import { h } from 'vue'
import { ElMessage, ElMessageBox } from 'element-plus'

/**
 * 将文本写入剪贴板。优先 Clipboard API，HTTP 等非安全上下文回退 execCommand。
 */
export async function copyTextToClipboard(text: string): Promise<boolean> {
  if (navigator.clipboard?.writeText) {
    try {
      await navigator.clipboard.writeText(text)
      return true
    } catch {
      // 权限拒绝或异步后丢失用户手势时，尝试 legacy 方式
    }
  }

  try {
    const textarea = document.createElement('textarea')
    textarea.value = text
    textarea.setAttribute('readonly', '')
    textarea.style.cssText = 'position:fixed;left:-9999px;top:0;opacity:0'
    document.body.appendChild(textarea)
    textarea.focus()
    textarea.select()
    const ok = document.execCommand('copy')
    document.body.removeChild(textarea)
    return ok
  } catch {
    return false
  }
}

/**
 * 复制文本；失败时弹窗展示内容供手动复制（适用于 HTTP 测试环境等受限场景）。
 */
export async function copyTextWithFallback(
  text: string,
  options?: { successMessage?: string; fallbackTitle?: string }
): Promise<void> {
  const ok = await copyTextToClipboard(text)
  if (ok) {
    ElMessage.success(options?.successMessage ?? '已复制到剪贴板')
    return
  }

  await ElMessageBox.alert(
    h('textarea', {
      value: text,
      readonly: true,
      style:
        'width:100%;min-height:88px;padding:8px 12px;border:1px solid var(--el-border-color);border-radius:8px;font-size:14px;line-height:1.5;resize:none;',
      onVnodeMounted(vnode) {
        const el = vnode.el as HTMLTextAreaElement | null
        el?.focus()
        el?.select()
      }
    }),
    options?.fallbackTitle ?? '请手动复制短信内容',
    {
      confirmButtonText: '关闭',
      customClass: 'copy-text-fallback-dialog'
    }
  )
}