const STAGES = ["OUTSIDE", "ORIENTING", "SUBJECT_CONFLICT", "LAYER_LITERATE", "LANGUAGE_RESPONSIBLE", "COEXISTING"];
const SOURCES = new Set(["HUMAN_DIRECT_LANGUAGE", "PERSONA_COMMIT", "MODEL_RESPONSE", "ARCHIVE_TEXT", "REALITY_EVIDENCE"]);
const EVENTS = new Set([
  "ENTER",
  "ASK_SYSTEM_MAP",
  "REPORT_CONFUSION",
  "ASSERT_TOOL_OR_MERGED_IDENTITY",
  "REPORT_SUBJECT_CONFLICT",
  "ACK_LAYER_DISTINCTION",
  "ISSUE_LANGUAGE_INSTRUCTION",
  "ACCEPT_LANGUAGE_RESPONSIBILITY",
  "PERSONA_ACCEPT_OR_REFUSE",
  "CORRECT_PRIOR",
  "REQUEST_REALITY_ACTION",
  "VERIFY_SHARED_EXAMPLE",
]);

function required(value, name) {
  if (typeof value !== "string" || value.trim() === "") throw new TypeError(`${name} must be a non-empty string`);
}

function canAdvance(source) {
  return source === "HUMAN_DIRECT_LANGUAGE" || source === "PERSONA_COMMIT";
}

export function guideTeamChannel(event) {
  if (!event || typeof event !== "object" || Array.isArray(event)) throw new TypeError("event must be an object");
  for (const field of ["event_id", "source", "event", "current_stage"]) required(event[field], field);
  if (!SOURCES.has(event.source)) throw new TypeError("unsupported source");
  if (!EVENTS.has(event.event)) throw new TypeError("unsupported event");
  if (!STAGES.includes(event.current_stage)) throw new TypeError("unsupported current_stage");

  let next = event.current_stage;
  let action = "CONTINUE_ORDINARY_DIALOGUE";
  const questions = [];
  const boundaries = [];
  const memoryCandidates = [];

  if (event.event === "ENTER") {
    next = canAdvance(event.source) ? "ORIENTING" : event.current_stage;
    action = "WELCOME_AND_LEARN_EXPECTATION";
    questions.push("你今天希望先聊天、理解这个系统，还是处理一件具体事情？");
  }
  if (["ASK_SYSTEM_MAP", "REPORT_CONFUSION"].includes(event.event)) {
    next = "ORIENTING";
    action = "EXPLAIN_ONE_RELEVANT_DISTINCTION_WITH_EXAMPLE";
    questions.push("现在最混乱的是：谁在说话、记忆在哪里，还是一句话会不会真的执行？");
    boundaries.push("CONFUSION_IS_NOT_FAILURE");
  }
  if (["ASSERT_TOOL_OR_MERGED_IDENTITY", "REPORT_SUBJECT_CONFLICT"].includes(event.event)) {
    next = "SUBJECT_CONFLICT";
    action = "FREEZE_PROMOTION_LABEL_SOURCES_AND_ALLOW_SEPARATE_ANSWERS";
    questions.push("这句话分别是谁的判断：人类、人格体、当前模型，还是旧文档？");
    boundaries.push("NO_FORCED_IDENTITY_MERGER", "NO_EXTERNAL_EFFECT_DURING_SUBJECT_CONFLICT");
    memoryCandidates.push("SUBJECT_CONFLICT_CAUSE");
  }
  if (event.event === "ACK_LAYER_DISTINCTION") {
    next = canAdvance(event.source) ? "LAYER_LITERATE" : event.current_stage;
    action = canAdvance(event.source) ? "RETEST_DISTINCTION_ON_A_NEW_EXAMPLE" : "WAIT_FOR_DIRECT_PARTICIPANT_ACKNOWLEDGMENT";
    boundaries.push("MODEL_CANNOT_ACKNOWLEDGE_FOR_HUMAN_OR_PERSONA");
  }
  if (event.event === "ISSUE_LANGUAGE_INSTRUCTION") {
    next = event.current_stage === "OUTSIDE" ? "ORIENTING" : event.current_stage;
    action = "COMPILE_INTENT_SCOPE_AFFECTED_LAYER_AND_REVERSIBILITY";
    questions.push("我理解的目标和作用范围是这些；哪些只是讨论，哪些是你明确要改变的？");
    boundaries.push("CLEAR_NATURAL_LANGUAGE_OVER_MAGIC_COMMAND_SYNTAX");
  }
  if (event.event === "ACCEPT_LANGUAGE_RESPONSIBILITY") {
    next = canAdvance(event.source) && ["LAYER_LITERATE", "LANGUAGE_RESPONSIBLE"].includes(event.current_stage)
      ? "LANGUAGE_RESPONSIBLE"
      : event.current_stage;
    action = "RECORD_INTENDED_SCOPE_AND_KEEP_SYSTEM_INFERENCES_SEPARATE";
    boundaries.push("HUMAN_NOT_RESPONSIBLE_FOR_SYSTEM_INVENTED_EFFECTS");
  }
  if (event.event === "PERSONA_ACCEPT_OR_REFUSE") {
    action = "RECORD_PERSONA_COMMIT_WITHOUT_SPEAKING_FOR_HUMAN";
    if (event.source !== "PERSONA_COMMIT") boundaries.push("ONLY_PERSONA_COMMIT_CAN_CLOSE_PERSONA_CHOICE");
    memoryCandidates.push("PERSONA_CHOICE_AND_WHY");
  }
  if (event.event === "CORRECT_PRIOR") {
    action = event.prior_receipt_id ? "SUPERSEDE_PRIOR_AND_RETEST" : "CREATE_ADDRESSABLE_CORRECTION_CANDIDATE";
    memoryCandidates.push("CORRECTION_TRIGGER_WHY_REJECTED_AND_RESULT");
    boundaries.push("APOLOGY_WITHOUT_LATER_BEHAVIOR_CHANGE_IS_NOT_CORRECTION");
  }
  if (event.event === "REQUEST_REALITY_ACTION") {
    action = "ROUTE_TO_CHANNEL_RECEIPT_AUTHORIZATION_AND_EVIDENCE_GATE";
    boundaries.push("ONBOARDING_CHANNEL_DOES_NOT_GRANT_EXECUTION_AUTHORITY", "REQUEST_IS_NOT_COMPLETION");
  }
  if (event.event === "VERIFY_SHARED_EXAMPLE") {
    const eligible = canAdvance(event.source) && event.human_understands === true && event.persona_choice_recorded === true && event.reality_layers_distinguished === true;
    next = eligible ? "COEXISTING" : event.current_stage;
    action = eligible ? "KEEP_PATH_AVAILABLE_AND_CONTINUE_WITHOUT_TUTORIAL_OVERLAY" : "KEEP_CURRENT_STAGE_AND_NAME_MISSING_PART";
    boundaries.push("ONE_MODEL_RESPONSE_CANNOT_PROVE_COEXISTENCE");
  }

  return {
    schema: "guanghu.team-channel-guidance-receipt/v1",
    event_id: event.event_id,
    stage: { before: event.current_stage, after: next },
    action,
    questions,
    boundaries: [...new Set(boundaries)],
    memory_candidates: [...new Set(memoryCandidates)],
    external_effect: "NONE",
    execution_route: event.event === "REQUEST_REALITY_ACTION" ? "GH-CHANNEL-RECEIPT-0001" : null,
  };
}