/** Copy only after a user action; WebViews may not expose the async Clipboard API. */
export async function copyText(text: string): Promise<void> {
    if (navigator.clipboard?.writeText) {
        try {
            await navigator.clipboard.writeText(text);
            return;
        } catch {
            // Embedded browsers can deny the async API while allowing a selected copy.
        }
    }

    const active = document.activeElement;
    const selection = window.getSelection();
    const ranges = selection
        ? Array.from({ length: selection.rangeCount }, (_, index) =>
              selection.getRangeAt(index).cloneRange(),
          )
        : [];
    const inputSelection =
        active instanceof HTMLInputElement ||
        active instanceof HTMLTextAreaElement
            ? ([
                  active.selectionStart,
                  active.selectionEnd,
                  active.selectionDirection,
              ] as const)
            : null;
    const field = document.createElement('textarea');
    field.value = text;
    field.readOnly = true;
    field.style.cssText =
        'position:fixed;opacity:0;pointer-events:none;font-size:16px';
    (active?.closest('[role="dialog"]') ?? document.body).append(field);
    try {
        field.focus({ preventScroll: true });
        field.select();
        field.setSelectionRange(0, text.length);
        if (!document.execCommand('copy')) {
            throw new Error('Clipboard access unavailable');
        }
    } finally {
        field.remove();
        if (active instanceof HTMLElement) {
            active.focus({ preventScroll: true });
        }
        if (selection) {
            selection.removeAllRanges();
            ranges.forEach((range) => selection.addRange(range));
        }
        if (
            inputSelection &&
            inputSelection[0] !== null &&
            inputSelection[1] !== null &&
            (active instanceof HTMLInputElement ||
                active instanceof HTMLTextAreaElement)
        ) {
            active.setSelectionRange(
                inputSelection[0],
                inputSelection[1],
                inputSelection[2] ?? undefined,
            );
        }
    }
}