import { useState, useEffect } from 'react';
import { invokeWithTracking } from '@/lib/edgeFunctionTracking';
import { Button } from '@/components/ui/button';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Separator } from '@/components/ui/separator';
import { Skeleton } from '@/components/ui/skeleton';
import { Switch } from '@/components/ui/switch';
import { Label } from '@/components/ui/label';
import { useAuth } from '@/hooks/useAuth';
import { useProfile } from '@/hooks/useProfile';
import { supabase } from '@/lib/supabaseClient';
import { handleError, handleSuccess, handleNonCriticalError, AppError } from '@/lib/errorHandler';
import { Download, Activity, BarChart3, AlertCircle, Clock } from 'lucide-react';
import type { 
  UserStatistics, 
  ActivityLogEntry, 
  ExportOptions,
  ExportRequestResult 
} from '@/types/data-export';
import { 
  exportOptionsSchema, 
  DEFAULT_EXPORT_OPTIONS 
} from '@/lib/dataExportValidation';

export function DataExportTab() {
  const { user } = useAuth();
  const { data: profile } = useProfile(user?.id);
  const [loading, setLoading] = useState(true);
  const [exporting, setExporting] = useState(false);
  const [statistics, setStatistics] = useState<UserStatistics | null>(null);
  const [recentActivity, setRecentActivity] = useState<ActivityLogEntry[]>([]);
  const [exportOptions, setExportOptions] = useState<ExportOptions>(DEFAULT_EXPORT_OPTIONS);
  const [rateLimited, setRateLimited] = useState(false);
  const [nextAvailableAt, setNextAvailableAt] = useState<string | null>(null);

  useEffect(() => {
    if (user && profile) {
      loadStatistics();
      loadRecentActivity();
    }
  }, [user, profile]);

  const loadStatistics = async () => {
    if (!user || !profile) return;

    try {
      // Fetch additional counts
      const { count: photoCount } = await supabase
        .from('photos')
        .select('*', { count: 'exact', head: true })
        .eq('submitted_by', user.id);

      // Note: user_lists table needs to be created for this to work
      // For now, setting to 0 as placeholder
      const listCount = 0;

      const { count: submissionCount } = await supabase
        .from('content_submissions')
        .select('*', { count: 'exact', head: true })
        .eq('user_id', user.id);

      const stats: UserStatistics = {
        ride_count: profile.ride_count || 0,
        coaster_count: profile.coaster_count || 0,
        park_count: profile.park_count || 0,
        review_count: profile.review_count || 0,
        reputation_score: profile.reputation_score || 0,
        photo_count: photoCount || 0,
        list_count: listCount || 0,
        submission_count: submissionCount || 0,
        account_created: profile.created_at,
        last_updated: profile.updated_at
      };

      setStatistics(stats);
    } catch (error: unknown) {
      handleError(error, {
        action: 'Load statistics',
        userId: user.id
      });
    }
  };

  const loadRecentActivity = async () => {
    if (!user) return;

    try {
      const { data, error } = await supabase
        .from('profile_audit_log')
        .select(`
          id, 
          action, 
          created_at, 
          changed_by, 
          ip_address_hash, 
          user_agent,
          profile_change_fields(field_name, old_value, new_value)
        `)
        .eq('user_id', user.id)
        .order('created_at', { ascending: false })
        .limit(10);

      if (error) {
        throw error;
      }

      // Transform the data to match our type
      const activityData: ActivityLogEntry[] = (data || []).map(item => {
        const changes: Record<string, any> = {};
        if (item.profile_change_fields) {
          for (const field of item.profile_change_fields) {
            changes[field.field_name] = {
              old: field.old_value,
              new: field.new_value
            };
          }
        }
        
        return {
          id: item.id,
          action: item.action,
          changes,
          created_at: item.created_at,
          changed_by: item.changed_by,
          ip_address_hash: item.ip_address_hash || undefined,
          user_agent: item.user_agent || undefined
        };
      });

      setRecentActivity(activityData);
    } catch (error: unknown) {
      handleError(error, {
        action: 'Load activity log',
        userId: user.id
      });
    } finally {
      setLoading(false);
    }
  };

  const handleDataExport = async () => {
    if (!user) return;

    setExporting(true);

    try {
      // Validate export options
      const validatedOptions = exportOptionsSchema.parse(exportOptions);

      // Call edge function for secure export
      const { data, error, requestId } = await invokeWithTracking<ExportRequestResult>(
        'export-user-data',
        validatedOptions,
        user.id
      );

      if (error) {
        throw error;
      }

      if (!data?.success) {
        if (data?.rate_limited) {
          setRateLimited(true);
          setNextAvailableAt(data.next_available_at || null);
          
          handleError(
            new AppError(
              'Rate limited',
              'RATE_LIMIT_EXCEEDED',
              data.error || 'You can export your data once per hour. Please try again later.'
            ),
            { action: 'Export data', userId: user.id }
          );
          return;
        }

        throw new Error(data?.error || 'Export failed');
      }

      // Download the data as JSON
      const blob = new Blob([JSON.stringify(data.data, null, 2)], { 
        type: 'application/json' 
      });
      const url = URL.createObjectURL(blob);
      const link = document.createElement('a');
      link.href = url;
      link.download = `thrillwiki-data-export-${new Date().toISOString().split('T')[0]}.json`;
      document.body.appendChild(link);
      link.click();
      document.body.removeChild(link);
      URL.revokeObjectURL(url);

      handleSuccess(
        'Data exported successfully',
        'Your data has been downloaded as a JSON file.'
      );

      // Refresh activity log to show the export action
      await loadRecentActivity();
    } catch (error: unknown) {
      handleError(error, {
        action: 'Export data',
        userId: user.id
      });
    } finally {
      setExporting(false);
    }
  };

  const formatActionName = (action: string): string => {
    return action
      .split('_')
      .map(word => word.charAt(0).toUpperCase() + word.slice(1))
      .join(' ');
  };

  const formatDate = (dateString: string): string => {
    return new Date(dateString).toLocaleString('en-US', {
      year: 'numeric',
      month: 'short',
      day: 'numeric',
      hour: '2-digit',
      minute: '2-digit'
    });
  };

  if (loading) {
    return (
      <div className="space-y-8">
        <Card>
          <CardHeader>
            <Skeleton className="h-6 w-48" />
            <Skeleton className="h-4 w-full max-w-md" />
          </CardHeader>
          <CardContent className="space-y-4">
            <Skeleton className="h-12 w-full" />
            <Skeleton className="h-12 w-full" />
          </CardContent>
        </Card>
      </div>
    );
  }

  return (
    <div className="space-y-6">
      {/* Statistics + Recent Activity Grid */}
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
        {/* Personal Statistics */}
        <Card>
          <CardHeader>
            <div className="flex items-center gap-2">
              <BarChart3 className="w-5 h-5" />
              <CardTitle>Personal Statistics</CardTitle>
            </div>
            <CardDescription>
              Your activity and contribution statistics on ThrillWiki
            </CardDescription>
          </CardHeader>
          <CardContent>
            {statistics && (
              <div className="grid grid-cols-2 md:grid-cols-4 gap-4">
                <div className="space-y-1">
                  <p className="text-sm text-muted-foreground">Reviews</p>
                  <p className="text-2xl font-bold">{statistics.review_count}</p>
                </div>
                <div className="space-y-1">
                  <p className="text-sm text-muted-foreground">Rides Tracked</p>
                  <p className="text-2xl font-bold">{statistics.ride_count}</p>
                </div>
                <div className="space-y-1">
                  <p className="text-sm text-muted-foreground">Coasters</p>
                  <p className="text-2xl font-bold">{statistics.coaster_count}</p>
                </div>
                <div className="space-y-1">
                  <p className="text-sm text-muted-foreground">Parks Visited</p>
                  <p className="text-2xl font-bold">{statistics.park_count}</p>
                </div>
                <div className="space-y-1">
                  <p className="text-sm text-muted-foreground">Photos</p>
                  <p className="text-2xl font-bold">{statistics.photo_count}</p>
                </div>
                <div className="space-y-1">
                  <p className="text-sm text-muted-foreground">Lists</p>
                  <p className="text-2xl font-bold">{statistics.list_count}</p>
                </div>
                <div className="space-y-1">
                  <p className="text-sm text-muted-foreground">Submissions</p>
                  <p className="text-2xl font-bold">{statistics.submission_count}</p>
                </div>
                <div className="space-y-1">
                  <p className="text-sm text-muted-foreground">Reputation</p>
                  <p className="text-2xl font-bold">{statistics.reputation_score}</p>
                </div>
              </div>
            )}
          </CardContent>
        </Card>

        {/* Account Activity */}
        <Card>
          <CardHeader>
            <div className="flex items-center gap-2">
              <Activity className="w-5 h-5" />
              <CardTitle>Recent Activity</CardTitle>
            </div>
            <CardDescription>
              Recent account activity and changes
            </CardDescription>
          </CardHeader>
          <CardContent>
            {recentActivity.length === 0 ? (
              <p className="text-sm text-muted-foreground text-center py-4">
                No recent activity to display
              </p>
            ) : (
              <div className="space-y-4">
                {recentActivity.map((activity) => (
                  <div key={activity.id} className="flex items-start gap-3 pb-4 border-b last:border-0 last:pb-0">
                    <Activity className="w-4 h-4 text-muted-foreground mt-1" />
                    <div className="flex-1 space-y-1">
                      <p className="text-sm font-medium">
                        {formatActionName(activity.action)}
                      </p>
                      <p className="text-xs text-muted-foreground">
                        {formatDate(activity.created_at)}
                      </p>
                    </div>
                  </div>
                ))}
              </div>
            )}
          </CardContent>
        </Card>
      </div>

      {/* Export Your Data - Full Width */}
      <Card>
        <CardHeader>
          <div className="flex items-center gap-2">
            <Download className="w-5 h-5" />
            <CardTitle>Export Your Data</CardTitle>
          </div>
          <CardDescription>
            Export all your ThrillWiki data in JSON format. This includes your profile, reviews, lists, and activity history.
          </CardDescription>
        </CardHeader>
        <CardContent className="space-y-6">
          {rateLimited && nextAvailableAt && (
            <div className="flex items-start gap-3 p-4 border border-yellow-500/20 bg-yellow-500/10 rounded-lg">
              <Clock className="w-5 h-5 text-yellow-500 mt-0.5" />
              <div className="space-y-1">
                <p className="text-sm font-medium">Rate Limited</p>
                <p className="text-sm text-muted-foreground">
                  You can export your data once per hour. Next export available at{' '}
                  {formatDate(nextAvailableAt)}.
                </p>
              </div>
            </div>
          )}

          <div className="space-y-4">
            <p className="text-sm text-muted-foreground">
              Choose what to include in your export:
            </p>

            <div className="space-y-3">
              <div className="flex items-center justify-between">
                <Label htmlFor="include_reviews">Include Reviews</Label>
                <Switch
                  id="include_reviews"
                  checked={exportOptions.include_reviews}
                  onCheckedChange={(checked) =>
                    setExportOptions({ ...exportOptions, include_reviews: checked })
                  }
                />
              </div>

              <div className="flex items-center justify-between">
                <Label htmlFor="include_lists">Include Lists</Label>
                <Switch
                  id="include_lists"
                  checked={exportOptions.include_lists}
                  onCheckedChange={(checked) =>
                    setExportOptions({ ...exportOptions, include_lists: checked })
                  }
                />
              </div>

              <div className="flex items-center justify-between">
                <Label htmlFor="include_activity_log">Include Activity Log</Label>
                <Switch
                  id="include_activity_log"
                  checked={exportOptions.include_activity_log}
                  onCheckedChange={(checked) =>
                    setExportOptions({ ...exportOptions, include_activity_log: checked })
                  }
                />
              </div>

              <div className="flex items-center justify-between">
                <Label htmlFor="include_preferences">Include Preferences</Label>
                <Switch
                  id="include_preferences"
                  checked={exportOptions.include_preferences}
                  onCheckedChange={(checked) =>
                    setExportOptions({ ...exportOptions, include_preferences: checked })
                  }
                />
              </div>
            </div>
          </div>

          <div className="flex items-start gap-3 p-4 border rounded-lg">
            <AlertCircle className="w-5 h-5 text-blue-500 mt-0.5" />
            <div className="space-y-1">
              <p className="text-sm font-medium">GDPR Compliance</p>
              <p className="text-sm text-muted-foreground">
                This export includes all personal data we store about you. You can use this for backup purposes or to migrate to another service.
              </p>
            </div>
          </div>

          <Button 
            onClick={handleDataExport} 
            disabled={exporting || rateLimited}
            className="w-full"
          >
            <Download className="w-4 h-4 mr-2" />
            {exporting ? 'Exporting Data...' : 'Export My Data'}
          </Button>
        </CardContent>
      </Card>
    </div>
  );
}
