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

import {
  TAU,
  angularTravelConstraint,
  crankSliderDisplacement,
  formatKinematicValidationReport,
  phaseRatioConstraint,
  runKinematicValidation,
  type KinematicValidationSuite,
  type ScalarTrack,
  willisPlanetaryConstraint
} from './kinematicIntegrity';

describe('kinematic integrity validators', () => {
  it('computes crank-slider top and bottom dead-center positions from geometry', () => {
    const crankRadiusMeters = 0.04;
    const rodLengthMeters = 0.14;

    expect(crankSliderDisplacement(0, crankRadiusMeters, rodLengthMeters)).toBeCloseTo(
      rodLengthMeters + crankRadiusMeters,
      12
    );
    expect(crankSliderDisplacement(Math.PI, crankRadiusMeters, rodLengthMeters)).toBeCloseTo(
      rodLengthMeters - crankRadiusMeters,
      12
    );
  });

  it('passes a correctly constrained fixed-ring planetary gear set', () => {
    const sunTeeth = 24;
    const ringTeeth = 72;
    const carrierRatio = sunTeeth / (sunTeeth + ringTeeth);
    const sun = scalarTrack('sun', (timeSeconds) => TAU * timeSeconds);
    const ring = scalarTrack('ring', () => 0);
    const carrier = scalarTrack('carrier', (timeSeconds) => carrierRatio * sun.sample(timeSeconds));

    const suite: KinematicValidationSuite = {
      id: 'planetary.valid',
      machineId: 'planetary-gearbox',
      title: 'Valid planetary gearbox',
      durationSeconds: 1,
      sampleCount: 49,
      constraints: [
        willisPlanetaryConstraint({
          sunAngle: sun,
          ringAngle: ring,
          carrierAngle: carrier,
          sunTeeth,
          ringTeeth,
          tolerance: { absolute: 1e-10, relative: 1e-10 }
        }),
        phaseRatioConstraint({
          driver: sun,
          driven: carrier,
          ratio: carrierRatio,
          tolerance: { absolute: 1e-10, relative: 1e-10 }
        }),
        angularTravelConstraint({
          track: carrier,
          expectedDeltaRadians: TAU * carrierRatio,
          tolerance: { absolute: 1e-10, relative: 1e-10 }
        })
      ]
    };

    const report = runKinematicValidation([suite]);

    expect(report.ok, formatKinematicValidationReport(report)).toBe(true);
  });

  it('fails a planetary gearbox when the carrier ratio violates Willis equation', () => {
    const sunTeeth = 24;
    const ringTeeth = 72;
    const sun = scalarTrack('sun', (timeSeconds) => TAU * timeSeconds);
    const ring = scalarTrack('ring', () => 0);
    const carrier = scalarTrack('carrier', (timeSeconds) => 0.3 * sun.sample(timeSeconds));

    const suite: KinematicValidationSuite = {
      id: 'planetary.invalid',
      machineId: 'planetary-gearbox',
      title: 'Invalid planetary gearbox',
      durationSeconds: 1,
      sampleCount: 25,
      constraints: [
        willisPlanetaryConstraint({
          sunAngle: sun,
          ringAngle: ring,
          carrierAngle: carrier,
          sunTeeth,
          ringTeeth,
          tolerance: { absolute: 1e-10, relative: 1e-10 }
        })
      ]
    };

    const report = runKinematicValidation([suite]);

    expect(report.ok).toBe(false);
    expect(report.errorCount).toBeGreaterThan(0);
    expect(report.suiteReports[0].issues.some((issue) => issue.code === 'planetary.willis')).toBe(true);
  });
});

function scalarTrack(id: string, sample: (timeSeconds: number) => number): ScalarTrack {
  return {
    id,
    units: 'radians',
    sample
  };
}