import type { Group, Object3D } from 'three';

export type Vec3 = readonly [number, number, number];

export type Axis = 'x' | 'y' | 'z';

export type CameraPresetId = 'front' | 'back' | 'left' | 'right' | 'top' | 'isometric';

export type MachineDifficulty = 'Beginner' | 'Intermediate' | 'Advanced';

export type MachineCategory =
  | 'Engines'
  | 'Gearboxes & Drives'
  | 'Pumps & Fluid Systems'
  | 'Mechanisms'
  | 'Structural / Other'
  | string;

export type MachineAssetKind = 'procedural' | 'gltf' | 'hybrid';

export type ViewerLoadingPhase = 'idle' | 'loading' | 'preparing' | 'ready' | 'error';

export interface EngineeringFact {
  label: string;
  value: string;
  detail?: string;
}

export interface ViewerPart {
  id: string;
  name: string;
  shortName?: string;
  description: string;
  material?: string;
  color?: string;
  engineeringFacts?: EngineeringFact[];
  specs?: Record<string, string | number | boolean>;
  explodeDirection?: Vec3;
  annotationPosition?: Vec3;
  annotationLabel?: string;
  defaultVisible?: boolean;
  defaultOpacity?: number;
  nodeNames?: string[];
  keywords?: string[];
}

export interface ViewerAnnotation {
  id: string;
  partId: string;
  label: string;
  position: Vec3;
  offset?: Vec3;
}

export interface ViewerPartRuntimeSettings {
  visible: boolean;
  opacity: number;
}

export interface MachineMetadata {
  id: string;
  slug?: string;
  title: string;
  subtitle?: string;
  category?: MachineCategory;
  difficulty?: MachineDifficulty;
  description: string;
  keywords?: string[];
  facts?: EngineeringFact[];
  parts: ViewerPart[];
  relatedMachineIds?: string[];
  approximateBounds?: ViewerSceneBounds;
}

export interface ViewerSceneBounds {
  center: Vec3;
  radius: number;
  min?: Vec3;
  max?: Vec3;
}

export interface LoadedMachineAsset {
  root: Group;
  metadata: MachineMetadata;
  parts: ViewerPart[];
  source: {
    kind: MachineAssetKind;
    url?: string;
    generatedAt?: string;
  };
  dispose?: () => void;
}

export interface MachineAssetDefinition {
  id: string;
  kind: MachineAssetKind;
  metadata: MachineMetadata;
  url?: string;
  dracoPath?: string | boolean;
  ktx2TranscoderPath?: string;
  meshopt?: boolean;
  preload?: boolean;
  create?: () => LoadedMachineAsset;
  partNameMap?: Record<string, string>;
}

export interface CameraSnapshot {
  position: Vec3;
  target: Vec3;
  up?: Vec3;
  zoom?: number;
  fov?: number;
}

export interface ExplodedViewState {
  enabled: boolean;
  distance: number;
}

export interface CrossSectionState {
  enabled: boolean;
  axis: Axis;
  offset: number;
  invert: boolean;
  showPlane: boolean;
}

export interface ViewerDisplaySettings {
  wireframe: boolean;
  annotations: boolean;
  shadows: boolean;
  grid: boolean;
  ambientOcclusion: boolean;
  environment: boolean;
  exposure: number;
  exploded: ExplodedViewState;
  crossSection: CrossSectionState;
}

export interface ViewerHoveredPart {
  partId: string;
  name: string;
  clientX: number;
  clientY: number;
  worldPosition?: Vec3;
}

export interface ViewerLoadingState {
  phase: ViewerLoadingPhase;
  progress: number;
  label?: string;
  error?: string;
}

export type ViewerCameraRequest =
  | {
      id: number;
      type: 'preset';
      preset: CameraPresetId;
    }
  | {
      id: number;
      type: 'reset';
    }
  | {
      id: number;
      type: 'snapshot';
      snapshot: CameraSnapshot;
    };

export interface ViewerUrlSnapshot {
  machineId?: string;
  camera?: CameraSnapshot;
  cameraPreset?: CameraPresetId;
  selectedPartId?: string;
  exploded?: Partial<ExplodedViewState>;
  wireframe?: boolean;
  annotations?: boolean;
  crossSection?: Partial<CrossSectionState>;
  hiddenPartIds?: string[];
  partOpacity?: Record<string, number>;
}

export interface PartInteractionPayload {
  partId: string;
  object: Object3D;
  point?: Vec3;
  nativeEvent?: PointerEvent;
}

export interface AssetFactoryContext {
  machineId: string;
  reducedMotion?: boolean;
}