"use client";

import { useCallback, useEffect, useRef, useState } from "react";
import Cropper, { type Area } from "react-easy-crop";
import "react-easy-crop/react-easy-crop.css";
import {
  UploadCloud, ZoomIn, Check, Loader2, Images, RotateCcw, Trash2, AlertTriangle, Crop,
} from "lucide-react";
import {
  apiMyMedia, apiUploadAvatar, apiUseAvatar, apiDeleteAttachment,
  type MediaAttachment,
} from "@/lib/api";
import { getCroppedAvatarWebp } from "@/lib/cropImage";
import Modal from "@/components/Modal";

interface AvatarCropModalProps {
  open: boolean;
  onClose: () => void;
  currentAvatar: string;
  /** 头像变更（新 URL）或被删除（空串）时触发 */
  onChanged: (avatar: string) => void;
  /** 外部拖入的图片：打开后直接进入裁剪 */
  seedFile?: File | null;
  /** 已消费 seedFile（成功或校验失败后均调用，便于父级清空） */
  onSeedConsumed?: () => void;
}

// 源文件大小保护（防止手机相册原图撑爆浏览器内存；最终限制以裁剪后 2MB 为准）
const SOURCE_MAX_BYTES = 15 * 1024 * 1024;

export default function AvatarCropModal({
  open, onClose, currentAvatar, onChanged, seedFile, onSeedConsumed,
}: AvatarCropModalProps) {
  const [media, setMedia] = useState<MediaAttachment[]>([]);
  const [imageSrc, setImageSrc] = useState<string | null>(null); // blob: 或同源 /uploads URL
  const [srcIsBlob, setSrcIsBlob] = useState(false);
  const [crop, setCrop] = useState({ x: 0, y: 0 });
  const [zoom, setZoom] = useState(1);
  const [pixelCrop, setPixelCrop] = useState<Area | null>(null);
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState("");
  const [confirmDeleteId, setConfirmDeleteId] = useState<number | null>(null);
  // 正在"直接选用"的历史头像 id（区别于裁剪上传，走 PUT /avatar/use）
  const [usingId, setUsingId] = useState<number | null>(null);
  const [dragOver, setDragOver] = useState(false);
  const fileInputRef = useRef<HTMLInputElement>(null);
  const confirmTimer = useRef<ReturnType<typeof setTimeout> | null>(null);

  // 打开时拉取媒体库
  useEffect(() => {
    if (!open) return;
    setError("");
    apiMyMedia()
      .then((res) => setMedia(res.attachments || []))
      .catch(() => setMedia([]));
  }, [open]);

  // 关闭时复位并释放本地 blob URL（媒体库的同源 URL 不能 revoke）
  useEffect(() => {
    if (!open) {
      setImageSrc((prev) => {
        if (prev && prev.startsWith("blob:")) URL.revokeObjectURL(prev);
        return null;
      });
      setSrcIsBlob(false);
      setCrop({ x: 0, y: 0 });
      setZoom(1);
      setPixelCrop(null);
      setError("");
      setBusy(false);
      setConfirmDeleteId(null);
      setUsingId(null);
      setDragOver(false);
    }
  }, [open]);

  useEffect(() => () => {
    if (confirmTimer.current) clearTimeout(confirmTimer.current);
  }, []);

  const onCropComplete = useCallback((_: Area, areaPixels: Area) => {
    setPixelCrop(areaPixels);
  }, []);

  const enterCrop = useCallback((src: string, isBlob: boolean) => {
    setError("");
    setImageSrc((prev) => {
      if (prev && prev.startsWith("blob:")) URL.revokeObjectURL(prev);
      return src;
    });
    setSrcIsBlob(isBlob);
    setCrop({ x: 0, y: 0 });
    setZoom(1);
  }, []);

  /** 校验并进入裁剪；返回错误文案，成功返回空串 */
  const acceptImageFile = useCallback((file: File): string => {
    if (!file.type.startsWith("image/")) {
      return "请选择图片文件（JPG / PNG / GIF / WebP）";
    }
    if (file.size > SOURCE_MAX_BYTES) {
      return "原图不能超过 15MB，裁剪后的头像需在 2MB 以内";
    }
    enterCrop(URL.createObjectURL(file), true);
    return "";
  }, [enterCrop]);

  // 外部拖入：弹窗打开后立刻进入裁剪
  useEffect(() => {
    if (!open || !seedFile) return;
    const errMsg = acceptImageFile(seedFile);
    if (errMsg) setError(errMsg);
    onSeedConsumed?.();
  }, [open, seedFile, acceptImageFile, onSeedConsumed]);

  /**
   * 点击媒体库图片：
   *  - 成品头像（kind=avatar，本就是合规正方形 WebP）：直接选用已有文件，
   *    走 PUT /avatar/use，绝不重新裁剪上传产生重复文件；
   *  - 其他图片（kind=image，如帖子插图，可能非正方形）：进入裁剪界面，
   *    裁剪后才生成新的头像文件上传。
   */
  const handlePick = async (item: MediaAttachment) => {
    if (busy || item.url === currentAvatar) return;
    if (item.kind === "image") {
      enterCrop(item.url, false);
      return;
    }
    setBusy(true);
    setUsingId(item.id);
    setError("");
    try {
      const res = await apiUseAvatar(item.url);
      if (!res.url) {
        setError(res.error || "设置失败，请重试");
        return;
      }
      onChanged(res.url);
    } catch {
      setError("网络错误，请重试");
    } finally {
      setBusy(false);
      setUsingId(null);
    }
  };

  const onFileChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    e.target.value = "";
    if (!file) return;
    const errMsg = acceptImageFile(file);
    if (errMsg) setError(errMsg);
  };

  const onDropZoneDragOver = (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    if (!busy) setDragOver(true);
  };

  const onDropZoneDragLeave = (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    setDragOver(false);
  };

  const onDropZoneDrop = (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    setDragOver(false);
    if (busy) return;
    const file = e.dataTransfer.files?.[0];
    if (!file) return;
    const errMsg = acceptImageFile(file);
    if (errMsg) setError(errMsg);
  };

  const backToLibrary = () => {
    if (imageSrc && srcIsBlob) URL.revokeObjectURL(imageSrc);
    setImageSrc(null);
    setSrcIsBlob(false);
    setError("");
  };

  const confirmUpload = async () => {
    if (!imageSrc || !pixelCrop || busy) return;
    setBusy(true);
    setError("");
    try {
      // 浏览器端裁剪并以 WebP 导出（质量自适应，直到 ≤ 2MB）
      const blob = await getCroppedAvatarWebp(imageSrc, pixelCrop);
      const res = await apiUploadAvatar(blob);
      if (!res.url) {
        setError(res.error || "上传失败，请重试");
        return;
      }
      onChanged(res.url); // 父组件负责关窗、广播与刷新
    } catch (err) {
      setError(err instanceof Error ? err.message : "上传失败，请重试");
    } finally {
      setBusy(false);
    }
  };

  const handleDelete = async (item: MediaAttachment) => {
    if (busy) return;
    // 两阶段确认：第一次点击进入红色确认态，3.5 秒内再点才执行
    if (confirmDeleteId !== item.id) {
      setConfirmDeleteId(item.id);
      if (confirmTimer.current) clearTimeout(confirmTimer.current);
      confirmTimer.current = setTimeout(() => setConfirmDeleteId(null), 3500);
      return;
    }
    if (confirmTimer.current) clearTimeout(confirmTimer.current);
    setConfirmDeleteId(null);
    setBusy(true);
    setError("");
    try {
      const res = await apiDeleteAttachment(item.id);
      if (res.ok === undefined && res.error) {
        setError(res.error);
        return;
      }
      setMedia((prev) => prev.filter((m) => m.id !== item.id));
      // 删的正是当前头像：清空（回到字母头像）并关闭弹窗
      if (item.url === currentAvatar) {
        onChanged("");
      }
    } catch {
      setError("网络错误，请重试");
    } finally {
      setBusy(false);
    }
  };

  return (
    <Modal
      open={open}
      title={imageSrc ? "裁剪头像" : "更换头像"}
      onClose={onClose}
      busy={busy}
      dismissOnOverlay={!busy}
      maxWidthClass="max-w-[440px]"
      panelClassName="p-5"
      ariaLabel="更换头像"
    >
        {error && <div className="alert-error mb-4">{error}</div>}

        {!imageSrc ? (
          <>
            {/* 选择新图片：点击或拖放 */}
            <button
              type="button"
              onClick={() => fileInputRef.current?.click()}
              onDragOver={onDropZoneDragOver}
              onDragLeave={onDropZoneDragLeave}
              onDrop={onDropZoneDrop}
              className="w-full flex flex-col items-center justify-center gap-2 rounded-xl py-7 px-4 text-center transition-colors hover:border-[var(--accent)]"
              style={{
                border: `1.5px dashed ${dragOver ? "var(--accent)" : "var(--line-2)"}`,
                background: dragOver
                  ? "color-mix(in srgb, var(--accent) 10%, var(--panel-2))"
                  : "var(--panel-2)",
                color: "var(--ink-2)",
              }}
            >
              <span
                className="inline-flex w-11 h-11 items-center justify-center rounded-full"
                style={{ background: "var(--accent-soft)", color: "var(--accent)" }}
              >
                <UploadCloud size={20} />
              </span>
              <span className="text-[13.5px] font-bold" style={{ color: "var(--ink)" }}>
                {dragOver ? "松开即可开始裁剪" : "点击选择或拖放图片"}
              </span>
              <span className="text-[12px] leading-relaxed" style={{ color: "var(--ink-3)" }}>
                支持 JPG / PNG / GIF / WebP，裁剪后统一转为 WebP，大小不超过 2MB
              </span>
            </button>
            <input
              ref={fileInputRef}
              type="file"
              accept="image/*"
              className="hidden"
              onChange={onFileChange}
            />

            {/* 媒体库：本人上传过的全部图片（头像 + 帖子插图） */}
            {media.length > 0 && (
              <div className="mt-5">
                <p
                  className="flex items-center gap-1.5 text-[12px] font-bold tracking-[0.04em] mb-2.5"
                  style={{ color: "var(--ink-3)" }}
                >
                  <Images size={13} /> 我的图片（历史头像点击直接使用，其他图片点击后裁剪；右上角可删除）
                </p>
                <div className="grid grid-cols-6 gap-2">
                  {media.map((item) => {
                    const active = item.url === currentAvatar;
                    const confirming = confirmDeleteId === item.id;
                    return (
                      <div
                        key={item.id}
                        // self-center：禁用网格项默认的 align-self:stretch，
                        // 否则它会与 aspect-ratio 冲突把容器拉高，光环变成竖椭圆
                        className="relative group rounded-full justify-self-center self-center w-full"
                        style={{
                          aspectRatio: "1 / 1",
                          boxShadow: active
                            ? "0 0 0 2px var(--panel), 0 0 0 4px var(--accent)"
                            : "0 0 0 1px var(--line)",
                        }}
                      >
                        <button
                          type="button"
                          onClick={() => handlePick(item)}
                          disabled={busy || active}
                          data-tip={
                            active
                              ? "当前头像"
                              : item.kind === "image"
                                ? "裁剪后设为头像"
                                : "直接设为头像（不会重复上传）"
                          }
                          // absolute inset-0：以正方形容器为确定包含块铺满，
                          // 避免 h-full 在 aspect-ratio 尺寸上的百分比解析歧义
                          className="absolute inset-0 rounded-full overflow-hidden bg-[var(--panel-2)] transition-transform hover:scale-105 disabled:cursor-default disabled:hover:scale-100"
                        >
                          {/* eslint-disable-next-line @next/next/no-img-element */}
                          <img src={item.url} alt="" className="w-full h-full object-cover" loading="lazy" />
                        </button>

                        {/* hover 指示：成品头像=直接使用，其他图片=裁剪；选用中显示 spinner */}
                        {!active && (
                          <span
                            className="pointer-events-none absolute inset-0 rounded-full flex items-center justify-center opacity-0 group-hover:opacity-100 transition-opacity"
                            style={{ background: "color-mix(in srgb, var(--ink) 45%, transparent)", color: "#fff" }}
                          >
                            {usingId === item.id ? (
                              <Loader2 size={14} className="animate-spin" />
                            ) : item.kind === "image" ? (
                              <Crop size={13} />
                            ) : (
                              <Check size={14} strokeWidth={2.6} />
                            )}
                          </span>
                        )}

                        {/* 当前头像勾选标记 */}
                        {active && (
                          <span
                            className="pointer-events-none absolute inset-0 flex items-center justify-center rounded-full"
                            style={{ background: "color-mix(in srgb, var(--accent) 35%, transparent)", color: "#fff" }}
                          >
                            <Check size={15} strokeWidth={3} />
                          </span>
                        )}

                        {/* 删除按钮（两阶段确认） */}
                        {!active && (
                          <button
                            type="button"
                            onClick={(e) => {
                              e.stopPropagation();
                              handleDelete(item);
                            }}
                            disabled={busy}
                            aria-label={confirming ? "再次点击确认删除" : "删除图片"}
                            data-tip={confirming ? "再次点击确认彻底删除" : "彻底删除"}
                            className="absolute -top-1.5 -right-1.5 w-5 h-5 rounded-full flex items-center justify-center opacity-0 group-hover:opacity-100 transition-opacity disabled:opacity-50"
                            style={{
                              background: confirming ? "var(--red, #dc2626)" : "var(--panel)",
                              color: confirming ? "#fff" : "var(--ink-2)",
                              border: "1px solid " + (confirming ? "var(--red, #dc2626)" : "var(--line-2)"),
                              boxShadow: "0 1px 4px rgba(0,0,0,0.18)",
                            }}
                          >
                            {confirming ? <AlertTriangle size={11} /> : <Trash2 size={10.5} />}
                          </button>
                        )}
                      </div>
                    );
                  })}
                </div>
              </div>
            )}
          </>
        ) : (
          <>
            {/* 裁剪区 */}
            <div
              className="relative w-full h-72 rounded-xl overflow-hidden"
              style={{ background: "#0c0d12" }}
            >
              <Cropper
                image={imageSrc}
                crop={crop}
                zoom={zoom}
                aspect={1}
                cropShape="round"
                showGrid={false}
                onCropChange={setCrop}
                onZoomChange={setZoom}
                onCropComplete={onCropComplete}
              />
            </div>

            {/* 缩放 */}
            <div className="flex items-center gap-3 mt-4">
              <span style={{ color: "var(--ink-3)" }}><ZoomIn size={15} /></span>
              <input
                type="range"
                min={1}
                max={3}
                step={0.01}
                value={zoom}
                onChange={(e) => setZoom(Number(e.target.value))}
                className="flex-1 h-1.5 rounded-full appearance-none cursor-pointer"
                style={{ accentColor: "var(--accent)", background: "var(--panel-3)" }}
                aria-label="缩放"
              />
              <span style={{ color: "var(--ink-3)" }}><ZoomIn size={19} /></span>
            </div>

            {/* 输出说明 + 操作 */}
            <div className="flex items-center justify-between mt-5">
              <span className="text-[12px]" style={{ color: "var(--ink-3)" }}>
                输出 320×320 WebP
              </span>
              <div className="flex items-center gap-2">
                <button type="button" onClick={backToLibrary} disabled={busy} className="btn btn-line btn-sm">
                  <RotateCcw size={13.5} /> 重选
                </button>
                <button type="button" onClick={confirmUpload} disabled={busy} className="btn btn-primary btn-sm">
                  {busy ? <Loader2 size={14} className="animate-spin" /> : <Check size={14} />}
                  {busy ? "上传中" : "确认上传"}
                </button>
              </div>
            </div>
          </>
        )}
    </Modal>
  );
}