import { describe, expect, it } from "vitest";

import {
  getToolcraftSliderStepPositionCount,
  getToolcraftVisualDiscreteSliderMarkerIssue,
  TOOLCRAFT_VISUAL_DISCRETE_POSITION_LIMIT,
} from "./slider-marker-policy";

describe("Toolcraft slider marker policy", () => {
  it("counts integer step positions including both endpoints", () => {
    expect(
      getToolcraftSliderStepPositionCount({ min: 0, max: 31, step: 1 }),
    ).toBe(32);
  });

  it("counts exact fractional step positions", () => {
    expect(
      getToolcraftSliderStepPositionCount({ min: 0, max: 0.5, step: 0.1 }),
    ).toBe(6);
  });

  it("preserves the existing position count for a non-divisible range", () => {
    expect(
      getToolcraftSliderStepPositionCount({ min: 0, max: 1, step: 0.3 }),
    ).toBe(5);
  });

  it("scales near-integer tolerance for larger fractional domains", () => {
    const domain = { min: 61.3, max: 64.4, step: 0.1 };

    expect(getToolcraftSliderStepPositionCount(domain)).toBe(32);
    expect(
      getToolcraftVisualDiscreteSliderMarkerIssue({
        ...domain,
        type: "slider",
        variant: "discrete",
      }),
    ).toBeNull();
  });

  it("defines a 32-position visual-discrete budget", () => {
    expect(TOOLCRAFT_VISUAL_DISCRETE_POSITION_LIMIT).toBe(32);
  });

  it("accepts a visual-discrete slider at the position budget", () => {
    expect(
      getToolcraftVisualDiscreteSliderMarkerIssue({
        type: "slider",
        variant: "discrete",
        min: 0,
        max: 31,
        step: 1,
      }),
    ).toBeNull();
  });

  it("reports a visual-discrete slider above the position budget", () => {
    expect(
      getToolcraftVisualDiscreteSliderMarkerIssue({
        type: "slider",
        variant: "discrete",
        min: 0,
        max: 32,
        step: 1,
      }),
    ).toEqual({ kind: "budget", limit: 32, positionCount: 33 });
  });

  it.each(["slider", "rangeSlider"] as const)(
    "reports invalid %s visual-discrete domains",
    (type) => {
      const invalidDomains = [
        { max: 10, step: 1 },
        { min: 0, step: 1 },
        { min: 0, max: 10 },
        { min: Number.NaN, max: 10, step: 1 },
        { min: 0, max: Number.POSITIVE_INFINITY, step: 1 },
        { min: 0, max: 10, step: Number.NEGATIVE_INFINITY },
        { min: 10, max: 0, step: 1 },
        { min: 0, max: 0, step: 1 },
        { min: 0, max: 10, step: 0 },
        { min: 0, max: 10, step: -1 },
      ];

      for (const domain of invalidDomains) {
        expect(
          getToolcraftVisualDiscreteSliderMarkerIssue({
            type,
            variant: "discrete",
            ...domain,
          }),
        ).toEqual({ kind: "domain" });
      }
    },
  );

  it.each(["slider", "rangeSlider"] as const)(
    "does not apply the marker budget to a continuous %s",
    (type) => {
      expect(
        getToolcraftVisualDiscreteSliderMarkerIssue({
          type,
          variant: "continuous",
          min: 0,
          max: 64,
          step: 1,
        }),
      ).toBeNull();
    },
  );
});