"use client";

import { useEffect, useMemo, useRef, useState } from "react";

import { AppShell } from "@/components/AppShell";
import type { ProjectResponse, ReviewHistoryItem } from "@/lib/api/types";
import {
  allResolved,
  emptyDecisions,
  setNote,
  setVerdict,
  unresolvedIndices,
  type DecisionDraft,
  type Verdict,
} from "@/lib/review/decisions";
import { normalizeConflicts } from "@/lib/review/history";
import { useAccept } from "@/lib/review/useAccept";
import { useReviewStream } from "@/lib/review/useReviewStream";
import type { ReviewConflict } from "@/lib/review/sse";
import { AcceptPanel } from "./AcceptPanel";
import { AnnotatedText } from "./AnnotatedText";
import { ConflictCard } from "./ConflictCard";

interface ReviewReportProps {
  project: ProjectResponse;
  chapterNo: number;
  initialReview: ReviewHistoryItem | undefined;
  initialDraft: string;
}

// 审稿报告页主体（UX §6.4 / §8.3 / §9）。
// 数据源：进页用历史留痕 conflicts 种入；「重新审稿」用当前终稿跑 SSE 覆盖。
// 裁决草稿随 conflicts 长度对齐；未决禁验收（gate）。
export function ReviewReport({
  project,
  chapterNo,
  initialReview,
  initialDraft,
}: ReviewReportProps) {
  const review = useReviewStream();
  const accept = useAccept();

  const [finalText, setFinalText] = useState(initialDraft);
  const [drafts, setDrafts] = useState<DecisionDraft[]>(() =>
    emptyDecisions(normalizeConflicts(initialReview).length),
  );
  const [focusedIndex, setFocusedIndex] = useState<number | null>(null);
  const [missing, setMissing] = useState<Set<number>>(new Set());
  const seededRef = useRef(false);

  // 进页一次性把历史 conflicts 种入流状态（无需重审即可裁决）。
  const seededConflicts = useMemo(
    () => normalizeConflicts(initialReview),
    [initialReview],
  );
  useEffect(() => {
    if (seededRef.current) return;
    seededRef.current = true;
    if (seededConflicts.length > 0) review.seed(seededConflicts);
  }, [review, seededConflicts]);

  // 当前生效冲突 = 流状态（重审后即时更新，否则种入的历史）。
  const conflicts: ReviewConflict[] = review.state.conflicts;

  // 重审完成（done 边沿）→ 重置裁决草稿对齐新冲突集（冲突可能整组变化）。
  const conflictCount = conflicts.length;
  const wasReviewingRef = useRef(false);
  useEffect(() => {
    if (review.state.phase === "reviewing") {
      wasReviewingRef.current = true;
      return;
    }
    if (review.state.phase === "done" && wasReviewingRef.current) {
      wasReviewingRef.current = false;
      setDrafts(emptyDecisions(conflictCount));
      setMissing(new Set());
    }
  }, [review.state.phase, conflictCount]);

  const onReReview = (): void => {
    setMissing(new Set());
    void review.start(project.id, chapterNo, finalText);
  };

  const onVerdict = (index: number, verdict: Verdict): void => {
    setDrafts((prev) => setVerdict(prev, index, verdict));
    setMissing((prev) => {
      if (!prev.has(index)) return prev;
      const next = new Set(prev);
      next.delete(index);
      return next;
    });
  };
  const onNote = (index: number, note: string): void =>
    setDrafts((prev) => setNote(prev, index, note));

  const jumpToCard = (index: number): void => {
    setFocusedIndex(index);
    document
      .getElementById(`conflict-card-${index}`)
      ?.scrollIntoView({ behavior: "smooth", block: "center" });
  };
  const jumpToAnchor = (index: number): void => {
    setFocusedIndex(index);
    document
      .getElementById(`anchor-${index}`)
      ?.scrollIntoView({ behavior: "smooth", block: "center" });
  };

  const onAccept = async (): Promise<void> => {
    const outcome = await accept.accept(
      project.id,
      chapterNo,
      finalText,
      drafts,
    );
    if (outcome.missingIndices.length > 0) {
      setMissing(new Set(outcome.missingIndices));
    }
  };

  const resolved = allResolved(drafts);
  const unresolved = unresolvedIndices(drafts).length;
  const reviewing = review.isReviewing;

  return (
    <AppShell
      title={`〈${project.title}〉`}
      subtitle={`第 ${chapterNo} 章 · 审稿报告`}
    >
      <div className="grid h-[calc(100vh-4rem)] grid-cols-1 lg:grid-cols-[1fr_24rem]">
        {/* 左：终稿正文 + 就地标注 */}
        <section className="flex min-w-0 flex-col bg-bg">
          <div className="flex items-center gap-3 border-b border-line bg-panel px-6 py-3">
            <h1 className="font-serif text-lg text-ink">
              第 {chapterNo} 章 审稿报告
            </h1>
            <span className="font-mono text-xs text-ink-soft">
              {conflictCount} 冲突
            </span>
            <div className="ml-auto">
              {reviewing ? (
                <button
                  type="button"
                  onClick={review.stop}
                  className="rounded border border-conflict px-3 py-1.5 text-sm text-conflict"
                >
                  停
                </button>
              ) : (
                <button
                  type="button"
                  onClick={onReReview}
                  className="rounded bg-cinnabar px-3 py-1.5 text-sm text-panel hover:opacity-90"
                >
                  ✦ 重新审稿
                </button>
              )}
            </div>
          </div>

          {review.state.error ? (
            <p className="border-b border-line bg-panel px-6 py-2 text-sm text-conflict">
              审稿失败（{review.state.error.code}）：
              {review.state.error.message}
              {review.state.error.code === "LLM_UNAVAILABLE" ? (
                <>
                  {" "}
                  <a
                    href="/settings/providers"
                    className="underline hover:text-cinnabar"
                  >
                    去设置提供商
                  </a>
                </>
              ) : null}
            </p>
          ) : null}

          <div className="flex-1 overflow-auto px-6 py-6">
            <AnnotatedText
              text={finalText}
              conflicts={conflicts}
              focusedIndex={focusedIndex}
              onAnchorClick={jumpToCard}
            />
            <details className="mt-4">
              <summary className="cursor-pointer text-xs text-ink-soft hover:text-cinnabar">
                展开/编辑终稿（裁决时可改稿 — 摘要从终稿提炼）
              </summary>
              <label htmlFor="final-text" className="sr-only">
                终稿正文
              </label>
              <textarea
                id="final-text"
                value={finalText}
                onChange={(e) => setFinalText(e.target.value)}
                className="mt-2 min-h-[20vh] w-full resize-y rounded border border-line bg-panel p-3 font-serif text-[16px] leading-[1.9] text-ink focus:border-cinnabar focus:outline-none"
              />
            </details>
          </div>
        </section>

        {/* 右：审稿分区 + 冲突裁决 + 验收 gate */}
        <aside className="flex flex-col overflow-auto border-l border-line bg-panel px-4 py-4">
          <section className="mb-4">
            <h2 className="text-xs font-semibold uppercase tracking-wide text-ink-soft">
              一致性 (continuity)
            </h2>
            <SectionStatusLine
              reviewing={reviewing}
              done={review.state.phase === "done"}
              conflictCount={conflictCount}
              sections={review.state.sections}
            />
          </section>

          <section className="flex-1">
            {conflicts.length === 0 ? (
              <p className="rounded border border-dashed border-line p-4 text-xs text-ink-soft">
                {review.state.phase === "done" || seededConflicts.length === 0
                  ? "未发现一致性冲突。"
                  : "进页未带审稿留痕，点「重新审稿」开始。"}
              </p>
            ) : (
              <ul className="space-y-3">
                {conflicts.map((c, i) => (
                  <ConflictCard
                    key={i}
                    index={i}
                    conflict={c}
                    draft={drafts[i] ?? { verdict: null, note: "" }}
                    missing={missing.has(i)}
                    onVerdict={onVerdict}
                    onNote={onNote}
                    onJump={jumpToAnchor}
                  />
                ))}
              </ul>
            )}
          </section>

          <section className="mt-4">
            <AcceptPanel
              conflictCount={conflictCount}
              unresolvedCount={resolved ? 0 : unresolved}
              accepting={accept.status === "accepting"}
              result={accept.result}
              onAccept={() => void onAccept()}
            />
          </section>
        </aside>
      </div>
    </AppShell>
  );
}

interface SectionStatusLineProps {
  reviewing: boolean;
  done: boolean;
  conflictCount: number;
  sections: { name: string; status: string }[];
}

// 四审进行中骨架逐项点亮（UX §9）；M2 仅 continuity 一项。
function SectionStatusLine({
  reviewing,
  done,
  conflictCount,
  sections,
}: SectionStatusLineProps) {
  if (reviewing) {
    return (
      <p className="mt-1 text-xs text-info" aria-live="polite">
        审稿进行中…
      </p>
    );
  }
  if (done || sections.length > 0) {
    return (
      <p className="mt-1 text-xs">
        {conflictCount > 0 ? (
          <span className="text-conflict">⚠ {conflictCount} 冲突</span>
        ) : (
          <span className="text-pass">✓ 通过</span>
        )}
      </p>
    );
  }
  return null;
}
