interface LexicalTextNode {
  type: string;
  text?: unknown;
  children?: unknown[];
}

interface LexicalBlock {
  type: string;
  children?: unknown[];
}

export type SerializedLexicalState = {
  root: {
    type: "root";
    children: {
      type: "paragraph";
      children: { type: "text"; text: string; version: number }[];
      direction: null;
      format: "";
      indent: number;
      version: number;
    }[];
    direction: "ltr" | "rtl" | null;
    format: "left" | "start" | "center" | "right" | "end" | "justify" | "";
    indent: number;
    version: number;
  };
};

function collectText(node: unknown): string {
  if (typeof node !== "object" || node === null) return "";
  const n = node as LexicalTextNode;
  if (n.type === "linebreak") return "\n";
  if (typeof n.text === "string") return n.text;
  if (!Array.isArray(n.children)) return "";
  return n.children.map(collectText).join("");
}

function collectBlockText(node: unknown): string {
  if (typeof node !== "object" || node === null) return "";
  const n = node as LexicalBlock;
  if (!Array.isArray(n.children)) return "";
  return n.children.map(collectText).join("");
}

export function lexicalToText(details: unknown): string {
  if (typeof details !== "object" || details === null) return "";
  const root = (details as SerializedLexicalState).root;
  if (!root || !Array.isArray(root.children)) return "";
  return root.children
    .map(collectBlockText)
    .filter((line, i, all) => line.trim() !== "" || (i > 0 && i < all.length - 1))
    .join("\n");
}

export function textToLexical(text: string): SerializedLexicalState {
  const lines = text.split("\n");
  return {
    root: {
      type: "root",
      children: (lines.length > 0 ? lines : [""]).map((line) => ({
        type: "paragraph",
        children:
          line === ""
            ? []
            : [
                {
                  type: "text",
                  text: line,
                  version: 1,
                },
              ],
        direction: null,
        format: "",
        indent: 0,
        version: 1,
      })),
      direction: "ltr",
      format: "",
      indent: 0,
      version: 1,
    },
  };
}