stack/packages/ui/src/components/Textarea.tsx

import { useState } from "react";
import type { TextareaHTMLAttributes, ReactElement } from "react";

export interface TextareaProps extends Omit<TextareaHTMLAttributes<HTMLTextAreaElement>, "size"> {
  label?: string;
  error?: string;
  helperText?: string;
  fullWidth?: boolean;
  resize?: "none" | "both" | "horizontal" | "vertical";
}

export function Textarea({
  label,
  error,
  helperText,
  fullWidth = false,
  resize = "vertical",
  className = "",
  id,
  style,
  onFocus,
  onBlur,
  ...props
}: TextareaProps): ReactElement {
  const [isFocused, setIsFocused] = useState(false);
  const textareaId = id ?? `textarea-${Math.random().toString(36).substring(2, 11)}`;
  const errorId = error ? `${textareaId}-error` : undefined;
  const helperId = helperText ? `${textareaId}-helper` : undefined;

  const resizeStyles: Record<string, string> = {
    none: "resize-none",
    both: "resize",
    horizontal: "resize-x",
    vertical: "resize-y",
  };

  const textareaStyle: React.CSSProperties = {
    background: "var(--bg-mid)",
    border: error
      ? `1px solid var(--danger)`
      : isFocused
        ? `1px solid var(--primary)`
        : `1px solid var(--border)`,
    color: "var(--text)",
    outline: "none",
    boxShadow: isFocused ? `0 0 0 2px rgba(47,128,255,0.2)` : "none",
    ...style,
  };

  const widthClass = fullWidth ? "w-full" : "";

  return (
    <div className={fullWidth ? "w-full" : ""}>
      {label && (
        <label
          htmlFor={textareaId}
          className="block text-sm font-medium mb-1"
          style={{ color: "var(--text-2)" }}
        >
          {label}
        </label>
      )}
      <textarea
        id={textareaId}
        className={`px-3 py-2 rounded-md transition-colors ${widthClass} ${resizeStyles[resize] ?? "resize-y"} ${className}`}
        style={textareaStyle}
        aria-invalid={error ? "true" : "false"}
        aria-describedby={[errorId, helperId].filter(Boolean).join(" ") || undefined}
        onFocus={(e) => {
          setIsFocused(true);
          onFocus?.(e);
        }}
        onBlur={(e) => {
          setIsFocused(false);
          onBlur?.(e);
        }}
        {...props}
      />
      {error && (
        <p id={errorId} className="mt-1 text-sm" style={{ color: "var(--danger)" }} role="alert">
          {error}
        </p>
      )}
      {helperText && !error && (
        <p id={helperId} className="mt-1 text-sm" style={{ color: "var(--muted)" }}>
          {helperText}
        </p>
      )}
    </div>
  );
}