const { computeGrade } = require('../../src/services/grader');

function makeStepResults(overrides = {}) {
  return {
    seasonDelta: 0,
    recentDelta: 0,
    situationalDelta: 0,
    lineEdge: 0,
    killConditions: [],
    gamesPlayed: 65,
    seasonAndRecentAgree: null,
    ...overrides,
  };
}

describe('grader', () => {
  describe('grade assignment', () => {
    test('composite >= 3.0 returns grade A with confidence 80-95', () => {
      // composite = (4*1 + 4*1.5 + 4*1.2 + 4*0.8) / 4.5 = 18/4.5 = 4.0
      const result = computeGrade(makeStepResults({
        seasonDelta: 4, recentDelta: 4, situationalDelta: 4, lineEdge: 4,
      }));
      expect(result.grade).toBe('A');
      expect(result.confidence).toBeGreaterThanOrEqual(80);
      expect(result.confidence).toBeLessThanOrEqual(95);
    });

    test('composite 1.5-2.99 returns grade B with confidence 65-79', () => {
      // composite = (2*1 + 2*1.5 + 2*1.2 + 2*0.8) / 4.5 = 9/4.5 = 2.0
      const result = computeGrade(makeStepResults({
        seasonDelta: 2, recentDelta: 2, situationalDelta: 2, lineEdge: 2,
      }));
      expect(result.grade).toBe('B');
      expect(result.confidence).toBeGreaterThanOrEqual(65);
      expect(result.confidence).toBeLessThanOrEqual(79);
    });

    test('composite 0.5-1.49 returns grade C with confidence 50-64', () => {
      // composite = (1*1 + 1*1.5 + 1*1.2 + 0*0.8) / 4.5 = 3.7/4.5 ≈ 0.82
      const result = computeGrade(makeStepResults({
        seasonDelta: 1, recentDelta: 1, situationalDelta: 1, lineEdge: 0,
      }));
      expect(result.grade).toBe('C');
      expect(result.confidence).toBeGreaterThanOrEqual(50);
      expect(result.confidence).toBeLessThanOrEqual(64);
    });

    test('composite < 0.5 returns grade D with confidence 30-49', () => {
      const result = computeGrade(makeStepResults({
        seasonDelta: -1, recentDelta: -1, situationalDelta: -1, lineEdge: 0,
      }));
      expect(result.grade).toBe('D');
      expect(result.confidence).toBeGreaterThanOrEqual(30);
      expect(result.confidence).toBeLessThanOrEqual(49);
    });
  });

  describe('kill condition penalty', () => {
    test('caps grade at C and reduces confidence by 15', () => {
      const result = computeGrade(makeStepResults({
        seasonDelta: 4, recentDelta: 4, situationalDelta: 4, lineEdge: 4,
        killConditions: [{ code: 'blowout_risk' }],
      }));
      expect(result.grade).toBe('C');
      // Original would be A (80+), minus 15 = 65+
      expect(result.confidence).toBeLessThan(85);
    });

    test('grade B with kill condition becomes C', () => {
      const result = computeGrade(makeStepResults({
        seasonDelta: 2, recentDelta: 2, situationalDelta: 2, lineEdge: 2,
        killConditions: [{ code: 'low_minutes' }],
      }));
      expect(result.grade).toBe('C');
    });
  });

  describe('bonuses', () => {
    test('sample bonus +5 for > 50 games', () => {
      const with50 = computeGrade(makeStepResults({ seasonDelta: 1, recentDelta: 1, gamesPlayed: 55 }));
      const without = computeGrade(makeStepResults({ seasonDelta: 1, recentDelta: 1, gamesPlayed: 20 }));
      expect(with50.confidence).toBe(without.confidence + 5);
    });

    test('sample bonus +3 for > 30 games', () => {
      const with30 = computeGrade(makeStepResults({ seasonDelta: 1, recentDelta: 1, gamesPlayed: 35 }));
      const without = computeGrade(makeStepResults({ seasonDelta: 1, recentDelta: 1, gamesPlayed: 20 }));
      expect(with30.confidence).toBe(without.confidence + 3);
    });

    test('consistency bonus +5 when season and recent agree', () => {
      const agree = computeGrade(makeStepResults({
        seasonDelta: 2, recentDelta: 2, seasonAndRecentAgree: true,
      }));
      const noInfo = computeGrade(makeStepResults({
        seasonDelta: 2, recentDelta: 2, seasonAndRecentAgree: null,
      }));
      expect(agree.confidence).toBe(noInfo.confidence + 5);
    });

    test('consistency penalty -5 when season and recent conflict', () => {
      const conflict = computeGrade(makeStepResults({
        seasonDelta: 2, recentDelta: 2, seasonAndRecentAgree: false,
      }));
      const noInfo = computeGrade(makeStepResults({
        seasonDelta: 2, recentDelta: 2, seasonAndRecentAgree: null,
      }));
      expect(conflict.confidence).toBe(noInfo.confidence - 5);
    });
  });
});