"use client";

import { Images, Loader2 } from "lucide-react";
import { useEffect, useState } from "react";
import Modal from "@/components/Modal";
import { apiMyMedia, type MediaAttachment } from "@/lib/api";
import { isOwnImage, variantURL, widthSrcSet } from "@/lib/responsiveImage";

/** 来源标签映射 */
const SOURCE_LABELS: Record<string, string> = {
  library_cover: "书籍封面",
  library_content: "书籍内容",
  post: "帖子插图",
};

function sourceLabel(source?: string): string {
  return SOURCE_LABELS[source || "post"] || source || "帖子插图";
}

/** 按来源分组（library_cover 优先，其次 library_content，最后 post/其他） */
function groupBySource(items: MediaAttachment[]): [string, MediaAttachment[]][] {
  const groups = new Map<string, MediaAttachment[]>();
  for (const item of items) {
    const key = item.source || "post";
    if (!groups.has(key)) groups.set(key, []);
    groups.get(key)!.push(item);
  }
  // 按优先级排序
  const order = ["library_cover", "library_content", "post"];
  return Array.from(groups.entries()).sort(
    ([a], [b]) => order.indexOf(a) - order.indexOf(b)
  );
}

/** 书籍封面图库选择弹窗：列出本人媒体库图片，按来源分组 */
export default function LibraryCoverPicker({
  open,
  onClose,
  onPick,
}: {
  open: boolean;
  onClose: () => void;
  onPick: (item: MediaAttachment) => void;
}) {
  const [items, setItems] = useState<MediaAttachment[]>([]);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState("");

  useEffect(() => {
    if (!open) return;
    let cancelled = false;
    setLoading(true);
    setError("");
    void apiMyMedia()
      .then((res) => {
        if (cancelled) return;
        if (res.error) {
          setError(res.error);
          setItems([]);
          return;
        }
        setItems((res.attachments || []).filter((item) => item.kind === "image"));
      })
      .catch(() => {
        if (!cancelled) setError("加载媒体库失败");
      })
      .finally(() => {
        if (!cancelled) setLoading(false);
      });
    return () => {
      cancelled = true;
    };
  }, [open]);

  const groups = groupBySource(items);

  return (
    <Modal
      open={open}
      title="从图库选择封面"
      description="已选作封面的图片会单独分组，再次选择直接复用。"
      onClose={onClose}
      maxWidthClass="max-w-2xl"
      dismissOnOverlay
    >
      {loading ? (
        <p className="meta text-[13px] flex items-center gap-2 py-6 justify-center">
          <Loader2 size={14} className="animate-spin" /> 加载中
        </p>
      ) : error ? (
        <p className="text-[13px] py-4" style={{ color: "var(--danger, #b42318)" }}>
          {error}
        </p>
      ) : items.length === 0 ? (
        <p className="meta text-[13px] py-6 text-center">
          图库还没有图片。上传封面或发帖插图后，会自动出现在这里。
        </p>
      ) : (
        <div className="flex flex-col gap-5 max-h-[60vh] overflow-y-auto">
          {groups.map(([source, groupItems]) => (
            <section key={source}>
              <h4
                className="text-[11.5px] font-bold tracking-wide uppercase mb-2 px-0.5"
                style={{ color: "var(--ink-3)" }}
              >
                {sourceLabel(source)}
                <span className="ml-1.5 font-normal opacity-70">({groupItems.length})</span>
              </h4>
              <div className="grid grid-cols-4 sm:grid-cols-5 gap-2">
                {groupItems.map((item) => (
                  <button
                    key={item.id}
                    type="button"
                    onClick={() => {
                      onPick(item);
                      onClose();
                    }}
                    className="relative group aspect-square rounded-xl overflow-hidden"
                    style={{ boxShadow: "0 0 0 1px var(--line)", background: "var(--panel-2)" }}
                    data-tip={
                      item.source === "library_cover"
                        ? "已作封面，点击直接复用"
                        : "复制一份用作封面"
                    }
                  >
                    {/* eslint-disable-next-line @next/next/no-img-element */}
                    <img
                      src={isOwnImage(item.url) ? variantURL(item.url, 160) : item.url}
                      srcSet={isOwnImage(item.url) ? widthSrcSet(item.url, [96, 160, 256, 384]) : undefined}
                      sizes="(max-width:520px) 23vw, 96px"
                      alt="图库候选封面"
                      className="w-full h-full object-contain"
                      loading="lazy"
                    />
                    <span
                      className="pointer-events-none absolute inset-0 flex items-center justify-center opacity-0 group-hover:opacity-100"
                      style={{ background: "color-mix(in srgb, var(--ink) 40%, transparent)", color: "#fff" }}
                    >
                      <Images size={14} />
                    </span>
                  </button>
                ))}
              </div>
            </section>
          ))}
        </div>
      )}
    </Modal>
  );
}