export const MACHINE_CATEGORIES = [
  'Engines',
  'Gearboxes & Drives',
  'Pumps & Fluid Systems',
  'Mechanisms',
  'Structural / Other'
] as const;

export type MachineCategory = (typeof MACHINE_CATEGORIES)[number];

export const DIFFICULTIES = ['Beginner', 'Intermediate', 'Advanced'] as const;

export type Difficulty = (typeof DIFFICULTIES)[number];

export const RELEASE_PHASES = ['core', 'stretch'] as const;

export type ReleasePhase = (typeof RELEASE_PHASES)[number];

export const SORT_OPTIONS = [
  {
    value: 'name',
    label: 'Name A–Z',
    description: 'Alphabetical by machine title'
  },
  {
    value: 'newest',
    label: 'Newest',
    description: 'Most recently added to the reference catalogue'
  },
  {
    value: 'complexity',
    label: 'Complexity',
    description: 'Highest engineering complexity first'
  }
] as const;

export type SortKey = (typeof SORT_OPTIONS)[number]['value'];

export const CATALOGUE_VIEW_MODES = ['comfortable', 'compact'] as const;

export type CatalogueViewMode = (typeof CATALOGUE_VIEW_MODES)[number];

export type ThumbnailVariant =
  | 'inline-engine'
  | 'vee-engine'
  | 'rotary'
  | 'turbine'
  | 'geartrain'
  | 'pump'
  | 'mechanism'
  | 'bearing'
  | 'brake'
  | 'electric'
  | 'fluid';

export interface ThumbnailConfig {
  readonly variant: ThumbnailVariant;
  readonly accent: string;
  readonly secondary?: string;
  readonly background?: string;
}

export interface MachineFact {
  readonly label: string;
  readonly value: string;
  readonly unit?: string;
  readonly tone?: 'neutral' | 'accent' | 'warm' | 'success' | 'warning';
}

export interface MachinePart {
  readonly id: string;
  readonly name: string;
  readonly description: string;
  readonly material?: string;
  readonly function?: string;
  readonly defaultVisible?: boolean;
  readonly defaultOpacity?: number;
  readonly specs?: readonly MachineFact[];
}

export interface MachineRegistryItem {
  readonly id: string;
  readonly slug: string;
  readonly title: string;
  readonly subtitle: string;
  readonly shortDescription: string;
  readonly description: string;
  readonly category: MachineCategory;
  readonly difficulty: Difficulty;
  readonly releasePhase: ReleasePhase;
  readonly publishedAt: string;
  readonly complexity: number;
  readonly estimatedPartCount: number;
  readonly tags: readonly string[];
  readonly keywords: readonly string[];
  readonly thumbnail: ThumbnailConfig;
  readonly facts: readonly MachineFact[];
  readonly parts: readonly MachinePart[];
  readonly applications: readonly string[];
  readonly learningObjectives: readonly string[];
  readonly relatedSlugs: readonly string[];
}

export interface CatalogueFilters {
  readonly query: string;
  readonly categories: readonly MachineCategory[];
  readonly difficulties: readonly Difficulty[];
  readonly phases: readonly ReleasePhase[];
  readonly sort: SortKey;
  readonly favouritesOnly: boolean;
}