"use client";

import Link from "@tiptap/extension-link";
import Placeholder from "@tiptap/extension-placeholder";
import { Table } from "@tiptap/extension-table";
import TableCell from "@tiptap/extension-table-cell";
import TableHeader from "@tiptap/extension-table-header";
import TableRow from "@tiptap/extension-table-row";
import TextAlign from "@tiptap/extension-text-align";
import Underline from "@tiptap/extension-underline";
import { EditorContent, useEditor } from "@tiptap/react";
import StarterKit from "@tiptap/starter-kit";
import { useEffect, useMemo, useRef, useState } from "react";

type EditorMode = "basic" | "news";

type RichTextEditorProps = {
  label: string;
  value: string;
  placeholder?: string;
  minHeightClassName?: string;
  mode?: EditorMode;
  onChange: (next: string) => void;
};

type BlockAction = {
  id: string;
  label: string;
  run: () => void;
};

type SlashMenuState = {
  open: boolean;
  top: number;
  left: number;
  slashPos: number | null;
};

function normalizeHtml(html: string) {
  const trimmed = html.trim();
  if (!trimmed) return "";
  if (trimmed === "<br>" || trimmed === "<p><br></p>") return "";
  return trimmed;
}

function buttonClass(active = false) {
  return `px-2 py-1 rounded text-xs transition-colors ${
    active ? "bg-[#ECFDF5] text-[#0F766E]" : "text-gray-700 hover:bg-gray-200"
  }`;
}

export function RichTextEditor({
  label,
  value,
  placeholder,
  minHeightClassName = "min-h-[180px]",
  mode = "basic",
  onChange,
}: RichTextEditorProps) {
  const containerRef = useRef<HTMLDivElement>(null);
  const [blockMenuOpen, setBlockMenuOpen] = useState(false);
  const [slashMenu, setSlashMenu] = useState<SlashMenuState>({
    open: false,
    top: 0,
    left: 0,
    slashPos: null,
  });

  const editor = useEditor({
    extensions: [
      StarterKit.configure({
        heading: { levels: [2, 3] },
      }),
      Underline,
      Link.configure({
        openOnClick: false,
        HTMLAttributes: {
          rel: "noopener noreferrer",
          target: "_blank",
        },
      }),
      TextAlign.configure({ types: ["heading", "paragraph"] }),
      Placeholder.configure({
        placeholder: placeholder ?? "Inhalt schreiben...",
      }),
      Table.configure({
        resizable: true,
        HTMLAttributes: { class: "nf-editor-table" },
      }),
      TableRow,
      TableHeader,
      TableCell,
    ],
    content: value || "",
    immediatelyRender: false,
    onUpdate: ({ editor: ed }) => {
      onChange(normalizeHtml(ed.getHTML()));
    },
  });

  const blockActions = useMemo<BlockAction[]>(() => {
    if (!editor) return [];
    return [
      { id: "paragraph", label: "Absatz", run: () => editor.chain().focus().setParagraph().run() },
      { id: "h2", label: "Überschrift H2", run: () => editor.chain().focus().toggleHeading({ level: 2 }).run() },
      { id: "h3", label: "Überschrift H3", run: () => editor.chain().focus().toggleHeading({ level: 3 }).run() },
      { id: "bullet", label: "Aufzählung", run: () => editor.chain().focus().toggleBulletList().run() },
      { id: "ordered", label: "Nummerierte Liste", run: () => editor.chain().focus().toggleOrderedList().run() },
      { id: "quote", label: "Zitat", run: () => editor.chain().focus().toggleBlockquote().run() },
      {
        id: "table",
        label: "Tabelle (3x3)",
        run: () =>
          editor
            .chain()
            .focus()
            .insertTable({ rows: 3, cols: 3, withHeaderRow: true })
            .run(),
      },
    ];
  }, [editor]);

  useEffect(() => {
    if (!editor) return;
    const normalized = value || "";
    if (editor.getHTML() !== normalized) {
      editor.commands.setContent(normalized, { emitUpdate: false });
    }
  }, [editor, value]);

  useEffect(() => {
    if (!editor || mode !== "news") return;

    const onKeyDown = (event: KeyboardEvent) => {
      if (!editor.isFocused) return;

      if (event.key === "Escape") {
        setSlashMenu((prev) => ({ ...prev, open: false }));
        return;
      }

      if (event.key !== "/") return;

      setTimeout(() => {
        if (!containerRef.current) return;
        const pos = editor.state.selection.from;
        const coords = editor.view.coordsAtPos(pos);
        const containerRect = containerRef.current.getBoundingClientRect();
        setSlashMenu({
          open: true,
          top: coords.bottom - containerRect.top + 6,
          left: Math.max(8, coords.left - containerRect.left),
          slashPos: pos,
        });
      }, 0);
    };

    window.addEventListener("keydown", onKeyDown);
    return () => window.removeEventListener("keydown", onKeyDown);
  }, [editor, mode]);

  useEffect(() => {
    function onClickOutside(event: MouseEvent) {
      if (!containerRef.current) return;
      if (!containerRef.current.contains(event.target as Node)) {
        setBlockMenuOpen(false);
        setSlashMenu((prev) => ({ ...prev, open: false }));
      }
    }
    window.addEventListener("mousedown", onClickOutside);
    return () => window.removeEventListener("mousedown", onClickOutside);
  }, []);

  function applyBlockAction(action: BlockAction) {
    if (!editor) return;

    if (slashMenu.open && slashMenu.slashPos) {
      editor
        .chain()
        .focus()
        .deleteRange({ from: slashMenu.slashPos - 1, to: slashMenu.slashPos })
        .run();
    }

    action.run();
    setBlockMenuOpen(false);
    setSlashMenu((prev) => ({ ...prev, open: false, slashPos: null }));
  }

  function handleLink() {
    if (!editor) return;
    const url = window.prompt("Link-URL eingeben (https://...)");
    if (url === null) return;
    const trimmedUrl = url.trim();
    if (!trimmedUrl) {
      editor.chain().focus().extendMarkRange("link").unsetLink().run();
      return;
    }
    editor.chain().focus().extendMarkRange("link").setLink({ href: trimmedUrl }).run();
  }

  if (!editor) {
    return null;
  }

  const showNewsBlockFeatures = mode === "news";

  return (
    <div ref={containerRef} className="relative">
      <label className="block text-sm font-medium text-gray-700 mb-1">{label}</label>
      <div className="border border-gray-200 rounded-md overflow-hidden bg-white">
        <div className="flex flex-wrap items-center gap-1 border-b border-gray-200 bg-gray-50 px-2 py-1.5">
          {showNewsBlockFeatures && (
            <div className="relative">
              <button
                type="button"
                onClick={() => setBlockMenuOpen((value) => !value)}
                className="px-2 py-1 rounded text-xs font-medium text-gray-700 hover:bg-gray-200"
                title="Block-Menü"
              >
                Block +
              </button>
              {blockMenuOpen && (
                <div className="absolute top-8 left-0 z-20 w-56 rounded-md border border-gray-200 bg-white shadow-lg p-1">
                  {blockActions.map((action) => (
                    <button
                      key={action.id}
                      type="button"
                      onClick={() => applyBlockAction(action)}
                      className="w-full text-left px-3 py-2 text-sm rounded hover:bg-gray-100"
                    >
                      {action.label}
                    </button>
                  ))}
                </div>
              )}
            </div>
          )}

          <button
            type="button"
            onClick={() => editor.chain().focus().toggleBold().run()}
            className={`${buttonClass(editor.isActive("bold"))} font-semibold`}
            title="Fett"
          >
            B
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().toggleItalic().run()}
            className={`${buttonClass(editor.isActive("italic"))} italic`}
            title="Kursiv"
          >
            I
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().toggleUnderline().run()}
            className={`${buttonClass(editor.isActive("underline"))} underline`}
            title="Unterstrichen"
          >
            U
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().toggleStrike().run()}
            className={`${buttonClass(editor.isActive("strike"))} line-through`}
            title="Durchgestrichen"
          >
            S
          </button>

          <span className="w-px h-4 bg-gray-300 mx-1" />

          <button
            type="button"
            onClick={() => editor.chain().focus().setParagraph().run()}
            className={buttonClass(editor.isActive("paragraph"))}
            title="Absatz"
          >
            P
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().toggleHeading({ level: 2 }).run()}
            className={buttonClass(editor.isActive("heading", { level: 2 }))}
            title="Überschrift 2"
          >
            H2
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().toggleHeading({ level: 3 }).run()}
            className={buttonClass(editor.isActive("heading", { level: 3 }))}
            title="Überschrift 3"
          >
            H3
          </button>

          <span className="w-px h-4 bg-gray-300 mx-1" />

          <button
            type="button"
            onClick={() => editor.chain().focus().toggleBulletList().run()}
            className={buttonClass(editor.isActive("bulletList"))}
            title="Aufzählung"
          >
            Liste
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().toggleOrderedList().run()}
            className={buttonClass(editor.isActive("orderedList"))}
            title="Nummerierte Liste"
          >
            1.
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().toggleBlockquote().run()}
            className={buttonClass(editor.isActive("blockquote"))}
            title="Zitat"
          >
            Quote
          </button>

          {showNewsBlockFeatures && (
            <>
              <span className="w-px h-4 bg-gray-300 mx-1" />
              <button
                type="button"
                onClick={() => editor.chain().focus().insertTable({ rows: 3, cols: 3, withHeaderRow: true }).run()}
                className={buttonClass(editor.isActive("table"))}
                title="Tabelle einfügen"
              >
                Tabelle
              </button>
              <button
                type="button"
                onClick={() => editor.chain().focus().addRowAfter().run()}
                className={buttonClass(false)}
                title="Zeile hinzufügen"
              >
                +Zeile
              </button>
              <button
                type="button"
                onClick={() => editor.chain().focus().addColumnAfter().run()}
                className={buttonClass(false)}
                title="Spalte hinzufügen"
              >
                +Spalte
              </button>
              <button
                type="button"
                onClick={() => editor.chain().focus().deleteTable().run()}
                className={buttonClass(false)}
                title="Tabelle entfernen"
              >
                -Tabelle
              </button>
            </>
          )}

          <span className="w-px h-4 bg-gray-300 mx-1" />

          <button
            type="button"
            onClick={handleLink}
            className={buttonClass(editor.isActive("link"))}
            title="Link einfügen"
          >
            Link
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().unsetAllMarks().clearNodes().run()}
            className={buttonClass(false)}
            title="Formatierung entfernen"
          >
            Reset
          </button>

          <span className="w-px h-4 bg-gray-300 mx-1" />

          <button
            type="button"
            onClick={() => editor.chain().focus().setTextAlign("left").run()}
            className={buttonClass(editor.isActive({ textAlign: "left" }))}
            title="Linksbündig"
          >
            L
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().setTextAlign("center").run()}
            className={buttonClass(editor.isActive({ textAlign: "center" }))}
            title="Zentriert"
          >
            C
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().setTextAlign("right").run()}
            className={buttonClass(editor.isActive({ textAlign: "right" }))}
            title="Rechtsbündig"
          >
            R
          </button>

          <span className="w-px h-4 bg-gray-300 mx-1" />

          <button
            type="button"
            onClick={() => editor.chain().focus().undo().run()}
            disabled={!editor.can().undo()}
            className={`${buttonClass(false)} disabled:opacity-40`}
            title="Rückgängig"
          >
            Undo
          </button>
          <button
            type="button"
            onClick={() => editor.chain().focus().redo().run()}
            disabled={!editor.can().redo()}
            className={`${buttonClass(false)} disabled:opacity-40`}
            title="Wiederholen"
          >
            Redo
          </button>
        </div>

        <EditorContent
          editor={editor}
          className={`w-full px-3 py-2 text-sm rounded-b-md focus-within:ring-1 focus-within:ring-[#0F766E] ${minHeightClassName} [&_.ProseMirror]:outline-none [&_.ProseMirror]:min-h-[inherit] [&_.ProseMirror_h2]:text-xl [&_.ProseMirror_h2]:font-semibold [&_.ProseMirror_h3]:text-lg [&_.ProseMirror_h3]:font-semibold [&_.ProseMirror_ul]:list-disc [&_.ProseMirror_ul]:ml-5 [&_.ProseMirror_ol]:list-decimal [&_.ProseMirror_ol]:ml-5 [&_.ProseMirror_blockquote]:border-l-4 [&_.ProseMirror_blockquote]:border-gray-300 [&_.ProseMirror_blockquote]:pl-3 [&_.ProseMirror_a]:text-[#0F766E] [&_.ProseMirror_a]:underline [&_.ProseMirror_table]:w-full [&_.ProseMirror_table]:border-collapse [&_.ProseMirror_table]:border [&_.ProseMirror_td]:border [&_.ProseMirror_td]:border-gray-300 [&_.ProseMirror_td]:p-2 [&_.ProseMirror_th]:border [&_.ProseMirror_th]:border-gray-300 [&_.ProseMirror_th]:p-2 [&_.ProseMirror_th]:bg-gray-100`}
        />
      </div>

      {showNewsBlockFeatures && slashMenu.open && (
        <div
          className="absolute z-30 w-60 rounded-md border border-gray-200 bg-white shadow-lg p-1"
          style={{ top: slashMenu.top, left: slashMenu.left }}
        >
          <p className="px-3 py-1 text-[11px] text-gray-500">Slash-Menü</p>
          {blockActions.map((action) => (
            <button
              key={`slash-${action.id}`}
              type="button"
              onClick={() => applyBlockAction(action)}
              className="w-full text-left px-3 py-2 text-sm rounded hover:bg-gray-100"
            >
              {action.label}
            </button>
          ))}
        </div>
      )}
    </div>
  );
}