"use client";

import { BlockNoteView } from "@blocknote/mantine";
import { de } from "@blocknote/core/locales";
import { useCreateBlockNote } from "@blocknote/react";
import { useEffect } from "react";

const API_URL = process.env.NEXT_PUBLIC_API_URL ?? "http://localhost:3002";

type NewsBlockNoteEditorProps = {
  label?: string;
  value: string;
  placeholder?: string;
  minHeightClassName?: string;
  ensureLeadingHeading?: boolean;
  onChange: (next: string) => void;
};

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

function plainTextFromHtml(html: string) {
  return html.replace(/<[^>]*>/g, " ").replace(/\s+/g, " ").trim();
}

async function uploadEditorImage(file: File) {
  const formData = new FormData();
  formData.append("file", file);

  const response = await fetch(`${API_URL}/api/uploads/image`, {
    method: "POST",
    credentials: "include",
    body: formData,
  });

  const payload = (await response.json().catch(() => ({}))) as { url?: string; error?: string };
  if (!response.ok || !payload.url) {
    throw new Error(payload.error ?? "Bild-Upload fehlgeschlagen");
  }

  return payload.url;
}

export function NewsBlockNoteEditor({
  label,
  value,
  placeholder = "Hier den Beitrag schreiben...",
  minHeightClassName = "min-h-[480px]",
  ensureLeadingHeading = false,
  onChange,
}: NewsBlockNoteEditorProps) {
  const editor = useCreateBlockNote({
    dictionary: {
      ...de,
      placeholders: {
        ...(de as { placeholders?: Record<string, string> }).placeholders,
        default: placeholder,
        emptyDocument: placeholder,
      },
    },
    uploadFile: uploadEditorImage,
  });

  useEffect(() => {
    const currentHtml = normalizeHtml(editor.blocksToHTMLLossy(editor.document));
    const targetHtml = normalizeHtml(value || "");
    if (currentHtml === targetHtml) return;

    const starterBlocks = [
      {
        type: "heading",
        props: { level: 1 },
      },
      {
        type: "paragraph",
      },
    ] as never;

    try {
      const blocks = targetHtml ? editor.tryParseHTMLToBlocks(targetHtml) : [];
      if (blocks.length > 0) {
        editor.replaceBlocks(editor.document, blocks);
        return;
      }

      const fallbackText = plainTextFromHtml(targetHtml);
      if (!fallbackText) {
        editor.replaceBlocks(editor.document, ensureLeadingHeading ? starterBlocks : []);
        return;
      }

      editor.replaceBlocks(editor.document, [
        {
          type: "paragraph",
          content: fallbackText,
        } as never,
      ]);
    } catch {
      const fallbackText = plainTextFromHtml(targetHtml);
      if (!fallbackText) {
        if (ensureLeadingHeading) {
          editor.replaceBlocks(editor.document, starterBlocks);
        }
        return;
      }
      editor.replaceBlocks(editor.document, [
        {
          type: "paragraph",
          content: fallbackText,
        } as never,
      ]);
    }
  }, [editor, ensureLeadingHeading, value]);

  return (
    <div>
      {label ? <label className="block text-sm font-medium text-gray-700 mb-1">{label}</label> : null}
      <div
        className={`rounded-md border border-gray-200 overflow-hidden bg-white ${minHeightClassName}`}
      >
        <BlockNoteView
          editor={editor}
          theme="light"
          onChange={() => {
            const html = normalizeHtml(editor.blocksToHTMLLossy(editor.document));
            onChange(html);
          }}
          slashMenu
          formattingToolbar
          sideMenu
          tableHandles
          className="bg-white"
        />
      </div>
    </div>
  );
}