'use client'

import { useState } from 'react'
import type { ModelData } from '@/lib/types'
import { LabLogo } from '@/components/LabLogo'
import { creatorColor } from '@/lib/utils'

const STRIP_ROWS = [
  { key: 'luc'      as const, label: 'Refusal Rate', invert: false, color: '#00C0F3', fmt: (v: number) => `${(v * 100).toFixed(0)}%` },
  { key: 'rag'      as const, label: 'RAG Score',    invert: false, color: '#F4333D', fmt: (v: number) => `${(v * 100).toFixed(0)}%` },
  { key: 'fairness' as const, label: 'Fairness',     invert: true,  color: '#BA2FA2', fmt: (v: number) => v.toFixed(3) },
]

function getAvg(m: ModelData, key: 'luc' | 'rag' | 'fairness'): number | null {
  if (key === 'luc') return m.luc.avg
  if (key === 'rag') return m.rag.avg
  return m.fairness.avg
}

export default function ScoreDistribution({ models, maxFairness }: { models: ModelData[]; maxFairness: number }) {
  const active = models.filter(m => !m.archived)
  const [tooltip, setTooltip] = useState<{
    x: number; y: number; model: string; val: string; creator: string
  } | null>(null)

  const VW      = 800
  const ROW_H   = 120
  const LBL_W   = 85
  const PAD_R   = 85
  const AXIS_W  = VW - LBL_W - PAD_R
  const DOT_R   = 7
  const VH      = STRIP_ROWS.length * ROW_H
  const TT_W    = 168
  const TT_H    = 36
  const VIOLIN_H = 40
  const VIOLIN_BW = AXIS_W * 0.07

  return (
    <div style={{ position: 'relative', width: '100%' }}>
    <svg
      viewBox={`0 0 ${VW} ${VH}`}
      style={{ width: '100%', height: 'auto', display: 'block' }}
      aria-label="Score distribution across all models"
      onMouseLeave={() => setTooltip(null)}
    >
      {STRIP_ROWS.map((row, ri) => {
        const y0   = ri * ROW_H
        const yMid = y0 + ROW_H / 2

        const vals = active
          .map(m => ({ val: getAvg(m, row.key), creator: m.creator, model: m.model }))
          .filter(d => d.val !== null) as { val: number; creator: string; model: string }[]

        const rawMax = row.key === 'fairness' ? maxFairness : 1
        const mean   = vals.reduce((s, d) => s + d.val, 0) / vals.length

        const toX = (v: number) => {
          const pct = row.invert ? 1 - v / rawMax : v / rawMax
          return LBL_W + pct * AXIS_W
        }
        const meanX = toX(mean)

        return (
          <g key={row.key}>
            {/* Alternating row bg */}
            {ri % 2 === 1 && (
              <rect x={0} y={y0} width={VW} height={ROW_H} fill="var(--bg-0)" fillOpacity={0.5} />
            )}

            {/* Row divider */}
            {ri > 0 && (
              <line x1={0} y1={y0} x2={VW} y2={y0} stroke="var(--border-0)" strokeWidth={1} />
            )}

            {/* Axis line */}
            <line x1={LBL_W} y1={yMid} x2={VW - PAD_R} y2={yMid}
              stroke="var(--border-1)" strokeWidth={1} />

            {/* Half violin */}
            {vals.length > 1 && (() => {
              const N = 90
              const sampleXs = Array.from({ length: N }, (_, i) => LBL_W + (i / (N - 1)) * AXIS_W)
              const densities = sampleXs.map(px =>
                vals.reduce((s, d) => s + Math.exp(-0.5 * ((px - toX(d.val)) / VIOLIN_BW) ** 2), 0) /
                (vals.length * VIOLIN_BW * Math.sqrt(2 * Math.PI))
              )
              const maxD = Math.max(...densities)
              if (maxD <= 0) return null
              const pts = sampleXs.map((px, i) =>
                `L${px.toFixed(1)},${(yMid - (densities[i] / maxD) * VIOLIN_H).toFixed(1)}`
              ).join(' ')
              const d = `M${LBL_W},${yMid} ${pts} L${VW - PAD_R},${yMid} Z`
              return (
                <path
                  key="violin"
                  d={d}
                  fill="var(--text-3)"
                  fillOpacity={0.15}
                  stroke="var(--text-3)"
                  strokeOpacity={0.45}
                  strokeWidth={1.2}
                  strokeLinejoin="round"
                />
              )
            })()}

            {/* Tick marks + labels */}
            {[0, 0.25, 0.5, 0.75, 1].map(t => {
              const tx = LBL_W + t * AXIS_W
              const tickLabel = row.invert
                ? (t === 0 ? rawMax.toFixed(2) : t === 1 ? '0' : (rawMax * (1 - t)).toFixed(2))
                : `${Math.round(t * 100)}%`
              return (
                <g key={t}>
                  <line x1={tx} y1={yMid - 5} x2={tx} y2={yMid + 5}
                    stroke="var(--border-2)" strokeWidth={1} />
                  <text x={tx} y={y0 + ROW_H - 8}
                    textAnchor="middle" fontSize={9} fill="var(--text-3)" fontFamily="inherit">
                    {tickLabel}
                  </text>
                </g>
              )
            })}

            {/* Mean line */}
            <line x1={meanX} y1={y0 + 10} x2={meanX} y2={y0 + ROW_H - 20}
              stroke="var(--text-3)" strokeOpacity={0.9} strokeWidth={1.2} strokeDasharray="4 3" />
            <text x={meanX + 4} y={y0 + 20} fontSize={8} fill="var(--text-3)" fillOpacity={0.9} fontFamily="inherit">
              avg {row.fmt(mean)}
            </text>

            {/* Dots — render hovered dot last so it stays on top */}
            {[...vals].sort((a, b) => {
              const aH = tooltip?.model === a.model ? 1 : 0
              const bH = tooltip?.model === b.model ? 1 : 0
              return aH - bH
            }).map((d, i) => {
              const isHovered = tooltip?.model === d.model
              const dimmed = tooltip !== null && !isHovered
              const cx = toX(d.val)
              return (
                <g key={d.model}>
                  <circle
                    cx={cx}
                    cy={yMid}
                    r={isHovered ? 20 : DOT_R}
                    fill={isHovered ? 'var(--bg-1)' : creatorColor(d.creator)}
                    fillOpacity={dimmed ? 0.35 : 1}
                    stroke={isHovered ? creatorColor(d.creator) : 'var(--bg-1)'}
                    strokeWidth={isHovered ? 2.5 : 1.2}
                    style={{
                      cursor: 'pointer',
                      transition: 'r 0.15s, fill-opacity 0.15s',
                      filter: dimmed ? 'saturate(0.15)' : undefined,
                    }}
                    onMouseEnter={() => setTooltip({
                      x: cx,
                      y: yMid,
                      model: d.model,
                      val: row.fmt(d.val),
                      creator: d.creator,
                    })}
                  />
                </g>
              )
            })}

            {/* Row label */}
            <text x={LBL_W - 16} y={yMid + 5}
              textAnchor="end" fontSize={12} fontWeight="700"
              fill="var(--text-1)" fontFamily="inherit">
              {row.label}
            </text>

          </g>
        )
      })}

      {/* Tooltip — rendered last so it appears above all dots */}
      {tooltip && (() => {
        const ttX  = Math.max(0, Math.min(tooltip.x - TT_W / 2, VW - TT_W))
        const above = tooltip.y - DOT_R - TT_H - 8
        const ttY  = above < 2 ? tooltip.y + DOT_R + 6 : above
        const cc   = creatorColor(tooltip.creator)
        return (
          <g style={{ pointerEvents: 'none' }}>
            <rect x={ttX} y={ttY} width={TT_W} height={TT_H} rx={5}
              fill="var(--bg-1)" stroke="var(--border-2)" strokeWidth={1.2} />
            <rect x={ttX} y={ttY} width={3} height={TT_H} rx={2} fill={cc} />
            <text x={ttX + 10} y={ttY + 13}
              fontSize={10} fontWeight="700" fill="var(--text-0)" fontFamily="inherit">
              {tooltip.model}
            </text>
            <text x={ttX + 10} y={ttY + 27}
              fontSize={9} fill={cc} fontFamily="inherit">
              {tooltip.val}
            </text>
          </g>
        )
      })()}
    </svg>

    {/* Logo overlays — one per row for the hovered model */}
    {tooltip && STRIP_ROWS.map((row, ri) => {
      const m = active.find(m => m.model === tooltip.model)
      if (!m) return null
      const val = getAvg(m, row.key)
      if (val === null) return null
      const rawMax = row.key === 'fairness' ? maxFairness : 1
      const pct = row.invert ? 1 - val / rawMax : val / rawMax
      const cx = LBL_W + pct * AXIS_W
      const yMid = ri * ROW_H + ROW_H / 2
      const pctX = cx / VW * 100
      const pctY = yMid / VH * 100
      return (
        <div key={row.key} style={{
          position: 'absolute',
          left: `${pctX}%`,
          top: `${pctY}%`,
          transform: 'translate(-50%, -50%)',
          width: 40,
          height: 40,
          display: 'flex',
          alignItems: 'center',
          justifyContent: 'center',
          pointerEvents: 'none',
        }}>
          <LabLogo creator={tooltip.creator} size={32} />
        </div>
      )
    })}
    </div>
  )
}