/**
 * A tapped choice (answer, stop, skip this probe) from the rectification chat:
 * the local answered mark and live row, the structured POST, the transcript
 * merge after the Case re-read, the follow-up turn on the same row, and the
 * roll-back when the tap did not land (BUG-1046). Moved out of
 * RectificationAgenticChat's `submitStructuredChoice` unchanged
 * (TASK-rectification-code-split-20260926). A parameter function: the
 * component hands in its state, setters and refs; no React hooks here.
 */
import type { Dispatch, MutableRefObject, SetStateAction } from "react";
import type { ChatMessage } from "@/lib/chat-message-view";
import { emptyActivityTrace } from "@/lib/agent-activity-trace";
import { RECTIFICATION_ACTIVITY_PROGRESS_LABELS } from "@/lib/rectification-activity-labels";
import {
  RECTIFICATION_CHOICE_SUBMIT_FAILED_COPY,
  isAbortError,
} from "@/lib/rectification-surface-state";
import {
  CHOICE_ACTION,
  SKIP_PROBE_ACTION,
  STOP_ACTION,
  shouldContinueAfterStructuredChoice,
  type ChoiceOptionId,
} from "@/lib/rectification-agentic/v9/choice-action";
import { isPersistedFocusId, type ChoiceKey, type RectificationChoiceCard as ChoiceCardModel } from "@/lib/rectification-agentic/v9/choice-card";
import {
  appendUnseenAssistantTurns,
  applySnapshotTurnsToMessages,
  mergeTurnQuestions,
} from "@/lib/rectification-snapshot-messages";
import {
  markQuestionAnswered,
  messagesFromTurns,
  withdrawAnswerMark,
  type PersistedTurn,
} from "@/lib/rectification-chat-messages";
import type { CurrentQuestionModel } from "@/lib/rectification-chat-snapshot";
import type {
  RectificationRunOutcome,
  RectificationSnapshotLoader,
  RectificationTurnAction,
  RectificationTurnContinuation,
} from "@/lib/rectification-chat-turn-run";
import type { RenderMessage } from "@/components/rectification-message-entry";

export type RectificationStructuredChoiceAction = typeof CHOICE_ACTION | typeof STOP_ACTION | typeof SKIP_PROBE_ACTION;
export type RectificationStructuredChoiceOverride = Readonly<{
  focusId?: string;
  questionId?: string | null;
  probeId?: string | null;
  caseRevision?: number | null;
}>;

export type RectificationStructuredChoiceDeps = Readonly<{
  caseId: string;
  sessionId: string;
  busy: boolean;
  readonly: boolean;
  choiceCard: ChoiceCardModel | null;
  currentQuestion: CurrentQuestionModel | null;
  keyCounter: MutableRefObject<number>;
  runAbort: MutableRefObject<AbortController | null>;
  lastRunOutcome: MutableRefObject<RectificationRunOutcome>;
  conversationAnchor: Readonly<{ pinLatestTurn: () => void }>;
  actionIdForChoice: (focusId: string, optionId: ChoiceOptionId) => string;
  setError: Dispatch<SetStateAction<string>>;
  setMessages: Dispatch<SetStateAction<RenderMessage[]>>;
  setChoiceNonce: Dispatch<SetStateAction<number>>;
  setNextUserActionId: Dispatch<SetStateAction<string | null>>;
  setPending: (value: boolean) => void;
  beginLiveRun: (baseLabel: string) => void;
  loadCaseSnapshot: RectificationSnapshotLoader;
  send: (
    action: RectificationTurnAction,
    messageText: string,
    continuation?: RectificationTurnContinuation,
  ) => Promise<void>;
  onCompleted?: () => void;
  onMessagesChange?: (messages: ChatMessage[]) => void;
  onProfileIncomplete?: () => void;
}>;

export async function runRectificationStructuredChoice(
  deps: RectificationStructuredChoiceDeps,
  action: RectificationStructuredChoiceAction,
  optionId: ChoiceKey | "stop" | "skip_probe",
  override?: RectificationStructuredChoiceOverride,
): Promise<void> {
  const {
    caseId,
    sessionId,
    busy,
    readonly,
    choiceCard,
    currentQuestion,
    keyCounter,
    runAbort,
    lastRunOutcome,
    conversationAnchor,
    actionIdForChoice,
    setError,
    setMessages,
    setChoiceNonce,
    setNextUserActionId,
    setPending,
    beginLiveRun,
    loadCaseSnapshot,
    send,
    onCompleted,
    onMessagesChange,
    onProfileIncomplete,
  } = deps;
  const focusId = override?.focusId ?? choiceCard?.focus_id ?? (
    action === STOP_ACTION && currentQuestion?.kind === "collect_spoken"
      ? currentQuestion.focus_id
      : null
  );
  if (busy || readonly) return;
  if (action !== STOP_ACTION && (!focusId || (!override && !choiceCard))) return;
  if (focusId && !isPersistedFocusId(focusId)) {
    setError("当前选择题已失效，请等待下一问。");
    return;
  }
  const questionId = override?.questionId ?? choiceCard?.question_id ?? currentQuestion?.question_id ?? null;
  const probeId = override?.probeId ?? choiceCard?.probe_id;
  const expectedRevision = override?.caseRevision ?? choiceCard?.case_revision ?? 0;
  const actionId = actionIdForChoice(focusId ?? caseId, optionId);
  setError("");
  keyCounter.current += 1;
  const turnKey = keyCounter.current;
  const assistantRenderKey = `v9-choice-assistant-${turnKey}`;
  const recordingLabel = RECTIFICATION_ACTIVITY_PROGRESS_LABELS.recording_answer;
  beginLiveRun(recordingLabel);
  setMessages((current) => [
    ...markQuestionAnswered(current, focusId ?? "", optionId),
    {
      role: "assistant",
      text: "",
      renderKey: assistantRenderKey,
      state: "thinking",
      activityTrace: emptyActivityTrace(),
      activity: {
        phase: "evidence-validation",
        label: recordingLabel,
        startedAt: Date.now(),
      },
    },
  ]);
  conversationAnchor.pinLatestTurn();
  setPending(true);
  // BUG-1046 (D2): a tap that did not land takes back its local answered
  // mark and placeholder; the card key changes (answer_option → nonce), so
  // the card remounts clean and one tappable card is left.
  const rollBackFailedChoice = () => {
    setMessages((current) => withdrawAnswerMark(
      current.filter((message) => message.renderKey !== assistantRenderKey),
      focusId ?? "",
      optionId,
    ));
    setChoiceNonce((current) => current + 1);
  };
  // The server may have moved on (stale_question, a dropped response after
  // it applied): re-read the Case so the card reflects what it holds.
  const reloadAfterFailedChoice = () => loadCaseSnapshot((turns) => {
    setMessages((current) => applySnapshotTurnsToMessages(
      current,
      turns,
      (incoming) => messagesFromTurns(incoming as readonly PersistedTurn[]),
    ));
  });
  const abortController = new AbortController();
  runAbort.current = abortController;
  try {
    const response = await fetch("/api/rectification/agent", {
      method: "POST",
      headers: { "content-type": "application/json" },
      signal: abortController.signal,
      body: JSON.stringify({
        caseId,
        sessionId,
        requestId: actionId,
        action,
        actionId,
        ...(focusId ? { focusId } : {}),
        ...(questionId ? { questionId } : {}),
        probeId: probeId ?? null,
        optionId: optionId === "stop" ? undefined : optionId,
        expectedRevision,
        origin: "choice_click",
        clientActionId: actionId,
      }),
    });
    const payload = await response.json().catch(() => null);
    if (!response.ok) {
      rollBackFailedChoice();
      if (payload?.code === "profile_incomplete") {
        onProfileIncomplete?.();
        return;
      }
      setError(RECTIFICATION_CHOICE_SUBMIT_FAILED_COPY);
      await reloadAfterFailedChoice();
      return;
    }
    const willContinue = shouldContinueAfterStructuredChoice(payload?.nextAction, payload);
    const payloadNextActionId = typeof payload?.next_user_action?.id === "string"
      ? payload.next_user_action.id.trim()
      : "";
    if (payloadNextActionId) setNextUserActionId(payloadNextActionId);
    onCompleted?.();
    await loadCaseSnapshot((turns) => {
      if (willContinue) {
        // D4 (BUG-1046, the same gap BUG-685 closed for the tie-break entry): a turn
        // the server wrote while applying the tap joins the transcript,
        // above the row the follow-up run continues on.
        setMessages((current) => mergeTurnQuestions(
          appendUnseenAssistantTurns(
            current,
            messagesFromTurns(turns as readonly PersistedTurn[]),
            { beforeRenderKey: assistantRenderKey },
          ),
          turns,
        ));
        return;
      }
      const narration = typeof payload?.narration === "string" && payload.narration.trim()
        ? payload.narration.trim()
        : "已记录你的选择。";
      setMessages((current) => {
        const withoutPlaceholder = current.filter((message) => message.renderKey !== assistantRenderKey);
        const withHistory = appendUnseenAssistantTurns(
          mergeTurnQuestions(withoutPlaceholder, turns),
          messagesFromTurns(turns as readonly PersistedTurn[]),
        );
        if (withHistory.length > withoutPlaceholder.length) return withHistory;
        return [
          ...withHistory,
          {
            role: "assistant" as const,
            text: narration,
            renderKey: assistantRenderKey,
            state: "settled" as const,
            activity: undefined,
          },
        ];
      });
    });
    if (willContinue) {
      // The follow-up turn continues on the row already in place: no removed
      // row, no effect hop, and `busy` never drops in between (so the next
      // card cannot flash before the turn hides it).
      await send("read_only", "", { reuseAssistantRenderKey: assistantRenderKey, label: recordingLabel });
    } else {
      const narration = typeof payload?.narration === "string" && payload.narration.trim()
        ? payload.narration.trim()
        : "已记录你的选择。";
      onMessagesChange?.([
        { role: "assistant", text: narration },
      ]);
    }
  } catch (caught) {
    if (isAbortError(caught)) {
      lastRunOutcome.current = "stopped";
      setMessages((current) => current.map((message) => (
        message.renderKey !== assistantRenderKey ? message : {
          ...message,
          state: "settled" as const,
          failed: false,
          stopped: true,
          activity: undefined,
        }
      )));
      return;
    }
    lastRunOutcome.current = "failed";
    rollBackFailedChoice();
    setError(RECTIFICATION_CHOICE_SUBMIT_FAILED_COPY);
    await reloadAfterFailedChoice();
  } finally {
    if (runAbort.current === abortController) runAbort.current = null;
    if (lastRunOutcome.current === null) lastRunOutcome.current = "succeeded";
    setPending(false);
  }
}