import { useState } from 'react'

// All 50 states + DC, matching the API's ALLOWED_STATES
const STATES = [
  'AL','AK','AZ','AR','CA','CO','CT','DE','DC','FL','GA','HI',
  'ID','IL','IN','IA','KS','KY','LA','ME','MD','MA','MI','MN','MS','MO','MT',
  'NE','NV','NH','NJ','NM','NY','NC','ND','OH','OK','OR','PA','RI','SC','SD',
  'TN','TX','UT','VT','VA','WA','WV','WI','WY'
]

const STATE_NAMES = {
  AL: 'Alabama', AK: 'Alaska', AZ: 'Arizona', AR: 'Arkansas', CA: 'California',
  CO: 'Colorado', CT: 'Connecticut', DE: 'Delaware', DC: 'District of Columbia', FL: 'Florida',
  GA: 'Georgia', HI: 'Hawaii', ID: 'Idaho', IL: 'Illinois', IN: 'Indiana', IA: 'Iowa',
  KS: 'Kansas', KY: 'Kentucky', LA: 'Louisiana', ME: 'Maine', MD: 'Maryland', MA: 'Massachusetts',
  MI: 'Michigan', MN: 'Minnesota', MS: 'Mississippi', MO: 'Missouri', MT: 'Montana',
  NE: 'Nebraska', NV: 'Nevada', NH: 'New Hampshire', NJ: 'New Jersey', NM: 'New Mexico',
  NY: 'New York', NC: 'North Carolina', ND: 'North Dakota', OH: 'Ohio', OK: 'Oklahoma',
  OR: 'Oregon', PA: 'Pennsylvania', RI: 'Rhode Island', SC: 'South Carolina', SD: 'South Dakota',
  TN: 'Tennessee', TX: 'Texas', UT: 'Utah', VT: 'Vermont', VA: 'Virginia',
  WA: 'Washington', WV: 'West Virginia', WI: 'Wisconsin', WY: 'Wyoming'
}

/**
 * Landing screen — prompts user to select a state.
 * Matches the Civilytics visual style with eyebrow label, stat callout, and clean card layout.
 */
export default function StateSelector({ onNext }) {
  const [query, setQuery] = useState('')

  // Filter states by code or name as user types
  const filtered = STATES.filter(
    (code) =>
      code.toLowerCase().includes(query.toLowerCase()) ||
      STATE_NAMES[code].toLowerCase().includes(query.toLowerCase())
  )

  return (
    <div style={{ padding: 'var(--space-5) 0 var(--space-7)' }}>
      {/* Eyebrow */}
      <span className="eyebrow">US Department of Education Civil Rights Data Collection</span>

      {/* Hero */}
      <h1 style={{ marginTop: 'var(--space-2)', marginBottom: 'var(--space-3)' }}>
        Explore school-based arrest rates by district
      </h1>

      <p style={{ fontSize: '1.1rem', lineHeight: 1.7, maxWidth: '48rem' }}>
        The Civil Rights Data Collection (CRDC) is the only source of data on school-related
        arrests for all U.S. public schools and districts. Enter a state to see estimates for
        any district — with Bayesian model comparisons that reveal how confident we can be in
        each rate, even when arrests are rare events.
      </p>

      {/* Stat callout — key context */}
      <div className="stat-callout" style={{ marginTop: 'var(--space-4)' }}>
        <div>
          <span className="stat-num">34,846</span>
          <span className="stat-label">students arrested in 2021–22</span>
        </div>
        <div>
          <span className="stat-num">0.72</span>
          <span className="stat-label accent">arrests per 1,000 students (national rate)</span>
        </div>
        <div>
          <span className="stat-num">11.6%</span>
          <span className="stat-label">of districts reported &gt;0 arrests</span>
        </div>
      </div>

      {/* Search input */}
      <div style={{ marginTop: 'var(--space-5)' }}>
        <label htmlFor="state-search" style={{ display: 'block', marginBottom: 'var(--space-2)', fontWeight: 600 }}>
          Select a state to begin:
        </label>
        <input
          id="state-search"
          type="text"
          placeholder="Type a state name or code (e.g., Texas, TX)…"
          value={query}
          onChange={(e) => setQuery(e.target.value)}
          style={{
            width: '100%', padding: 'var(--space-2)', fontSize: '1rem',
            border: '1px solid var(--cv-rule)', borderRadius: 'var(--radius-md)',
            fontFamily: 'var(--font-sans)'
          }}
          autoFocus
        />

        {/* Filtered grid of states */}
        {filtered.length > 0 && (
          <div style={{
            display: 'grid',
            gridTemplateColumns: 'repeat(auto-fill, minmax(120px, 1fr))',
            gap: 'var(--space-1)',
            marginTop: 'var(--space-3)'
          }}>
            {filtered.map((code) => (
              <button
                key={code}
                className="cv-card"
                style={{ textAlign: 'center', padding: 'var(--space-2)' }}
                onClick={() => onNext(code)}
              >
                <span style={{ fontSize: '1.25rem', fontWeight: 700, color: 'var(--cv-navy-600)' }}>
                  {code}
                </span>
                <span className="stat-label" style={{ marginTop: '0.25rem' }}>
                  {STATE_NAMES[code]}
                </span>
              </button>
            ))}
          </div>
        )}

        {filtered.length === 0 && (
          <p style={{ color: 'var(--cv-ink-3)', marginTop: 'var(--space-2)' }}>
            No states match "{query}". Try a full state name or two-letter code.
          </p>
        )}
      </div>

      {/* Context footer */}
      <div style={{ marginTop: 'var(--space-5)', paddingBottom: 'var(--space-3)', borderBottom: '1px solid var(--cv-rule)' }}>
        <span className="eyebrow">How it works</span>
        <p style={{ fontSize: '0.9rem', color: 'var(--cv-ink-2)', marginTop: 'var(--space-1)' }}>
          After selecting a state, you'll search for a school district and see arrest estimates from 10 Bayesian models —
          including one-year vs. three-year specifications and baseline vs. referral-rate covariate models.
          The app fetches data directly from the{' '}
          <a href="https://crdc-api.civilytics.org/api/v1/" target="_blank" rel="noopener noreferrer">
            CRDC Arrest Rate API
          </a>. No account or key required.
        </p>
      </div>
    </div>
  )
}