import { ValueHelper } from './value-helper';
import { CustomStepDefinition } from './options';

const precision: number = 0.0001;

describe('ValueHelper', () => {
  describe('linearValueToPosition', () => {
    it('converts using linear interpolation', () => {
      const number: number = 55;
      const minValue: number = 0;
      const maxValue: number = 100;
      expect(ValueHelper.linearValueToPosition(number, minValue, maxValue)).toBeCloseTo(0.55, precision);
    });
  });

  describe('linearPositionToValue', () => {
    it('converts using linear interpolation', () => {
      const percent: number = 0.55;
      const minValue: number = 0;
      const maxValue: number = 100;
      expect(ValueHelper.linearPositionToValue(percent, minValue, maxValue)).toBeCloseTo(55, precision);
    });
  });

  describe('logValueToPosition', () => {
    it('converts using log scale', () => {
      const number: number = 1e2;
      const minValue: number = 1e0;
      const maxValue: number = 1e10;
      expect(ValueHelper.logValueToPosition(number, minValue, maxValue)).toBeCloseTo(0.2, precision);
    });
  });

  describe('logPositionToValue', () => {
    it('converts using log scale', () => {
      const percent: number = 0.2;
      const minValue: number = 1e0;
      const maxValue: number = 1e10;
      expect(ValueHelper.logPositionToValue(percent, minValue, maxValue)).toBeCloseTo(1e2, precision);
    });
  });

  describe('findStepIndex', () => {
    it('finds the first equal index if value is equal', () => {
      const stepArray: CustomStepDefinition[] = [
        {
          value: 1
        },
        {
          value: 2
        },
        {
          value: 3
        }
      ];

      expect(ValueHelper.findStepIndex(1, stepArray)).toEqual(0);
      expect(ValueHelper.findStepIndex(2, stepArray)).toEqual(1);
      expect(ValueHelper.findStepIndex(3, stepArray)).toEqual(2);
    });

    it('finds the closest index if value is not equal', () => {
      const stepArray: CustomStepDefinition[] = [
        {
          value: 10
        },
        {
          value: 20
        },
        {
          value: 30
        }
      ];

      expect(ValueHelper.findStepIndex(9, stepArray)).toEqual(0);
      expect(ValueHelper.findStepIndex(11, stepArray)).toEqual(0);
      expect(ValueHelper.findStepIndex(15, stepArray)).toEqual(0);

      expect(ValueHelper.findStepIndex(16, stepArray)).toEqual(1);
      expect(ValueHelper.findStepIndex(19, stepArray)).toEqual(1);
      expect(ValueHelper.findStepIndex(21, stepArray)).toEqual(1);
      expect(ValueHelper.findStepIndex(25, stepArray)).toEqual(1);

      expect(ValueHelper.findStepIndex(26, stepArray)).toEqual(2);
      expect(ValueHelper.findStepIndex(29, stepArray)).toEqual(2);
      expect(ValueHelper.findStepIndex(31, stepArray)).toEqual(2);
    });
  });
});