/**
 * AI 生成失败的普通用户展示层。
 *
 * 页面只消费这里的稳定 code，不解析供应商名称、HTTP 状态、URL 或英文异常。
 * 本文件不发请求、不依赖 React，后续脚本/图片/视频页面可按需接入。
 */

export type GenerationOperation =
  | "script_generate"
  | "image_generate"
  | "base_asset_generate"
  | "triview_generate"
  | "storyboard_generate"
  | "video_generate"
  | "voiceover_generate"
  | "entity_extract";

export type GenerationErrorCode =
  | "provider_quota_exhausted"
  | "provider_rate_limited"
  | "provider_unavailable"
  | "provider_config_error"
  | "model_unavailable"
  | "content_rejected"
  | "invalid_input"
  | "asset_unavailable"
  | "user_credit_insufficient"
  | "task_timeout"
  | "processing_failed"
  | "unknown";

export type GenerationErrorAction = "retry" | "retry_later" | "revise_input" | "recharge" | "contact_support" | "none";

export type PublicGenerationError = {
  domain: "generation";
  code: GenerationErrorCode;
  operation: GenerationOperation;
  action: GenerationErrorAction;
  retryable: boolean;
  reference_id?: string;
};

export type GenerationErrorPresentation = {
  title: string;
  description: string;
  action: GenerationErrorAction;
  retryable: boolean;
  referenceId?: string;
};

const OPERATION_LABEL: Record<GenerationOperation, string> = {
  script_generate: "脚本",
  image_generate: "图片",
  base_asset_generate: "基础素材",
  triview_generate: "三视图",
  storyboard_generate: "故事板",
  video_generate: "视频",
  voiceover_generate: "配音",
  entity_extract: "脚本信息"
};

type Copy = (operation: string) => Pick<GenerationErrorPresentation, "title" | "description">;

const ERROR_COPY: Record<GenerationErrorCode, Copy> = {
  provider_quota_exhausted: (operation) => ({ title: `${operation}暂时不可用`, description: "生成服务正在处理中，请稍后再试。" }),
  provider_rate_limited: (operation) => ({ title: `${operation}请求较多`, description: "当前生成请求较多，请稍后再试。" }),
  provider_unavailable: (operation) => ({ title: `${operation}暂时不可用`, description: "生成服务暂时不可用，请稍后重试。" }),
  provider_config_error: (operation) => ({ title: `${operation}暂时不可用`, description: "平台正在处理该问题，请稍后再试。" }),
  model_unavailable: (operation) => ({ title: `${operation}暂时不可用`, description: "当前生成能力暂不可用，请稍后再试。" }),
  content_rejected: (operation) => ({ title: `${operation}内容需要调整`, description: "内容未通过生成审核，请调整描述或素材后重试。" }),
  invalid_input: (operation) => ({ title: `${operation}内容需检查`, description: "请检查描述、参数或素材格式后重试。" }),
  asset_unavailable: () => ({ title: "引用素材当前不可用", description: "请重新上传或更换素材后重试。" }),
  user_credit_insufficient: () => ({ title: "可用积分不足", description: "充值后可继续生成。" }),
  task_timeout: (operation) => ({ title: `${operation}生成时间过长`, description: "服务响应较慢，未完成生成，请重试。" }),
  processing_failed: (operation) => ({ title: `${operation}结果处理失败`, description: "本次未生成可用结果，请重试。" }),
  unknown: (operation) => ({ title: `${operation}遇到问题`, description: "请稍后重试；若多次出现，请提供任务编号以便排查。" })
};

export function isPublicGenerationError(value: unknown): value is PublicGenerationError {
  if (!value || typeof value !== "object") return false;
  const candidate = value as Partial<PublicGenerationError>;
  return candidate.domain === "generation"
    && typeof candidate.code === "string" && Object.hasOwn(ERROR_COPY, candidate.code)
    && typeof candidate.operation === "string" && Object.hasOwn(OPERATION_LABEL, candidate.operation)
    && typeof candidate.action === "string"
    && typeof candidate.retryable === "boolean";
}

export function presentGenerationError(error: PublicGenerationError): GenerationErrorPresentation {
  const copy = ERROR_COPY[error.code] ?? ERROR_COPY.unknown;
  return {
    ...copy(OPERATION_LABEL[error.operation] ?? "生成"),
    action: error.action,
    retryable: error.retryable,
    referenceId: error.reference_id
  };
}

export function generationErrorText(error: unknown, fallback: string): string {
  if (!isPublicGenerationError(error)) return fallback;
  const presentation = presentGenerationError(error);
  return `${presentation.title}：${presentation.description}`;
}