import React, { useMemo } from "react";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { AlertTriangle, BarChart3 } from "lucide-react";
import { PieChart, Pie, Cell, ResponsiveContainer } from "recharts";

interface RiskTypeStats {
  [riskType: string]: {
    count: number;
    percentage: number;
    affectedEntities: Set<string>;
    avgSeverity: number;
  };
}

interface RiskDistributionPieChartProps {
  riskTypeStats: RiskTypeStats;
  totalFailures: number;
  onRiskTypeClick: (riskType: string, stats: any) => void;
}

interface PieChartData {
  name: string;
  value: number;
  percentage: number;
  color: string;
  severity: number;
  affectedEntities: number;
}

export function RiskDistributionPieChart({
  riskTypeStats,
  totalFailures,
  onRiskTypeClick,
}: RiskDistributionPieChartProps) {
  const [hoveredIndex, setHoveredIndex] = React.useState<number | null>(null);

  // Add rotation animation styles
  React.useEffect(() => {
    const style = document.createElement("style");
    style.textContent = `
      .rotating-chart {
        animation: rotate 20s linear infinite;
        transform-origin: center;
      }
      .rotating-chart:hover {
        animation-play-state: paused;
      }
      @keyframes rotate {
        from {
          transform: rotate(0deg);
        }
        to {
          transform: rotate(360deg);
        }
      }
    `;
    document.head.appendChild(style);

    return () => {
      document.head.removeChild(style);
    };
  }, []);
  // Transform data for pie chart
  const chartData = useMemo<PieChartData[]>(() => {
    const colors = [
      "#ef4444", // red-500 - High severity
      "#f97316", // orange-500 - Medium-high severity
      "#eab308", // yellow-500 - Medium severity
      "#3b82f6", // blue-500 - Medium-low severity
      "#8b5cf6", // purple-500 - Low severity
      "#10b981", // emerald-500 - Very low severity
    ];

    // Guard against undefined or empty riskTypeStats
    if (!riskTypeStats || typeof riskTypeStats !== "object") {
      return [];
    }

    return Object.entries(riskTypeStats)
      .filter(
        ([riskType, stats]) => riskType && stats && typeof stats === "object"
      )
      .map(([riskType, stats], index) => ({
        name: riskType.replace(/_/g, " "),
        value: stats.count || 0,
        percentage: stats.percentage || 0,
        color: colors[index % colors.length] || "#6b7280",
        severity: stats.avgSeverity || 0,
        affectedEntities: stats.affectedEntities?.size || 0,
      }));
  }, [riskTypeStats]);

  // Handle pie chart segment click
  const handleSegmentClick = (data: PieChartData) => {
    // Guard against undefined data
    if (!data || !data.name) {
      return;
    }
    const originalRiskType = Object.keys(riskTypeStats).find(
      (key) => key.replace(/_/g, " ") === data.name
    );
    if (originalRiskType) {
      onRiskTypeClick(originalRiskType, riskTypeStats[originalRiskType]);
    }
  };

  if (totalFailures === 0) {
    return (
      <Card className="glass-card h-full flex flex-col">
        <CardHeader>
          <CardTitle className="flex items-center gap-2">
            <AlertTriangle className="h-5 w-5" />
            Risk Distribution
          </CardTitle>
        </CardHeader>
        <CardContent className="flex-1 flex items-center justify-center">
          <div className="text-center py-8 text-muted-foreground">
            <BarChart3 className="h-12 w-12 mx-auto mb-4 opacity-50" />
            <p>No risk data available</p>
            <p className="text-sm">
              Upload traces with failures to see distribution
            </p>
          </div>
        </CardContent>
      </Card>
    );
  }

  return (
    <Card className="glass-card shadow-sm h-full flex flex-col">
      <CardHeader className="pb-4">
        <div className="flex items-center justify-between">
          <div className="flex items-center gap-2">
            <AlertTriangle className="h-5 w-5 text-muted-foreground" />
            <CardTitle className="text-lg font-semibold">
              Risk Distribution
            </CardTitle>
          </div>
        </div>
        <p className="text-sm text-muted-foreground mt-2">
          Click segments for detailed analysis
        </p>
      </CardHeader>

      <CardContent className="flex-1">
        {/* Pie Chart with legend */}
        <div className="space-y-4">
          {/* Rotating Pie Chart */}
          <div id="risk-distribution-chart" className="h-80 w-full relative">
            {/* Glass overlay effect */}
            <div className="absolute inset-0 bg-gradient-to-br from-white/5 via-transparent to-white/5 rounded-lg pointer-events-none" />

            <ResponsiveContainer width="100%" height="100%">
              <PieChart className="rotating-chart">
                <Pie
                  data={chartData}
                  cx="50%"
                  cy="50%"
                  innerRadius={70}
                  outerRadius={120}
                  paddingAngle={2}
                  dataKey="value"
                  cursor="pointer"
                  onClick={handleSegmentClick}
                >
                  {chartData.map((entry, index) => (
                    <Cell
                      key={`cell-${index}`}
                      fill={entry.color}
                      stroke={
                        hoveredIndex === index
                          ? "rgba(255,255,255,0.4)"
                          : "rgba(255,255,255,0.1)"
                      }
                      strokeWidth={hoveredIndex === index ? 2 : 1}
                      className="transition-all duration-200"
                      style={{
                        filter:
                          hoveredIndex === index
                            ? "brightness(1.1) drop-shadow(0 0 8px rgba(255,255,255,0.3))"
                            : "none",
                      }}
                      onMouseEnter={() => setHoveredIndex(index)}
                      onMouseLeave={() => setHoveredIndex(null)}
                    />
                  ))}
                </Pie>
              </PieChart>
            </ResponsiveContainer>
          </div>

          {/* Legend Table */}
          <div className="grid grid-cols-1 gap-2">
            {chartData.map((entry, index) => (
              <div
                key={index}
                className={`flex items-center justify-between p-3 rounded-lg border transition-all cursor-pointer ${
                  hoveredIndex === index
                    ? "bg-gradient-to-r from-white/20 to-white/10 border-white/30 shadow-lg scale-[1.02]"
                    : "bg-gradient-to-r from-white/10 to-transparent border-white/10 hover:bg-white/5"
                }`}
                onClick={() => handleSegmentClick(entry)}
                onMouseEnter={() => setHoveredIndex(index)}
                onMouseLeave={() => setHoveredIndex(null)}
              >
                <div className="flex items-center gap-3">
                  <div
                    className="w-4 h-4 rounded-full border border-white/20"
                    style={{ backgroundColor: entry.color }}
                  />
                  <span className="text-sm font-medium text-foreground">
                    {entry.name}
                  </span>
                </div>
                <div className="flex items-center gap-4 text-sm text-muted-foreground">
                  <span className="font-medium">{entry.value} failures</span>
                  <span className="text-xs bg-slate-100 dark:bg-slate-800 px-2 py-1 rounded">
                    {entry.percentage}%
                  </span>
                </div>
              </div>
            ))}
          </div>
        </div>
      </CardContent>
    </Card>
  );
}