/**
 * AIInsightsBlock - AI Insights Dashboard Block
 *
 * Displays AI-generated insights for professional/enterprise tiers
 * Shows top 2-3 insights with links to full AI Insights page
 */

import React from 'react';
import { useTranslation } from 'react-i18next';
import { Lightbulb, ArrowRight, BarChart2, TrendingUp, TrendingDown, Shield, AlertTriangle } from 'lucide-react';

interface AIInsight {
  id: string;
  title: string;
  description: string;
  type: 'cost_optimization' | 'waste_reduction' | 'safety_stock' | 'demand_forecast' | 'risk_alert';
  impact: 'high' | 'medium' | 'low';
  impact_value?: string;
  impact_currency?: string;
  created_at: string;
}

interface AIInsightsBlockProps {
  insights: AIInsight[];
  loading?: boolean;
  onViewAll: () => void;
}

export function AIInsightsBlock({ insights = [], loading = false, onViewAll }: AIInsightsBlockProps) {
  const { t } = useTranslation(['dashboard', 'common']);

  // Get icon based on insight type
  const getInsightIcon = (type: string) => {
    switch (type) {
      case 'cost_optimization': return <TrendingUp className="w-5 h-5 text-[var(--color-success-600)]" />;
      case 'waste_reduction': return <TrendingDown className="w-5 h-5 text-[var(--color-success-600)]" />;
      case 'safety_stock': return <Shield className="w-5 h-5 text-[var(--color-info-600)]" />;
      case 'demand_forecast': return <BarChart2 className="w-5 h-5 text-[var(--color-primary-600)]" />;
      case 'risk_alert': return <AlertTriangle className="w-5 h-5 text-[var(--color-error-600)]" />;
      default: return <Lightbulb className="w-5 h-5 text-[var(--color-primary-600)]" />;
    }
  };

  // Get impact color based on level
  const getImpactColor = (impact: string) => {
    switch (impact) {
      case 'high': return 'bg-[var(--color-error-100)] text-[var(--color-error-700)]';
      case 'medium': return 'bg-[var(--color-warning-100)] text-[var(--color-warning-700)]';
      case 'low': return 'bg-[var(--color-info-100)] text-[var(--color-info-700)]';
      default: return 'bg-[var(--bg-secondary)] text-[var(--text-secondary)]';
    }
  };

  // Get impact label
  const getImpactLabel = (impact: string) => {
    switch (impact) {
      case 'high': return t('dashboard:ai_insights.impact_high');
      case 'medium': return t('dashboard:ai_insights.impact_medium');
      case 'low': return t('dashboard:ai_insights.impact_low');
      default: return '';
    }
  };

  if (loading) {
    return (
      <div className="rounded-xl shadow-lg p-6 border border-[var(--border-primary)] bg-[var(--bg-primary)] animate-pulse">
        <div className="flex items-center gap-4 mb-4">
          <div className="w-12 h-12 bg-[var(--bg-secondary)] rounded-full"></div>
          <div className="flex-1 space-y-2">
            <div className="h-5 bg-[var(--bg-secondary)] rounded w-1/3"></div>
            <div className="h-4 bg-[var(--bg-secondary)] rounded w-1/4"></div>
          </div>
        </div>
        <div className="space-y-4">
          <div className="h-16 bg-[var(--bg-secondary)] rounded"></div>
          <div className="h-16 bg-[var(--bg-secondary)] rounded"></div>
        </div>
      </div>
    );
  }

  // Show top 3 insights
  const topInsights = insights.slice(0, 3);

  return (
    <div className="rounded-xl shadow-lg border border-[var(--border-primary)] bg-[var(--bg-primary)] overflow-hidden">
      {/* Header */}
      <div className="p-6 pb-4">
        <div className="flex items-center gap-4">
          {/* Icon */}
          <div className="w-12 h-12 rounded-full flex items-center justify-center flex-shrink-0 bg-[var(--color-primary-100)]">
            <Lightbulb className="w-6 h-6 text-[var(--color-primary-600)]" />
          </div>

          {/* Title & Description */}
          <div className="flex-1">
            <h2 className="text-xl font-bold text-[var(--text-primary)]">
              {t('dashboard:ai_insights.title')}
            </h2>
            <p className="text-sm text-[var(--text-secondary)]">
              {t('dashboard:ai_insights.subtitle')}
            </p>
          </div>

          {/* View All Button */}
          <button
            onClick={onViewAll}
            className="flex items-center gap-2 px-3 py-2 rounded-lg border border-[var(--border-primary)] text-[var(--text-primary)] hover:bg-[var(--bg-secondary)] transition-colors text-sm font-medium"
          >
            <span>{t('dashboard:ai_insights.view_all')}</span>
            <ArrowRight className="w-4 h-4" />
          </button>
        </div>
      </div>

      {/* Insights List */}
      {topInsights.length > 0 ? (
        <div className="border-t border-[var(--border-primary)]">
          {topInsights.map((insight, index) => (
            <div
              key={insight.id || index}
              className={`p-4 ${index < topInsights.length - 1 ? 'border-b border-[var(--border-primary)]' : ''}`}
            >
              <div className="flex items-start gap-3">
                {/* Icon */}
                <div className="flex-shrink-0 mt-1">
                  {getInsightIcon(insight.type)}
                </div>

                {/* Content */}
                <div className="flex-1 min-w-0">
                  <div className="flex items-center gap-2 mb-1">
                    <h3 className="font-semibold text-[var(--text-primary)] text-sm">
                      {insight.title}
                    </h3>
                    {/* Impact Badge */}
                    <span className={`px-2 py-0.5 rounded-full text-xs font-medium ${getImpactColor(insight.impact)}`}>
                      {getImpactLabel(insight.impact)}
                    </span>
                  </div>

                  <p className="text-sm text-[var(--text-secondary)] mb-2">
                    {insight.description}
                  </p>

                  {/* Impact Value */}
                  {insight.impact_value && (
                    <div className="flex items-center gap-2">
                      {insight.type === 'cost_optimization' && (
                        <span className="text-sm font-semibold text-[var(--color-success-600)]">
                          {insight.impact_currency}{insight.impact_value} {t('dashboard:ai_insights.savings')}
                        </span>
                      )}
                      {insight.type === 'waste_reduction' && (
                        <span className="text-sm font-semibold text-[var(--color-success-600)]">
                          {insight.impact_value} {t('dashboard:ai_insights.reduction')}
                        </span>
                      )}
                    </div>
                  )}
                </div>
              </div>
            </div>
          ))}
        </div>
      ) : (
        /* Empty State */
        <div className="px-6 pb-6">
          <div className="flex items-center gap-3 p-4 rounded-lg bg-[var(--color-info-50)] border border-[var(--color-info-100)]">
            <Lightbulb className="w-6 h-6 text-[var(--color-info-600)]" />
            <p className="text-sm text-[var(--color-info-700)]">
              {t('dashboard:ai_insights.no_insights')}
            </p>
          </div>
        </div>
      )}
    </div>
  );
}

export default AIInsightsBlock;
