import type { ValueSchema } from "@wrnexus/blocks";

export interface TextRun { text: string; bold?: boolean; italic?: boolean; underline?: boolean }
export const richTextSchema: ValueSchema<TextRun[]> = {
  kind: "rich-text",
  parse(value = [], path = "richText") {
    if (!Array.isArray(value) || value.length > 4000 || value.some(run => !run || typeof run !== "object" || typeof run.text !== "string" || Object.keys(run).some(key => !["text", "bold", "italic", "underline"].includes(key)) || ["bold", "italic", "underline"].some(key => run[key] !== undefined && typeof run[key] !== "boolean")) || value.reduce((size, run) => size + run.text.length, 0) > 200000)
      return { ok: false, errors: [{code: "email.rich-text", message: "Invalid or oversized rich text.", severity: "error", path}] };
    return { ok: true, value };
  },
};

const escape = (value: string) => value.replaceAll("&", "&amp;").replaceAll("<", "&lt;").replaceAll(">", "&gt;").replaceAll('"', "&quot;").replaceAll("'", "&#39;").replace(/\r\n?|\n/g, "<br />");
/** Ignore stale formatting if a plain-text inspector or importer changed the text. */
export function renderRichText(props: Record<string, unknown>): string {
  const parsed = richTextSchema.parse(props.richText);
  const text = String(props.text ?? "");
  if (!parsed.ok || !parsed.value.length || parsed.value.map(run => run.text).join("") !== text) return escape(text);
  return parsed.value.map(run => {
    let result = escape(run.text);
    if (run.underline) result = `<u>${result}</u>`;
    if (run.italic) result = `<em>${result}</em>`;
    if (run.bold) result = `<strong>${result}</strong>`;
    return result;
  }).join("");
}