/**
 * User-visible run termination copy for Feishu teachers.
 * Keep messages short, actionable, and free of stack traces.
 */

export interface RunOutcomeNoticeInput {
  readonly wallTimeExceeded: boolean;
  readonly interrupted: boolean;
  readonly resultStatus: string;
  readonly resultError: string | undefined;
  readonly maxTurns: number;
  readonly maxRunSeconds: number;
  readonly hasPartialText: boolean;
}

export interface RunOutcomeNotice {
  /** Mark the streaming card as failed (red footer). */
  readonly isError: boolean;
  /**
   * Teacher-facing explanation. Appended after any partial answer text so the
   * cause of a stop is never silent.
   */
  readonly notice: string | undefined;
}

export function teacherFacingRunOutcome(input: RunOutcomeNoticeInput): RunOutcomeNotice {
  if (input.wallTimeExceeded) {
    return {
      isError: true,
      notice: noticeLine(
        input.hasPartialText,
        `\u23F1 \u4EFB\u52A1\u8D85\u65F6\uFF1A\u5DF2\u8FBE\u5230\u5355\u6B21\u8FD0\u884C\u65F6\u95F4\u4E0A\u9650\uFF08${input.maxRunSeconds} \u79D2\uFF09\u3002\u8BF7\u62C6\u5206\u4EFB\u52A1\u540E\u91CD\u8BD5\uFF0C\u6216\u8054\u7CFB\u7BA1\u7406\u5458\u8C03\u9AD8\u8FD0\u884C\u65F6\u957F\u4E0A\u9650\u3002`,
      ),
    };
  }

  if (input.interrupted) {
    return { isError: false, notice: undefined };
  }

  if (input.resultStatus === "completed") {
    return { isError: false, notice: undefined };
  }

  const err = input.resultError ?? "";
  if (isMaxTurnsError(err) || input.resultStatus === "length") {
    return {
      isError: true,
      notice: noticeLine(
        input.hasPartialText,
        `\u26A0\uFE0F \u4EFB\u52A1\u4E2D\u65AD\uFF1A\u5DF2\u8FBE\u5230\u6700\u5927\u6B65\u9AA4\u6570\uFF08${input.maxTurns} \u8F6E\uFF09\u3002\u8BF7\u62C6\u5206\u4EFB\u52A1\u540E\u7EE7\u7EED\uFF0C\u6216\u8054\u7CFB\u7BA1\u7406\u5458\u8C03\u9AD8\u6B65\u9AA4\u4E0A\u9650\u3002`,
      ),
    };
  }

  if (err.trim() !== "") {
    const brief = sanitizeErrorBrief(err);
    return {
      isError: true,
      notice: noticeLine(
        input.hasPartialText,
        `\u274C \u4EFB\u52A1\u5931\u8D25\uFF1A${brief}\u3002\u8BF7\u91CD\u8BD5\uFF1B\u82E5\u591A\u6B21\u51FA\u73B0\u8BF7\u8054\u7CFB\u7BA1\u7406\u5458\u3002`,
      ),
    };
  }

  return {
    isError: true,
    notice: noticeLine(
      input.hasPartialText,
      "\u274C \u4EFB\u52A1\u672A\u6B63\u5E38\u5B8C\u6210\u3002\u8BF7\u91CD\u8BD5\uFF1B\u82E5\u591A\u6B21\u51FA\u73B0\u8BF7\u8054\u7CFB\u7BA1\u7406\u5458\u3002",
    ),
  };
}

export function appendTeacherNotice(body: string, notice: string | undefined): string {
  if (notice === undefined || notice === "") return body;
  if (body.trim() === "") return notice;
  return `${body.trimEnd()}\n\n${notice}`;
}

export function isMaxTurnsError(error: string): boolean {
  const lower = error.toLowerCase();
  return (
    lower.includes("maximum number of turns") ||
    lower.includes("max_turns") ||
    lower.includes("error_max_turns") ||
    lower.includes("result_error_max_turns") ||
    (lower.includes("result_error_during_execution") && lower.includes("turn"))
  );
}

function noticeLine(hasPartialText: boolean, message: string): string {
  if (!hasPartialText) return message;
  return `${message}\n\uFF08\u4E0A\u65B9\u4E3A\u5DF2\u751F\u6210\u7684\u90E8\u5206\u7ED3\u679C\u3002\uFF09`;
}

function sanitizeErrorBrief(error: string): string {
  const oneLine = error.replace(/\s+/g, " ").trim();
  // Drop common SDK prefixes for readability.
  const stripped = oneLine
    .replace(/^Claude Code returned an error result:\s*/i, "")
    .replace(/^Error:\s*/i, "");
  if (stripped.length <= 160) return stripped;
  return `${stripped.slice(0, 157)}...`;
}