/**
 * Concrete finish reasons for rectification Agent runs.
 *
 * Incomplete turns must not be described only as “请稍后再试”. The code is
 * durable; the Chinese copy is for the live client and is not persisted as a
 * chat message.
 */

export const RECTIFICATION_FINISH_REASONS = [
  "stop",
  "tool_calls",
  "length",
  "timeout",
  "max_steps",
  "provider_error",
  "aborted",
  "unknown",
] as const;

export type RectificationFinishReason = (typeof RECTIFICATION_FINISH_REASONS)[number];

export type RectificationRunDiagnostic = Readonly<{
  runId: string;
  modelId: string;
  finishReason: RectificationFinishReason;
  inputTokens: number | null;
  reasoningTokens: number | null;
  outputTokens: number | null;
  stepCount: number;
  toolCallCount: number;
  readCasePayloadBytes: number | null;
  elapsedMs: number;
  lastCompletedTool: string | null;
  stateMutationCommitted: boolean;
  expectedWrite: "evidence" | "none" | "unknown" | null;
  collectIntent: "classified" | "unclassified" | null;
}>;

const USER_COPY: Readonly<Record<string, string>> = {
  answer_truncated: "模型输出达到上限，状态已记录。",
  length: "模型输出达到上限，状态已记录。",
  run_timeout: "服务端运行超时，状态已记录。",
  timeout: "服务端运行超时，状态已记录。",
  stream_aborted: "服务端运行超时，状态已记录。",
  stream_unfinished: "服务端运行超时，状态已记录。",
  max_steps: "本轮达到步骤上限，状态已记录。",
  tool_calls: "本轮达到步骤上限，状态已记录。",
  provider_error: "上游模型连接失败，状态已记录。",
  run_failed: "上游模型连接失败，状态已记录。",
  empty_stream: "本轮没有生成可展示的回复，状态已记录。",
  evidence_not_written: "这件我还没记上。请再说一次大概年月和发生的事。",
};

export function finishReasonFromErrorCode(errorCode: string | null | undefined): RectificationFinishReason {
  if (errorCode === "answer_truncated") return "length";
  if (errorCode === "run_timeout" || errorCode === "stream_unfinished") return "timeout";
  if (errorCode === "stream_aborted") return "aborted";
  if (errorCode === "max_steps") return "max_steps";
  if (errorCode === "provider_error" || errorCode === "run_failed") return "provider_error";
  return "unknown";
}

export function userFacingRunFailure(errorCode: string | null | undefined): string {
  if (!errorCode) return "本轮没有完成，状态已记录。";
  return USER_COPY[errorCode] ?? "本轮没有完成，状态已记录。";
}

export function isIncompleteRunBanner(text: string): boolean {
  return /本轮处理未完成|当前进度已保留|请稍后再试/.test(text);
}

export function mapModelFinishToErrorCode(input: {
  finishReason: string | null;
  aborted: boolean;
  timedOut: boolean;
  answerText: string;
  stepCount: number;
  maxSteps: number;
}): string | null {
  if (input.timedOut) return "run_timeout";
  if (input.aborted) return "stream_aborted";
  if (input.finishReason === "length") return "answer_truncated";
  if (input.finishReason === "error") return "provider_error";
  if (
    (input.finishReason === "tool-calls" || input.finishReason === "tool_calls")
    && !input.answerText.trim()
  ) {
    return "max_steps";
  }
  if (input.stepCount >= input.maxSteps && !input.answerText.trim()) return "max_steps";
  return null;
}