import { createClient } from "https://esm.sh/@supabase/supabase-js@2";

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

Deno.serve(async (req) => {
  if (req.method === "OPTIONS") {
    return new Response(null, { headers: corsHeaders });
  }

  try {
    const supabaseUrl = Deno.env.get("SUPABASE_URL")!;
    const serviceKey = Deno.env.get("SUPABASE_SERVICE_ROLE_KEY")!;
    const supabase = createClient(supabaseUrl, serviceKey);

    const now = new Date();
    const in24h = new Date(now.getTime() + 24 * 60 * 60 * 1000);

    // Find reminders due within 24 hours that haven't been notified recently
    const { data: reminders, error } = await supabase
      .from("reminders")
      .select("*")
      .neq("status", "completed")
      .lte("due_date", in24h.toISOString())
      .gte("due_date", now.toISOString());

    if (error) throw error;
    if (!reminders || reminders.length === 0) {
      return new Response(JSON.stringify({ success: true, processed: 0 }), {
        headers: { ...corsHeaders, "Content-Type": "application/json" },
      });
    }

    // Filter out recently notified (within last 12 hours)
    const twelveHoursAgo = new Date(now.getTime() - 12 * 60 * 60 * 1000);
    const dueReminders = reminders.filter((r: any) => {
      if (!r.last_notified_at) return true;
      return new Date(r.last_notified_at) < twelveHoursAgo;
    });

    // Get active SMTP sender
    const { data: senders } = await supabase
      .from("email_senders")
      .select("*")
      .eq("is_active", true)
      .eq("verified", true)
      .limit(1);

    const sender = senders?.[0];

    let processed = 0;

    for (const reminder of dueReminders) {
      const userId = reminder.assigned_to || reminder.created_by;
      if (!userId) continue;

      // Create in-app notification
      await supabase.rpc("insert_notification", {
        p_user_id: userId,
        p_type: "reminder_due",
        p_title: "Reminder Due Soon",
        p_message: `"${reminder.title}" is due ${new Date(reminder.due_date).toLocaleString()}.`,
        p_related_item_type: "reminder",
        p_link: "/dashboard/settings/reminders",
      });

      // Send email if SMTP is configured
      if (sender) {
        try {
          const { data: userData } = await supabase.auth.admin.getUserById(userId);
          if (userData?.user?.email) {
            const senderFrom = sender.sender_name
              ? `${sender.sender_name} <${sender.email_address}>`
              : sender.email_address;

            await supabase.functions.invoke("send-smtp-email", {
              body: {
                sender: {
                  host: sender.smtp_host,
                  port: sender.smtp_port,
                  username: sender.smtp_username,
                  password: sender.smtp_password,
                  use_tls: sender.use_tls,
                  use_ssl: sender.use_ssl,
                  from: senderFrom,
                },
                recipient: [userData.user.email],
                subject: `Reminder Due: ${reminder.title}`,
                body: `<h3>Reminder Due Soon</h3><p>Your reminder "<strong>${reminder.title}</strong>" is due on ${new Date(reminder.due_date).toLocaleString()}.</p>${reminder.description ? `<p>${reminder.description}</p>` : ""}<p>Please log in to the portal to manage your reminders.</p>`,
                html: `<h3>Reminder Due Soon</h3><p>Your reminder "<strong>${reminder.title}</strong>" is due on ${new Date(reminder.due_date).toLocaleString()}.</p>${reminder.description ? `<p>${reminder.description}</p>` : ""}<p>Please log in to the portal to manage your reminders.</p>`,
                debug: false,
              },
            });
          }
        } catch (emailErr) {
          console.error(`Failed to send email for reminder ${reminder.id}:`, emailErr);
        }
      }

      // Update last_notified_at
      await supabase
        .from("reminders")
        .update({ last_notified_at: now.toISOString() })
        .eq("id", reminder.id);

      processed++;
    }

    return new Response(JSON.stringify({ success: true, processed }), {
      headers: { ...corsHeaders, "Content-Type": "application/json" },
    });
  } catch (error) {
    console.error("check-reminder-emails error:", error);
    return new Response(JSON.stringify({ success: false, error: (error as Error).message }), {
      status: 500,
      headers: { ...corsHeaders, "Content-Type": "application/json" },
    });
  }
});