interface MauticToken {
  access_token: string;
  expires_in: number;
  token_type: string;
}

let cachedToken: MauticToken | null = null;
let tokenExpiresAt: number = 0;

async function getMauticToken(): Promise<string> {
  if (cachedToken && Date.now() < tokenExpiresAt - 60000) {
    return cachedToken.access_token;
  }

  const clientId = process.env.MAUTIC_CLIENT_ID;
  const clientSecret = process.env.MAUTIC_CLIENT_SECRET;
  const apiUrl = process.env.MAUTIC_API_URL || "https://mautic.nodecrew.me";
  
  if (!clientId || !clientSecret) {
    throw new Error("Mautic credentials not configured");
  }

  const response = await fetch(`${apiUrl}/oauth/v2/token`, {
    method: "POST",
    headers: {
      "Content-Type": "application/x-www-form-urlencoded",
    },
    body: new URLSearchParams({
      grant_type: "client_credentials",
      client_id: clientId,
      client_secret: clientSecret,
    }),
  });

  if (!response.ok) {
    const errorText = await response.text();
    console.error("Mautic token error:", response.status, errorText);
    throw new Error(`Failed to get Mautic token: ${response.status} - ${errorText}`);
  }

  const token: MauticToken = await response.json();
  cachedToken = token;
  tokenExpiresAt = Date.now() + token.expires_in * 1000;
  
  return token.access_token;
}

export async function createMauticContact(
  email: string,
  tags: string[],
  additionalData?: {
    firstName?: string;
    lastName?: string;
    country?: string;
    city?: string;
    phone?: string;
    website?: string;
    preferredLocale?: string;
    ipAddress?: string;
    utmSource?: string;
    utmMedium?: string;
    utmCampaign?: string;
    utmContent?: string;
    pageUrl?: string;
  }
): Promise<{ success: boolean; alreadyExists?: boolean; contactId?: number }> {
  try {
    const token = await getMauticToken();
    const apiUrl = process.env.MAUTIC_API_URL || "https://mautic.nodecrew.me";
    
    const payload: any = {
      email,
      tags: tags.join(","),
    };

    if (additionalData) {
      if (additionalData.firstName) payload.firstname = additionalData.firstName;
      if (additionalData.lastName) payload.lastname = additionalData.lastName;
      if (additionalData.country) payload.country = additionalData.country;
      if (additionalData.city) payload.city = additionalData.city;
      if (additionalData.phone) payload.phone = additionalData.phone;
      if (additionalData.preferredLocale) payload.preferred_locale = additionalData.preferredLocale;
      if (additionalData.utmSource) payload.utm_source = additionalData.utmSource;
      if (additionalData.utmMedium) payload.utm_medium = additionalData.utmMedium;
      if (additionalData.utmCampaign) payload.utm_campaign = additionalData.utmCampaign;
      if (additionalData.utmContent) payload.utm_content = additionalData.utmContent;
      if (additionalData.pageUrl) payload.page_url = additionalData.pageUrl;
    }
    
    const response = await fetch(`${apiUrl}/api/contacts/new`, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        "Authorization": `Bearer ${token}`,
      },
      body: JSON.stringify(payload),
    });

    if (response.status === 409) {
      return { success: true, alreadyExists: true };
    }

    if (!response.ok) {
      const errorText = await response.text();
      console.error("Mautic API error:", response.status, errorText);
      throw new Error(`Mautic API error: ${response.status} - ${errorText}`);
    }

    const responseData = await response.json();
    console.log("Mautic API success:", responseData);

    return { 
      success: true, 
      contactId: responseData.contact?.id 
    };
  } catch (error) {
    console.error("Mautic contact creation failed:", error);
    throw error;
  }
}