export interface Folder {
  name: string;
  id: string;
  totalCount: number;
  unreadCount: number;
  childFolderCount: number;
}

type SoapRequest = (body: string, soapAction: string) => Promise<any>;

export async function extractFolders(
  soapRequest: SoapRequest,
  parentFolderId: string,
  recursive: boolean = false,
): Promise<Folder[]> {
  const DISTINGUISHED_FOLDERS: Record<string, string> = {
    inbox: "inbox",
    "входящие": "inbox",
    sent: "sentitems",
    "отправленные": "sentitems",
    drafts: "drafts",
    "черновики": "drafts",
    deleted: "deleteditems",
    "удаленные": "deleteditems",
    junk: "junkemail",
    "нежелательная почта": "junkemail",
    outbox: "outbox",
    "исходящие": "outbox",
    calendar: "calendar",
    "календарь": "calendar",
  };

  function buildSoapEnvelope(body: string): string {
    return `<?xml version="1.0" encoding="utf-8"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"
  xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages"
  xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
  <s:Body>
${body}
  </s:Body>
</s:Envelope>`;
  }

  function extractResponseMessages(data: any): any[] {
    const body = data?.Envelope?.Body;
    if (!body) return [];
    const firstKey = Object.keys(body).find((k) => k.endsWith("Response"));
    if (!firstKey) return [];
    const rm = body[firstKey]?.ResponseMessages;
    if (!rm) return [];
    const msgKey = Object.keys(rm).find((k) => k.endsWith("ResponseMessage"));
    if (!msgKey) return [];
    const msgs = rm[msgKey];
    return Array.isArray(msgs) ? msgs : [msgs];
  }

  const traversal = recursive ? "Deep" : "Shallow";
  const isDistinguished =
    DISTINGUISHED_FOLDERS[parentFolderId.toLowerCase()] !== undefined
    || ["msgfolderroot"].includes(parentFolderId.toLowerCase());

  const folderIdXml = isDistinguished
    ? `<t:DistinguishedFolderId Id="${parentFolderId}"/>`
    : `<t:FolderId Id="${parentFolderId}"/>`;

  const soap = buildSoapEnvelope(`\
    <m:FindFolder Traversal="${traversal}">
      <m:FolderShape>
        <t:BaseShape>Default</t:BaseShape>
      </m:FolderShape>
      <m:ParentFolderIds>
        ${folderIdXml}
      </m:ParentFolderIds>
      <m:IndexedPageFolderView MaxEntriesReturned="200" Offset="0" BasePoint="Beginning"/>
    </m:FindFolder>`);

  const data = await soapRequest(
    soap,
    "http://schemas.microsoft.com/exchange/services/2006/messages/FindFolder",
  );

  const folders: Folder[] = [];

  for (const msg of extractResponseMessages(data)) {
    const folderList = msg?.RootFolder?.Folders?.Folder;
    if (!folderList) continue;
    const list = Array.isArray(folderList) ? folderList : [folderList];

    for (const f of list) {
      folders.push({
        name: f.DisplayName ?? "Unknown",
        id: f.FolderId?.["@_Id"] ?? "",
        totalCount: f.TotalCount ?? 0,
        unreadCount: f.UnreadCount ?? 0,
        childFolderCount: f.ChildFolderCount ?? 0,
      });
    }
  }

  return folders;
}