"use client";

import { Plus, RotateCcw, X } from "lucide-react";
import { useCallback, useMemo, useRef, useState, type KeyboardEvent } from "react";
import { DEFAULT_ATTACHMENT_EXTS } from "@/lib/api";
import ConfirmDialog from "@/components/ConfirmDialog";

/** 分组一键加入（只补缺，不删已有） */
export const ATTACHMENT_EXT_GROUPS: { id: string; label: string; exts: string[] }[] = [
  {
    id: "doc",
    label: "文档",
    exts: ["pdf", "txt", "md", "csv", "json", "doc", "docx", "xls", "xlsx", "ppt", "pptx"],
  },
  {
    id: "archive",
    label: "压缩包",
    exts: ["zip", "7z", "rar", "tar", "gz", "tgz"],
  },
  {
    id: "image",
    label: "图片",
    exts: ["jpg", "jpeg", "png", "webp", "gif"],
  },
  {
    id: "media",
    label: "音视频",
    exts: ["mp3", "wav", "ogg", "mp4", "webm"],
  },
  {
    id: "install",
    label: "安装包",
    exts: ["exe", "msi", "msp", "apk", "dmg", "iso", "deb", "rpm", "dll"],
  },
  {
    id: "web",
    label: "网页与脚本",
    exts: ["html", "htm", "js", "mjs", "css", "svg", "xml", "bat", "cmd", "ps1", "sh"],
  },
];

function parseInputTokens(raw: string): string[] {
  return raw
    .split(/[,，;\s]+/)
    .map((s) => s.trim().toLowerCase().replace(/^\./, ""))
    .filter(Boolean);
}

function isValidExt(e: string): boolean {
  return /^[a-z0-9]{1,16}$/.test(e);
}

/**
 * 附件扩展名芯片编辑器：增删、批量输入、分组补缺、恢复默认。
 * 列表变更需显式保存（由父级 dirty + 保存按钮控制）。
 */
export default function AdminExtChipEditor({
  value,
  onChange,
  disabled,
  maxCount = 80,
}: {
  value: string[];
  onChange: (next: string[]) => void;
  disabled?: boolean;
  maxCount?: number;
}) {
  const [draft, setDraft] = useState("");
  const [hint, setHint] = useState("");
  const [confirmReset, setConfirmReset] = useState(false);
  const inputRef = useRef<HTMLInputElement>(null);

  const setHintBrief = useCallback((msg: string) => {
    setHint(msg);
    window.setTimeout(() => setHint(""), 2200);
  }, []);

  const addExts = useCallback(
    (raw: string[]) => {
      if (disabled) return;
      const next = [...value];
      const seen = new Set(next);
      let added = 0;
      let invalid = 0;
      for (const token of raw) {
        if (!isValidExt(token)) {
          invalid++;
          continue;
        }
        if (seen.has(token)) continue;
        if (next.length >= maxCount) {
          setHintBrief(`最多 ${maxCount} 个扩展名`);
          break;
        }
        seen.add(token);
        next.push(token);
        added++;
      }
      if (invalid && !added) setHintBrief("扩展名仅允许字母与数字");
      else if (invalid) setHintBrief(`已加入 ${added} 个，跳过非法项`);
      else if (!added && raw.length) setHintBrief("已在列表中");
      if (added) onChange(next);
      setDraft("");
    },
    [disabled, maxCount, onChange, setHintBrief, value]
  );

  const removeAt = (idx: number) => {
    if (disabled) return;
    onChange(value.filter((_, i) => i !== idx));
  };

  const mergeGroup = (exts: string[]) => {
    if (disabled) return;
    const seen = new Set(value);
    const next = [...value];
    for (const e of exts) {
      if (seen.has(e)) continue;
      if (next.length >= maxCount) break;
      seen.add(e);
      next.push(e);
    }
    onChange(next);
  };

  const onKeyDown = (e: KeyboardEvent<HTMLInputElement>) => {
    if (e.key === "Enter" || e.key === ",") {
      e.preventDefault();
      addExts(parseInputTokens(draft));
      return;
    }
    if (e.key === "Backspace" && draft === "" && value.length > 0) {
      e.preventDefault();
      removeAt(value.length - 1);
    }
  };

  const emptyWarn = value.length === 0;

  const groupButtons = useMemo(
    () =>
      ATTACHMENT_EXT_GROUPS.map((g) => (
        <button
          key={g.id}
          type="button"
          className="btn btn-line btn-sm !py-1 !px-2 text-[12px]"
          disabled={disabled}
          onClick={() => mergeGroup(g.exts)}
        >
          + {g.label}
        </button>
      )),
    // eslint-disable-next-line react-hooks/exhaustive-deps
    [disabled, value]
  );

  return (
    <div className={`j13-ext-editor${disabled ? " is-disabled" : ""}`}>
      {emptyWarn ? (
        <p className="j13-ext-warn" role="status">
          当前列表为空：开启限制时将无法上传任何附件
        </p>
      ) : null}

      <div className="j13-ext-groups" aria-label="分组一键加入">
        {groupButtons}
        <button
          type="button"
          className="btn btn-line btn-sm !py-1 !px-2 text-[12px] inline-flex items-center gap-1"
          disabled={disabled}
          onClick={() => setConfirmReset(true)}
        >
          <RotateCcw size={12} />
          恢复默认
        </button>
      </div>

      <div
        className="j13-ext-wall"
        onClick={() => inputRef.current?.focus()}
        role="group"
        aria-label="扩展名列表"
      >
        {value.map((ext, idx) => (
          <span key={ext} className="j13-ext-chip">
            .{ext}
            <button
              type="button"
              className="j13-ext-chip-x"
              disabled={disabled}
              aria-label={`移除 ${ext}`}
              onClick={(e) => {
                e.stopPropagation();
                removeAt(idx);
              }}
            >
              <X size={12} />
            </button>
          </span>
        ))}
        <span className="j13-ext-input-wrap">
          <Plus size={14} className="opacity-40 shrink-0" aria-hidden />
          <input
            ref={inputRef}
            type="text"
            className="j13-ext-input"
            value={draft}
            disabled={disabled}
            placeholder="输入扩展名，Enter 添加"
            aria-label="添加扩展名"
            onChange={(e) => setDraft(e.target.value)}
            onKeyDown={onKeyDown}
            onBlur={() => {
              if (draft.trim()) addExts(parseInputTokens(draft));
            }}
          />
        </span>
      </div>

      {hint ? (
        <p className="meta text-[12px] mt-1.5" role="status">
          {hint}
        </p>
      ) : (
        <p className="meta text-[12px] mt-1.5">
          支持 <code className="text-[11px]">.msi</code> / <code className="text-[11px]">msi</code>{" "}
          或逗号批量；最多 {maxCount} 个
        </p>
      )}

      <ConfirmDialog
        open={confirmReset}
        title="恢复默认扩展名"
        message="将用站点默认列表覆盖当前编辑内容（需再点保存才会生效）。"
        confirmLabel="恢复默认"
        onCancel={() => setConfirmReset(false)}
        onConfirm={() => {
          onChange([...DEFAULT_ATTACHMENT_EXTS]);
          setConfirmReset(false);
        }}
      />
    </div>
  );
}