/* ============================================================
   Contact-quality challenger (contact-v1) — nominate, don't swap.
   Two-sided: elite contact leans the over, poor contact leans against,
   thin/unmapped ABSTAIN (null, never a silent fallback), champion untouched.
   ============================================================ */

const cc = require('../../src/services/contactChallenger');

// A league population spanning the real 2026 percentiles (barrel p50 7.4,
// hard_hit p50 38.4, k p50 22.4), all sufficient-sample batters.
const POP = [];
for (let i = 0; i < 21; i++) {
  const f = i / 20; // 0..1
  POP.push({
    role: 'batter', sample_pa: 300,
    barrel_pct: 2 + f * 13,      // 2 .. 15
    hard_hit_pct: 26 + f * 24,   // 26 .. 50
    k_pct: 12 + f * 24,          // 12 .. 36
  });
}
const REFS = cc.buildRefs(POP);

const row = (over) => ({ role: 'batter', sample_pa: 300, ...over });

describe('buildRefs', () => {
  it('builds sorted refs per mapped metric from sufficient-sample batters only', () => {
    const refs = cc.buildRefs([
      ...POP,
      { role: 'batter', sample_pa: 10, barrel_pct: 99 }, // thin → excluded
      { role: 'pitcher', sample_ip: 100, barrel_pct: 99 }, // wrong role → excluded
    ]);
    expect(refs.barrel_pct.length).toBe(POP.length);
    expect(refs.barrel_pct).not.toContain(99);
    // sorted ascending
    expect([...refs.k_pct].sort((a, b) => a - b)).toEqual(refs.k_pct);
  });
});

describe('metric → prop mapping (barrels for HR/TB, k_pct-inverse for hits)', () => {
  it('HOME RUNS reads barrel_pct — elite barrels lean the over UP', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'home_runs', row: row({ barrel_pct: 15 }), refs: REFS });
    expect(res.p_win_contact).toBeGreaterThan(0.5);
    expect(res.contact_adjustments[0].metric).toBe('barrel_pct');
    expect(res.contact_adjustments[0].tier).toBe('elite');
  });

  it('TOTAL BASES reads hard_hit_pct (not barrels)', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'total_bases', row: row({ hard_hit_pct: 50 }), refs: REFS });
    expect(res.contact_adjustments[0].metric).toBe('hard_hit_pct');
    expect(res.p_win_contact).toBeGreaterThan(0.5);
  });

  it('HITS reads k_pct INVERSE — a low-K contact hitter leans the over UP', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'hits', row: row({ k_pct: 12 }), refs: REFS });
    expect(res.contact_adjustments[0].metric).toBe('k_pct');
    expect(res.p_win_contact).toBeGreaterThan(0.5); // low K = more contact = more hits
  });

  it('HITS — a high-K hitter leans the over DOWN (barrels would mislead here)', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'hits', row: row({ k_pct: 36 }), refs: REFS });
    expect(res.p_win_contact).toBeLessThan(0.5);
  });

  it('UNDER flips the sign', () => {
    const over = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'home_runs', row: row({ barrel_pct: 15 }), refs: REFS });
    const under = cc.contactAdjust({ pWin: 0.5, direction: 'under', statType: 'home_runs', row: row({ barrel_pct: 15 }), refs: REFS });
    expect(over.p_win_contact).toBeGreaterThan(0.5);
    expect(under.p_win_contact).toBeLessThan(0.5);
  });
});

describe('honest abstention — null projection, never a silent fallback', () => {
  it('thin sample (< MIN_PA) → abstains (p_win_contact null)', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'hits', row: { role: 'batter', sample_pa: 20, k_pct: 12 }, refs: REFS });
    expect(res.p_win_contact).toBeNull();
    expect(res.contact_delta).toBeNull();
    expect(res.reason).toBe('thin_sample');
  });

  it('unmapped stat (rbi — opportunity-driven) → abstains, never guesses', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'rbi', row: row({ barrel_pct: 15 }), refs: REFS });
    expect(res.p_win_contact).toBeNull();
    expect(res.reason).toBe('stat_not_mapped');
  });

  it('non-batter profile → abstains (no wrong-role contact read)', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'hits', row: { role: 'pitcher', sample_ip: 100, k_pct: 12 }, refs: REFS });
    expect(res.p_win_contact).toBeNull();
    expect(res.reason).toBe('no_batter_profile');
  });

  it('absent coverage (no row) → abstains', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'hits', row: null, refs: REFS });
    expect(res.p_win_contact).toBeNull();
  });
});

describe('measured-but-unremarkable ≠ abstention', () => {
  it('a mid-pack metric is a real no-lean projection equal to the champion (delta 0)', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'home_runs', row: row({ barrel_pct: 7.4 }), refs: REFS });
    expect(res.p_win_contact).toBe(0.5); // equals champion — a projection, not an abstention
    expect(res.contact_delta).toBe(0);
    expect(res.reason).toBe('metric_unremarkable');
  });
});

describe('distinct + isolated challenger', () => {
  it('is tagged contact-v1 (distinguishable from the arch-v1 challenger)', () => {
    expect(cc.CONTACT_VERSION).toBe('contact-v1');
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'home_runs', row: row({ barrel_pct: 15 }), refs: REFS });
    expect(res.version).toBe('contact-v1');
  });

  it('attachContactChallenger NEVER mutates the champion or the arch-v1 fields', async () => {
    const grades = [{
      player: 'Slugger', stat_type: 'home_runs', direction: 'over', p_win: 0.5,
      p_win_challenger: 0.55, challenger_version: 'arch-v1', grade: 'B', // champion + arch-v1
    }];
    const rowFor = () => row({ barrel_pct: 15 });
    const out = await cc.attachContactChallenger(grades, rowFor, REFS);
    expect(out[0].p_win).toBe(0.5);                 // champion untouched
    expect(out[0].p_win_challenger).toBe(0.55);     // arch-v1 untouched
    expect(out[0].challenger_version).toBe('arch-v1');
    expect(out[0].grade).toBe('B');                 // published grade untouched
    expect(out[0].contact_version).toBe('contact-v1');
    expect(out[0].p_win_contact).toBeGreaterThan(0.5);
  });

  it('the nudge is capped — no re-forecast', () => {
    const res = cc.contactAdjust({ pWin: 0.5, direction: 'over', statType: 'home_runs', row: row({ barrel_pct: 15 }), refs: REFS });
    expect(Math.abs(res.p_win_contact - 0.5)).toBeLessThanOrEqual(0.12); // ~elite nudge at p=0.5
  });
});