/**
 * Edge-side efficiency shading CHALLENGER (specs/edge-shading-challenger.md).
 * MEASURED, NEVER SERVED — these tests lock the properties that make it un-inflatable.
 */
const c = require('../../src/services/challengers/efficiencyShading');

describe('f(efficiency) is BOUNDED — this is what makes it un-inflatable', () => {
  test('soft market is INTACT, never amplified above the raw edge', () => {
    expect(c.shadingFactor(c.E_SOFTEST)).toBe(1);
    // even a hypothetical score BELOW the anchor cannot amplify
    expect(c.shadingFactor(0.10)).toBe(1);
    expect(c.shadingFactor(0.01)).toBe(1);
  });

  test('sharper markets shade DOWN monotonically, toward but never past zero', () => {
    const f55 = c.shadingFactor(0.55), f60 = c.shadingFactor(0.60);
    const f80 = c.shadingFactor(0.80), f85 = c.shadingFactor(0.85);
    expect(f55).toBeGreaterThan(f60);
    expect(f60).toBeGreaterThan(f80);
    expect(f80).toBeGreaterThan(f85);
    for (const f of [f55, f60, f80, f85]) {
      expect(f).toBeGreaterThan(0);
      expect(f).toBeLessThanOrEqual(1);
    }
  });

  test('an UNSCORED market gets f=1 and is FLAGGED, never silently scaled', () => {
    expect(c.shadingFactor(null)).toBe(1);
    const row = c.gradeRow({ sport: 'mlb', stat: 'hits', edge: 40 });
    expect(row.unscored).toBe(true);
    expect(row.f).toBe(1);
    expect(row.efficiency).toBeNull();
  });
});

describe('the FIXED bar never moves', () => {
  test('bands are identical regardless of sport or market', () => {
    const soft = c.gradeRow({ sport: 'mlb', stat: 'total_bases', edge: 5 });
    const unscored = c.gradeRow({ sport: 'wnba', stat: 'points', edge: 5 });
    // same raw edge, both f=1 here -> identical band. The bar is one bar.
    expect(soft.grade).toBe(unscored.grade);
    expect(c.bandFor(10)).toBe('A+');
    expect(c.bandFor(5)).toBe('A');
    expect(c.bandFor(3)).toBe('B');
    expect(c.bandFor(1)).toBe('C');
    expect(c.bandFor(0)).toBe('D');
    expect(c.bandFor(-0.1)).toBe('F');
  });

  test('shading can only ever LOWER a grade, never raise it', () => {
    for (const e of [0.55, 0.60, 0.80, 0.85, null]) {
      for (const edge of [0.5, 2, 4, 6, 12, 60]) {
        const r = c.gradeRow({ sport: 'x', stat: 'y', edge });
        const adj = edge * c.shadingFactor(e);
        expect(adj).toBeLessThanOrEqual(edge + 1e-9);   // never amplified
        expect(r.baseline_grade).toBeTruthy();
      }
    }
  });
});

describe('cross-market behaviour (the point of the design)', () => {
  test('the SAME raw edge grades LOWER in an efficient market than a soft one', () => {
    const raw = 6;
    const soft = c.gradeRow({ sport: 'mlb', stat: 'total_bases', edge: raw }); // 0.55 -> f 1.00
    const sharp = c.gradeRow({ sport: 'nba', stat: 'points', edge: raw });     // 0.80 -> f 0.688
    expect(soft.grade).toBe('A');
    expect(sharp.grade).toBe('B');
    expect(sharp.adjusted_edge).toBeLessThan(soft.adjusted_edge);
  });
});

describe('absent input is absent, never zero', () => {
  test('a missing edge returns null rather than grading F', () => {
    expect(c.gradeRow({ sport: 'mlb', stat: 'hits', edge: null })).toBeNull();
    expect(c.gradeRow({ sport: 'mlb', stat: 'hits', edge: '' })).toBeNull();
    expect(c.gradeRow({ sport: 'mlb', stat: 'hits', edge: 'x' })).toBeNull();
    expect(c.gradeRow(null)).toBeNull();
  });

  test('a real negative edge DOES grade F (not confused with absent)', () => {
    expect(c.gradeRow({ sport: 'mlb', stat: 'hits', edge: -5 }).grade).toBe('F');
  });
});

describe('MEASURED-NEVER-SERVED fence', () => {
  test('no production grade path imports this challenger', () => {
    const fs = require('fs'), path = require('path');
    const files = [
      'src/services/gradeSlateService.js',
      'src/services/intelligence/analyzeViaEngine1.js',
      'src/services/intelligence/engine1.js',
      'src/services/snapshotService.js',
      'src/utils/gradeAdapter.js',
    ];
    for (const f of files) {
      const src = fs.readFileSync(path.join(__dirname, '../../', f), 'utf8');
      expect(src).not.toMatch(/efficiencyShading/);
    }
  });
});