brackt/app/models/__tests__/qualifying-points.test.ts

import { describe, it, expect } from "vitest";
import {
  calculateSplitQualifyingPoints,
  DEFAULT_QP_VALUES,
  diffChangedQualifyingPoints,
} from "../qualifying-points";

describe("diffChangedQualifyingPoints", () => {
  it("flags a changed value, a first-time score (null → value), and ignores unchanged", () => {
    const before = [
      { id: "A", qp: "10.00" },
      { id: "B", qp: "5.00" },
      { id: "C", qp: null },
    ];
    const after = [
      { id: "A", qp: "10.00" }, // unchanged
      { id: "B", qp: "8.00" }, // changed
      { id: "C", qp: "3.00" }, // first-time score
    ];

    expect([...diffChangedQualifyingPoints(before, after)].toSorted()).toEqual(["B", "C"]);
  });

  it("normalizes decimal formatting so 10 and 10.00 are equal", () => {
    const changed = diffChangedQualifyingPoints([{ id: "A", qp: "10" }], [{ id: "A", qp: "10.00" }]);
    expect(changed.size).toBe(0);
  });

  it("does not report participants absent from the after set", () => {
    const changed = diffChangedQualifyingPoints(
      [
        { id: "A", qp: "10.00" },
        { id: "D", qp: "2.00" },
      ],
      [{ id: "A", qp: "10.00" }],
    );
    expect(changed.size).toBe(0);
  });

  it("treats a value → zero drop as a change", () => {
    const changed = diffChangedQualifyingPoints([{ id: "A", qp: "10.00" }], [{ id: "A", qp: "0.00" }]);
    expect([...changed]).toEqual(["A"]);
  });
});

describe("Qualifying Points Configuration", () => {
  describe("DEFAULT_QP_VALUES", () => {
    it("should have 16 placement values", () => {
      expect(DEFAULT_QP_VALUES).toHaveLength(16);
    });

    it("should have correct QP values for top placements", () => {
      expect(DEFAULT_QP_VALUES[0]).toEqual({ placement: 1, points: 20 });
      expect(DEFAULT_QP_VALUES[1]).toEqual({ placement: 2, points: 14 });
      expect(DEFAULT_QP_VALUES[2]).toEqual({ placement: 3, points: 10 });
      expect(DEFAULT_QP_VALUES[3]).toEqual({ placement: 4, points: 8 });
    });

    it("should have 5 QP for 5th and 6th place", () => {
      expect(DEFAULT_QP_VALUES[4]).toEqual({ placement: 5, points: 5 });
      expect(DEFAULT_QP_VALUES[5]).toEqual({ placement: 6, points: 5 });
    });

    it("should have 3 QP for 7th and 8th place", () => {
      expect(DEFAULT_QP_VALUES[6]).toEqual({ placement: 7, points: 3 });
      expect(DEFAULT_QP_VALUES[7]).toEqual({ placement: 8, points: 3 });
    });

    it("should have 2 QP for 9th-12th place", () => {
      expect(DEFAULT_QP_VALUES[8]).toEqual({ placement: 9, points: 2 });
      expect(DEFAULT_QP_VALUES[9]).toEqual({ placement: 10, points: 2 });
      expect(DEFAULT_QP_VALUES[10]).toEqual({ placement: 11, points: 2 });
      expect(DEFAULT_QP_VALUES[11]).toEqual({ placement: 12, points: 2 });
    });

    it("should have 1 QP for 13th-16th place", () => {
      expect(DEFAULT_QP_VALUES[12]).toEqual({ placement: 13, points: 1 });
      expect(DEFAULT_QP_VALUES[13]).toEqual({ placement: 14, points: 1 });
      expect(DEFAULT_QP_VALUES[14]).toEqual({ placement: 15, points: 1 });
      expect(DEFAULT_QP_VALUES[15]).toEqual({ placement: 16, points: 1 });
    });

    it("should be sorted by placement (ascending)", () => {
      for (let i = 0; i < DEFAULT_QP_VALUES.length - 1; i++) {
        expect(DEFAULT_QP_VALUES[i].placement).toBeLessThan(
          DEFAULT_QP_VALUES[i + 1].placement
        );
      }
    });

    it("should have descending point values for higher placements", () => {
      expect(DEFAULT_QP_VALUES[0].points).toBeGreaterThan(DEFAULT_QP_VALUES[1].points);
      expect(DEFAULT_QP_VALUES[1].points).toBeGreaterThan(DEFAULT_QP_VALUES[2].points);
      expect(DEFAULT_QP_VALUES[2].points).toBeGreaterThan(DEFAULT_QP_VALUES[3].points);
    });
  });

  describe("QP Accumulation Logic", () => {
    it("should accumulate QP across multiple events", () => {
      // Simulating participant earning QP from 4 majors
      const event1QP = 20; // 1st place
      const event2QP = 14; // 2nd place
      const event3QP = 10; // 3rd place
      const event4QP = 8; // 4th place

      const totalQP = event1QP + event2QP + event3QP + event4QP;

      expect(totalQP).toBe(52);
    });

    it("should handle decimal QP values", () => {
      const qp1 = 20.5;
      const qp2 = 14.25;

      const total = qp1 + qp2;

      expect(total).toBe(34.75);
    });

    it("should handle zero QP awards", () => {
      const event1QP = 20;
      const event2QP = 0; // Finished beyond 16th

      const total = event1QP + event2QP;

      expect(total).toBe(20);
    });
  });

  describe("QP Ranking Logic", () => {
    it("should rank participants by total QP (highest first)", () => {
      const standings = [
        { name: "Player A", qp: 44 },
        { name: "Player B", qp: 50 },
        { name: "Player C", qp: 38 },
      ];

      const sorted = standings.toSorted((a, b) => b.qp - a.qp);

      expect(sorted[0].name).toBe("Player B"); // 50 QP
      expect(sorted[1].name).toBe("Player A"); // 44 QP
      expect(sorted[2].name).toBe("Player C"); // 38 QP
    });

    it("should handle ties in QP totals", () => {
      const standings = [
        { name: "Player A", qp: 30 },
        { name: "Player B", qp: 30 },
        { name: "Player C", qp: 20 },
      ];

      const sorted = standings.toSorted((a, b) => b.qp - a.qp);

      // Both players with 30 QP should be before Player C
      expect(sorted[2].name).toBe("Player C");
      expect(sorted[0].qp).toBe(30);
      expect(sorted[1].qp).toBe(30);
    });
  });

  describe("QP to Fantasy Placement Conversion", () => {
    it("should assign top 8 QP leaders to fantasy placements 1-8", () => {
      const qpRankings = [50, 44, 38, 30, 25, 20, 15, 10, 5, 2];

      const top8 = qpRankings.slice(0, 8);

      expect(top8).toHaveLength(8);
      expect(top8[0]).toBe(50); // 1st place
      expect(top8[7]).toBe(10); // 8th place
    });

    it("should assign 0 fantasy points to participants beyond top 8", () => {
      const qpRankings = [50, 44, 38, 30, 25, 20, 15, 10, 5, 2];

      const beyond8 = qpRankings.slice(8);

      expect(beyond8).toHaveLength(2);
      // These would get 0 fantasy points
      const fantasyPoints = beyond8.map(() => 0);
      expect(fantasyPoints).toEqual([0, 0]);
    });

    it("should handle ties at the cutoff (8th place)", () => {
      // Scenario: Two players tied for 8th place QP
      const qpRankings = [
        { name: "P1", qp: 50 }, // 1st
        { name: "P2", qp: 44 }, // 2nd
        { name: "P3", qp: 38 }, // 3rd
        { name: "P4", qp: 30 }, // 4th
        { name: "P5", qp: 25 }, // 5th
        { name: "P6", qp: 20 }, // 6th
        { name: "P7", qp: 15 }, // 7th
        { name: "P8", qp: 10 }, // Tied for 8th
        { name: "P9", qp: 10 }, // Tied for 8th
      ];

      // Both should get placement 8
      const tied8th = qpRankings.filter(p => p.qp === 10);
      expect(tied8th).toHaveLength(2);

      // In implementation, both would share 8th place fantasy placement
      const placement = 8;
      expect(placement).toBe(8);
    });
  });

  describe("Tie Handling During QP Awards", () => {
    const pointsByPlacement = new Map(
      DEFAULT_QP_VALUES.map(({ placement, points }) => [placement, points])
    );

    it("rounds a 4-way golf tie for 15th to the nearest hundredth", () => {
      expect(calculateSplitQualifyingPoints(15, 4, pointsByPlacement)).toBe(0.5);
    });

    it("should correctly split QP among tied participants", () => {
      // Scenario: 7 players tied for 14th place
      // They occupy positions 14-20
      // Positions 14, 15, 16 get 1 QP each = 3 total QP
      // Positions 17-20 get 0 QP
      // Total: 3 QP divided by 7 players = 3/7 = 0.428571... per player

      const tieCount = 7;
      const startPosition = 14;

      // Calculate total QP for positions 14-20
      const qpMap: Record<number, number> = {
        14: 1,
        15: 1,
        16: 1,
        17: 0,
        18: 0,
        19: 0,
        20: 0,
      };

      let totalQP = 0;
      for (let pos = startPosition; pos < startPosition + tieCount; pos++) {
        totalQP += qpMap[pos] || 0;
      }

      const qpPerPlayer = totalQP / tieCount;

      expect(totalQP).toBe(3);
      expect(calculateSplitQualifyingPoints(14, 7, pointsByPlacement)).toBe(0.43);
      expect(qpPerPlayer).toBeCloseTo(0.428571, 5);
    });

    it("should handle 2-way tie for 5th place", () => {
      // 2 players tied for 5th occupy positions 5 and 6
      // Position 5: 5 QP, Position 6: 5 QP
      // Total: 10 QP / 2 players = 5 QP each

      const tieCount = 2;
      const startPosition = 5;
      const qpMap: Record<number, number> = { 5: 5, 6: 5 };

      let totalQP = 0;
      for (let pos = startPosition; pos < startPosition + tieCount; pos++) {
        totalQP += qpMap[pos];
      }

      const qpPerPlayer = totalQP / tieCount;

      expect(totalQP).toBe(10);
      expect(qpPerPlayer).toBe(5);
    });

    it("should handle 3-way tie for 1st place", () => {
      // 3 players tied for 1st occupy positions 1, 2, 3
      // Position 1: 20 QP, Position 2: 14 QP, Position 3: 10 QP
      // Total: 44 QP / 3 players = 14.666... QP each

      const tieCount = 3;
      const startPosition = 1;
      const qpMap: Record<number, number> = { 1: 20, 2: 14, 3: 10 };

      let totalQP = 0;
      for (let pos = startPosition; pos < startPosition + tieCount; pos++) {
        totalQP += qpMap[pos];
      }

      const qpPerPlayer = totalQP / tieCount;

      expect(totalQP).toBe(44);
      expect(calculateSplitQualifyingPoints(1, 3, pointsByPlacement)).toBe(14.67);
      expect(qpPerPlayer).toBeCloseTo(14.666667, 5);
    });
  });

  describe("Reprocessing Events", () => {
    it("should handle reprocessing by removing old QP before adding new QP", () => {
      // Scenario: Admin enters results, processes QP, then realizes there's an error
      // They fix the placements and reprocess

      // Initial processing
      const participant1InitialQP = 20; // 1st place
      const participant2InitialQP = 14; // 2nd place

      let totalQP1 = participant1InitialQP;
      let totalQP2 = participant2InitialQP;

      // Admin realizes participant 1 should have been 3rd, not 1st
      // Reprocessing: subtract old QP, add new QP
      totalQP1 = totalQP1 - participant1InitialQP + 10; // Remove 20, add 10 (3rd place)
      totalQP2 = totalQP2 - participant2InitialQP + 20; // Remove 14, add 20 (moved to 1st)

      expect(totalQP1).toBe(10); // Should have 10 QP (3rd place)
      expect(totalQP2).toBe(20); // Should have 20 QP (1st place)
    });

  });

  describe("Scoring Workflow", () => {
    it("should process 4 majors and calculate final standings", () => {
      // Simulating a full season with 4 majors
      const participants = [
        { name: "Tiger Woods", qp: 0, events: 0 },
        { name: "Rory McIlroy", qp: 0, events: 0 },
        { name: "Scottie Scheffler", qp: 0, events: 0 },
      ];

      // Event 1: The Masters
      participants[0].qp += 20; // Tiger wins
      participants[0].events++;
      participants[1].qp += 14; // Rory 2nd
      participants[1].events++;
      participants[2].qp += 10; // Scottie 3rd
      participants[2].events++;

      // Event 2: PGA Championship
      participants[1].qp += 20; // Rory wins
      participants[1].events++;
      participants[0].qp += 14; // Tiger 2nd
      participants[0].events++;
      participants[2].qp += 10; // Scottie 3rd
      participants[2].events++;

      // Event 3: U.S. Open
      participants[2].qp += 20; // Scottie wins
      participants[2].events++;
      participants[0].qp += 14; // Tiger 2nd
      participants[0].events++;
      participants[1].qp += 10; // Rory 3rd
      participants[1].events++;

      // Event 4: The Open
      participants[0].qp += 20; // Tiger wins
      participants[0].events++;
      participants[1].qp += 14; // Rory 2nd
      participants[1].events++;
      participants[2].qp += 10; // Scottie 3rd
      participants[2].events++;

      // Final standings
      participants.sort((a, b) => b.qp - a.qp);

      expect(participants[0].name).toBe("Tiger Woods");
      expect(participants[0].qp).toBe(68); // 20+14+14+20
      expect(participants[0].events).toBe(4);

      expect(participants[1].name).toBe("Rory McIlroy");
      expect(participants[1].qp).toBe(58); // 14+20+10+14
      expect(participants[1].events).toBe(4);

      expect(participants[2].name).toBe("Scottie Scheffler");
      expect(participants[2].qp).toBe(50); // 10+10+20+10
      expect(participants[2].events).toBe(4);
    });
  });
});