brackt/app/services/simulations/__tests__/input-policy.test.ts

import { describe, expect, it } from "vitest";
import {
  getSimulatorInputPolicy,
  prefersFuturesOdds,
  resolveRatings,
  resolveSourceElos,
  ELO_FIRST_SOURCE_PRIORITY,
  FUTURES_FIRST_SOURCE_PRIORITY,
} from "../input-policy";
import type { SimulatorManifestProfile } from "../manifest";

const profile = {
  derivableInputs: { sourceElo: ["projectedWins", "sourceOdds"] },
} as Pick<SimulatorManifestProfile, "derivableInputs">;

const tablePointsProfile = {
  derivableInputs: { sourceElo: ["projectedTablePoints"] },
} as Pick<SimulatorManifestProfile, "derivableInputs">;

describe("simulator input policy", () => {
  it("keeps direct Elo ahead of derived values", () => {
    const resolved = resolveSourceElos(
      [{ participantId: "team-1", sourceElo: 1600, rating: null, sourceOdds: 2000, projectedWins: 20, projectedTablePoints: null }],
      profile,
      { seasonGames: 82 }
    );

    expect(resolved.get("team-1")).toMatchObject({ sourceElo: 1600, method: "direct" });
  });

  it("derives Elo from projected wins when Elo is missing", () => {
    const resolved = resolveSourceElos(
      [{ participantId: "team-1", sourceElo: null, rating: null, sourceOdds: null, projectedWins: 60, projectedTablePoints: null }],
      profile,
      { seasonGames: 82, parityFactor: 400 }
    );

    expect(resolved.get("team-1")?.method).toBe("projectedWins");
    expect(resolved.get("team-1")?.sourceElo).toBeGreaterThan(1500);
  });

  it("uses parityFactor as the projected table points to Elo spread", () => {
    const input = {
      participantId: "team-1",
      sourceElo: null,
      rating: null,
      sourceOdds: null,
      projectedWins: null,
      projectedTablePoints: 76,
    };

    const compressed = resolveSourceElos([input], tablePointsProfile, {
      seasonGames: 38,
      parityFactor: 250,
    });
    const wider = resolveSourceElos([input], tablePointsProfile, {
      seasonGames: 38,
      parityFactor: 1000,
    });

    expect(compressed.get("team-1")?.sourceElo).toBeLessThan(wider.get("team-1")?.sourceElo ?? 0);
  });

  it("blocks missing Elo unless a fallback strategy is configured", () => {
    const inputs = [{ participantId: "team-1", sourceElo: null, rating: null, sourceOdds: null, projectedWins: null, projectedTablePoints: null }];

    expect(resolveSourceElos(inputs, profile, {}).has("team-1")).toBe(false);
    expect(resolveSourceElos(inputs, profile, {
      inputPolicy: { missingEloStrategy: "fallbackElo", fallbackElo: 1375 },
    }).get("team-1")).toMatchObject({ sourceElo: 1375, method: "fallbackElo" });
  });

  it("supports worst-known-minus tail fallback", () => {
    const resolved = resolveSourceElos(
      [
        { participantId: "known-1", sourceElo: 1500, rating: null, sourceOdds: null, projectedWins: null, projectedTablePoints: null },
        { participantId: "known-2", sourceElo: 1430, rating: null, sourceOdds: null, projectedWins: null, projectedTablePoints: null },
        { participantId: "tail", sourceElo: null, rating: null, sourceOdds: null, projectedWins: null, projectedTablePoints: null },
      ],
      profile,
      { inputPolicy: { missingEloStrategy: "worstKnownMinus", fallbackEloDelta: 30 } }
    );

    expect(resolved.get("tail")).toMatchObject({ sourceElo: 1400, method: "worstKnownMinus" });
  });

  it("derives Elo from futures odds when no direct Elo is present", () => {
    const resolved = resolveSourceElos(
      [
        { participantId: "favorite", sourceElo: null, rating: null, sourceOdds: 300, projectedWins: null, projectedTablePoints: null },
        { participantId: "longshot", sourceElo: null, rating: null, sourceOdds: 20000, projectedWins: null, projectedTablePoints: null },
      ],
      profile,
      {}
    );

    expect(resolved.get("favorite")?.method).toBe("sourceOdds");
    expect(resolved.get("longshot")?.method).toBe("sourceOdds");
    expect(resolved.get("favorite")?.sourceElo).toBeGreaterThan(resolved.get("longshot")?.sourceElo ?? Infinity);
  });

  it("ignores a lone sourceOdds participant rather than assigning a flat Elo", () => {
    const inputs = [
      { participantId: "only", sourceElo: null, rating: null, sourceOdds: 300, projectedWins: null, projectedTablePoints: null },
    ];

    // Needs at least 2 odds to derive a spread; with block strategy it stays unresolved.
    expect(resolveSourceElos(inputs, profile, {}).has("only")).toBe(false);

    // With a fallback strategy it resolves via that method, not "sourceOdds".
    expect(
      resolveSourceElos(inputs, profile, {
        inputPolicy: { missingEloStrategy: "fallbackElo", fallbackElo: 1400 },
      }).get("only")
    ).toMatchObject({ sourceElo: 1400, method: "fallbackElo" });
  });

  it("derives Elo from odds once a prior direct Elo has been cleared", () => {
    // Regression: after entering futures odds the simulator inputs row keeps
    // sourceOdds but has its sourceElo nulled. The resolver must pick "sourceOdds",
    // not resurrect a "direct" Elo.
    const resolved = resolveSourceElos(
      [
        { participantId: "favorite", sourceElo: null, rating: null, sourceOdds: 300, projectedWins: null, projectedTablePoints: null },
        { participantId: "longshot", sourceElo: null, rating: null, sourceOdds: 20000, projectedWins: null, projectedTablePoints: null },
      ],
      profile,
      {}
    );

    expect(resolved.get("favorite")?.method).toBe("sourceOdds");
    expect(resolved.get("longshot")?.method).toBe("sourceOdds");
  });

  it("derives ratings from futures odds when the profile allows it", () => {
    const resolved = resolveRatings(
      [
        { participantId: "favorite", sourceElo: null, rating: null, sourceOdds: 300, projectedWins: null, projectedTablePoints: null },
        { participantId: "longshot", sourceElo: null, rating: null, sourceOdds: 20000, projectedWins: null, projectedTablePoints: null },
      ],
      { derivableInputs: { rating: ["sourceOdds"] } },
      { inputPolicy: { ratingMin: -10, ratingMax: 35 } }
    );

    expect(resolved.get("favorite")?.method).toBe("sourceOdds");
    expect(resolved.get("longshot")?.method).toBe("sourceOdds");
    expect(resolved.get("favorite")?.rating).toBeGreaterThan(resolved.get("longshot")?.rating ?? 999);
  });

  it("blocks missing ratings unless a rating fallback strategy is configured", () => {
    const inputs = [
      { participantId: "known", sourceElo: null, rating: null, sourceOdds: 300, projectedWins: null, projectedTablePoints: null },
      { participantId: "longshot", sourceElo: null, rating: null, sourceOdds: 20000, projectedWins: null, projectedTablePoints: null },
      { participantId: "tail", sourceElo: null, rating: null, sourceOdds: null, projectedWins: null, projectedTablePoints: null },
    ];
    const ratingProfile = { derivableInputs: { rating: ["sourceOdds"] } } as Pick<SimulatorManifestProfile, "derivableInputs">;

    expect(resolveRatings(inputs, ratingProfile, {
      inputPolicy: { ratingMin: -10, ratingMax: 35 },
    }).has("tail")).toBe(false);

    expect(resolveRatings(inputs, ratingProfile, {
      inputPolicy: {
        missingRatingStrategy: "fallbackRating",
        fallbackRating: -4,
        ratingMin: -10,
        ratingMax: 35,
      },
    }).get("tail")).toMatchObject({ rating: -4, method: "fallbackRating" });
  });

  it("supports worst-known-minus rating fallback with clamping", () => {
    const resolved = resolveRatings(
      [
        { participantId: "favorite", sourceElo: null, rating: 30, sourceOdds: null, projectedWins: null, projectedTablePoints: null },
        { participantId: "known-tail", sourceElo: null, rating: -8, sourceOdds: null, projectedWins: null, projectedTablePoints: null },
        { participantId: "missing-tail", sourceElo: null, rating: null, sourceOdds: null, projectedWins: null, projectedTablePoints: null },
      ],
      { derivableInputs: { rating: ["sourceOdds"] } },
      {
        inputPolicy: {
          missingRatingStrategy: "worstKnownMinus",
          fallbackRatingDelta: 5,
          ratingMin: -10,
          ratingMax: 35,
        },
      }
    );

    expect(resolved.get("missing-tail")).toMatchObject({ rating: -10, method: "worstKnownMinus" });
  });

  it("lets a futures-first priority override a stored direct Elo", () => {
    const inputs = [
      { participantId: "favorite", sourceElo: 1800, rating: null, sourceOdds: 300, projectedWins: null, projectedTablePoints: null },
      { participantId: "longshot", sourceElo: 1200, rating: null, sourceOdds: 20000, projectedWins: null, projectedTablePoints: null },
    ];

    // Default (Elo-first): the stored direct Elo wins.
    const eloFirst = resolveSourceElos(inputs, profile, {});
    expect(eloFirst.get("favorite")).toMatchObject({ sourceElo: 1800, method: "direct" });

    // Futures-first: odds win even though a direct Elo is present.
    const futuresFirst = resolveSourceElos(inputs, profile, {
      inputPolicy: { sourceEloPriority: FUTURES_FIRST_SOURCE_PRIORITY },
    });
    expect(futuresFirst.get("favorite")?.method).toBe("sourceOdds");
    expect(futuresFirst.get("longshot")?.method).toBe("sourceOdds");
  });

  it("lets a futures-first priority override stored projected wins", () => {
    const inputs = [
      { participantId: "team-1", sourceElo: null, rating: null, sourceOdds: 300, projectedWins: 60, projectedTablePoints: null },
      { participantId: "team-2", sourceElo: null, rating: null, sourceOdds: 20000, projectedWins: 20, projectedTablePoints: null },
    ];

    // Default (Elo-first): projectedWins outranks odds.
    expect(resolveSourceElos(inputs, profile, { seasonGames: 82 }).get("team-1")?.method).toBe("projectedWins");

    // Futures-first: odds win over projections.
    const futuresFirst = resolveSourceElos(inputs, profile, {
      seasonGames: 82,
      inputPolicy: { sourceEloPriority: FUTURES_FIRST_SOURCE_PRIORITY },
    });
    expect(futuresFirst.get("team-1")?.method).toBe("sourceOdds");
  });

  it("lets a futures-first priority override a stored direct rating", () => {
    const ratingProfile = { derivableInputs: { rating: ["sourceOdds"] } } as Pick<SimulatorManifestProfile, "derivableInputs">;
    const inputs = [
      { participantId: "favorite", sourceElo: null, rating: 30, sourceOdds: 300, projectedWins: null, projectedTablePoints: null },
      { participantId: "longshot", sourceElo: null, rating: -5, sourceOdds: 20000, projectedWins: null, projectedTablePoints: null },
    ];

    // Default: direct rating wins.
    expect(resolveRatings(inputs, ratingProfile, { inputPolicy: { ratingMin: -10, ratingMax: 35 } }).get("favorite"))
      .toMatchObject({ rating: 30, method: "direct" });

    // Futures-first: odds win.
    expect(
      resolveRatings(inputs, ratingProfile, {
        inputPolicy: { ratingMin: -10, ratingMax: 35, sourceEloPriority: FUTURES_FIRST_SOURCE_PRIORITY },
      }).get("favorite")?.method
    ).toBe("sourceOdds");
  });

  it("parses and clamps the input policy source priority and odds weight", () => {
    const defaults = getSimulatorInputPolicy({});
    expect(defaults.sourceEloPriority).toEqual(ELO_FIRST_SOURCE_PRIORITY);
    expect(defaults.oddsWeight).toBe(0.3);

    // oddsWeight can be sourced from the top-level config or the input policy,
    // and is clamped to [0, 1]; junk priority entries are dropped.
    expect(getSimulatorInputPolicy({ oddsWeight: 0.6 }).oddsWeight).toBe(0.6);
    expect(getSimulatorInputPolicy({ inputPolicy: { oddsWeight: 5 } }).oddsWeight).toBe(1);
    expect(getSimulatorInputPolicy({ inputPolicy: { oddsWeight: -2 } }).oddsWeight).toBe(0);
    expect(
      getSimulatorInputPolicy({ inputPolicy: { sourceEloPriority: ["sourceOdds", "bogus", "sourceElo"] } }).sourceEloPriority
    ).toEqual(["sourceOdds", "sourceElo"]);
    // An empty/all-invalid priority falls back to the default.
    expect(getSimulatorInputPolicy({ inputPolicy: { sourceEloPriority: ["nope"] } }).sourceEloPriority).toEqual(
      ELO_FIRST_SOURCE_PRIORITY
    );
  });

  it("detects whether a priority prefers futures odds", () => {
    expect(prefersFuturesOdds(ELO_FIRST_SOURCE_PRIORITY)).toBe(false);
    expect(prefersFuturesOdds(FUTURES_FIRST_SOURCE_PRIORITY)).toBe(true);
    expect(prefersFuturesOdds(["projectedWins", "sourceElo"])).toBe(false);
    expect(prefersFuturesOdds(["sourceOdds"])).toBe(true);
  });

  it("uses NCAAW-style rating scale when deriving and falling back", () => {
    const resolved = resolveRatings(
      [
        { participantId: "favorite", sourceElo: null, rating: null, sourceOdds: 300, projectedWins: null, projectedTablePoints: null },
        { participantId: "longshot", sourceElo: null, rating: null, sourceOdds: 20000, projectedWins: null, projectedTablePoints: null },
        { participantId: "tail", sourceElo: null, rating: null, sourceOdds: null, projectedWins: null, projectedTablePoints: null },
      ],
      { derivableInputs: { rating: ["sourceOdds"] } },
      {
        inputPolicy: {
          missingRatingStrategy: "worstKnownMinus",
          fallbackRatingDelta: 0.05,
          ratingMin: 0.15,
          ratingMax: 0.99,
        },
      }
    );

    expect(resolved.get("favorite")?.rating).toBeLessThanOrEqual(0.99);
    expect(resolved.get("tail")).toMatchObject({ rating: 0.15, method: "worstKnownMinus" });
  });
});