"use client";

import { useEffect, useRef, useState } from "react";
import { Check, MessageSquarePlus, MessagesSquare, RotateCcw, X } from "lucide-react";

import { ThinkingIndicator } from "@/components/ThinkingIndicator";
import { Button } from "@/components/ui/Button";
import { SectionHeader } from "@/components/ui/SectionHeader";
import { StatusNote } from "@/components/ui/StatusNote";
import { TextArea } from "@/components/ui/TextArea";
import { useRefine } from "@/lib/workbench/useRefine";
import { useClarify } from "@/lib/workbench/useClarify";
import { foldClarifications, needsClarifyGate } from "@/lib/workbench/clarify";
import type {
  AiTurnInput,
  AiTurnMessage,
} from "@/lib/workbench/useAiConversation";
import { ChoiceChips } from "./ChoiceChips";

// 门控阈值：再沟通意见 trim 后短于此字数才自动预检反问（清晰意见不交往返税）。
const CLARIFY_MIN_CHARS = 10;

interface RefinePanelProps {
  projectId: string;
  chapterNo: number;
  // 选中原文；打开即对其回炉一次。
  original: string;
  // 接受回填：把选段替换为该产出（调用方按内容重锚落回草稿）。
  onAccept: (refined: string) => void;
  // 留痕：把本轮往复（含缓冲的 clarify Q&A）作为一批 append（fail-soft，不阻塞回炉）。
  appendMessages: (turn: AiTurnInput) => void;
  onClose: () => void;
}

// 润色 / 再沟通结果卡（内联，非模态）：打开即润色选段；作者可「再沟通」追加意见迭代出新版，
// 择版接受回填正文，或放弃。原文只读、生成不写库（不变量 #3），accept 才动草稿。
export function RefinePanel({
  projectId,
  chapterNo,
  original,
  onAccept,
  appendMessages,
  onClose,
}: RefinePanelProps) {
  const { status, versions, latest, refine, recommunicate } = useRefine();
  const clarify = useClarify();
  const [instruction, setInstruction] = useState("");
  const [pendingInstruction, setPendingInstruction] = useState<string | null>(null);
  const ranRef = useRef(false);
  // 本面板一次会话 = 一个 thread；所有润色/再沟通/澄清往复归此组。版本号 repo 无关，本地累加。
  const threadId = useRef(crypto.randomUUID()).current;
  const versionNoRef = useRef(0);

  // 一版 ai 产出气泡：content=产出，meta 存版本号 + 原选段（每版都存，供任意版 re-accept 重锚）。
  const aiRow = (refined: string): AiTurnMessage => {
    versionNoRef.current += 1;
    return {
      role: "ai",
      content: refined,
      meta: { version_no: versionNoRef.current, segment: original },
    };
  };

  // 打开即对选段回炉一次（仅一次，避免重复请求）；成功后留痕 [author(原选段), ai(润色)]。
  useEffect(() => {
    if (ranRef.current) return;
    ranRef.current = true;
    void (async () => {
      const v = await refine(projectId, chapterNo, original);
      if (v) {
        appendMessages({
          threadId,
          kind: "refine",
          chapterNo,
          messages: [{ role: "author", content: original }, aiRow(v.refined)],
        });
      }
    })();
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [projectId, chapterNo, original, refine]);

  const busy = status === "refining";
  const clarifying = clarify.status === "checking";
  const firstQuestion = clarify.decision?.questions[0] ?? null;
  const asking = clarify.status === "asking" && firstQuestion !== null;

  // 折入澄清答案（或原意见）后回炉，结束后留痕；clarifyTurns 非空时把缓冲的 Q&A 一并落库。
  const runRecommunicate = (
    finalInstruction: string,
    clarifyTurns: AiTurnMessage[] | null,
  ): void => {
    clarify.reset();
    setPendingInstruction(null);
    setInstruction("");
    void (async () => {
      const v = await recommunicate(projectId, chapterNo, finalInstruction);
      if (!v) return;
      // clarify 分支：作者答复 IS 本轮 author 输入，不再另加 author(意见) 气泡；否则记 author(意见)。
      const messages = clarifyTurns
        ? [...clarifyTurns, aiRow(v.refined)]
        : [{ role: "author" as const, content: finalInstruction }, aiRow(v.refined)];
      appendMessages({ threadId, kind: "refine", chapterNo, messages });
    })();
  };

  // 「再改一版」：意见含糊/极短（或 force）先预检反问；否则直接回炉。
  const onRecommunicate = async (force: boolean): Promise<void> => {
    const trimmed = instruction.trim();
    if (!trimmed || busy || clarifying) return;
    if (force || needsClarifyGate(trimmed, CLARIFY_MIN_CHARS)) {
      const segment = latest?.refined ?? original;
      const vm = await clarify.check(projectId, chapterNo, segment, trimmed);
      if (vm.needClarification && vm.questions.length > 0) {
        setPendingInstruction(trimmed); // 记住原意见，等作者答完折进去
        return;
      }
    }
    runRecommunicate(trimmed, null);
  };

  // 作者答复澄清（点选 value 或自由输入）→ 缓冲 Q&A（原意见→反问→答复）+ 折进意见 → 回炉。
  const onClarifyAnswer = (answer: string): void => {
    const q = clarify.decision?.questions[0];
    const question = q?.question ?? "";
    const base = pendingInstruction ?? instruction.trim();
    // 缓冲三条：原含糊意见(author) → AI 反问(ai, 选项进 meta) → 作者答复(author)，随本轮产出一起落库。
    const clarifyTurns: AiTurnMessage[] = [
      { role: "author", content: base },
      {
        role: "ai",
        content: question,
        meta: {
          parent_kind: "refine",
          options: (q?.options ?? []).map((o) => ({
            label: o.label,
            value: o.value,
          })),
          allow_free_text: q?.allowFreeText ?? false,
          verification: clarify.decision?.verification ?? "",
        },
      },
      { role: "author", content: answer },
    ];
    runRecommunicate(foldClarifications(base, [{ question, answer }]), clarifyTurns);
  };

  return (
    <div className="border-b border-line bg-panel px-4 py-3 sm:px-6">
      <div className="flex items-center justify-between gap-3">
        <SectionHeader
          title="润色 / 再沟通"
          description="对选中段回炉；不满意可追加意见让 AI 再改一版，满意后接受回填。"
        />
        <Button onClick={onClose} variant="ghost" size="icon" aria-label="关闭润色">
          <X className="h-4 w-4" aria-hidden="true" />
        </Button>
      </div>

      <div className="mt-3 grid gap-3 sm:grid-cols-2">
        <figure className="rounded border border-line bg-bg p-3">
          <figcaption className="mb-1 text-2xs text-ink-soft">原文</figcaption>
          <p className="whitespace-pre-wrap text-sm text-ink-soft">{original}</p>
        </figure>
        <figure className="rounded border border-cinnabar/40 bg-bg p-3">
          <figcaption className="mb-1 flex items-center gap-2 text-2xs text-ink-soft">
            改写
            {versions.length > 0 ? (
              <span className="rounded bg-panel px-1.5 py-0.5 tabular-nums">
                第 {versions.length} 版
              </span>
            ) : null}
          </figcaption>
          {busy && !latest ? (
            <ThinkingIndicator label="润色中" className="text-xs text-cinnabar" />
          ) : latest ? (
            <p className="whitespace-pre-wrap text-sm text-ink">{latest.refined}</p>
          ) : status === "error" ? (
            <StatusNote variant="danger" className="text-xs" title="回炉失败">
              <button
                type="button"
                onClick={() => void refine(projectId, chapterNo, original)}
                className="mt-1 inline-flex items-center gap-1 text-cinnabar hover:underline"
              >
                <RotateCcw className="h-3.5 w-3.5" aria-hidden="true" />
                重试
              </button>
            </StatusNote>
          ) : null}
        </figure>
      </div>

      <div className="mt-3 space-y-2">
        <label className="block">
          <span className="sr-only">再沟通意见</span>
          <TextArea
            value={instruction}
            onChange={(e) => setInstruction(e.target.value)}
            rows={2}
            placeholder="再沟通：想怎么改？（意见太笼统时 AI 会先反问、给方向选项）"
          />
        </label>
        {asking && firstQuestion ? (
          // role="status"：AI 反问动态出现时向读屏播报（WCAG 4.1.3 Status Messages）。
          <div role="status" className="rounded border border-cinnabar/40 bg-bg p-3">
            <p className="mb-2 text-2xs text-ink-soft">AI 想先跟你确认一下：</p>
            <ChoiceChips
              question={firstQuestion.question}
              options={firstQuestion.options}
              allowFreeText={firstQuestion.allowFreeText}
              onPick={onClarifyAnswer}
              onFreeText={onClarifyAnswer}
            />
          </div>
        ) : null}
        <div className="flex flex-wrap items-center gap-2">
          <Button
            onClick={() => void onRecommunicate(false)}
            disabled={busy || clarifying || instruction.trim().length === 0}
            variant="secondary"
            size="sm"
          >
            <MessageSquarePlus className="h-4 w-4" aria-hidden="true" />
            再改一版
          </Button>
          <Button
            onClick={() => void onRecommunicate(true)}
            disabled={busy || clarifying || instruction.trim().length === 0}
            variant="ghost"
            size="sm"
            title="让 AI 先反问、给方向选项再改"
          >
            <MessagesSquare className="h-4 w-4" aria-hidden="true" />
            帮我理清方向
          </Button>
          <Button
            onClick={() => latest && onAccept(latest.refined)}
            disabled={busy || !latest}
            variant="primary"
            size="sm"
          >
            <Check className="h-4 w-4" aria-hidden="true" />
            接受回填
          </Button>
          {busy || clarifying ? (
            <ThinkingIndicator
              label={clarifying ? "琢磨要不要反问" : "生成中"}
              className="text-xs text-cinnabar"
            />
          ) : null}
        </div>
      </div>
    </div>
  );
}
