import type { ContactEntry } from "./block-types";

function vcardEscape(s: string): string {
  return s.replace(/\\/g, "\\\\").replace(/,/g, "\\,").replace(/;/g, "\\;").replace(/\n/g, "\\n");
}

function buildVCard(c: ContactEntry): string {
  const name = vcardEscape(c.name ?? "");
  const orgs = (c.organisations ?? [])
    .filter((o): o is { name?: string } => typeof o === "object" && !!o.name)
    .map((o) => vcardEscape(o.name ?? ""))
    .join(", ");
  return [
    "BEGIN:VCARD",
    "VERSION:3.0",
    `FN:${name}`,
    "N:;;;;",
    orgs ? `ORG:${orgs}` : null,
    c.role ? `TITLE:${vcardEscape(c.role)}` : null,
    c.phone ? `TEL;TYPE=CELL:${c.phone.replace(/\s/g, "")}` : null,
    c.email ? `EMAIL:${vcardEscape(c.email)}` : null,
    c.note ? `ADR:;;${vcardEscape(c.note)};;;;` : null,
    "END:VCARD",
  ].filter(Boolean).join("\r\n");
}

export function buildVCardString(c: ContactEntry): string {
  return buildVCard(c);
}

function triggerDownload(content: string, filename: string): void {
  const blob = new Blob([content], { type: "text/vcard;charset=utf-8" });
  const url = URL.createObjectURL(blob);
  const a = document.createElement("a");
  a.href = url;
  a.download = filename;
  a.click();
  URL.revokeObjectURL(url);
}

export function downloadVCard(c: ContactEntry): void {
  triggerDownload(buildVCard(c), `${(c.name ?? "kontakt").toLowerCase().replace(/\s+/g, "-")}.vcf`);
}

export function downloadVCardAll(contacts: ContactEntry[], filename = "kontakte.vcf"): void {
  triggerDownload(contacts.map(buildVCard).join("\r\n"), filename);
}