import { describe, expect, it } from 'vitest';
import {
  createAudioIntentCoordinator,
  type AudioIntentSample,
} from '@/audio/audio-intent-coordinator';
import type { SectionId } from '@/content/types';

const sectionIds = [
  'start', 'profile', 'experience', 'infrastructure',
  'selected-builds', 'additional-work', 'toolkit', 'contact',
] as const satisfies readonly SectionId[];

const baseSample = (
  overrides: Partial<AudioIntentSample> = {},
): AudioIntentSample => ({
  now: 0,
  visible: true,
  scrollY: 0,
  activeSectionId: 'start',
  acceleration: 0,
  sectionActivation: {
    layoutRevision: 1,
    activeHeadingOffsetVh: -0.1,
    nextHeadingOffsetVh: 0.8,
  },
  navigation: {
    epoch: 1,
    source: 'passive-scroll',
    phase: 'idle',
    destinationId: null,
    signDestinationId: null,
  },
  ...overrides,
});

describe('audio intent coordinator', () => {
  it('commits once only after 6vh hysteresis and 400 ms dwell', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    expect(coordinator.sample(baseSample({
      now: 10,
      scrollY: 10,
      activeSectionId: 'profile',
      sectionActivation: {
        layoutRevision: 1,
        activeHeadingOffsetVh: -0.059,
        nextHeadingOffsetVh: 0.8,
      },
    }))).toMatchObject({ chapter: null, needsFrame: false });

    expect(coordinator.sample(baseSample({ now: 100, scrollY: 10, activeSectionId: 'profile' })))
      .toMatchObject({ chapter: null, needsFrame: true });
    expect(coordinator.sample(baseSample({ now: 499, scrollY: 10, activeSectionId: 'profile' })))
      .toMatchObject({ chapter: null });
    expect(coordinator.sample(baseSample({ now: 500, scrollY: 10, activeSectionId: 'profile' })).chapter)
      .toMatchObject({ sectionId: 'profile', mood: 'open', generation: 1 });
    expect(coordinator.sample(baseSample({ now: 900, scrollY: 10, activeSectionId: 'profile' })).chapter)
      .toBeNull();
  });

  it('clears a passive candidate on reversal or structural remeasurement', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    coordinator.sample(baseSample({ now: 0, scrollY: 10, activeSectionId: 'profile' }));
    expect(coordinator.sample(baseSample({ now: 250, scrollY: 9, activeSectionId: 'start' })).needsFrame)
      .toBe(false);
    coordinator.sample(baseSample({ now: 300, scrollY: 12, activeSectionId: 'profile' }));
    expect(coordinator.sample(baseSample({
      now: 800,
      scrollY: 12,
      activeSectionId: 'profile',
      sectionActivation: {
        layoutRevision: 2,
        activeHeadingOffsetVh: -0.2,
        nextHeadingOffsetVh: 0.7,
      },
    }))).toMatchObject({ chapter: null, needsFrame: false });
  });

  it('commits only the latest settled explicit destination', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    coordinator.sample(baseSample({
      navigation: {
        epoch: 2,
        source: 'explicit-navigation',
        phase: 'travelling',
        destinationId: 'contact',
        signDestinationId: null,
      },
    }));
    coordinator.sample(baseSample({
      activeSectionId: 'toolkit',
      navigation: {
        epoch: 3,
        source: 'explicit-navigation',
        phase: 'travelling',
        destinationId: 'toolkit',
        signDestinationId: null,
      },
    }));
    expect(coordinator.sample(baseSample({
      now: 600,
      activeSectionId: 'toolkit',
      navigation: {
        epoch: 3,
        source: 'explicit-navigation',
        phase: 'settled',
        destinationId: 'toolkit',
        signDestinationId: null,
      },
    }))).toMatchObject({
      chapter: { sectionId: 'toolkit', mood: 'resolve', generation: 1 },
    });
  });

  it('dead-bands tiny input and caps programmatic travel below lift entry', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    expect(coordinator.sample(baseSample({ now: 0, acceleration: 0.07 })).drive).toBeNull();
    expect(coordinator.sample(baseSample({ now: 40, acceleration: 0.7 })).drive)
      .toEqual({ energy: expect.closeTo((0.7 - 0.08) / 0.92), source: 'physical' });
    expect(coordinator.sample(baseSample({
      now: 80,
      acceleration: 1,
      navigation: {
        epoch: 2,
        source: 'explicit-navigation',
        phase: 'travelling',
        destinationId: 'contact',
        signDestinationId: null,
      },
    })).drive).toEqual({ energy: 0.35, source: 'navigation' });
    expect(coordinator.sample(baseSample({ now: 120, acceleration: 0 })).drive)
      .toEqual({ energy: 0, source: 'idle' });
  });

  it('rate-limits small drive changes but emits exact threshold, source, and zero crossings', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    const physicalAcceleration = (energy: number): number => 0.08 + energy * 0.92;

    expect(coordinator.sample(baseSample({ now: 0, acceleration: physicalAcceleration(0.3) })).drive)
      .toEqual({ energy: expect.closeTo(0.3), source: 'physical' });
    expect(coordinator.sample(baseSample({ now: 10, acceleration: physicalAcceleration(0.31) })).drive)
      .toBeNull();
    expect(coordinator.sample(baseSample({ now: 11, acceleration: physicalAcceleration(0.32) })).drive)
      .toEqual({ energy: expect.closeTo(0.32), source: 'physical' });
    expect(coordinator.sample(baseSample({ now: 12, acceleration: physicalAcceleration(0.62) })).drive)
      .toEqual({ energy: expect.closeTo(0.62), source: 'physical' });
    expect(coordinator.sample(baseSample({
      now: 13,
      acceleration: 0.2,
      navigation: {
        epoch: 2,
        source: 'explicit-navigation',
        phase: 'travelling',
        destinationId: 'contact',
        signDestinationId: null,
      },
    })).drive).toEqual({ energy: 0.2, source: 'navigation' });
    expect(coordinator.sample(baseSample({ now: 14, acceleration: 0 })).drive)
      .toEqual({ energy: 0, source: 'idle' });
  });

  it('cannot turn a layout-only active-section shift into a passive commit', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    expect(coordinator.sample(baseSample({
      now: 100,
      activeSectionId: 'profile',
      sectionActivation: {
        layoutRevision: 2,
        activeHeadingOffsetVh: -0.2,
        nextHeadingOffsetVh: 0.7,
      },
    }))).toMatchObject({ chapter: null, needsFrame: false });
    expect(coordinator.sample(baseSample({
      now: 600,
      activeSectionId: 'profile',
      sectionActivation: {
        layoutRevision: 2,
        activeHeadingOffsetVh: -0.2,
        nextHeadingOffsetVh: 0.7,
      },
    })).chapter).toBeNull();

    expect(coordinator.sample(baseSample({
      now: 650,
      scrollY: 2,
      activeSectionId: 'profile',
      sectionActivation: {
        layoutRevision: 2,
        activeHeadingOffsetVh: -0.2,
        nextHeadingOffsetVh: 0.7,
      },
    })).needsFrame).toBe(true);
    expect(coordinator.sample(baseSample({
      now: 1_050,
      scrollY: 2,
      activeSectionId: 'profile',
      sectionActivation: {
        layoutRevision: 2,
        activeHeadingOffsetVh: -0.2,
        nextHeadingOffsetVh: 0.7,
      },
    })).chapter).toMatchObject({ sectionId: 'profile' });
  });

  it('defers a genuine settlement across remeasurement but ignores old settled state', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    coordinator.sample(baseSample({
      navigation: {
        epoch: 2,
        source: 'explicit-navigation',
        phase: 'travelling',
        destinationId: 'contact',
        signDestinationId: null,
      },
    }));
    expect(coordinator.sample(baseSample({
      now: 100,
      activeSectionId: 'contact',
      sectionActivation: {
        layoutRevision: 2,
        activeHeadingOffsetVh: -0.2,
        nextHeadingOffsetVh: null,
      },
      navigation: {
        epoch: 2,
        source: 'explicit-navigation',
        phase: 'settled',
        destinationId: 'contact',
        signDestinationId: null,
      },
    }))).toMatchObject({ chapter: null, needsFrame: true });
    expect(coordinator.sample(baseSample({
      now: 116,
      activeSectionId: 'contact',
      sectionActivation: {
        layoutRevision: 2,
        activeHeadingOffsetVh: -0.2,
        nextHeadingOffsetVh: null,
      },
      navigation: {
        epoch: 2,
        source: 'explicit-navigation',
        phase: 'settled',
        destinationId: 'contact',
        signDestinationId: null,
      },
    })).chapter).toMatchObject({ sectionId: 'contact' });
  });

  it('starts one final dwell after wheel events advance passive epochs', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    const passive = (epoch: number) => ({
      epoch,
      source: 'passive-scroll' as const,
      phase: 'idle' as const,
      destinationId: null,
      signDestinationId: null,
    });
    coordinator.sample(baseSample({
      now: 100,
      scrollY: 24,
      activeSectionId: 'profile',
      navigation: passive(2),
    }));
    expect(coordinator.sample(baseSample({
      now: 180,
      scrollY: 48,
      activeSectionId: 'profile',
      navigation: passive(3),
    })).needsFrame).toBe(true);
    expect(coordinator.sample(baseSample({
      now: 580,
      scrollY: 48,
      activeSectionId: 'profile',
      navigation: passive(3),
    })).chapter).toMatchObject({ sectionId: 'profile' });
  });

  it('suppresses a navigation that settled while hidden', () => {
    const coordinator = createAudioIntentCoordinator(sectionIds, 'start', 1, 0);
    const settled = {
      epoch: 2,
      source: 'explicit-navigation',
      phase: 'settled',
      destinationId: 'contact',
      signDestinationId: null,
    } as const;
    coordinator.reset({
      navigation: settled,
      scrollY: 0,
      sectionActivation: baseSample().sectionActivation,
    });
    expect(coordinator.sample(baseSample({
      now: 1_000,
      activeSectionId: 'contact',
      navigation: settled,
    })).chapter).toBeNull();
  });
});