"use client"

interface LatencyChartProps {
  series: Record<string, number[]>
}

// Maps to CSS variables defined in globals.css
const COLORS: Record<string, string> = {
  msk: "var(--chart-line-1)",
  spb: "var(--chart-line-2)",
  fra: "var(--chart-line-3)",
  ams: "var(--chart-line-4)",
}

const LABELS: Record<string, string> = {
  msk: "MSK",
  spb: "SPB",
  fra: "FRA",
  ams: "AMS",
}

export function LatencyChart({ series }: LatencyChartProps) {
  const W = 800, H = 220
  const pad = { l: 44, r: 12, t: 12, b: 28 }
  const iw = W - pad.l - pad.r
  const ih = H - pad.t - pad.b

  const allVals = Object.values(series).flat()
  const maxVal = Math.ceil(Math.max(...allVals) / 20) * 20 + 10

  const xAt = (i: number, n: number) => pad.l + (i / (n - 1)) * iw
  const yAt = (v: number) => pad.t + (1 - v / maxVal) * ih

  const gridLines = [0, 0.25, 0.5, 0.75, 1]

  return (
    <div>
      <svg viewBox={`0 0 ${W} ${H}`} style={{ width: "100%", height: 220, display: "block" }}>
        {gridLines.map((p, i) => (
          <g key={i}>
            <line
              x1={pad.l} x2={W - pad.r}
              y1={pad.t + ih * p} y2={pad.t + ih * p}
              style={{ stroke: "var(--border)" }}
              strokeDasharray={p === 1 ? "0" : "2 4"}
            />
            <text
              x={pad.l - 8} y={pad.t + ih * p + 4}
              textAnchor="end" fontSize="10"
              style={{ fill: "var(--muted-foreground)" }}
              fontFamily="var(--font-mono, monospace)"
            >
              {Math.round(maxVal * (1 - p))}мс
            </text>
          </g>
        ))}
        {[0, 15, 30, 45, 59].map((i) => (
          <text
            key={i}
            x={xAt(i, 60)} y={H - 6}
            textAnchor="middle" fontSize="10"
            style={{ fill: "var(--muted-foreground)" }}
            fontFamily="var(--font-mono, monospace)"
          >
            -{60 - i}м
          </text>
        ))}
        {Object.entries(series).map(([key, arr]) => {
          const pts = arr.map((v, i) => `${xAt(i, arr.length).toFixed(1)},${yAt(v).toFixed(1)}`).join(" ")
          const color = COLORS[key] ?? "var(--chart-line-1)"
          return (
            <polyline key={key} points={pts} fill="none"
              style={{ stroke: color }}
              strokeWidth="1.6" strokeLinejoin="round" />
          )
        })}
      </svg>
      <div className="flex gap-4 pt-2 pl-11">
        {Object.keys(series).map((k) => {
          const color = COLORS[k] ?? "var(--chart-line-1)"
          return (
            <div key={k} className="flex items-center gap-1.5 text-xs">
              <span className="w-3 h-0.5 rounded" style={{ background: color }} />
              <span className="font-mono text-foreground">{LABELS[k]}</span>
            </div>
          )
        })}
      </div>
    </div>
  )
}
