import { serve } from "https://deno.land/std@0.190.0/http/server.ts";
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',
};

interface ProcessApprovalRequest {
  submissionId: string;
  selectedItemIds: string[];
  moderatorId: string;
}

interface ProcessedItem {
  id: string;
  entityType: string;
  entityId: string | null;
  status: 'success' | 'failed';
  error?: string;
}

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

  try {
    const supabaseClient = createClient(
      Deno.env.get('SUPABASE_URL') ?? '',
      Deno.env.get('SUPABASE_SERVICE_ROLE_KEY') ?? '',
      {
        auth: {
          autoRefreshToken: false,
          persistSession: false
        }
      }
    );

    const authHeader = req.headers.get('Authorization');
    if (!authHeader) {
      throw new Error('No authorization header');
    }

    const token = authHeader.replace('Bearer ', '');
    const { data: { user }, error: authError } = await supabaseClient.auth.getUser(token);
    
    if (authError || !user) {
      throw new Error('Unauthorized');
    }

    // Verify user is moderator or admin
    const { data: userRoles } = await supabaseClient
      .from('user_roles')
      .select('role')
      .eq('user_id', user.id);

    const isModerator = userRoles?.some(r => 
      ['moderator', 'admin', 'superuser'].includes(r.role)
    );

    if (!isModerator) {
      throw new Error('Insufficient permissions');
    }

    const { submissionId, selectedItemIds, moderatorId }: ProcessApprovalRequest = await req.json();

    console.log('Processing selective approval:', { submissionId, selectedItemIds, moderatorId });

    // Fetch all selected items with their dependencies
    const { data: items, error: itemsError } = await supabaseClient
      .from('submission_items')
      .select('*')
      .in('id', selectedItemIds)
      .eq('submission_id', submissionId);

    if (itemsError) {
      throw new Error(`Failed to fetch items: ${itemsError.message}`);
    }

    // Topological sort to process items in correct order
    const sortedItems = topologicalSort(items || []);
    const processedItems: ProcessedItem[] = [];
    const entityMap = new Map<string, string>(); // temp_id -> real_id mapping

    // Process each item in dependency order
    for (const item of sortedItems) {
      try {
        let entityId: string | null = null;

        // Resolve parent dependency if exists
        if (item.depends_on && entityMap.has(item.depends_on)) {
          item.item_data.parent_id = entityMap.get(item.depends_on);
        }

        // Create the entity based on type
        switch (item.item_type) {
          case 'manufacturer':
            const { data: manufacturer, error: mfgError } = await supabaseClient
              .from('companies')
              .insert({
                name: item.item_data.name,
                slug: item.item_data.slug,
                company_type: 'MANUFACTURER',
                description: item.item_data.description,
                founded_year: item.item_data.founded_year,
                headquarters_location: item.item_data.headquarters_location,
                website_url: item.item_data.website_url,
              })
              .select('id')
              .single();

            if (mfgError) throw mfgError;
            entityId = manufacturer.id;
            break;

          case 'designer':
            const { data: designer, error: designerError } = await supabaseClient
              .from('companies')
              .insert({
                name: item.item_data.name,
                slug: item.item_data.slug,
                company_type: 'DESIGNER',
                description: item.item_data.description,
                founded_year: item.item_data.founded_year,
                headquarters_location: item.item_data.headquarters_location,
                website_url: item.item_data.website_url,
              })
              .select('id')
              .single();

            if (designerError) throw designerError;
            entityId = designer.id;
            break;

          case 'ride_model':
            const { data: model, error: modelError } = await supabaseClient
              .from('ride_models')
              .insert({
                name: item.item_data.name,
                slug: item.item_data.slug,
                manufacturer_id: item.item_data.manufacturer_id || item.item_data.parent_id,
                description: item.item_data.description,
                model_type: item.item_data.model_type,
              })
              .select('id')
              .single();

            if (modelError) throw modelError;
            entityId = model.id;
            break;

          case 'ride':
            const { data: ride, error: rideError } = await supabaseClient
              .from('rides')
              .insert({
                name: item.item_data.name,
                slug: item.item_data.slug,
                park_id: item.item_data.park_id,
                manufacturer_id: item.item_data.manufacturer_id,
                designer_id: item.item_data.designer_id,
                model_id: item.item_data.model_id || item.item_data.parent_id,
                ride_type: item.item_data.ride_type,
                status: item.item_data.status,
                opening_date: item.item_data.opening_date,
                closing_date: item.item_data.closing_date,
                description: item.item_data.description,
              })
              .select('id')
              .single();

            if (rideError) throw rideError;
            entityId = ride.id;
            break;

          case 'park':
            const { data: park, error: parkError } = await supabaseClient
              .from('parks')
              .insert({
                name: item.item_data.name,
                slug: item.item_data.slug,
                operator_id: item.item_data.operator_id,
                property_owner_id: item.item_data.property_owner_id,
                location_id: item.item_data.location_id,
                status: item.item_data.status,
                opening_date: item.item_data.opening_date,
                closing_date: item.item_data.closing_date,
                description: item.item_data.description,
                website_url: item.item_data.website_url,
              })
              .select('id')
              .single();

            if (parkError) throw parkError;
            entityId = park.id;
            break;

          default:
            throw new Error(`Unknown item type: ${item.item_type}`);
        }

        // Update submission item status
        await supabaseClient
          .from('submission_items')
          .update({
            status: 'approved',
            entity_id: entityId,
            reviewed_by: moderatorId,
            reviewed_at: new Date().toISOString(),
          })
          .eq('id', item.id);

        // Store mapping for dependent items
        entityMap.set(item.id, entityId!);

        processedItems.push({
          id: item.id,
          entityType: item.item_type,
          entityId,
          status: 'success',
        });

        console.log(`Successfully processed ${item.item_type} ${item.id} -> ${entityId}`);
      } catch (error: any) {
        console.error(`Failed to process item ${item.id}:`, error);
        
        // Mark item as failed
        await supabaseClient
          .from('submission_items')
          .update({
            status: 'rejected',
            rejection_reason: error.message,
            reviewed_by: moderatorId,
            reviewed_at: new Date().toISOString(),
          })
          .eq('id', item.id);

        processedItems.push({
          id: item.id,
          entityType: item.item_type,
          entityId: null,
          status: 'failed',
          error: error.message,
        });
      }
    }

    // Update submission status if all items are processed
    const { data: remainingItems } = await supabaseClient
      .from('submission_items')
      .select('id')
      .eq('submission_id', submissionId)
      .eq('status', 'pending');

    if (!remainingItems || remainingItems.length === 0) {
      await supabaseClient
        .from('content_submissions')
        .update({
          status: 'approved',
          reviewed_at: new Date().toISOString(),
        })
        .eq('id', submissionId);
    }

    return new Response(
      JSON.stringify({
        success: true,
        processedItems,
        totalProcessed: processedItems.length,
        successCount: processedItems.filter(p => p.status === 'success').length,
        failureCount: processedItems.filter(p => p.status === 'failed').length,
      }),
      {
        headers: { ...corsHeaders, 'Content-Type': 'application/json' },
        status: 200,
      }
    );
  } catch (error: any) {
    console.error('Error in process-selective-approval:', error);
    return new Response(
      JSON.stringify({ error: error.message }),
      {
        headers: { ...corsHeaders, 'Content-Type': 'application/json' },
        status: 500,
      }
    );
  }
});

// Topological sort helper
function topologicalSort(items: any[]): any[] {
  const sorted: any[] = [];
  const visited = new Set<string>();
  const visiting = new Set<string>();

  function visit(item: any) {
    if (visited.has(item.id)) return;
    if (visiting.has(item.id)) {
      throw new Error('Circular dependency detected');
    }

    visiting.add(item.id);

    // Visit dependencies first
    if (item.depends_on) {
      const parent = items.find(i => i.id === item.depends_on);
      if (parent) {
        visit(parent);
      }
    }

    visiting.delete(item.id);
    visited.add(item.id);
    sorted.push(item);
  }

  items.forEach(item => visit(item));
  return sorted;
}