import Foundation

enum APIError: Error, LocalizedError {
    case invalidResponse              // 不是 HTTPURLResponse / URL 构造失败
    case http(status: Int, detail: String?)
    case unauthorized                 // 401 且刷新失败 → 需重新登录
    case decoding(Error)
    case network(Error)

    var errorDescription: String? {
        switch self {
        case .invalidResponse:
            return "服务器响应异常"
        case .http(let status, let detail):
            // 后端返回中文 detail(友好提示)直接透出;英文/技术性 detail 按状态码给中文兜底
            if let detail, detail.contains(where: { !$0.isASCII }) {
                return detail
            }
            switch status {
            case 400: return "请求有误,请重试"
            case 401: return "登录已过期,请重新登录"
            case 403: return "账号状态异常,请联系客服"
            case 404: return "内容不存在"
            case 429: return "操作太频繁,请稍后再试"
            case 500...: return "服务器繁忙,请稍后重试"
            default: return "请求失败(\(status))"
            }
        case .unauthorized:
            return "登录已过期,请重新登录"
        case .decoding:
            return "数据解析失败"
        case .network(let e):
            return "网络异常:\(e.localizedDescription)"
        }
    }
}