"use client";
import {
  Bold,
  Italic,
  Underline,
  Strikethrough,
  List,
  ListOrdered,
  Link2,
  X,
} from "lucide-react";
import { useEffect, useRef, useState } from "react";
import {
  createEditor,
  Editor,
  Element,
  Transforms,
  type Descendant,
} from "slate";
import { withHistory } from "slate-history";
import {
  Editable,
  Slate,
  withReact,
  ReactEditor,
  type RenderElementProps,
  type RenderLeafProps,
} from "slate-react";
import {
  type NoteDocument,
  type NoteParagraph,
  safeNoteLink,
  serializeNoteDocument,
} from "@/lib/flow-board/topic-notes";

export function XmindNotesEditor({
  value,
  onChange,
}: {
  value: NoteDocument;
  onChange: (value: NoteDocument) => void;
}) {
  const [editor] = useState(() => withHistory(withReact(createEditor())));
  const sourceRef = useRef(value);
  sourceRef.current = value;
  const onChangeRef = useRef(onChange);
  onChangeRef.current = onChange;
  const [revision, setRevision] = useState(0);
  const [linkOpen, setLinkOpen] = useState(false),
    [link, setLink] = useState("");
  const [linkError, setLinkError] = useState("");
  const savedSelection = useRef(editor.selection);
  useEffect(() => {
    if (
      JSON.stringify(serializeNoteDocument(editor.children as NoteDocument)) ===
      JSON.stringify(serializeNoteDocument(value))
    )
      return;
    editor.children = value as Descendant[];
    editor.selection = null;
    editor.history = { undos: [], redos: [] };
    editor.onChange();
  }, [editor, value]);
  const marks = Editor.marks(editor) as Record<string, unknown> | null;
  // Toolbar presses can arrive before Slate's throttled selection listener.
  const syncDOMSelection = () => {
    const selection = window.getSelection();
    if (
      !selection?.anchorNode ||
      !ReactEditor.hasDOMNode(editor, selection.anchorNode)
    )
      return;
    const range = ReactEditor.toSlateRange(editor, selection, {
      exactMatch: false,
      suppressThrow: true,
    });
    if (range) Transforms.select(editor, range);
  };
  const toggleMark = (
    mark: "bold" | "italic" | "underline" | "strikethrough"
  ) => {
    syncDOMSelection();
    const currentMarks = Editor.marks(editor) as Record<string, unknown> | null;
    if (currentMarks?.[mark]) Editor.removeMark(editor, mark);
    else Editor.addMark(editor, mark, true);
    setRevision((v) => v + 1);
  };
  const toggleList = (list: "bullet" | "number") => {
    syncDOMSelection();
    const match = Array.from(
      Editor.nodes(editor, { match: (n) => Element.isElement(n) })
    )[0];
    Transforms.setNodes(
      editor,
      {
        list: (match?.[0] as NoteParagraph)?.list === list ? undefined : list,
      } as Partial<Descendant>,
      { match: (n) => Element.isElement(n) }
    );
  };
  const applyLink = () => {
    const href = link.trim() ? safeNoteLink(link.trim()) : "";
    if (href === null) {
      setLinkError("请输入完整的网页或邮件链接。");
      return;
    }
    if (savedSelection.current)
      Transforms.select(editor, savedSelection.current);
    if (href) Editor.addMark(editor, "href", href);
    else Editor.removeMark(editor, "href");
    setLinkOpen(false);
    editor.onChange();
  };
  const leaf = ({ attributes, children, leaf }: RenderLeafProps) => {
    const t = leaf as {
      bold?: boolean;
      italic?: boolean;
      underline?: boolean;
      strikethrough?: boolean;
      href?: string;
    };
    const href = safeNoteLink(t.href || "");
    return (
      <span
        {...attributes}
        style={{
          fontWeight: t.bold ? 700 : undefined,
          fontStyle: t.italic ? "italic" : undefined,
          textDecoration:
            [
              t.underline ? "underline" : "",
              t.strikethrough ? "line-through" : "",
            ]
              .filter(Boolean)
              .join(" ") || undefined,
        }}
      >
        {href ? (
          <a
            href={href}
            title={href}
            rel="noopener noreferrer"
            onClick={(e) => {
              if (!e.metaKey && !e.ctrlKey) e.preventDefault();
            }}
            target="_blank"
          >
            {children}
          </a>
        ) : (
          children
        )}
      </span>
    );
  };
  const element = ({ attributes, children, element }: RenderElementProps) => {
    const p = element as NoteParagraph;
    return (
      <p
        {...attributes}
        data-note-list={p.list}
        style={{ marginLeft: Math.max(0, Math.min(120, p.indent || 0)) }}
      >
        {children}
      </p>
    );
  };
  return (
    <div className="xmind-notes-editor" data-editor-revision={revision}>
      <Slate
        editor={editor}
        initialValue={value as Descendant[]}
        onChange={(next) => {
          setRevision((v) => v + 1);
          if (editor.operations.every((o) => o.type === "set_selection"))
            return;
          const doc = next as NoteDocument;
          if (
            JSON.stringify(serializeNoteDocument(doc)) !==
            JSON.stringify(serializeNoteDocument(sourceRef.current))
          )
            onChangeRef.current(doc);
        }}
      >
        <div
          className="xmind-notes-toolbar"
          role="toolbar"
          aria-label="笔记格式"
        >
          {(
            [
              ["bold", "加粗", Bold],
              ["italic", "斜体", Italic],
              ["underline", "下划线", Underline],
              ["strikethrough", "删除线", Strikethrough],
            ] as const
          ).map(([mark, label, Icon]) => (
            <button
              key={mark}
              type="button"
              aria-label={`笔记${label}`}
              aria-pressed={Boolean(marks?.[mark])}
              onMouseDown={(e) => {
                e.preventDefault();
                toggleMark(mark);
              }}
            >
              <Icon size={17} />
            </button>
          ))}
          <button
            type="button"
            aria-label="笔记无序列表"
            onMouseDown={(e) => {
              e.preventDefault();
              toggleList("bullet");
            }}
          >
            <List size={17} />
          </button>
          <button
            type="button"
            aria-label="笔记有序列表"
            onMouseDown={(e) => {
              e.preventDefault();
              toggleList("number");
            }}
          >
            <ListOrdered size={17} />
          </button>
          <button
            type="button"
            aria-label="笔记链接"
            onMouseDown={(e) => {
              e.preventDefault();
              syncDOMSelection();
              savedSelection.current = editor.selection;
              setLink(String(marks?.href || ""));
              setLinkError("");
              setLinkOpen(!linkOpen);
            }}
          >
            <Link2 size={17} />
          </button>
        </div>
        {linkOpen ? (
          <div className="xmind-note-link-form">
            <input
              aria-label="笔记链接地址"
              placeholder="https://…"
              value={link}
              onChange={(e) => setLink(e.target.value)}
              onKeyDown={(e) => {
                if (e.key === "Enter") {
                  e.preventDefault();
                  applyLink();
                }
              }}
            />
            <button type="button" onClick={applyLink}>
              确定
            </button>
            <button
              type="button"
              aria-label="取消笔记链接"
              onClick={() => setLinkOpen(false)}
            >
              <X size={14} />
            </button>
            {linkError ? <p role="alert">{linkError}</p> : null}
          </div>
        ) : null}
        <Editable
          aria-label="主题备注"
          className="xmind-note-content"
          placeholder="为这个主题补充说明…"
          renderLeaf={leaf}
          renderElement={element}
          onKeyDown={(e) => {
            if (
              (e.metaKey || e.ctrlKey) &&
              ["b", "i", "u"].includes(e.key.toLowerCase())
            ) {
              e.preventDefault();
              toggleMark(
                (
                  { b: "bold", i: "italic", u: "underline" } as Record<
                    string,
                    "bold" | "italic" | "underline"
                  >
                )[e.key.toLowerCase()]
              );
            }
            if ((e.metaKey || e.ctrlKey) && e.key.toLowerCase() === "z")
              e.stopPropagation();
            if (e.key === "Tab") {
              e.preventDefault();
              const match = Array.from(
                Editor.nodes(editor, { match: (n) => Element.isElement(n) })
              )[0];
              const indent = (match?.[0] as NoteParagraph)?.indent || 0;
              Transforms.setNodes(
                editor,
                {
                  indent: Math.max(
                    0,
                    Math.min(120, indent + (e.shiftKey ? -20 : 20))
                  ),
                } as Partial<Descendant>,
                { match: (n) => Element.isElement(n) }
              );
            }
          }}
        />
      </Slate>
    </div>
  );
}