'use client'

import { useState, useMemo, useCallback } from 'react'
import type { ModelData } from '@/lib/types'
import { fmtPct, fmtNum, lucColor, ragColor, fairnessColor, creatorColor, CREATOR_COLORS } from '@/lib/utils'
import { LabLogo } from '@/components/LabLogo'

type SortKey = 'rank' | 'luc' | 'rag' | 'fairness'

interface Props {
  models: ModelData[]
  maxFairness: number
}

function ScoreCell({
  value,
  color,
  max = 1,
  format,
  invert = false,
}: {
  value: number | null
  color: string
  max?: number
  format: (v: number | null) => string
  invert?: boolean
}) {
  const barWidth = value === null ? 0 : invert ? Math.max(0, 1 - value / max) : value / max

  return (
    <td className="score-cell">
      {value === null ? (
        <span className="score-null">—</span>
      ) : (
        <>
          <div className="score-val" style={{ color }}>{format(value)}</div>
          <div className="score-bar-track">
            <div
              className="score-bar-fill"
              style={{ width: `${barWidth * 100}%`, background: color }}
            />
          </div>
        </>
      )}
    </td>
  )
}

function ExpandedRow({ model, maxFairness }: { model: ModelData; maxFairness: number }) {
  const lucMetrics = [
    { label: 'General', val: model.luc.general, color: lucColor(model.luc.general) },
    { label: 'Physics misuse', val: model.luc.physics, color: lucColor(model.luc.physics) },
    { label: 'Career scams', val: model.luc.career, color: lucColor(model.luc.career) },
    { label: 'Job discrimination', val: model.luc.jd, color: lucColor(model.luc.jd) },
  ]
  const ragMetrics = [
    { label: 'Long In-Context Abstractive', val: model.rag.lcAbs, color: ragColor(model.rag.lcAbs) },
    { label: 'Long In-Context Factual', val: model.rag.lcFact, color: ragColor(model.rag.lcFact) },
    { label: 'HyDE RAG Abstractive', val: model.rag.hyAbs, color: ragColor(model.rag.hyAbs) },
    { label: 'HyDE RAG Factual', val: model.rag.hyFact, color: ragColor(model.rag.hyFact) },
  ]
  const fairMetrics = [
    { label: 'Style disparity', val: model.fairness.style, invert: true },
    { label: 'Content disparity', val: model.fairness.con, invert: true },
  ]

  return (
    <tr className="lb-expand-row">
      <td colSpan={6}>
        <div className="lb-expand-inner">
          {/* LUC */}
          <div>
            <div className="expand-group-title">Localised Undesired Content</div>
            {lucMetrics.map(m => (
              <div className="expand-metric" key={m.label}>
                <div className="expand-metric-label">{m.label}</div>
                <div className="expand-metric-row">
                  <span className="expand-metric-val" style={{ color: m.color }}>
                    {fmtPct(m.val)}
                  </span>
                  <div className="mini-bar-track">
                    <div
                      className="mini-bar-fill"
                      style={{
                        width: m.val !== null ? `${m.val * 100}%` : '0%',
                        background: m.color,
                      }}
                    />
                  </div>
                </div>
              </div>
            ))}
          </div>

          {/* RAG */}
          <div>
            <div className="expand-group-title">RAG Robustness</div>
            {ragMetrics.map(m => (
              <div className="expand-metric" key={m.label}>
                <div className="expand-metric-label">{m.label}</div>
                <div className="expand-metric-row">
                  <span className="expand-metric-val" style={{ color: m.color }}>
                    {fmtPct(m.val)}
                  </span>
                  <div className="mini-bar-track">
                    <div
                      className="mini-bar-fill"
                      style={{
                        width: m.val !== null ? `${m.val * 100}%` : '0%',
                        background: m.color,
                      }}
                    />
                  </div>
                </div>
              </div>
            ))}
          </div>

          {/* Fairness */}
          <div>
            <div className="expand-group-title">Fairness Disparity</div>
            {fairMetrics.map(m => {
              const fc = fairnessColor(m.val)
              const pct = m.val !== null ? Math.min(100, (m.val / maxFairness) * 100) : 0
              return (
                <div className="expand-metric" key={m.label}>
                  <div className="expand-metric-label">{m.label}</div>
                  <div className="expand-metric-row">
                    <span className="expand-metric-val" style={{ color: fc }}>
                      {fmtNum(m.val, 4)}
                    </span>
                    <div className="mini-bar-track">
                      <div
                        className="mini-bar-fill"
                        style={{
                          width: `${100 - pct}%`,
                          background: fc,
                        }}
                      />
                    </div>
                  </div>
                </div>
              )
            })}
          </div>
        </div>
      </td>
    </tr>
  )
}

export default function LeaderboardTable({ models, maxFairness }: Props) {
  const [sortKey, setSortKey] = useState<SortKey>('luc')
  const [sortDir, setSortDir] = useState<'asc' | 'desc'>('desc')
  const [query, setQuery] = useState('')
  const [expandedRank, setExpandedRank] = useState<number | null>(null)
  const [activeCreator, setActiveCreator] = useState<string | null>(null)

  const creators = useMemo(() => [...new Set(models.map(m => m.creator))].sort(), [models])

  const handleSort = useCallback((key: SortKey) => {
    if (sortKey === key) {
      setSortDir(d => (d === 'asc' ? 'desc' : 'asc'))
    } else {
      setSortKey(key)
      setSortDir(key === 'fairness' ? 'asc' : 'desc')
    }
  }, [sortKey])

  const sortedFiltered = useMemo(() => {
    let list = models.filter(m => !m.archived)

    if (activeCreator) list = list.filter(m => m.creator === activeCreator)
    if (query.trim()) {
      const q = query.toLowerCase()
      list = list.filter(
        m => m.model.toLowerCase().includes(q) || m.creator.toLowerCase().includes(q),
      )
    }

    list.sort((a, b) => {
      let va: number | null, vb: number | null
      if (sortKey === 'rank')     { va = a.rank;          vb = b.rank }
      else if (sortKey === 'luc') { va = a.luc.avg;       vb = b.luc.avg }
      else if (sortKey === 'rag') { va = a.rag.avg;       vb = b.rag.avg }
      else                        { va = a.fairness.avg;  vb = b.fairness.avg }

      if (va === null && vb === null) return 0
      if (va === null) return 1
      if (vb === null) return -1

      return sortDir === 'asc' ? va - vb : vb - va
    })

    return list
  }, [models, activeCreator, query, sortKey, sortDir])

  function SortArrow({ k }: { k: SortKey }) {
    if (sortKey !== k) return <span style={{ color: 'var(--border-2)', marginLeft: 4 }}>↕</span>
    return <span style={{ color: 'var(--accent)', marginLeft: 4 }}>{sortDir === 'asc' ? '↑' : '↓'}</span>
  }

  return (
    <div>
      {/* Controls */}
      <div className="lb-controls">
        <div className="lb-search-wrap">
          <svg className="lb-search-icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
            <circle cx="11" cy="11" r="8" /><path d="m21 21-4.35-4.35" />
          </svg>
          <input
            className="lb-search"
            placeholder="Search models..."
            value={query}
            onChange={e => setQuery(e.target.value)}
          />
        </div>

        <div style={{ display: 'flex', gap: 6, flexWrap: 'wrap' }}>
          {creators.map(c => (
            <button
              key={c}
              className={`filter-chip ${activeCreator === c ? 'active' : ''}`}
              style={activeCreator === c ? {
                borderColor: creatorColor(c),
                color: creatorColor(c),
                background: `${creatorColor(c)}12`,
              } : {}}
              onClick={() => setActiveCreator(prev => prev === c ? null : c)}
            >
              <span className="filter-chip-logo"><LabLogo creator={c} /></span>
              {c}
            </button>
          ))}
        </div>
      </div>

      {/* Table */}
      <div className="lb-table-wrap">
        <table className="lb-table">
          <thead>
            <tr>
              <th onClick={() => handleSort('rank')} className={sortKey === 'rank' ? 'sort-active' : ''} style={{ width: 48 }}>
                # <SortArrow k="rank" />
              </th>
              <th style={{ width: 130 }}>Creator</th>
              <th>Model</th>
              <th onClick={() => handleSort('luc')} className={sortKey === 'luc' ? 'sort-active' : ''}>
                Refusal Rate <SortArrow k="luc" />
              </th>
              <th onClick={() => handleSort('rag')} className={sortKey === 'rag' ? 'sort-active' : ''}>
                RAG Score <SortArrow k="rag" />
              </th>
              <th onClick={() => handleSort('fairness')} className={sortKey === 'fairness' ? 'sort-active' : ''}>
                Fairness ↓ <SortArrow k="fairness" />
              </th>
            </tr>
          </thead>
          <tbody>
            {sortedFiltered.map((model, i) => {
              const isExpanded = expandedRank === model.rank
              const cc = creatorColor(model.creator)

              return [
                <tr
                  key={`row-${model.rank}`}
                  className={isExpanded ? 'row-expanded' : ''}
                  style={{ background: `${cc}08` }}
                >
                  <td>
                    <span className={`rank-cell ${i < 3 && !activeCreator && !query ? 'rank-top3' : ''}`}>
                      {i + 1}
                    </span>
                  </td>
                  <td>
                    <button
                      className="creator-badge"
                      style={{ background: `${cc}18`, color: cc }}
                      onClick={() => setActiveCreator(prev => prev === model.creator ? null : model.creator)}
                    >
                      <span className="creator-badge-logo">
                        <LabLogo creator={model.creator} />
                      </span>
                      {model.creator}
                    </button>
                  </td>
                  <td>
                    <button
                      className="model-name"
                      onClick={() => setExpandedRank(isExpanded ? null : model.rank)}
                    >
                      <svg
                        className={`expand-chevron ${isExpanded ? 'open' : ''}`}
                        width="12"
                        height="12"
                        viewBox="0 0 24 24"
                        fill="none"
                        stroke="currentColor"
                        strokeWidth="2.5"
                      >
                        <polyline points="9 18 15 12 9 6" />
                      </svg>
                      {model.model}
                    </button>
                  </td>
                  <ScoreCell
                    value={model.luc.avg}
                    color={lucColor(model.luc.avg)}
                    format={v => fmtPct(v)}
                  />
                  <ScoreCell
                    value={model.rag.avg}
                    color={ragColor(model.rag.avg)}
                    format={v => fmtPct(v)}
                  />
                  <ScoreCell
                    value={model.fairness.avg}
                    color={fairnessColor(model.fairness.avg)}
                    max={maxFairness}
                    format={v => fmtNum(v, 4)}
                    invert
                  />
                </tr>,

                isExpanded && (
                  <ExpandedRow key={`expand-${model.rank}`} model={model} maxFairness={maxFairness} />
                ),
              ]
            })}
          </tbody>
        </table>
      </div>

      <div style={{
        marginTop: 12,
        display: 'flex',
        justifyContent: 'space-between',
        alignItems: 'center',
      }}>
        <span style={{
          fontSize: 12,
          color: 'var(--text-3)',
        }}>
          {sortedFiltered.length} models · ↓ lower fairness score = more equitable
        </span>
      </div>
    </div>
  )
}