import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import { supabase } from '@/integrations/supabase/client';
import { useAuth } from './useAuth';
import { useUserRole } from './useUserRole';
import { useToast } from './use-toast';
import { useCallback, useMemo } from 'react';

interface AdminSetting {
  id: string;
  setting_key: string;
  setting_value: any;
  category: string;
  description: string;
}

export function useAdminSettings() {
  const { user } = useAuth();
  const { isSuperuser } = useUserRole();
  const { toast } = useToast();
  const queryClient = useQueryClient();

  const {
    data: settings,
    isLoading,
    error
  } = useQuery({
    queryKey: ['admin-settings'],
    queryFn: async () => {
      const { data, error } = await supabase
        .from('admin_settings')
        .select('*')
        .order('category', { ascending: true });
      
      if (error) throw error;
      return data as AdminSetting[];
    },
    enabled: !!user && isSuperuser()
  });

  // Memoize settings into a stable map to prevent cascading re-renders
  const settingsMap = useMemo(() => {
    if (!settings) return {};
    return Object.fromEntries(
      settings.map(s => [s.setting_key, s.setting_value])
    );
  }, [settings]);

  const updateSettingMutation = useMutation({
    mutationFn: async ({ key, value }: { key: string; value: any }) => {
      const { error } = await supabase
        .from('admin_settings')
        .update({ 
          setting_value: value,
          updated_by: user?.id,
          updated_at: new Date().toISOString()
        })
        .eq('setting_key', key);
      
      if (error) throw error;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['admin-settings'] });
      toast({
        title: "Setting Updated",
        description: "The setting has been saved successfully.",
      });
    },
    onError: (error: any) => {
      toast({
        title: "Error",
        description: error.message || "Failed to update setting",
        variant: "destructive",
      });
    }
  });

  const getSettingValue = useCallback((key: string, defaultValue: any = null) => {
    return settingsMap[key] ?? defaultValue;
  }, [settingsMap]);

  const updateSetting = async (key: string, value: any) => {
    return updateSettingMutation.mutateAsync({ key, value });
  };

  // Helper functions for common settings (memoized with useCallback for stable references)
  const getAutoFlagThreshold = useCallback(() => {
    return parseInt(getSettingValue('moderation.auto_flag_threshold', '3'));
  }, [getSettingValue]);

  const getRequireApproval = useCallback(() => {
    const value = getSettingValue('moderation.require_approval', 'true');
    return value === true || value === 'true';
  }, [getSettingValue]);

  const getBanDurations = useCallback(() => {
    const value = getSettingValue('moderation.ban_durations', ['1d', '7d', '30d', 'permanent']);
    return Array.isArray(value) ? value : JSON.parse(value || '[]');
  }, [getSettingValue]);

  const getEmailAlertsEnabled = useCallback(() => {
    const value = getSettingValue('notifications.email_alerts', 'true');
    return value === true || value === 'true';
  }, [getSettingValue]);

  const getReportThreshold = useCallback(() => {
    return parseInt(getSettingValue('notifications.report_threshold', '5'));
  }, [getSettingValue]);

  const getAuditRetentionDays = useCallback(() => {
    return parseInt(getSettingValue('system.audit_retention_days', '365'));
  }, [getSettingValue]);

  const getAutoCleanupEnabled = useCallback(() => {
    const value = getSettingValue('system.auto_cleanup', 'false');
    return value === true || value === 'true';
  }, [getSettingValue]);

  const getAdminPanelRefreshMode = useCallback(() => {
    const value = getSettingValue('system.admin_panel_refresh_mode', 'auto');
    // Remove quotes if they exist (JSON string stored in DB)
    return typeof value === 'string' ? value.replace(/"/g, '') : value;
  }, [getSettingValue]);

  const getAdminPanelPollInterval = useCallback(() => {
    const value = getSettingValue('system.admin_panel_poll_interval', 30);
    return parseInt(value?.toString() || '30') * 1000; // Convert to milliseconds
  }, [getSettingValue]);

  /**
   * Get auto-refresh strategy setting
   * Returns: 'merge' | 'replace' | 'notify'
   */
  const getAutoRefreshStrategy = useCallback((): 'merge' | 'replace' | 'notify' => {
    const value = getSettingValue('auto_refresh_strategy', 'merge');
    const cleanValue = typeof value === 'string' ? value.replace(/"/g, '') : value;
    return cleanValue as 'merge' | 'replace' | 'notify';
  }, [getSettingValue]);

  /**
   * Get preserve interaction state setting
   * Returns: boolean
   */
  const getPreserveInteractionState = useCallback((): boolean => {
    const value = getSettingValue('preserve_interaction_state', 'true');
    const cleanValue = typeof value === 'string' ? value.replace(/"/g, '') : value;
    return cleanValue === 'true' || cleanValue === true;
  }, [getSettingValue]);

  const getNotificationRecipients = useCallback(() => {
    return getSettingValue('notifications.recipients', []);
  }, [getSettingValue]);

  const getUseRealtimeQueue = useCallback((): boolean => {
    const value = getSettingValue('system.use_realtime_queue', 'true');
    const cleanValue = typeof value === 'string' ? value.replace(/"/g, '') : value;
    return cleanValue === 'true' || cleanValue === true;
  }, [getSettingValue]);

  const getRefreshOnTabVisible = useCallback((): boolean => {
    const value = getSettingValue('system.refresh_on_tab_visible', 'false');
    const cleanValue = typeof value === 'string' ? value.replace(/"/g, '') : value;
    return cleanValue === 'true' || cleanValue === true;
  }, [getSettingValue]);

  const getSetting = useCallback((key: string) => {
    return settings?.find(s => s.setting_key === key);
  }, [settings]);

  const getSettingsByCategory = useCallback((category: string) => {
    return settings?.filter(s => s.category === category) || [];
  }, [settings]);

  return {
    settings,
    isLoading,
    error,
    updateSetting,
    isUpdating: updateSettingMutation.isPending,
    getSetting,
    getSettingValue,
    getSettingsByCategory,
    // Helper functions
    getAutoFlagThreshold,
    getRequireApproval,
    getBanDurations,
    getEmailAlertsEnabled,
    getNotificationRecipients,
    getReportThreshold,
    getAuditRetentionDays,
    getAutoCleanupEnabled,
    getAdminPanelRefreshMode,
    getAdminPanelPollInterval,
    getAutoRefreshStrategy,
    getPreserveInteractionState,
    getUseRealtimeQueue,
    getRefreshOnTabVisible,
  };
}