import { createClient } from 'https://esm.sh/@supabase/supabase-js@2.39.3'

declare const Deno: any;

const corsHeaders = {
  'Access-Control-Allow-Origin': '*',
  'Access-Control-Allow-Headers': 'authorization, x-client-info, apikey, content-type',
}

Deno.serve(async (req: any) => {
  if (req.method === 'OPTIONS') {
    return new Response('ok', { headers: corsHeaders })
  }

  try {
    const supabase = createClient(
      Deno.env.get('SUPABASE_URL') ?? '',
      Deno.env.get('SUPABASE_SERVICE_ROLE_KEY') ?? ''
    )

    // Fetch active subscriptions
    const { data: subscriptions, error } = await supabase
      .from('maintenance_subscriptions')
      .select('*, order:orders(*)')
      .eq('status', 'active');

    if (error) throw error;

    const notificationsToSend: any[] = [];
    const today = new Date();

    // Mock email sending function for now
    const sendEmailMock = async (payload: any) => {
        console.log("Mock email sent:", payload);
        // In production, you would invoke the 'resend' function here
    };

    if (subscriptions) {
      for (const sub of subscriptions) {
        const billingDate = new Date(sub.next_billing_date);
        const daysUntil = Math.ceil((billingDate.getTime() - today.getTime()) / (1000 * 60 * 60 * 24));

        // Logic: Notify if <= 30 days and not notified recently (e.g. in last 14 days)
        let shouldNotify = false;
        
        // If it's already overdue or coming up in 30 days
        if (daysUntil <= 30) {
            if (!sub.last_notified_at) {
                shouldNotify = true;
            } else {
                const lastNotified = new Date(sub.last_notified_at);
                const daysSinceLastNotification = Math.ceil((today.getTime() - lastNotified.getTime()) / (1000 * 60 * 60 * 24));
                // Only notify if 2 weeks passed since last notification
                if (daysSinceLastNotification > 14) {
                    shouldNotify = true;
                }
            }
        }

        if (shouldNotify) {
            const payload = {
                to: sub.client_email,
                subject: `Emlékeztető: Éves díj esedékes (${daysUntil} nap)`,
                daysLeft: daysUntil,
                domain: sub.order?.details?.domainName || 'Weboldal',
                subscriptionId: sub.id
            };

            notificationsToSend.push(payload);
            
            // Itt hívnánk meg a sendEmail függvényt
            await sendEmailMock(payload);

            // Update last_notified_at to keep data consistent
            const { error: updateError } = await supabase
              .from('maintenance_subscriptions')
              .update({ last_notified_at: new Date().toISOString() })
              .eq('id', sub.id);
              
            if (updateError) {
                console.error(`Failed to update subscription ${sub.id}:`, updateError);
            }
        }
      }
    }

    return new Response(
      JSON.stringify({ success: true, notifications: notificationsToSend }),
      {
        headers: { ...corsHeaders, 'Content-Type': 'application/json' },
        status: 200,
      }
    )
  } catch (err: any) {
    return new Response(
      JSON.stringify({ error: err.message }),
      {
        headers: { ...corsHeaders, 'Content-Type': 'application/json' },
        status: 400,
      }
    )
  }
})