import { useState } from 'react';
import { useQuery } from '@tanstack/react-query';
import { supabase } from '@/lib/supabaseClient';
import { AdminLayout } from '@/components/layout/AdminLayout';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Input } from '@/components/ui/input';
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
import { Badge } from '@/components/ui/badge';
import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
import { AlertCircle, XCircle } from 'lucide-react';
import { RefreshButton } from '@/components/ui/refresh-button';
import { ErrorDetailsModal } from '@/components/admin/ErrorDetailsModal';
import { ApprovalFailureModal } from '@/components/admin/ApprovalFailureModal';
import { ErrorAnalytics } from '@/components/admin/ErrorAnalytics';
import { PipelineHealthAlerts } from '@/components/admin/PipelineHealthAlerts';
import { format } from 'date-fns';

// Helper to calculate date threshold for filtering
const getDateThreshold = (range: '1h' | '24h' | '7d' | '30d'): string => {
  const now = new Date();
  const msMap = {
    '1h': 60 * 60 * 1000,           // 1 hour in milliseconds
    '24h': 24 * 60 * 60 * 1000,     // 1 day
    '7d': 7 * 24 * 60 * 60 * 1000,  // 7 days
    '30d': 30 * 24 * 60 * 60 * 1000, // 30 days
  };
  
  const threshold = new Date(now.getTime() - msMap[range]);
  return threshold.toISOString();
};

interface EnrichedApprovalFailure {
  id: string;
  submission_id: string;
  moderator_id: string;
  submitter_id: string;
  items_count: number;
  duration_ms: number | null;
  error_message: string | null;
  request_id: string | null;
  rollback_triggered: boolean | null;
  created_at: string | null;
  success: boolean;
  moderator?: {
    user_id: string;
    username: string | null;
    avatar_url: string | null;
  };
  submission?: {
    id: string;
    submission_type: string;
    user_id: string;
  };
}

export default function ErrorMonitoring() {
  const [selectedError, setSelectedError] = useState<any>(null);
  const [selectedFailure, setSelectedFailure] = useState<any>(null);
  const [searchTerm, setSearchTerm] = useState('');
  const [errorTypeFilter, setErrorTypeFilter] = useState<string>('all');
  const [dateRange, setDateRange] = useState<'1h' | '24h' | '7d' | '30d'>('24h');

  // Fetch recent errors
  const { data: errors, isLoading, refetch, isFetching } = useQuery({
    queryKey: ['admin-errors', dateRange, errorTypeFilter, searchTerm],
    queryFn: async () => {
      let query = supabase
        .from('request_metadata')
        .select(`
          *,
          request_breadcrumbs(
            timestamp,
            category,
            message,
            level,
            sequence_order
          )
        `)
        .not('error_type', 'is', null)
        .gte('created_at', getDateThreshold(dateRange))
        .order('created_at', { ascending: false })
        .limit(100);

      if (errorTypeFilter !== 'all') {
        query = query.eq('error_type', errorTypeFilter);
      }

      if (searchTerm) {
        query = query.or(`request_id.ilike.%${searchTerm}%,error_message.ilike.%${searchTerm}%,endpoint.ilike.%${searchTerm}%`);
      }

      const { data, error } = await query;
      if (error) throw error;
      return data;
    },
    refetchInterval: 30000, // Auto-refresh every 30 seconds
  });

  // Fetch error summary
  const { data: errorSummary } = useQuery({
    queryKey: ['error-summary'],
    queryFn: async () => {
      const { data, error } = await supabase
        .from('error_summary')
        .select('*');
      if (error) throw error;
      return data;
    },
  });

  // Fetch approval metrics (last 24h)
  const { data: approvalMetrics } = useQuery({
    queryKey: ['approval-metrics'],
    queryFn: async () => {
      const { data, error } = await supabase
        .from('approval_transaction_metrics')
        .select('id, success, duration_ms, created_at')
        .gte('created_at', getDateThreshold('24h'))
        .order('created_at', { ascending: false })
        .limit(1000);
      if (error) throw error;
      return data;
    },
  });

  // Fetch approval failures
  const { data: approvalFailures, refetch: refetchFailures, isFetching: isFetchingFailures } = useQuery<EnrichedApprovalFailure[]>({
    queryKey: ['approval-failures', dateRange, searchTerm],
    queryFn: async () => {
      let query = supabase
        .from('approval_transaction_metrics')
        .select('*')
        .eq('success', false)
        .gte('created_at', getDateThreshold(dateRange))
        .order('created_at', { ascending: false })
        .limit(50);

      if (searchTerm) {
        query = query.or(`submission_id.ilike.%${searchTerm}%,error_message.ilike.%${searchTerm}%`);
      }

      const { data, error } = await query;
      if (error) throw error;

      // Fetch moderator and submission data separately
      if (data && data.length > 0) {
        const moderatorIds = [...new Set(data.map(f => f.moderator_id))];
        const submissionIds = [...new Set(data.map(f => f.submission_id))];

        const [moderatorsData, submissionsData] = await Promise.all([
          supabase.from('profiles').select('user_id, username, avatar_url').in('user_id', moderatorIds),
          supabase.from('content_submissions').select('id, submission_type, user_id').in('id', submissionIds)
        ]);

        // Enrich data with moderator and submission info
        return data.map(failure => ({
          ...failure,
          moderator: moderatorsData.data?.find(m => m.user_id === failure.moderator_id),
          submission: submissionsData.data?.find(s => s.id === failure.submission_id)
        })) as EnrichedApprovalFailure[];
      }

      return (data || []) as EnrichedApprovalFailure[];
    },
    refetchInterval: 30000,
  });

  return (
    <AdminLayout>
      <div className="space-y-6">
        <div className="flex justify-between items-center">
          <div>
            <h1 className="text-3xl font-bold tracking-tight">Error Monitoring</h1>
            <p className="text-muted-foreground">Track and analyze application errors</p>
          </div>
          <RefreshButton
            onRefresh={async () => { await refetch(); }}
            isLoading={isFetching}
            variant="outline"
            size="sm"
          />
        </div>

        {/* Pipeline Health Alerts */}
        <PipelineHealthAlerts />

        {/* Analytics Section */}
        <ErrorAnalytics errorSummary={errorSummary} approvalMetrics={approvalMetrics} />

        {/* Tabs for Errors and Approval Failures */}
        <Tabs defaultValue="errors" className="w-full">
          <TabsList>
            <TabsTrigger value="errors">Application Errors</TabsTrigger>
            <TabsTrigger value="approvals">Approval Failures</TabsTrigger>
          </TabsList>

          <TabsContent value="errors" className="space-y-4">
            <Card>
              <CardHeader>
                <CardTitle>Error Log</CardTitle>
                <CardDescription>Recent errors across the application</CardDescription>
              </CardHeader>
              <CardContent>
                <div className="flex gap-4 mb-6">
                  <div className="flex-1">
                    <Input
                      placeholder="Search by request ID, endpoint, or error message..."
                      value={searchTerm}
                      onChange={(e) => setSearchTerm(e.target.value)}
                      className="w-full"
                    />
                  </div>
                  <Select value={dateRange} onValueChange={(v: any) => setDateRange(v)}>
                    <SelectTrigger className="w-[180px]">
                      <SelectValue />
                    </SelectTrigger>
                    <SelectContent>
                      <SelectItem value="1h">Last Hour</SelectItem>
                      <SelectItem value="24h">Last 24 Hours</SelectItem>
                      <SelectItem value="7d">Last 7 Days</SelectItem>
                      <SelectItem value="30d">Last 30 Days</SelectItem>
                    </SelectContent>
                  </Select>
                  <Select value={errorTypeFilter} onValueChange={setErrorTypeFilter}>
                    <SelectTrigger className="w-[200px]">
                      <SelectValue placeholder="Error type" />
                    </SelectTrigger>
                    <SelectContent>
                      <SelectItem value="all">All Types</SelectItem>
                      <SelectItem value="FunctionsFetchError">Functions Fetch</SelectItem>
                      <SelectItem value="FunctionsHttpError">Functions HTTP</SelectItem>
                      <SelectItem value="Error">Generic Error</SelectItem>
                    </SelectContent>
                  </Select>
                </div>

                {isLoading ? (
                  <div className="text-center py-8 text-muted-foreground">Loading errors...</div>
                ) : errors && errors.length > 0 ? (
                  <div className="space-y-2">
                    {errors.map((error) => (
                      <div
                        key={error.id}
                        onClick={() => setSelectedError(error)}
                        className="p-4 border rounded-lg hover:bg-accent cursor-pointer transition-colors"
                      >
                        <div className="flex items-start justify-between">
                          <div className="flex-1">
                            <div className="flex items-center gap-2 mb-1">
                              <AlertCircle className="w-4 h-4 text-destructive" />
                              <span className="font-medium">{error.error_type}</span>
                              <Badge variant="outline" className="text-xs">
                                {error.endpoint}
                              </Badge>
                            </div>
                            <p className="text-sm text-muted-foreground mb-2">
                              {error.error_message}
                            </p>
                            <div className="flex items-center gap-4 text-xs text-muted-foreground">
                              <span>ID: {error.request_id.slice(0, 8)}</span>
                              <span>{format(new Date(error.created_at), 'PPp')}</span>
                              {error.duration_ms != null && <span>{error.duration_ms}ms</span>}
                            </div>
                          </div>
                        </div>
                      </div>
                    ))}
                  </div>
                ) : (
                  <div className="text-center py-8 text-muted-foreground">
                    No errors found for the selected filters
                  </div>
                )}
              </CardContent>
            </Card>
          </TabsContent>

          <TabsContent value="approvals" className="space-y-4">
            <Card>
              <CardHeader>
                <CardTitle>Approval Failures</CardTitle>
                <CardDescription>Failed approval transactions requiring investigation</CardDescription>
              </CardHeader>
              <CardContent>
                <div className="flex gap-4 mb-6">
                  <div className="flex-1">
                    <Input
                      placeholder="Search by submission ID or error message..."
                      value={searchTerm}
                      onChange={(e) => setSearchTerm(e.target.value)}
                      className="w-full"
                    />
                  </div>
                  <Select value={dateRange} onValueChange={(v: any) => setDateRange(v)}>
                    <SelectTrigger className="w-[180px]">
                      <SelectValue />
                    </SelectTrigger>
                    <SelectContent>
                      <SelectItem value="1h">Last Hour</SelectItem>
                      <SelectItem value="24h">Last 24 Hours</SelectItem>
                      <SelectItem value="7d">Last 7 Days</SelectItem>
                      <SelectItem value="30d">Last 30 Days</SelectItem>
                    </SelectContent>
                  </Select>
                </div>

                {isFetchingFailures ? (
                  <div className="text-center py-8 text-muted-foreground">Loading approval failures...</div>
                ) : approvalFailures && approvalFailures.length > 0 ? (
                  <div className="space-y-2">
                    {approvalFailures.map((failure) => (
                      <div
                        key={failure.id}
                        onClick={() => setSelectedFailure(failure)}
                        className="p-4 border rounded-lg hover:bg-accent cursor-pointer transition-colors"
                      >
                        <div className="flex items-start justify-between">
                          <div className="flex-1">
                            <div className="flex items-center gap-2 mb-1">
                              <XCircle className="w-4 h-4 text-destructive" />
                              <span className="font-medium">Approval Failed</span>
                              <Badge variant="outline" className="text-xs">
                                {failure.submission?.submission_type || 'Unknown'}
                              </Badge>
                              {failure.rollback_triggered && (
                                <Badge variant="destructive" className="text-xs">
                                  Rollback
                                </Badge>
                              )}
                            </div>
                            <p className="text-sm text-muted-foreground mb-2">
                              {failure.error_message || 'No error message available'}
                            </p>
                            <div className="flex items-center gap-4 text-xs text-muted-foreground">
                              <span>Moderator: {failure.moderator?.username || 'Unknown'}</span>
                              <span>{failure.created_at && format(new Date(failure.created_at), 'PPp')}</span>
                              {failure.duration_ms != null && <span>{failure.duration_ms}ms</span>}
                              <span>{failure.items_count} items</span>
                            </div>
                          </div>
                        </div>
                      </div>
                    ))}
                  </div>
                ) : (
                  <div className="text-center py-8 text-muted-foreground">
                    No approval failures found for the selected filters
                  </div>
                )}
              </CardContent>
            </Card>
          </TabsContent>
        </Tabs>
      </div>

      {/* Error Details Modal */}
      {selectedError && (
        <ErrorDetailsModal
          error={selectedError}
          onClose={() => setSelectedError(null)}
        />
      )}

      {/* Approval Failure Modal */}
      {selectedFailure && (
        <ApprovalFailureModal
          failure={selectedFailure}
          onClose={() => setSelectedFailure(null)}
        />
      )}
    </AdminLayout>
  );
}
