/**
 * GcseSection — KS4 headline results. Secondary pages. Server component.
 */

import type { School, SchoolResult } from '@/lib/types';
import { formatPercentage, formatProgress, formatAcademicYear } from '@/lib/utils';
import { MetricTooltip } from '../MetricTooltip';
import { DeltaChip } from '../DeltaChip';
import { SpecialSchoolNote } from '../SpecialSchoolNote';
import { Section, sectionStyles as styles, progressClass } from './sectionShared';

export function GcseSection({
  latestResults, schoolInfo, secondaryAvg, p8Suspended, suppressComparison,
}: {
  latestResults: SchoolResult;
  schoolInfo: School;
  secondaryAvg: Record<string, number>;
  p8Suspended: boolean;
  suppressComparison: boolean;
}) {
  return (
    <section id="gcse" className={styles.card}>
      <h2 className={styles.sectionTitle}>
        GCSE Results ({formatAcademicYear(latestResults.year)})
      </h2>
      <p className={styles.sectionSubtitle}>
        GCSE results for Year 11 pupils.{!suppressComparison && ' England averages shown for comparison.'}
      </p>

      <SpecialSchoolNote school={schoolInfo} />

      {p8Suspended && (
        <div className={styles.p8Banner}>
          Progress 8 isn&apos;t published for 2024/25: this GCSE year group sat no KS2 tests
          (COVID), so DfE has no starting point to measure their progress from.
        </div>
      )}

      {/* Hero stat cards — top GCSE metrics */}
      <div className={styles.heroStatGrid}>
        {latestResults.attainment_8_score != null && (
          <div className={styles.heroStatCard}>
            <div className={styles.heroStatLabel}>
              Attainment 8 score
              <MetricTooltip metricKey="attainment_8_score" />
            </div>
            <div className={styles.heroStatValue}>
              {latestResults.attainment_8_score.toFixed(1)}
              {!suppressComparison && secondaryAvg.attainment_8_score != null && (
                <DeltaChip
                  value={latestResults.attainment_8_score}
                  baseline={secondaryAvg.attainment_8_score}
                  unit="pts"
                  size="sm"
                />
              )}
            </div>
            {!suppressComparison && secondaryAvg.attainment_8_score != null && (
              <div className={styles.heroStatHint}>England avg: {secondaryAvg.attainment_8_score.toFixed(1)}</div>
            )}
          </div>
        )}
        {latestResults.progress_8_score != null && (
          <div className={styles.heroStatCard}>
            <div className={styles.heroStatLabel}>
              Progress 8 score
              <MetricTooltip metricKey="progress_8_score" />
            </div>
            <div className={`${styles.heroStatValue} ${progressClass(latestResults.progress_8_score)}`}>
              {formatProgress(latestResults.progress_8_score)}
            </div>
            {(latestResults.progress_8_lower_ci != null && latestResults.progress_8_upper_ci != null) ? (
              <div className={styles.heroStatHint}>
                CI: {latestResults.progress_8_lower_ci.toFixed(2)} to {latestResults.progress_8_upper_ci.toFixed(2)}
              </div>
            ) : (
              <div className={styles.heroStatHint}>National baseline: 0.0</div>
            )}
          </div>
        )}
        {latestResults.english_maths_strong_pass_pct != null && (
          <div className={styles.heroStatCard}>
            <div className={styles.heroStatLabel}>
              English &amp; Maths Grade 5+
              <MetricTooltip metricKey="english_maths_strong_pass_pct" />
            </div>
            <div className={styles.heroStatValue}>
              {formatPercentage(latestResults.english_maths_strong_pass_pct)}
              {!suppressComparison && secondaryAvg.english_maths_strong_pass_pct != null && (
                <DeltaChip
                  value={latestResults.english_maths_strong_pass_pct}
                  baseline={secondaryAvg.english_maths_strong_pass_pct}
                  unit="pts"
                  size="sm"
                />
              )}
            </div>
            {!suppressComparison && secondaryAvg.english_maths_strong_pass_pct != null && (
              <div className={styles.heroStatHint}>England avg: {secondaryAvg.english_maths_strong_pass_pct.toFixed(0)}%</div>
            )}
          </div>
        )}
        {latestResults.english_maths_standard_pass_pct != null && (
          <div className={styles.heroStatCard}>
            <div className={styles.heroStatLabel}>
              English &amp; Maths Grade 4+
              <MetricTooltip metricKey="english_maths_standard_pass_pct" />
            </div>
            <div className={styles.heroStatValue}>
              {formatPercentage(latestResults.english_maths_standard_pass_pct)}
              {!suppressComparison && secondaryAvg.english_maths_standard_pass_pct != null && (
                <DeltaChip
                  value={latestResults.english_maths_standard_pass_pct}
                  baseline={secondaryAvg.english_maths_standard_pass_pct}
                  unit="pts"
                  size="sm"
                />
              )}
            </div>
            {!suppressComparison && secondaryAvg.english_maths_standard_pass_pct != null && (
              <div className={styles.heroStatHint}>England avg: {secondaryAvg.english_maths_standard_pass_pct.toFixed(0)}%</div>
            )}
          </div>
        )}
      </div>

      {/* Attainment 8 visual bar (0–80 scale). This viz is explicitly
          "school vs national", so it's dropped for special schools where
          that comparison isn't meaningful. */}
      {!suppressComparison && latestResults.attainment_8_score != null && (
        <div className={styles.att8Viz}>
          <div className={styles.att8VizLabel}>Attainment 8 — school vs national</div>
          <div className={styles.att8VizTrack}>
            <div
              className={styles.att8VizFill}
              style={{ width: `${Math.min((latestResults.attainment_8_score / 80) * 100, 100)}%` }}
            />
            {secondaryAvg.attainment_8_score != null && (
              <div
                className={styles.att8VizNatLine}
                style={{ left: `${(secondaryAvg.attainment_8_score / 80) * 100}%` }}
              >
                <div className={styles.att8VizNatPill}>
                  Nat avg {secondaryAvg.attainment_8_score.toFixed(1)}
                </div>
              </div>
            )}
          </div>
          <div className={styles.att8VizTicks}>
            <span>0</span><span>20</span><span>40</span><span>60</span><span>80</span>
          </div>
        </div>
      )}

      {/* Progress 8 number line with CI */}
      {latestResults.progress_8_score != null && !p8Suspended && (
        <div className={styles.p8Viz}>
          <div className={styles.p8VizLabel}>Progress 8 — relative to national baseline (0)</div>
          {(() => {
            const p8 = latestResults.progress_8_score!;
            const lo = latestResults.progress_8_lower_ci ?? p8;
            const hi = latestResults.progress_8_upper_ci ?? p8;
            const range = 6; // −3 to +3
            const toX = (v: number) => `${Math.min(Math.max(((v + 3) / range) * 100, 0), 100)}%`;
            return (
              <div className={styles.p8VizTrack}>
                {/* CI band */}
                <div
                  className={styles.p8VizCi}
                  style={{ left: toX(lo), width: `calc(${toX(hi)} - ${toX(lo)})` }}
                />
                {/* Zero line */}
                <div className={styles.p8VizZero} style={{ left: toX(0) }} />
                {/* Score dot */}
                <div
                  className={`${styles.p8VizDot} ${p8 < 0 ? styles.p8VizDotNeg : ''}`}
                  style={{ left: toX(p8) }}
                />
              </div>
            );
          })()}
          <div className={styles.p8VizTicks}>
            <span>−3</span><span>−2</span><span>−1</span><span>0</span><span>+1</span><span>+2</span><span>+3</span>
          </div>
        </div>
      )}

      {/* Progress 8 component breakdown */}
      {(latestResults.progress_8_english != null || latestResults.progress_8_maths != null ||
        latestResults.progress_8_ebacc != null || latestResults.progress_8_open != null) && (
        <>
          <h3 className={styles.subSectionTitle}>Attainment 8 Components (Progress 8 contribution)</h3>
          <div className={styles.metricTable}>
            {[
              { label: 'English', val: latestResults.progress_8_english },
              { label: 'Maths', val: latestResults.progress_8_maths },
              { label: 'EBacc subjects', val: latestResults.progress_8_ebacc },
              { label: 'Open (other GCSEs)', val: latestResults.progress_8_open },
            ].filter(r => r.val != null).map(({ label, val }) => (
              <div key={label} className={styles.metricRow}>
                <span className={styles.metricName}>{label}</span>
                <span className={`${styles.metricValue} ${progressClass(val)}`}>
                  {formatProgress(val!)}
                </span>
              </div>
            ))}
          </div>
        </>
      )}

      {/* EBacc */}
      {(latestResults.ebacc_entry_pct != null || latestResults.ebacc_standard_pass_pct != null) && (
        <>
          <h3 className={styles.subSectionTitle} style={{ marginTop: '1rem' }}>
            English Baccalaureate (EBacc)
            <MetricTooltip metricKey="ebacc_entry_pct" />
          </h3>
          <div className={styles.metricTable}>
            {latestResults.ebacc_entry_pct != null && (
              <div className={styles.metricRow}>
                <span className={styles.metricName}>Pupils entered for EBacc</span>
                <span className={styles.metricValue}>{formatPercentage(latestResults.ebacc_entry_pct)}</span>
              </div>
            )}
            {latestResults.ebacc_standard_pass_pct != null && (
              <div className={styles.metricRow}>
                <span className={styles.metricName}>EBacc Grade 4+</span>
                <span className={styles.metricValue}>{formatPercentage(latestResults.ebacc_standard_pass_pct)}</span>
              </div>
            )}
            {latestResults.ebacc_strong_pass_pct != null && (
              <div className={styles.metricRow}>
                <span className={styles.metricName}>EBacc Grade 5+</span>
                <span className={styles.metricValue}>{formatPercentage(latestResults.ebacc_strong_pass_pct)}</span>
              </div>
            )}
            {latestResults.ebacc_avg_score != null && (
              <div className={styles.metricRow}>
                <span className={styles.metricName}>EBacc average point score</span>
                <span className={styles.metricValue}>{latestResults.ebacc_avg_score.toFixed(2)}</span>
              </div>
            )}
          </div>
        </>
      )}

    </section>
  );
}