import axios, { type AxiosInstance, type AxiosRequestConfig, type AxiosResponse } from 'axios';
import { wrapper } from 'axios-cookiejar-support';
import { JSDOM } from 'jsdom';
import { CookieJar } from 'tough-cookie';
import type {
  AgrarmonitorApiCustomer,
  AgrarmonitorConnectorOptions,
  AgrarmonitorConnectorResult,
  AgrarmonitorDeviceRegistrationOptions,
  AgrarmonitorDeviceRegistrationResult,
  AgrarmonitorFetchCustomersOptions,
  AgrarmonitorFreischaltungStatus,
  AgrarmonitorLoginStrategy,
  AgrarmonitorRegistrierungStatus,
  EingangsrechnungLivesearchResult,
  Logger,
  Rechnungsdaten,
} from './types';

type RetryableAxiosRequestConfig = AxiosRequestConfig & {
  _agrarmonitorRetry?: boolean;
};

export class AgrarmonitorConnector implements AgrarmonitorConnectorResult {
  public http!: AxiosInstance;

  private static readonly s3DateienBaseUrl = 'https://s3-eu-central-1.amazonaws.com/dateien.agrarmonitor.de/07';

  private readonly baseUrl: string;
  private readonly apiBaseUrl: string;
  private readonly timeoutMs: number;
  private readonly autoLogin: boolean;
  private readonly autoRetry: boolean;
  private readonly loginStrategy: AgrarmonitorLoginStrategy;
  private readonly logger?: Logger;
  private cookieJar!: CookieJar;
  private apiHttp!: AxiosInstance;
  private loginInProgress: Promise<void> | null = null;

  constructor(private readonly options: AgrarmonitorConnectorOptions) {
    this.baseUrl = options.baseUrl ?? 'https://admin7.agrarmonitor.de';
    this.apiBaseUrl = this.normalizeApiBaseUrl(options.apiBaseUrl ?? 'https://api.agrarmonitor.de/v1');
    this.timeoutMs = options.timeoutMs ?? 15000;
    this.autoLogin = options.autoLogin ?? true;
    this.autoRetry = options.autoRetry ?? true;
    this.loginStrategy = options.loginStrategy ?? 'auto';
    this.logger = options.logger;
  }

  async init(): Promise<this> {
    this.cookieJar = await this.options.cookieStore.load();
    this.http = this.createHttpClient();
    this.apiHttp = this.createApiHttpClient();

    if (this.autoLogin) {
      const valid = await this.isSessionValid();

      if (!valid) {
        await this.login();
      }
    }

    return this;
  }

  async login(): Promise<void> {
    if (this.loginInProgress) {
      return this.loginInProgress;
    }

    this.loginInProgress = this.performLogin().finally(() => {
      this.loginInProgress = null;
    });

    return this.loginInProgress;
  }

  async clearSession(): Promise<void> {
    this.cookieJar = new CookieJar();
    await this.options.cookieStore.clear();
    this.http = this.createHttpClient();
    this.apiHttp = this.createApiHttpClient();
  }

  async saveSession(): Promise<void> {
    await this.options.cookieStore.save(this.cookieJar);
  }

  async getCookieCount(url = this.baseUrl): Promise<number> {
    return this.cookieJar.getCookiesSync(url).length;
  }

  async checkFreigeschaltet(): Promise<AgrarmonitorFreischaltungStatus> {
    const response = await this.http.get('/', {
      maxRedirects: 0,
      validateStatus: status => status >= 200 && status < 400,
    });

    await this.saveSession();

    const redirectLocation = this.getHeader(response, 'location');
    const redirected = response.status >= 300 && response.status < 400 && this.isFreischaltungUrl(redirectLocation);

    return {
      freigeschaltet: !redirected,
      status: response.status,
      redirected,
      redirectLocation,
      timestamp: new Date().toISOString(),
      cookies: await this.getCookieCount(),
    };
  }

  async checkRegistriert(): Promise<AgrarmonitorRegistrierungStatus> {
    const response = await this.http.get('/', {
      maxRedirects: 5,
      validateStatus: status => status >= 200 && status < 500,
    });

    await this.saveSession();

    const pageContent = typeof response.data === 'string' ? response.data : '';
    const hasRegistrationText = pageContent.includes('Neues Gerät registrieren');

    return {
      registriert: !hasRegistrationText,
      status: response.status,
      hasRegistrationText,
      timestamp: new Date().toISOString(),
      cookies: await this.getCookieCount(),
    };
  }

  async registerDevice(
    registration: AgrarmonitorDeviceRegistrationOptions
  ): Promise<AgrarmonitorDeviceRegistrationResult> {
    const agrarmonitorId = registration.agrarmonitorId.trim();
    const pcName = registration.pcName.trim();

    if (!agrarmonitorId || !pcName) {
      throw new Error('AgrarmonitorID und PC-Name sind erforderlich');
    }

    const freischaltungResponse = await this.http.get('/freischaltung/');
    const responseContent = typeof freischaltungResponse.data === 'string' ? freischaltungResponse.data : '';
    const nonce = this.extractNonce(responseContent, '#nonce, input[name="nonce"]');

    const registerResponse = await this.http.post(
      '/freischaltung/api/register.php',
      {
        firma: agrarmonitorId,
        name: pcName,
        nonce,
      },
      {
        headers: {
          'Content-Type': 'application/json',
        },
        validateStatus: status => status >= 200 && status < 500,
      }
    );

    await this.saveSession();

    const success = registerResponse.status >= 200 && registerResponse.status < 300;

    return {
      success,
      status: registerResponse.status,
      message: success ? 'Registrierung erfolgreich' : 'Registrierung fehlgeschlagen',
      data: {
        agrarmonitorId,
        pcName,
        nonce: this.maskNonce(nonce),
      },
      timestamp: new Date().toISOString(),
      cookies: await this.getCookieCount(),
    };
  }

  async fetchCustomers(options: AgrarmonitorFetchCustomersOptions = {}): Promise<AgrarmonitorApiCustomer[]> {
    const response = await this.apiRequest<{ data?: unknown }>('/kunden', {
      params: {
        per_page: options.perPage ?? 99999,
      },
      apiToken: options.apiToken,
    });

    const responseData = response.data;

    if (!responseData || !Array.isArray(responseData.data)) {
      throw new Error('Ungueltige Agrarmonitor API-Antwort');
    }

    return responseData.data as AgrarmonitorApiCustomer[];
  }

  async eingangsrechnungenLivesearch(suchstring: string): Promise<EingangsrechnungLivesearchResult[]> {
    const response = await this.http.get('/module/dateien/livesearch.php', {
      params: this.createDateienLivesearchParams(suchstring),
    });

    await this.saveSession();

    const document = this.parseHtmlDocument(response.data);
    const rows = Array.from(document.querySelectorAll<HTMLTableRowElement>('table#dateien tbody tr'));
    const results: EingangsrechnungLivesearchResult[] = [];

    for (const row of rows) {
      const cells = Array.from(row.querySelectorAll<HTMLTableCellElement>('td'));
      const typText = cells[3]?.textContent?.trim() ?? '';

      if (!typText.startsWith('Eingangsrechnungen')) {
        continue;
      }

      const dokumentId = this.parseNumber(row.getAttribute('data-file_id'));
      const dataFile = row.getAttribute('data-file') ?? '';
      const dokumentName = cells[2]?.querySelector('b > a')?.textContent?.trim() ?? '';
      const dateiName = cells[2]?.querySelector('span')?.textContent?.trim() ?? '';
      const belegLink = cells[3]?.querySelector<HTMLAnchorElement>('a');
      const belegTextParts = (belegLink?.textContent ?? '').split(',').map(part => part.trim()).filter(Boolean);
      const belegNummer = belegTextParts[0] ?? '';
      const belegDatum = this.parseGermanShortDateFromText(belegTextParts.at(-1) ?? '');
      const eingangId = this.parseNumber(this.lastPathSegment(belegLink?.getAttribute('href') ?? ''));
      const { interneBelegNummer, kundenId, betriebId, dokumentTyp } =
        await this.getEingangsrechnungEditMeta(eingangId);
      const { eingangsDatum, buchungsDatum } = await this.getEingangsrechnungDetailMeta(eingangId);

      results.push({
        dokumentId,
        vorschauUrl: `${AgrarmonitorConnector.s3DateienBaseUrl}/v_${this.fileBasename(dataFile)}.png`,
        dokumentUrl: `${AgrarmonitorConnector.s3DateienBaseUrl}/${dataFile}`,
        dokumentName,
        dateiName,
        belegNummer,
        interneBelegNummer,
        belegDatum,
        buchungsDatum,
        eingangsDatum,
        eingangId,
        kundenId,
        betriebId,
        dokumentTyp,
      });
    }

    return results;
  }

  async eingangsrechnungVorhanden(suchstring: string): Promise<boolean> {
    const response = await this.http.get('/module/dateien/livesearch.php', {
      params: this.createDateienLivesearchParams(suchstring),
    });

    await this.saveSession();

    return this.hasTableRows(response.data, 'table#dateien tbody tr');
  }

  async eingangsrechnungImDateieingangVorhanden(suchstring: string): Promise<boolean> {
    const response = await this.http.get('/module/dateien/eingang/livesearch.php', {
      params: {
        suchstring,
        seite: 1,
      },
    });

    await this.saveSession();

    return this.hasTableRows(response.data, 'table#dateien_eingang tbody tr');
  }

  async getRechnungsdaten(rechnungId: number): Promise<Rechnungsdaten> {
    const response = await this.http.get('/module/eingangsrechnungen/api/eingangsrechnungen.php', {
      params: {
        id: 'edit',
        rechnungId,
      },
    });

    await this.saveSession();

    const document = this.parseHtmlDocument(response.data);

    return {
      lieferschein: this.inputValue(document, 'lieferscheinnummer'),
      rechnung: this.inputValue(document, 'rechnungsnummer'),
      datum: this.requireDate(this.parseGermanShortDate(this.inputValue(document, 'rechnungsdatum')), 'rechnungsdatum'),
      kundenId: this.selectedNumberValue(document, 'rgempf'),
      adresstext: this.inputValue(document, 'addressName'),
    };
  }

  async setRechnungsdaten(rechnungId: number, daten: Rechnungsdaten): Promise<boolean> {
    const response = await this.http.post(
      `/module/eingangsrechnungen/api/eingangsrechnungen.php?id=update&rechnungId=${encodeURIComponent(rechnungId)}`,
      new URLSearchParams({
        lieferscheinnummer: daten.lieferschein,
        rechnungsnummer: daten.rechnung,
        rechnungsdatum: this.formatGermanShortDate(daten.datum),
        rgempf: String(daten.kundenId),
        adresstext: daten.adresstext,
      }),
      this.formPostConfig(`/eingangsrechnungen/detail/${rechnungId}`)
    );

    await this.saveSession();

    return response.status >= 200 && response.status < 300;
  }

  async setLieferscheinNummer(rechnungId: number, nummer: string): Promise<void> {
    const rechnungsdaten = await this.getRechnungsdaten(rechnungId);
    const success = await this.setRechnungsdaten(rechnungId, {
      ...rechnungsdaten,
      lieferschein: nummer,
    });

    if (!success) {
      throw new Error('Lieferscheinnummer konnte nicht gespeichert werden');
    }
  }

  async setEingangsdatum(rechnungId: number, datum: Date): Promise<boolean> {
    const response = await this.http.post(
      '/module/eingangsrechnungen/api/updateReceived.php',
      new URLSearchParams({
        datum: this.formatGermanShortDate(datum),
        receiptID: String(rechnungId),
      }),
      this.formPostConfig(`/eingangsrechnungen/detail/${rechnungId}`)
    );

    await this.saveSession();

    return response.status >= 200 && response.status < 300;
  }

  async getCustomerById(id: number): Promise<AgrarmonitorApiCustomer> {
    const response = await this.apiRequest<unknown>(`/kunden/${id}`);
    this.logDebug('Agrarmonitor customer API raw response', response.data);

    if (this.isWrappedApiCustomer(response.data)) {
      return response.data.data;
    }

    if (this.isApiCustomer(response.data)) {
      return response.data;
    }

    throw new Error('Ungueltige Agrarmonitor Kunden-API-Antwort');
  }

  private createHttpClient(): AxiosInstance {
    const client = wrapper(
      axios.create({
        baseURL: this.baseUrl,
        jar: this.cookieJar,
        withCredentials: true,
        timeout: this.timeoutMs,
        headers: {
          'User-Agent':
            'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
        },
        maxRedirects: 5,
        validateStatus: status => status >= 200 && status < 400,
      })
    );

    client.interceptors.response.use(
      async response => {
        await this.options.cookieStore.save(this.cookieJar);

        if (this.autoRetry && this.isLoginRequiredResponse(response)) {
          return this.retryAfterLogin(response.config);
        }

        return response;
      },
      async error => {
        const response = error.response as AxiosResponse | undefined;

        if (this.autoRetry && response && this.isLoginRequiredResponse(response)) {
          return this.retryAfterLogin(error.config);
        }

        throw error;
      }
    );

    return client;
  }

  private createApiHttpClient(apiToken = this.options.apiToken): AxiosInstance {
    return axios.create({
      baseURL: this.apiBaseUrl,
      timeout: this.timeoutMs,
      headers: {
        Accept: 'application/json',
        ...(apiToken ? { Authorization: `Bearer ${apiToken}` } : {}),
      },
      validateStatus: status => status >= 200 && status < 500,
    });
  }

  private async apiRequest<TData>(
    url: string,
    config: AxiosRequestConfig & { apiToken?: string } = {}
  ): Promise<AxiosResponse<TData>> {
    const apiToken = config.apiToken ?? this.options.apiToken;

    if (!apiToken) {
      throw new Error('Agrarmonitor API-Token nicht konfiguriert');
    }

    const { apiToken: _apiToken, ...axiosConfig } = config;
    const client = apiToken === this.options.apiToken ? this.apiHttp : this.createApiHttpClient(apiToken);
    return client.get<TData>(url, axiosConfig);
  }

  private async performLogin(): Promise<void> {
    if (!this.options.username || !this.options.password) {
      throw new Error('Agrarmonitor-Credentials nicht konfiguriert');
    }

    this.logger?.info?.('Fuehre Agrarmonitor-Login durch');

    if (this.loginStrategy === 'auth') {
      await this.performAuthLogin();
    } else if (this.loginStrategy === 'legacy') {
      await this.performLegacyLogin();
    } else {
      await this.performAutoLogin();
    }

    await this.options.cookieStore.save(this.cookieJar);
    this.logger?.info?.('Agrarmonitor-Login erfolgreich');
  }

  private async performAutoLogin(): Promise<void> {
    try {
      await this.performAuthLogin();
    } catch (authError) {
      this.logger?.warn?.('Agrarmonitor-Login via /auth/login fehlgeschlagen, versuche Legacy-Login', authError);
      await this.performLegacyLogin();
    }
  }

  private async performAuthLogin(): Promise<void> {
    await this.http.get('/auth/login');

    const loginData = new URLSearchParams({
      email: this.options.username,
      password: this.options.password,
      remember: 'on',
    });

    const response = await this.http.post('/auth/login', loginData, {
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
      },
    });

    const responseText = typeof response.data === 'string' ? response.data : '';

    if (responseText.includes('Anmeldung fehlgeschlagen')) {
      throw new Error('Agrarmonitor-Login fehlgeschlagen');
    }
  }

  private async performLegacyLogin(): Promise<void> {
    const loginPageResponse = await this.http.get('/');
    const loginPageText = typeof loginPageResponse.data === 'string' ? loginPageResponse.data : '';

    if (!this.isLoginPageText(loginPageText)) {
      return;
    }

    const nonce = this.extractNonce(loginPageText, 'input[name="nonce"]');
    const loginData = new URLSearchParams({
      username: this.options.username,
      passwort: this.options.password,
      nonce,
    });

    const response = await this.http.post('/redirect.php?id=benutzerverwaltung&action=login', loginData, {
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
      },
    });

    const responseText = typeof response.data === 'string' ? response.data : '';

    if (this.isLoginPageText(responseText)) {
      throw new Error('Agrarmonitor-Legacy-Login fehlgeschlagen');
    }
  }

  private async isSessionValid(): Promise<boolean> {
    try {
      const response = await this.http.get('/');
      return !this.isLoginRequiredResponse(response);
    } catch {
      return false;
    }
  }

  private isLoginRequiredResponse(response: AxiosResponse): boolean {
    const responseUrl = this.getResponseUrl(response);
    const responseText = typeof response.data === 'string' ? response.data : '';

    return (
      response.status === 401 ||
      response.status === 403 ||
      responseUrl.includes('/auth/login') ||
      responseText.includes('/auth/login') ||
      this.isLoginPageText(responseText) ||
      responseText.includes('Anmeldung') ||
      responseText.includes('Einloggen')
    );
  }

  private async retryAfterLogin(config: RetryableAxiosRequestConfig): Promise<AxiosResponse> {
    if (config._agrarmonitorRetry) {
      throw new Error('Agrarmonitor-Request nach erneutem Login weiterhin nicht autorisiert');
    }

    config._agrarmonitorRetry = true;

    this.logger?.info?.('Agrarmonitor-Session abgelaufen, erneuter Login wird ausgefuehrt');
    await this.login();

    return this.http.request(config);
  }

  private createDateienLivesearchParams(suchstring: string): Record<string, string | number> {
    return {
      suchstring,
      stammdatum_typ: -1,
      mobil: -1,
      sensibel: -1,
      firma: 0,
      itemsperpage: 100000,
      seite: 1,
    };
  }

  private async getEingangsrechnungEditMeta(rechnungId: number): Promise<{
    interneBelegNummer: string;
    kundenId: number;
    betriebId: number;
    dokumentTyp: number;
  }> {
    const response = await this.http.get('/module/eingangsrechnungen/api/eingangsrechnungen.php', {
      params: {
        id: 'edit',
        rechnungId,
      },
    });

    await this.saveSession();

    const document = this.parseHtmlDocument(response.data);

    return {
      interneBelegNummer: this.inputValue(document, 'lieferscheinnummer'),
      kundenId: this.selectedNumberValue(document, 'rgempf'),
      betriebId: this.selectedNumberValue(document, 'firma_id'),
      dokumentTyp: this.selectedNumberValue(document, 'typ'),
    };
  }

  private async getEingangsrechnungDetailMeta(rechnungId: number): Promise<{
    eingangsDatum: Date | null;
    buchungsDatum: Date | null;
  }> {
    const response = await this.http.get(`/eingangsrechnungen/detail/${rechnungId}`);

    await this.saveSession();

    const document = this.parseHtmlDocument(response.data);
    const receivedStatus = document.querySelector<HTMLElement>('#receivedStatus');
    const receivedText = receivedStatus?.textContent?.trim() ?? '';
    const parentParts = (receivedStatus?.parentElement?.textContent ?? '').split('-');
    const bookingText = parentParts.at(-1)?.trim() ?? '';

    return {
      eingangsDatum:
        !receivedText || receivedText === 'Nicht empfangen'
          ? null
          : this.parseGermanShortDateFromText(receivedText.slice(13).trim()),
      buchungsDatum:
        !bookingText || bookingText === 'Nicht gebucht'
          ? null
          : this.parseGermanShortDateFromText(bookingText.slice(11).trim()),
    };
  }

  private formPostConfig(refererPath: string): AxiosRequestConfig {
    return {
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        Referer: `${this.baseUrl}${refererPath}`,
        Origin: this.baseUrl,
      },
      validateStatus: status => status >= 200 && status < 400,
    };
  }

  private parseHtmlDocument(data: unknown): Document {
    return new JSDOM(typeof data === 'string' ? data : String(data ?? '')).window.document;
  }

  private hasTableRows(data: unknown, selector: string): boolean {
    return this.parseHtmlDocument(data).querySelectorAll(selector).length > 0;
  }

  private inputValue(document: Document, name: string): string {
    return document.querySelector<HTMLInputElement>(`input[name="${name}"]`)?.value.trim() ?? '';
  }

  private selectedNumberValue(document: Document, name: string): number {
    return this.parseNumber(
      document.querySelector<HTMLOptionElement>(`select[name="${name}"] option:checked`)?.value
    );
  }

  private parseNumber(value: unknown): number {
    const numberValue = Number(String(value ?? '').trim());
    return Number.isFinite(numberValue) ? numberValue : 0;
  }

  private parseGermanShortDate(value: string): Date | null {
    const match = value.trim().match(/^(\d{2})\.(\d{2})\.(\d{2})$/);

    if (!match) {
      return null;
    }

    const [, day, month, year] = match;
    const parsed = new Date(Number(`20${year}`), Number(month) - 1, Number(day));

    if (
      parsed.getFullYear() !== Number(`20${year}`) ||
      parsed.getMonth() !== Number(month) - 1 ||
      parsed.getDate() !== Number(day)
    ) {
      return null;
    }

    return parsed;
  }

  private requireDate(value: Date | null, fieldName: string): Date {
    if (!value) {
      throw new Error(`Ungueltiges Datumsformat fuer ${fieldName}`);
    }

    return value;
  }

  private formatGermanShortDate(date: Date): string {
    const day = String(date.getDate()).padStart(2, '0');
    const month = String(date.getMonth() + 1).padStart(2, '0');
    const year = String(date.getFullYear()).slice(-2);
    return `${day}.${month}.${year}`;
  }

  private lastPathSegment(value: string): string {
    return value.split('?')[0]?.split('/').filter(Boolean).at(-1) ?? '';
  }

  private fileBasename(fileName: string): string {
    const lastDotIndex = fileName.lastIndexOf('.');
    return lastDotIndex === -1 ? fileName : fileName.slice(0, lastDotIndex);
  }

  private normalizeApiBaseUrl(value: string): string {
    const withoutTrailingSlash = value.replace(/\/+$/, '');
    return withoutTrailingSlash.endsWith('/v1') ? withoutTrailingSlash : `${withoutTrailingSlash}/v1`;
  }

  private isWrappedApiCustomer(value: unknown): value is { data: AgrarmonitorApiCustomer } {
    return (
      typeof value === 'object' &&
      value !== null &&
      'data' in value &&
      this.isApiCustomer((value as { data?: unknown }).data)
    );
  }

  private isApiCustomer(value: unknown): value is AgrarmonitorApiCustomer {
    return (
      typeof value === 'object' &&
      value !== null &&
      'id' in value &&
      (typeof (value as { id?: unknown }).id === 'string' || typeof (value as { id?: unknown }).id === 'number')
    );
  }

  private parseGermanShortDateFromText(value: string): Date | null {
    const match = value.match(/(\d{2}\.\d{2}\.\d{2})/);
    return match ? this.parseGermanShortDate(match[1]) : null;
  }

  private logDebug(message: string, meta?: unknown): void {
    if (this.logger?.debug) {
      this.logger.debug(message, meta);
      return;
    }

    this.logger?.info?.(message, meta);
  }

  private getResponseUrl(response: AxiosResponse): string {
    const request = response.request as { res?: { responseUrl?: string } } | undefined;
    return request?.res?.responseUrl ?? '';
  }

  private getHeader(response: AxiosResponse, header: string): string | null {
    const value = response.headers[header.toLowerCase()];

    if (Array.isArray(value)) {
      return value[0] ?? null;
    }

    return typeof value === 'string' ? value : null;
  }

  private isFreischaltungUrl(value: string | null): boolean {
    return Boolean(value?.includes('freischaltung'));
  }

  private isLoginPageText(responseText: string): boolean {
    return responseText.includes('Anmeldung - AGRARMONITOR');
  }

  private extractNonce(html: string, selector: string): string {
    const dom = new JSDOM(html);
    const element = dom.window.document.querySelector<HTMLInputElement>(selector);
    const nonce = element?.getAttribute('value') ?? element?.value ?? '';

    if (!nonce) {
      throw new Error('Nonce-Element nicht gefunden oder leer');
    }

    return nonce;
  }

  private maskNonce(nonce: string): string {
    return nonce.length <= 10 ? nonce : `${nonce.slice(0, 10)}...`;
  }
}