import { useMemo } from 'react';

interface Props {
  realtime?: {
    pv_power: number;
    heatpump_power: number;
    total_load: number;
    grid_power: number;
  };
}

export default function EnergyFlow({ realtime }: Props) {
  const pv = realtime?.pv_power || 0;
  const load = realtime?.total_load || 0;
  const grid = realtime?.grid_power || 0;
  const hp = realtime?.heatpump_power || 0;

  // Calculate flows
  const pvToLoad = Math.min(pv, load);
  const pvToGrid = Math.max(0, pv - load);
  const gridToLoad = Math.max(0, grid);
  const gridExport = Math.max(0, -grid);

  const selfUseRate = load > 0 ? ((pvToLoad / load) * 100).toFixed(1) : '0.0';

  // Determine which flows are active (> 0.1 kW threshold)
  const flows = useMemo(() => ({
    pvToLoad: pvToLoad > 0.1,
    pvToGrid: pvToGrid > 0.1 || gridExport > 0.1,
    gridToLoad: gridToLoad > 0.1,
    gridToHp: hp > 0.1,
  }), [pvToLoad, pvToGrid, gridExport, gridToLoad, hp]);

  // SVG layout constants
  const W = 560;
  const H = 340;

  // Node positions (center points)
  const nodes = {
    pv:       { x: W / 2, y: 40 },
    load:     { x: 100,  y: 200 },
    grid:     { x: W - 100, y: 200 },
    heatpump: { x: W / 2, y: 300 },
  };

  return (
    <div style={{ width: '100%', position: 'relative' }}>
      <style>{`
        @keyframes dashFlow {
          to { stroke-dashoffset: -24; }
        }
        @keyframes dashFlowReverse {
          to { stroke-dashoffset: 24; }
        }
        @keyframes nodeGlow {
          0%, 100% { filter: drop-shadow(0 0 4px var(--glow-color)); }
          50% { filter: drop-shadow(0 0 12px var(--glow-color)); }
        }
        @keyframes pulseValue {
          0%, 100% { opacity: 1; }
          50% { opacity: 0.75; }
        }
        .ef-flow-line {
          fill: none;
          stroke-width: 3;
          stroke-dasharray: 12 12;
          animation: dashFlow 0.8s linear infinite;
        }
        .ef-flow-line-reverse {
          fill: none;
          stroke-width: 3;
          stroke-dasharray: 12 12;
          animation: dashFlowReverse 0.8s linear infinite;
        }
        .ef-flow-bg {
          fill: none;
          stroke-width: 6;
          opacity: 0.1;
        }
        .ef-node-rect {
          rx: 12;
          ry: 12;
          stroke-width: 2;
        }
        .ef-node-group {
          animation: nodeGlow 3s ease-in-out infinite;
        }
        .ef-node-icon {
          font-size: 22px;
          text-anchor: middle;
          dominant-baseline: central;
        }
        .ef-node-label {
          fill: rgba(255,255,255,0.65);
          font-size: 11px;
          text-anchor: middle;
          font-weight: 500;
        }
        .ef-node-value {
          fill: #fff;
          font-size: 15px;
          text-anchor: middle;
          font-weight: 700;
        }
        .ef-flow-value {
          font-size: 11px;
          font-weight: 600;
          text-anchor: middle;
          dominant-baseline: central;
        }
        .ef-active-value {
          animation: pulseValue 2s ease-in-out infinite;
        }
        .ef-inactive {
          opacity: 0.2;
        }
      `}</style>

      <svg
        viewBox={`0 0 ${W} ${H}`}
        style={{ width: '100%', height: 'auto', maxHeight: 340 }}
        xmlns="http://www.w3.org/2000/svg"
      >
        <defs>
          {/* Glow filters */}
          <filter id="glowGreen" x="-50%" y="-50%" width="200%" height="200%">
            <feDropShadow dx="0" dy="0" stdDeviation="4" floodColor="#52c41a" floodOpacity="0.6" />
          </filter>
          <filter id="glowBlue" x="-50%" y="-50%" width="200%" height="200%">
            <feDropShadow dx="0" dy="0" stdDeviation="4" floodColor="#1890ff" floodOpacity="0.6" />
          </filter>
          <filter id="glowOrange" x="-50%" y="-50%" width="200%" height="200%">
            <feDropShadow dx="0" dy="0" stdDeviation="4" floodColor="#ff8c00" floodOpacity="0.6" />
          </filter>
          <filter id="glowCyan" x="-50%" y="-50%" width="200%" height="200%">
            <feDropShadow dx="0" dy="0" stdDeviation="4" floodColor="#13c2c2" floodOpacity="0.6" />
          </filter>

          {/* Gradient for PV -> Load (green) */}
          <linearGradient id="gradPvLoad" x1={nodes.pv.x} y1={nodes.pv.y} x2={nodes.load.x} y2={nodes.load.y} gradientUnits="userSpaceOnUse">
            <stop offset="0%" stopColor="#52c41a" />
            <stop offset="100%" stopColor="#1890ff" />
          </linearGradient>
          {/* Gradient for PV -> Grid (green to orange) */}
          <linearGradient id="gradPvGrid" x1={nodes.pv.x} y1={nodes.pv.y} x2={nodes.grid.x} y2={nodes.grid.y} gradientUnits="userSpaceOnUse">
            <stop offset="0%" stopColor="#52c41a" />
            <stop offset="100%" stopColor="#ff8c00" />
          </linearGradient>
          {/* Gradient for Grid -> Load (orange to blue) */}
          <linearGradient id="gradGridLoad" x1={nodes.grid.x} y1={nodes.grid.y} x2={nodes.load.x} y2={nodes.load.y} gradientUnits="userSpaceOnUse">
            <stop offset="0%" stopColor="#ff8c00" />
            <stop offset="100%" stopColor="#1890ff" />
          </linearGradient>
          {/* Gradient for Grid -> HeatPump (orange to cyan) */}
          <linearGradient id="gradGridHp" x1={nodes.grid.x} y1={nodes.grid.y} x2={nodes.heatpump.x} y2={nodes.heatpump.y} gradientUnits="userSpaceOnUse">
            <stop offset="0%" stopColor="#ff8c00" />
            <stop offset="100%" stopColor="#13c2c2" />
          </linearGradient>
        </defs>

        {/* ===== FLOW LINES ===== */}

        {/* PV -> Load */}
        <path
          d={`M ${nodes.pv.x} ${nodes.pv.y + 30} C ${nodes.pv.x} ${nodes.pv.y + 80}, ${nodes.load.x} ${nodes.load.y - 80}, ${nodes.load.x} ${nodes.load.y - 30}`}
          className="ef-flow-bg"
          stroke="url(#gradPvLoad)"
        />
        <path
          d={`M ${nodes.pv.x} ${nodes.pv.y + 30} C ${nodes.pv.x} ${nodes.pv.y + 80}, ${nodes.load.x} ${nodes.load.y - 80}, ${nodes.load.x} ${nodes.load.y - 30}`}
          className={flows.pvToLoad ? 'ef-flow-line' : 'ef-flow-line ef-inactive'}
          stroke="url(#gradPvLoad)"
        />
        {flows.pvToLoad && (
          <text
            x={(nodes.pv.x + nodes.load.x) / 2 - 40}
            y={(nodes.pv.y + nodes.load.y) / 2 - 10}
            className="ef-flow-value ef-active-value"
            fill="#52c41a"
          >
            {pvToLoad.toFixed(1)} kW
          </text>
        )}

        {/* PV -> Grid (export) */}
        <path
          d={`M ${nodes.pv.x} ${nodes.pv.y + 30} C ${nodes.pv.x} ${nodes.pv.y + 80}, ${nodes.grid.x} ${nodes.grid.y - 80}, ${nodes.grid.x} ${nodes.grid.y - 30}`}
          className="ef-flow-bg"
          stroke="url(#gradPvGrid)"
        />
        <path
          d={`M ${nodes.pv.x} ${nodes.pv.y + 30} C ${nodes.pv.x} ${nodes.pv.y + 80}, ${nodes.grid.x} ${nodes.grid.y - 80}, ${nodes.grid.x} ${nodes.grid.y - 30}`}
          className={flows.pvToGrid ? 'ef-flow-line' : 'ef-flow-line ef-inactive'}
          stroke="url(#gradPvGrid)"
        />
        {flows.pvToGrid && (
          <text
            x={(nodes.pv.x + nodes.grid.x) / 2 + 40}
            y={(nodes.pv.y + nodes.grid.y) / 2 - 10}
            className="ef-flow-value ef-active-value"
            fill="#ff8c00"
          >
            {(pvToGrid || gridExport).toFixed(1)} kW
          </text>
        )}

        {/* Grid -> Load (import) */}
        <path
          d={`M ${nodes.grid.x} ${nodes.grid.y} L ${nodes.load.x + 70} ${nodes.load.y}`}
          className="ef-flow-bg"
          stroke="url(#gradGridLoad)"
        />
        <path
          d={`M ${nodes.grid.x} ${nodes.grid.y} L ${nodes.load.x + 70} ${nodes.load.y}`}
          className={flows.gridToLoad ? 'ef-flow-line-reverse' : 'ef-flow-line-reverse ef-inactive'}
          stroke="url(#gradGridLoad)"
        />
        {flows.gridToLoad && (
          <text
            x={(nodes.grid.x + nodes.load.x + 70) / 2}
            y={nodes.load.y - 14}
            className="ef-flow-value ef-active-value"
            fill="#ff8c00"
          >
            {gridToLoad.toFixed(1)} kW
          </text>
        )}

        {/* Load -> HeatPump */}
        <path
          d={`M ${nodes.load.x} ${nodes.load.y + 30} C ${nodes.load.x} ${nodes.load.y + 70}, ${nodes.heatpump.x} ${nodes.heatpump.y - 40}, ${nodes.heatpump.x} ${nodes.heatpump.y - 20}`}
          className="ef-flow-bg"
          stroke="url(#gradGridHp)"
        />
        <path
          d={`M ${nodes.load.x} ${nodes.load.y + 30} C ${nodes.load.x} ${nodes.load.y + 70}, ${nodes.heatpump.x} ${nodes.heatpump.y - 40}, ${nodes.heatpump.x} ${nodes.heatpump.y - 20}`}
          className={flows.gridToHp ? 'ef-flow-line' : 'ef-flow-line ef-inactive'}
          stroke="#13c2c2"
        />
        {flows.gridToHp && (
          <text
            x={(nodes.load.x + nodes.heatpump.x) / 2 - 20}
            y={nodes.heatpump.y - 30}
            className="ef-flow-value ef-active-value"
            fill="#13c2c2"
          >
            {hp.toFixed(1)} kW
          </text>
        )}

        {/* ===== NODES ===== */}

        {/* PV Solar Node */}
        <g className="ef-node-group" style={{ '--glow-color': '#52c41a' } as React.CSSProperties}>
          <rect
            x={nodes.pv.x - 55} y={nodes.pv.y - 28}
            width={110} height={56}
            className="ef-node-rect"
            fill="rgba(82, 196, 26, 0.12)"
            stroke="#52c41a"
            filter="url(#glowGreen)"
          />
          <text x={nodes.pv.x - 30} y={nodes.pv.y - 4} className="ef-node-icon">☀️</text>
          <text x={nodes.pv.x + 10} y={nodes.pv.y - 6} className="ef-node-label">光伏发电</text>
          <text x={nodes.pv.x} y={nodes.pv.y + 16} className="ef-node-value" fill="#52c41a">
            {pv.toFixed(1)} kW
          </text>
        </g>

        {/* Building Load Node */}
        <g className="ef-node-group" style={{ '--glow-color': '#1890ff' } as React.CSSProperties}>
          <rect
            x={nodes.load.x - 55} y={nodes.load.y - 28}
            width={110} height={56}
            className="ef-node-rect"
            fill="rgba(24, 144, 255, 0.12)"
            stroke="#1890ff"
            filter="url(#glowBlue)"
          />
          <text x={nodes.load.x - 30} y={nodes.load.y - 4} className="ef-node-icon">🏢</text>
          <text x={nodes.load.x + 10} y={nodes.load.y - 6} className="ef-node-label">建筑负载</text>
          <text x={nodes.load.x} y={nodes.load.y + 16} className="ef-node-value" fill="#1890ff">
            {load.toFixed(1)} kW
          </text>
        </g>

        {/* Grid Node */}
        <g className="ef-node-group" style={{ '--glow-color': '#ff8c00' } as React.CSSProperties}>
          <rect
            x={nodes.grid.x - 55} y={nodes.grid.y - 28}
            width={110} height={56}
            className="ef-node-rect"
            fill="rgba(255, 140, 0, 0.12)"
            stroke="#ff8c00"
            filter="url(#glowOrange)"
          />
          <text x={nodes.grid.x - 30} y={nodes.grid.y - 4} className="ef-node-icon">⚡</text>
          <text x={nodes.grid.x + 10} y={nodes.grid.y - 6} className="ef-node-label">
            {grid >= 0 ? '电网购入' : '电网输出'}
          </text>
          <text x={nodes.grid.x} y={nodes.grid.y + 16} className="ef-node-value" fill="#ff8c00">
            {Math.abs(grid).toFixed(1)} kW
          </text>
        </g>

        {/* HeatPump Node */}
        <g className="ef-node-group" style={{ '--glow-color': '#13c2c2' } as React.CSSProperties}>
          <rect
            x={nodes.heatpump.x - 55} y={nodes.heatpump.y - 28}
            width={110} height={56}
            className="ef-node-rect"
            fill="rgba(19, 194, 194, 0.12)"
            stroke="#13c2c2"
            filter="url(#glowCyan)"
          />
          <text x={nodes.heatpump.x - 30} y={nodes.heatpump.y - 4} className="ef-node-icon">🔥</text>
          <text x={nodes.heatpump.x + 10} y={nodes.heatpump.y - 6} className="ef-node-label">热泵系统</text>
          <text x={nodes.heatpump.x} y={nodes.heatpump.y + 16} className="ef-node-value" fill="#13c2c2">
            {hp.toFixed(1)} kW
          </text>
        </g>

        {/* Self-consumption badge */}
        <rect x={W / 2 - 60} y={H / 2 - 14} width={120} height={28} rx={14}
          fill="rgba(82, 196, 26, 0.15)" stroke="#52c41a" strokeWidth={1} />
        <text x={W / 2} y={H / 2 + 4} textAnchor="middle" fill="#52c41a"
          fontSize={12} fontWeight={600}>
          自消纳 {selfUseRate}%
        </text>
      </svg>
    </div>
  );
}