import { serve } from "https://deno.land/std@0.168.0/http/server.ts";
import { Novu } from "npm:@novu/api@1.6.0";
import { createClient } from "https://esm.sh/@supabase/supabase-js@2.57.4";

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

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

  try {
    const novuApiKey = Deno.env.get('NOVU_API_KEY');
    const supabaseUrl = Deno.env.get('SUPABASE_URL')!;
    const supabaseServiceKey = Deno.env.get('SUPABASE_SERVICE_ROLE_KEY')!;

    if (!novuApiKey) {
      throw new Error('NOVU_API_KEY is not configured');
    }

    const novu = new Novu({ 
      secretKey: novuApiKey 
    });

    const supabase = createClient(supabaseUrl, supabaseServiceKey);

    const { userId, preferences } = await req.json();

    console.log('Updating preferences for user:', userId);

    // Validate input
    if (!userId) {
      return new Response(
        JSON.stringify({
          success: false,
          error: 'userId is required',
        }),
        {
          headers: { ...corsHeaders, 'Content-Type': 'application/json' },
          status: 400,
        }
      );
    }

    if (!preferences?.channelPreferences) {
      return new Response(
        JSON.stringify({
          success: false,
          error: 'channelPreferences is required in preferences object',
        }),
        {
          headers: { ...corsHeaders, 'Content-Type': 'application/json' },
          status: 400,
        }
      );
    }

    // Get Novu subscriber ID from database
    const { data: prefData, error: prefError } = await supabase
      .from('user_notification_preferences')
      .select('novu_subscriber_id')
      .eq('user_id', userId)
      .single();

    if (prefError || !prefData?.novu_subscriber_id) {
      throw new Error('Novu subscriber not found');
    }

    const subscriberId = prefData.novu_subscriber_id;

    // Update channel preferences in Novu
    // Note: Novu's updatePreference updates one channel at a time for a specific workflow
    const channelPrefs = preferences.channelPreferences;
    const workflowId = preferences.workflowId || 'default';
    
    const channelTypes = ['email', 'sms', 'in_app', 'push'] as const;
    const results: { channel: string; success: boolean; error?: string }[] = [];
    
    for (const channelType of channelTypes) {
      if (channelPrefs[channelType] !== undefined) {
        try {
          await novu.subscribers.updatePreference(
            subscriberId,
            workflowId,
            {
              channel: {
                type: channelType as any, // Cast to any to handle SDK type limitations
                enabled: channelPrefs[channelType]
              },
            }
          );
          results.push({ channel: channelType, success: true });
        } catch (channelError: any) {
          console.error(`Failed to update ${channelType} preference:`, channelError.message);
          results.push({ 
            channel: channelType, 
            success: false, 
            error: channelError.message || 'Unknown error' 
          });
        }
      }
    }

    // Check if any updates failed
    const failedChannels = results.filter(r => !r.success);
    const allSucceeded = failedChannels.length === 0;

    if (!allSucceeded) {
      console.warn(`Some channel preferences failed to update:`, failedChannels);
      return new Response(
        JSON.stringify({
          success: false,
          error: 'Some channel preferences failed to update',
          results,
          failedChannels: failedChannels.map(c => c.channel),
        }),
        {
          headers: { ...corsHeaders, 'Content-Type': 'application/json' },
          status: 502, // Bad Gateway - external service failure
        }
      );
    }

    console.log('All preferences updated successfully');
    return new Response(
      JSON.stringify({
        success: true,
        results,
      }),
      {
        headers: { ...corsHeaders, 'Content-Type': 'application/json' },
        status: 200,
      }
    );
  } catch (error: any) {
    console.error('Error updating Novu preferences:', error);
    
    return new Response(
      JSON.stringify({
        success: false,
        error: error.message,
      }),
      {
        headers: { ...corsHeaders, 'Content-Type': 'application/json' },
        status: 500,
      }
    );
  }
});