import { useCallback, useState } from 'react';
import { apiFetch } from '../lib/api';

export type MailProvider =
  | 'gmail'
  | 'icloud'
  | 'outlook'
  | 'yahoo'
  | 'gmx'
  | 'other';

type ConnectBody = {
  email: string;
  password: string;
  // Provider-Feld wird NICHT an das Backend gesendet — der Server erkennt
  // den Provider automatisch via Email-Domain (detectImapProvider in connect.post.ts).
  // Optionale Custom-IMAP-Felder für "other":
  imapHost?: string;
  imapPort?: number;
  useTls?: boolean;
  rejectUnauthorized?: boolean;
};

type ConnectResult = {
  connected: boolean;
  email: string;
  provider: string;
  custom: boolean;
};

export type UseMailConnectReturn = {
  connect: (params: ConnectBody) => Promise<{ ok: boolean; error?: string }>;
  connecting: boolean;
  error: string | null;
  /** Leitet aus der Email-Domain den Provider ab (rein client-seitig, zur UI-Hilfe). */
  detectProvider: (email: string) => MailProvider;
};

const PROVIDER_DOMAIN_MAP: Record<string, MailProvider> = {
  'gmail.com': 'gmail',
  'googlemail.com': 'gmail',
  'icloud.com': 'icloud',
  'me.com': 'icloud',
  'mac.com': 'icloud',
  'outlook.com': 'outlook',
  'hotmail.com': 'outlook',
  'live.com': 'outlook',
  'msn.com': 'outlook',
  'yahoo.com': 'yahoo',
  'yahoo.de': 'yahoo',
  'yahoo.co.uk': 'yahoo',
  'ymail.com': 'yahoo',
  'gmx.de': 'gmx',
  'gmx.net': 'gmx',
  'gmx.at': 'gmx',
  'gmx.ch': 'gmx',
  'web.de': 'gmx',
};

export function detectProvider(email: string): MailProvider {
  const domain = email.trim().toLowerCase().split('@')[1] ?? '';
  return PROVIDER_DOMAIN_MAP[domain] ?? 'other';
}

/**
 * Kapselt POST /api/mail/connect.
 *
 * Backend erwartet: { email, password, imapHost?, imapPort?, useTls?, rejectUnauthorized? }
 * Provider-Detection passiert server-seitig — wir senden keinen provider-Key.
 */
export function useMailConnect(): UseMailConnectReturn {
  const [connecting, setConnecting] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const connect = useCallback(async (params: ConnectBody) => {
    setConnecting(true);
    setError(null);
    try {
      await apiFetch<ConnectResult>('/api/mail/connect', {
        method: 'POST',
        body: params,
      });
      return { ok: true };
    } catch (e: any) {
      const msg = e?.message ?? 'Verbindung fehlgeschlagen';
      setError(msg);
      return { ok: false, error: msg };
    } finally {
      setConnecting(false);
    }
  }, []);

  return { connect, connecting, error, detectProvider };
}