"use client";

import { ArrowLeft, FileText, Mic, Search, X } from "lucide-react";
import Image from "next/image";
import Link from "next/link";
import { useRouter, useSearchParams } from "next/navigation";
import {
  type FormEvent,
  useCallback,
  useEffect,
  useMemo,
  useRef,
  useState,
} from "react";
import { playbackContextQuery } from "@/lib/playback-context";
import type { SnippetPart } from "@/lib/search";
import { isVideoContentTag, VIDEO_CONTENT_TAGS } from "@/lib/video-tags";

// 匹配搜索结果类型（适配后端API）
type SearchResultItem = {
  id: string;
  awemeId: string;
  type: "video" | "image";
  score: number;
  matchedIn: ("desc" | "transcript")[];
  descParts: SnippetPart[]; // 完整描述，标出命中位置
  snippet: SnippetPart[] | null; // 语音转写的命中片段
  contentTags: string[];
  video?: {
    aweme_id: string;
    desc: string;
    cover_url: string | null;
    video_url: string | null;
    duration_ms: number;
    author: {
      sec_uid: string;
      nickname: string;
      avatar_url: string | null;
    };
  };
  imagePost?: {
    aweme_id: string;
    desc: string;
    cover_url: string | null;
    author: {
      sec_uid: string;
      nickname: string;
      avatar_url: string | null;
    };
  };
};

const PAGE_SIZE = 30;

function renderParts(parts: SnippetPart[]) {
  let offset = 0;
  return parts.map((part) => {
    const key = `${offset}-${part.text}`;
    offset += part.text.length;
    return part.hit ? (
      <mark
        key={key}
        className="rounded-sm bg-yellow-400/80 px-0.5 text-zinc-950"
      >
        {part.text}
      </mark>
    ) : (
      <span key={key}>{part.text}</span>
    );
  });
}

export default function SearchClient({
  initialQuery,
}: {
  initialQuery: string;
}) {
  const searchParams = useSearchParams();
  const router = useRouter();

  const [query, setQuery] = useState(initialQuery);
  const [results, setResults] = useState<SearchResultItem[]>([]);
  const [total, setTotal] = useState(0);
  const [page, setPage] = useState(1);
  const [loading, setLoading] = useState(false);
  const [loadingMore, setLoadingMore] = useState(false);
  // 只采用最近一次请求的结果，避免快速切换关键词时旧结果覆盖新结果
  const requestIdRef = useRef(0);
  const [searched, setSearched] = useState(false);
  const [selectedTag, setSelectedTag] = useState<string | null>(null);

  const buildSearchHref = useCallback((q: string, tag: string | null) => {
    const params = new URLSearchParams();
    const trimmed = q.trim();
    if (trimmed) params.set("q", trimmed);
    if (tag) params.set("tag", tag);
    const queryString = params.toString();
    return queryString ? `/search?${queryString}` : "/search";
  }, []);

  const fetchPage = useCallback(
    async (q: string, tag: string | null, pageNum: number) => {
      const params = new URLSearchParams({
        limit: String(PAGE_SIZE),
        page: String(pageNum),
      });
      if (q) params.set("q", q);
      if (tag) params.set("tag", tag);
      const res = await fetch(`/api/search?${params.toString()}`);
      if (!res.ok) throw new Error("Search failed");
      return (await res.json()) as {
        results?: SearchResultItem[];
        total?: number;
      };
    },
    [],
  );

  const performSearch = useCallback(
    async (q: string, tag: string | null) => {
      const trimmed = q.trim();
      const requestId = ++requestIdRef.current;
      if (!trimmed && !tag) {
        setResults([]);
        setTotal(0);
        setSearched(false);
        return;
      }
      setLoading(true);
      setSearched(true);
      setPage(1);
      try {
        const data = await fetchPage(trimmed, tag, 1);
        if (requestId !== requestIdRef.current) return;
        setResults(data.results || []);
        setTotal(data.total ?? 0);
      } catch (err) {
        if (requestId !== requestIdRef.current) return;
        console.error("Search error:", err);
        setResults([]);
        setTotal(0);
      } finally {
        if (requestId === requestIdRef.current) setLoading(false);
      }
    },
    [fetchPage],
  );

  const loadMore = async () => {
    const q = (searchParams.get("q") || "").trim();
    const tagParam = searchParams.get("tag") || "";
    const tag = tagParam && isVideoContentTag(tagParam) ? tagParam : null;
    const requestId = requestIdRef.current;
    const nextPage = page + 1;
    setLoadingMore(true);
    try {
      const data = await fetchPage(q, tag, nextPage);
      if (requestId !== requestIdRef.current) return;
      setResults((prev) => {
        const seen = new Set(prev.map((r) => r.id));
        return [
          ...prev,
          ...(data.results || []).filter((r) => !seen.has(r.id)),
        ];
      });
      setTotal(data.total ?? 0);
      setPage(nextPage);
    } catch (err) {
      console.error("Search error:", err);
    } finally {
      if (requestId === requestIdRef.current) setLoadingMore(false);
    }
  };

  // 初始 & URL 变化时同步（用 searchParams 订阅 URL 更稳妥）
  useEffect(() => {
    const q = searchParams.get("q") || "";
    const tagParam = searchParams.get("tag") || "";
    const tag = tagParam && isVideoContentTag(tagParam) ? tagParam : null;
    setQuery(q);
    setSelectedTag(tag);
    if (q || tag) {
      performSearch(q, tag);
    } else {
      requestIdRef.current++;
      setResults([]);
      setTotal(0);
      setSearched(false);
    }
  }, [searchParams, performSearch]);

  const handleSearch = (e: FormEvent) => {
    e.preventDefault();
    const trimmed = query.trim();
    if (!trimmed && !selectedTag) return;
    router.push(buildSearchHref(trimmed, selectedTag));
  };

  const handleTagSelect = (tag: string) => {
    const nextTag = selectedTag === tag ? null : tag;
    setSelectedTag(nextTag);
    router.push(buildSearchHref(query, nextTag));
  };

  const handleClear = () => {
    setQuery("");
    setSelectedTag(null);
    setResults([]);
    setTotal(0);
    setSearched(false);
    router.push("/search");
  };

  // 从搜索结果进入播放页时，上下切换在这次的搜索结果里移动（与当前 URL 上的搜索条件一致）
  const resultLinkQuery = useMemo(() => {
    const q = (searchParams.get("q") || "").trim();
    const tagParam = searchParams.get("tag") || "";
    const tag = tagParam && isVideoContentTag(tagParam) ? tagParam : null;
    if (!q && !tag) return "";
    return playbackContextQuery({ kind: "search", q, tag });
  }, [searchParams]);

  return (
    <div className="min-h-screen bg-zinc-950 text-white">
      {/* 顶部搜索栏 */}
      <header className="sticky top-0 z-50 bg-zinc-900/80 backdrop-blur-xl border-b border-white/10">
        <div className="max-w-7xl mx-auto px-4 py-4 flex items-center gap-4">
          <button
            type="button"
            onClick={() => router.push("/")}
            className="p-2 rounded-full hover:bg-white/10 transition-colors"
            aria-label="返回首页"
          >
            <ArrowLeft size={24} />
          </button>

          <form
            onSubmit={handleSearch}
            className="flex-1 flex items-center gap-3"
          >
            <div className="relative flex-1">
              <input
                type="text"
                value={query}
                onChange={(e) => setQuery(e.target.value)}
                placeholder="搜索视频、图文描述或语音内容..."
                className="w-full bg-white/5 border border-white/10 rounded-full px-5 py-3 pl-12 pr-12 text-white placeholder-white/40 focus:outline-none focus:ring-2 focus:ring-blue-500/50 focus:border-blue-500/50 transition-all"
              />
              <Search
                size={20}
                className="absolute left-4 top-1/2 -translate-y-1/2 text-white/40"
              />
              {(query || selectedTag) && (
                <button
                  type="button"
                  onClick={handleClear}
                  className="absolute right-4 top-1/2 -translate-y-1/2 p-1 rounded-full hover:bg-white/10 transition-colors"
                  aria-label="清空"
                >
                  <X size={18} className="text-white/60" />
                </button>
              )}
            </div>
            <button
              type="submit"
              className="px-6 py-3 bg-blue-600 hover:bg-blue-700 rounded-full font-medium transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
              disabled={loading || (!query.trim() && !selectedTag)}
            >
              {loading ? "搜索中..." : "搜索"}
            </button>
          </form>
        </div>
        <div className="max-w-7xl mx-auto px-4 pb-4">
          <div className="flex gap-2 overflow-x-auto">
            {VIDEO_CONTENT_TAGS.map((tag) => (
              <button
                key={tag}
                type="button"
                onClick={() => handleTagSelect(tag)}
                className={`flex-shrink-0 rounded-full border px-3 py-1.5 text-xs font-medium transition-colors ${
                  selectedTag === tag
                    ? "border-blue-400 bg-blue-500/20 text-blue-200"
                    : "border-white/10 bg-white/5 text-white/60 hover:border-white/20 hover:text-white"
                }`}
              >
                {tag}
              </button>
            ))}
          </div>
        </div>
      </header>

      {/* 结果区域 */}
      <main className="max-w-7xl mx-auto px-4 py-8">
        {loading && (
          <div className="flex items-center justify-center py-20">
            <div className="flex flex-col items-center gap-4">
              <div className="w-12 h-12 border-4 border-blue-500/30 border-t-blue-500 rounded-full animate-spin" />
              <p className="text-white/60">正在搜索...</p>
            </div>
          </div>
        )}

        {!loading && searched && results.length === 0 && (
          <div className="flex flex-col items-center justify-center py-20 text-white/60">
            <Search size={64} className="mb-4 opacity-20" />
            <p className="text-xl">未找到相关内容</p>
            <p className="text-sm mt-2">试试其他关键词</p>
          </div>
        )}

        {!loading && !searched && !query && !selectedTag && (
          <div className="flex flex-col items-center justify-center py-20 text-white/40">
            <Search size={64} className="mb-4 opacity-20" />
            <p className="text-xl">输入关键词开始搜索</p>
            <p className="text-sm mt-2">
              按原文匹配描述和语音转写，多个关键词用空格分隔，以 - 开头表示排除
            </p>
          </div>
        )}

        {!loading && results.length > 0 && (
          <div>
            <div className="mb-6 flex items-center justify-between">
              <h2 className="text-lg text-white/80">
                找到 <span className="text-white font-semibold">{total}</span>{" "}
                个结果
              </h2>
            </div>

            {/* 单列列表布局 */}
            <div className="space-y-4">
              {results.map((item) => {
                const content =
                  item.type === "video" ? item.video : item.imagePost;
                if (!content) return null;

                return (
                  <div
                    key={item.id}
                    className="bg-white/5 backdrop-blur-sm border border-white/10 rounded-2xl overflow-hidden hover:border-white/20 transition-all hover:-translate-y-1"
                  >
                    {/* 主内容区 */}
                    <div className="flex gap-4 p-4">
                      {/* 左侧：封面预览 */}
                      <Link
                        href={`/aweme/${content.aweme_id}${resultLinkQuery}`}
                        target="_blank"
                        className="flex-shrink-0 w-64 h-80 sm:w-70 sm:h-96 rounded-xl overflow-hidden bg-zinc-900 group"
                      >
                        {content.cover_url ? (
                          <Image
                            src={content.cover_url}
                            alt={content.desc}
                            width={280}
                            height={384}
                            unoptimized
                            className="w-full h-full object-cover transition-transform duration-300 group-hover:scale-105"
                          />
                        ) : (
                          <div className="h-full w-full bg-zinc-800" />
                        )}
                      </Link>

                      {/* 右侧：信息区 */}
                      <div className="flex-1 min-w-0 flex flex-col">
                        {/* 类型标签 */}
                        <div className="flex items-center gap-2 mb-2">
                          <span
                            className={`px-2 py-0.5 text-xs rounded ${
                              item.type === "video"
                                ? "bg-blue-600/20 text-blue-300"
                                : "bg-purple-600/20 text-purple-300"
                            }`}
                          >
                            {item.type === "video" ? "视频" : "图文"}
                          </span>
                          {item.matchedIn.includes("desc") && (
                            <span className="flex items-center gap-1 px-2 py-0.5 bg-green-600/20 text-green-300 text-xs rounded">
                              <FileText size={12} />
                              描述命中
                            </span>
                          )}
                          {item.matchedIn.includes("transcript") && (
                            <span className="flex items-center gap-1 px-2 py-0.5 bg-green-600/20 text-green-300 text-xs rounded">
                              <Mic size={12} />
                              语音命中
                            </span>
                          )}
                          {item.contentTags.map((tag) => (
                            <span
                              key={tag}
                              className="px-2 py-0.5 text-xs rounded bg-blue-500/15 text-blue-200"
                            >
                              {tag}
                            </span>
                          ))}
                        </div>

                        {/* 描述 */}
                        <Link
                          href={`/aweme/${content.aweme_id}${resultLinkQuery}`}
                          target="_blank"
                        >
                          <p className="text-white/90 text-sm sm:text-base line-clamp-3 mb-3 hover:text-white transition-colors">
                            {item.descParts.length > 0
                              ? renderParts(item.descParts)
                              : "无描述"}
                          </p>
                        </Link>

                        {/* 作者信息 */}
                        <div className="flex items-center gap-2 mb-4">
                          {content.author.avatar_url ? (
                            <Image
                              src={content.author.avatar_url}
                              alt={content.author.nickname}
                              width={24}
                              height={24}
                              unoptimized
                              className="w-6 h-6 rounded-full ring-1 ring-white/20"
                            />
                          ) : (
                            <div className="h-6 w-6 rounded-full bg-white/10 ring-1 ring-white/20" />
                          )}
                          <span className="text-xs text-white/60">
                            {content.author.nickname}
                          </span>
                        </div>

                        {/* 语音转写片段：命中时展示命中位置附近的文字 */}
                        {item.snippet && item.snippet.length > 0 && (
                          <div>
                            <h4 className="flex items-center gap-2 text-xs font-medium text-green-300 mb-1.5">
                              <Mic size={14} />
                              {item.matchedIn.includes("transcript")
                                ? "语音内容"
                                : "语音转写"}
                            </h4>
                            <div
                              className="text-xs text-white/70 bg-white/5 rounded-lg p-2 leading-relaxed"
                              style={{ wordBreak: "break-word" }}
                            >
                              {renderParts(item.snippet)}
                            </div>
                          </div>
                        )}
                      </div>
                    </div>
                  </div>
                );
              })}
            </div>

            {results.length < total && (
              <div className="mt-8 flex justify-center">
                <button
                  type="button"
                  onClick={loadMore}
                  disabled={loadingMore}
                  className="rounded-full border border-white/10 bg-white/5 px-6 py-2.5 text-sm text-white/80 transition-colors hover:border-white/20 hover:text-white disabled:opacity-50"
                >
                  {loadingMore
                    ? "加载中..."
                    : `加载更多（还有 ${total - results.length} 个）`}
                </button>
              </div>
            )}
          </div>
        )}
      </main>
    </div>
  );
}