import { XMLParser } from "fast-xml-parser";
import https from "node:https";
import { createRequire } from "node:module";
import { promisify } from "node:util";
import { extractEmail, type Email } from "../utils/extract_email.ts";
import { extractFolders, type Folder } from "../utils/extract_folder.ts";
import {
  loadConfig,
  saveConfig,
  clearConfig,
  setPassword,
  getPassword,
  hasPassword,
  initDataDir,
  type LoginConfig,
} from "../utils/config.ts";

const ntlm: any = createRequire(import.meta.url)("httpntlm");
const postAsync = promisify(ntlm.post.bind(ntlm));

const SSL_OP_LEGACY_SERVER_CONNECT = 0x00000004;

const AGENT = new https.Agent({
  keepAlive: true,
  rejectUnauthorized: false,
  secureOptions: SSL_OP_LEGACY_SERVER_CONNECT,
});

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>`;
}

const PARSER = new XMLParser({
  ignoreAttributes: false,
  attributeNamePrefix: "@_",
  removeNSPrefix: true,
  textNodeName: "#text",
});

export class EwsClient {
  private config: LoginConfig;
  private ewsUrl: string;

  constructor(config: LoginConfig, password?: string) {
    this.config = config;
    this.ewsUrl = `${config.serverUrl.replace(/\/+$/, "")}/EWS/Exchange.asmx`;
    if (password) setPassword(password);
  }

  private get domain(): string {
    return this.config.domain ?? "corp";
  }

  private get password(): string {
    const pw = getPassword();
    if (!pw) throw new Error("Not logged in. Password not found in memory.");
    return pw;
  }

  private async soapRequest(body: string, soapAction: string): Promise<any> {
    const res = await postAsync({
      url: this.ewsUrl,
      username: this.config.username,
      domain: this.domain,
      password: this.password,
      agent: AGENT,
      headers: {
        "Content-Type": "text/xml; charset=utf-8",
        SOAPAction: soapAction,
      },
      body,
    });

    if (typeof res.body !== "string") {
      throw new Error(`NTLM request failed, status=${res.statusCode}`);
    }

    return PARSER.parse(res.body);
  }

  private 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];
  }

  async verifyConnection(): Promise<{ ok: boolean; error?: string }> {
    try {
      await this.getFolderId("inbox");
      return { ok: true };
    } catch (error: any) {
      return { ok: false, error: error.message ?? String(error) };
    }
  }

  async getFolderId(folderName: string): Promise<string> {
    const lower = folderName.toLowerCase();
    const distinguished = (DISTINGUISHED_FOLDERS as Record<string, string>)[lower];

    if (distinguished) {
      const soap = buildSoapEnvelope(`\
    <m:GetFolder>
      <m:FolderShape>
        <t:BaseShape>IdOnly</t:BaseShape>
      </m:FolderShape>
      <m:FolderIds>
        <t:DistinguishedFolderId Id="${distinguished}"/>
      </m:FolderIds>
    </m:GetFolder>`);

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

      for (const msg of this.extractResponseMessages(data)) {
        const folder = msg?.Folders?.Folder;
        if (folder?.FolderId?.["@_Id"]) {
          return folder.FolderId["@_Id"];
        }
      }
    }

    const soap = buildSoapEnvelope(`\
    <m:FindFolder Traversal="Shallow">
      <m:FolderShape>
        <t:BaseShape>Default</t:BaseShape>
      </m:FolderShape>
      <m:ParentFolderIds>
        <t:DistinguishedFolderId Id="msgfolderroot"/>
      </m:ParentFolderIds>
      <m:IndexedPageFolderView MaxEntriesReturned="200" Offset="0" BasePoint="Beginning"/>
    </m:FindFolder>`);

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

    for (const msg of this.extractResponseMessages(data)) {
      const folders = msg?.RootFolder?.Folders?.Folder;
      if (!folders) continue;
      const list = Array.isArray(folders) ? folders : [folders];
      for (const f of list) {
        if (f.DisplayName?.toLowerCase() === lower) {
          return f.FolderId?.["@_Id"] ?? "";
        }
      }
    }

    throw new Error(`Folder '${folderName}' not found`);
  }

  async findItems(
    folderId: string,
    options: {
      limit?: number;
      offset?: number;
      baseShape?: string;
      restriction?: string;
      traversal?: string;
    } = {},
  ): Promise<any[]> {
    const {
      limit = 10,
      offset = 0,
      baseShape = "AllProperties",
      restriction = "",
      traversal = "Shallow",
    } = options;

    const isDistinguished =
      (DISTINGUISHED_FOLDERS as Record<string, string>)[folderId.toLowerCase()] !== undefined;

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

    const soap = buildSoapEnvelope(`\
    <m:FindItem Traversal="${traversal}">
      <m:ItemShape>
        <t:BaseShape>${baseShape}</t:BaseShape>
      </m:ItemShape>
      <m:IndexedPageItemView MaxEntriesReturned="${limit}" Offset="${offset}" BasePoint="Beginning"/>
      <m:ParentFolderIds>
        ${folderIdXml}
      </m:ParentFolderIds>
      <m:SortOrder>
        <t:FieldOrder Order="Descending">
          <t:FieldURI FieldURI="item:DateTimeReceived"/>
        </t:FieldOrder>
      </m:SortOrder>
${restriction}
    </m:FindItem>`);

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

    for (const msg of this.extractResponseMessages(data)) {
      const items = msg?.RootFolder?.Items?.Message
        ?? msg?.RootFolder?.Items?.CalendarItem;
      if (!items) continue;
      return Array.isArray(items) ? items : [items];
    }

    return [];
  }

  async getItem(itemId: string): Promise<any> {
    const soap = buildSoapEnvelope(`\
    <m:GetItem>
      <m:ItemShape>
        <t:BaseShape>AllProperties</t:BaseShape>
        <t:BodyType>HTML</t:BodyType>
      </m:ItemShape>
      <m:ItemIds>
        <t:ItemId Id="${itemId}"/>
      </m:ItemIds>
    </m:GetItem>`);

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

    for (const msg of this.extractResponseMessages(data)) {
      const items = msg?.Items;
      if (!items) continue;

      const itemKey = Object.keys(items).find((k) =>
        [
          "Message",
          "CalendarItem",
          "MeetingRequest",
          "MeetingResponse",
          "MeetingCancellation",
        ].includes(k)
      );
      if (itemKey) {
        return items[itemKey];
      }
    }

    throw new Error(`Item '${itemId}' not found`);
  }

  async findFolders(
    parentFolderId: string,
    recursive: boolean = false,
  ): Promise<Folder[]> {
    return extractFolders(
      (body, soapAction) => this.soapRequest(body, soapAction),
      parentFolderId,
      recursive,
    );
  }

  extractEmail(item: any): Email {
    return extractEmail(item);
  }

  async updateItems(
    itemIds: string[],
    updates: { fieldUri: string; value: string | boolean }[],
  ): Promise<any[]> {
    const propName = (fieldUri: string): string => {
      const parts = fieldUri.split(":");
      return parts[parts.length - 1];
    };

    const changesXml = itemIds.map((id) => {
      const updatesXml = updates.map((u) => {
        const val = typeof u.value === "boolean"
          ? (u.value ? "true" : "false")
          : u.value;
        return `\
            <t:SetItemField>
              <t:FieldURI FieldURI="${u.fieldUri}"/>
              <t:Message>
                <t:${propName(u.fieldUri)}>${String(val)}</t:${
          propName(u.fieldUri)
        }>
              </t:Message>
            </t:SetItemField>`;
      }).join("\n");

      return `\
        <t:ItemChange>
          <t:ItemId Id="${id}"/>
          <t:Updates>
${updatesXml}
          </t:Updates>
        </t:ItemChange>`;
    }).join("\n");

    const soap = buildSoapEnvelope(`\
    <m:UpdateItem MessageDisposition="SaveOnly" ConflictResolution="AutoResolve">
      <m:ItemChanges>
${changesXml}
      </m:ItemChanges>
    </m:UpdateItem>`);

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

    return this.extractResponseMessages(data);
  }

  async getAttachment(
    attachmentId: string,
  ): Promise<{ content: Buffer; name: string; contentType: string }> {
    const soap = buildSoapEnvelope(`\
    <m:GetAttachment>
      <m:AttachmentIds>
        <t:AttachmentId Id="${attachmentId}"/>
      </m:AttachmentIds>
    </m:GetAttachment>`);

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

    for (const msg of this.extractResponseMessages(data)) {
      const attachments = msg?.Attachments?.FileAttachment;
      if (!attachments) continue;
      const list = Array.isArray(attachments) ? attachments : [attachments];
      for (const a of list) {
        const contentBase64 = a.Content ?? "";
        const content = Buffer.from(contentBase64, "base64");
        return {
          content,
          name: a.Name ?? "attachment",
          contentType: a.ContentType ?? "application/octet-stream",
        };
      }
    }

    throw new Error(`Attachment '${attachmentId}' not found`);
  }

  async findCalendarItems(
    folderId: string,
    startDate: string,
    endDate: string,
  ): Promise<any[]> {
    const soap = buildSoapEnvelope(`\
    <m:FindItem Traversal="Shallow">
      <m:ItemShape>
        <t:BaseShape>AllProperties</t:BaseShape>
        <t:BodyType>HTML</t:BodyType>
      </m:ItemShape>
      <m:ParentFolderIds>
        <t:FolderId Id="${folderId}"/>
      </m:ParentFolderIds>
      <m:CalendarView MaxEntriesReturned="200" StartDate="${startDate}" EndDate="${endDate}"/>
    </m:FindItem>`);

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

    for (const msg of this.extractResponseMessages(data)) {
      const items = msg?.RootFolder?.Items?.CalendarItem;
      if (!items) continue;
      return Array.isArray(items) ? items : [items];
    }

    return [];
  }

  async getUserAvailability(
    emails: string[],
    startDate: string,
    endDate: string,
    requestedView: string = "DetailedMerged",
  ): Promise<any> {
    const mailboxDataXml = emails.map((email) =>
      `\
        <t:MailboxData>
          <t:Email>
            <t:Address>${
        email.replace(/&/g, "&amp;").replace(/</g, "&lt;")
      }</t:Address>
          </t:Email>
          <t:AttendeeType>Required</t:AttendeeType>
        </t:MailboxData>`
    ).join("\n");

    const soap = `<?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>
    <m:GetUserAvailabilityRequest>
      <m:MailboxDataArray>
${mailboxDataXml}
      </m:MailboxDataArray>
      <m:FreeBusyViewOptions>
        <t:TimeWindow>
          <t:StartTime>${startDate}T00:00:00</t:StartTime>
          <t:EndTime>${endDate}T23:59:59</t:EndTime>
        </t:TimeWindow>
        <t:MergedFreeBusyIntervalInMinutes>30</t:MergedFreeBusyIntervalInMinutes>
        <t:RequestedView>${requestedView}</t:RequestedView>
      </m:FreeBusyViewOptions>
    </m:GetUserAvailabilityRequest>
  </s:Body>
</s:Envelope>`;

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

    return data;
  }

  async resolveNames(
    query: string,
    fullContact: boolean = true,
  ): Promise<any[]> {
    const soap = buildSoapEnvelope(`\
    <m:ResolveNames ReturnFullContactData="${fullContact}" SearchScope="ActiveDirectoryContacts">
      <m:UnresolvedEntry>${
      query.replace(/&/g, "&amp;").replace(/</g, "&lt;")
    }</m:UnresolvedEntry>
    </m:ResolveNames>`);

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

    for (const msg of this.extractResponseMessages(data)) {
      const resolutions = msg?.ResolutionSet?.Resolution;
      if (resolutions) {
        return Array.isArray(resolutions) ? resolutions : [resolutions];
      }
    }

    return [];
  }
}

// Re-export for backward compatibility
export {
  initDataDir,
  loadConfig,
  saveConfig,
  clearConfig,
  setPassword,
  getPassword,
  hasPassword,
} from "../utils/config.ts";