import { MODEL_QUADRANTS } from '../hooks/useApi.js'
import ChartLegend from '../components/ChartLegend.jsx'
import { OBSERVED_MARK_COLOR, MODELED_AGGREGATE_COLOR } from '../utils/colors.js'

/**
 * Chart 4: Modeled vs. observed arrests, faceted by the four model-quadrant
 * specifications (one-year/three-year × baseline/+referral-rate covariate).
 * Plain SVG (no D3) — the quadrant label already conveys 1yr/3yr, so all
 * four panels share one ink-diamond/navy-point-range convention rather than
 * doubling up with a redundant per-quadrant hue.
 */

const WAVE_LABELS = { '15-16': '2015–16', '17-18': '2017–18', '21-22': '2021–22' }
const ALL_WAVES = ['15-16', '17-18', '21-22']

export default function ModelDrawsComparison({ data, waves = ALL_WAVES, districtName }) {
  const waveData = waves.map((year) => {
    const rows = (data.waves && data.waves[year]) || []
    return { year, arrests: rows.reduce((sum, r) => sum + (r.observed_arrests || 0), 0) }
  })

  const quadModels = (data && data.quadData) || {}

  const allValues = waveData.map((d) => d.arrests)
  Object.values(quadModels).forEach((rows) => {
    ;(rows || []).forEach((r) => {
      allValues.push(r.count_median || 0, r.count_upper || 0)
    })
  })
  const maxArrests = Math.min(Math.max(...allValues, 1), 50) // cap for readability

  return (
    <div className="cv-card" style={{ padding: 'var(--space-2)' }}>
      <h3 style={{ fontSize: '0.85rem', marginBottom: 'var(--space-1)', color: 'var(--cv-ink-2)' }}>
        Model predictions vs. observed — by wave &amp; model specification
      </h3>

      <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 'var(--space-2)' }}>
        {MODEL_QUADRANTS.map((q) => (
          <QuadrantPanel key={q.model} q={q} waveData={waveData} quadModels={quadModels} maxArrests={maxArrests} />
        ))}
      </div>

      <ChartLegend items={[
        { shape: 'diamond', color: OBSERVED_MARK_COLOR, label: 'Observed' },
        { shape: 'line', color: MODELED_AGGREGATE_COLOR, label: 'Modeled (median + 90% interval)' },
      ]} />

      <p style={{ fontSize: '0.72rem', color: 'var(--cv-ink-3)', marginTop: 'var(--space-1)' }}>
        Three-year models span all three CRDC waves; one-year models show 2021–22 only.{' '}
        {districtName ? `District: ${districtName}.` : ''}
      </p>
    </div>
  )
}

function QuadrantPanel({ q, waveData, quadModels, maxArrests }) {
  const isThreeYear = q.model.includes('m3') || q.model.includes('m4')
  const showYears = isThreeYear ? ALL_WAVES : ['21-22']

  const width = 260
  const height = 190
  const margin = { top: 26, right: 12, bottom: 26, left: 34 }
  const innerWidth = width - margin.left - margin.right
  const innerHeight = height - margin.top - margin.bottom

  const xScale = (i) => margin.left + (showYears.length > 1 ? (i / (showYears.length - 1)) * innerWidth : innerWidth / 2)
  const yScale = (val) => margin.top + innerHeight - (Math.min(val, maxArrests) / maxArrests) * innerHeight

  return (
    <div style={{ border: '1px solid var(--cv-rule)', borderRadius: 'var(--radius-md)', padding: 'var(--space-1)' }}>
      <svg width="100%" viewBox={`0 0 ${width} ${height}`} style={{ maxWidth: '100%' }}>
        <text x={width / 2} y={14} textAnchor="middle" fontSize="0.65rem" fontWeight={600} fill="var(--cv-ink-2)">
          {q.label}
        </text>

        {[0, 0.25, 0.5, 0.75, 1].map((frac) => {
          const val = frac * maxArrests
          const y = yScale(val)
          return (
            <g key={frac}>
              <line x1={margin.left} y1={y} x2={margin.left + innerWidth} y2={y} stroke="var(--cv-rule)" strokeWidth={1} />
              <text x={margin.left - 6} y={y + 3} textAnchor="end" fontSize="0.55rem" fill="var(--cv-ink-3)">{Math.round(val)}</text>
            </g>
          )
        })}

        {showYears.map((year, i) => {
          const x = xScale(i)
          const obs = waveData.find((d) => d.year === year)?.arrests ?? 0
          const yearRow = (quadModels[q.model] || []).find((r) => r.year === year)
          const obsY = yScale(obs)

          return (
            <g key={year}>
              <text x={x} y={height - 6} textAnchor="middle" fontSize="0.55rem" fill="var(--cv-ink-3)">
                {WAVE_LABELS[year]}
              </text>

              {yearRow && (
                <>
                  <line
                    x1={x} y1={yScale(yearRow.count_upper ?? yearRow.count_median ?? 0)}
                    x2={x} y2={yScale(yearRow.count_lower ?? yearRow.count_median ?? 0)}
                    stroke={MODELED_AGGREGATE_COLOR} strokeWidth={1.5}
                  />
                  <circle cx={x} cy={yScale(yearRow.count_median ?? 0)} r={3.5} fill={MODELED_AGGREGATE_COLOR} stroke="#fff" strokeWidth={1} />
                </>
              )}

              <rect
                x={x - 4} y={obsY - 4} width={8} height={8}
                fill={OBSERVED_MARK_COLOR} stroke="#fff" strokeWidth={1}
                transform={`rotate(45 ${x} ${obsY})`}
              />
            </g>
          )
        })}
      </svg>
    </div>
  )
}