+const useFormField = () => {
+  const fieldContext = React.useContext(FormFieldContext);
+  const itemContext = React.useContext(FormItemContext);
+  const { getFieldState, formState } = useFormContext();
+
+  const fieldState = getFieldState(fieldContext.name, formState);
+
+  if (!fieldContext) {
+    throw new Error("useFormField should be used within <FormField>");
+  }
+
+  const id = itemContext.id;
+
+  return {
+    id,
+    name: fieldContext.name,
+    formItemId: `${id}-form-item`,
+    formDescriptionId: `${id}-form-item-description`,
+    formMessageId: `${id}-form-item-message`,
+    ...fieldState,
+  };
+};
+
+const FormItemContext = React.createContext<{ id: string }>(
+  {} as { id: string }
+);
+
+const FormItem = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => {
+  const id = React.useId();
+
+  return (
+    <FormItemContext.Provider value={{ id }}>
+      <div ref={ref} className={cn("space-y-2", className)} {...props} />
+    </FormItemContext.Provider>
+  );
+});
+FormItem.displayName = "FormItem";
+
+const FormLabel = React.forwardRef<
+  React.ElementRef<typeof LabelPrimitive.Root>,
+  React.ComponentPropsWithoutRef<typeof LabelPrimitive.Root>
+>(({ className, ...props }, ref) => {
+  const { error, formItemId } = useFormField();
+
+  return (
+    <LabelPrimitive.Root
+      ref={ref}
+      className={cn(error && "text-destructive", className)}
+      htmlFor={formItemId}
+      {...props}
+    />
+  );
+});
+FormLabel.displayName = LabelPrimitive.Root.displayName;
+
+const FormControl = React.forwardRef<
+  React.ElementRef<typeof Slot>,
+  React.ComponentPropsWithoutRef<typeof Slot>
+>(({ ...props }, ref) => {
+  const { formItemId, formDescriptionId, formMessageId } = useFormField();
+
+  return (
+    <Slot
+      ref={ref}
+      id={formItemId}
+      aria-describedby={`${formDescriptionId} ${formMessageId}`}
+      {...props}
+    />
+  );
+});
+FormControl.displayName = "FormControl";
+
+const FormDescription = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLParagraphElement>
+>(({ className, ...props }, ref) => {
+  const { formDescriptionId } = useFormField();
+
+  return (
+    <p
+      ref={ref}
+      id={formDescriptionId}
+      className={cn("text-sm text-muted-foreground", className)}
+      {...props}
+    />
+  );
+});
+FormDescription.displayName = "FormDescription";
+
+const FormMessage = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLParagraphElement>
+>(({ className, children, ...props }, ref) => {
+  const { error, formMessageId } = useFormField();
+  const body = error?.message ?? children;
+
+  if (!body) {
+    return null;
+  }
+
+  return (
+    <p
+      ref={ref}
+      id={formMessageId}
+      className={cn("text-sm font-medium text-destructive", className)}
+      {...props}
+    >
+      {body}
+    </p>
+  );
+});
+FormMessage.displayName = "FormMessage";
+
+export {
+  Form,
+  FormField,
+  FormItem,
+  FormLabel,
+  FormControl,
+  FormDescription,
+  FormMessage,
+  useFormField,
+};