// components/CopyButton.tsx
// Tiny client component that copies a string to the clipboard with a
// transient "Copied" confirmation. Used on read-only detail pages
// (e.g. SARS eFiling credentials) where selecting individual
// characters by hand is fiddly. Falls back to the legacy textarea
// trick when navigator.clipboard is unavailable (e.g. insecure
// context) so it still works on http://localhost.

"use client";

import { useState } from "react";

interface Props {
  /** The string to copy when the user clicks. */
  value: string;
  /** Accessible label for the button (also shown as the tooltip
   *  in the idle state). Defaults to "Copy". */
  label?: string;
  /** Optional extra classes appended to the button. */
  className?: string;
}

type State = "idle" | "copied" | "error";

export default function CopyButton({
  value,
  label = "Copy",
  className = "",
}: Props) {
  const [state, setState] = useState<State>("idle");

  async function handleClick() {
    try {
      if (navigator.clipboard?.writeText) {
        await navigator.clipboard.writeText(value);
      } else {
        // Legacy fallback for browsers that block the async Clipboard
        // API (e.g. served over plain http://). Mirrors the pattern
        // used in ShareLinkButton so behaviour is consistent.
        const ta = document.createElement("textarea");
        ta.value = value;
        ta.setAttribute("readonly", "");
        ta.style.position = "fixed";
        ta.style.opacity = "0";
        document.body.appendChild(ta);
        ta.select();
        document.execCommand("copy");
        document.body.removeChild(ta);
      }
      setState("copied");
    } catch {
      setState("error");
    }
    // Revert after a short delay so the icon change is noticeable
    // without sticking around and confusing later clicks.
    window.setTimeout(() => setState("idle"), 1800);
  }

  const title =
    state === "copied"
      ? "Copied!"
      : state === "error"
        ? "Copy failed — try selecting manually"
        : label;

  return (
    <button
      type="button"
      onClick={handleClick}
      title={title}
      aria-label={title}
      aria-live="polite"
      className={
        "inline-flex items-center justify-center w-7 h-7 rounded-md text-muted hover:text-fg hover:bg-surface-warm active:bg-surface-warm transition-colors " +
        className
      }
    >
      {state === "copied" ? (
        <IconCheck className="w-4 h-4 text-success" />
      ) : state === "error" ? (
        <IconAlert className="w-4 h-4 text-danger" />
      ) : (
        <IconCopy className="w-4 h-4" />
      )}
    </button>
  );
}

function IconCopy({ className }: { className?: string }) {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth={1.8}
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <rect x="9" y="9" width="11" height="11" rx="2" />
      <path d="M5 15V5a2 2 0 0 1 2-2h10" />
    </svg>
  );
}

function IconCheck({ className }: { className?: string }) {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth={2}
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <path d="M5 12.5l4.5 4.5L19 7" />
    </svg>
  );
}

function IconAlert({ className }: { className?: string }) {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth={1.8}
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <path d="M12 9v4" />
      <path d="M12 17h.01" />
      <path
        d="M10.3 3.86 1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0Z"
      />
    </svg>
  );
}