import type { Signal, AssetType, RateRegime } from '../types';

export const SIGNAL = {
  STRONG_BUY: '✅ Strong Buy' as Signal,
  MOMENTUM: '⚡ Momentum' as Signal,
  SPECULATION: '⚠️  Speculation' as Signal,
  NEUTRAL: '🔄 Neutral' as Signal,
  AVOID: '❌ Avoid' as Signal,
};

export const ASSET_TYPE = {
  STOCK: 'STOCK' as AssetType,
  ETF: 'ETF' as AssetType,
  BOND: 'BOND' as AssetType,
  CRYPTO: 'crypto',
};

// ── Why some constants use `as const` and others don't ────────────────────
//
// SIGNAL / ASSET_TYPE / REGIME — each member is individually cast to its
// named type (e.g. `'✅ Strong Buy' as Signal`).  TypeScript already knows
// the exact literal type of each value, so `as const` on the object would
// be redundant.
//
// SECTOR / SCORE_MODE / CAP_CATEGORY / GROWTH_CATEGORY — these use
// `as const` because their public type aliases are *derived* from the
// object itself via `(typeof X)[keyof typeof X]`.  Without `as const`,
// TypeScript widens every value to `string`, and the derived union
// collapses to `string` instead of `'TECHNOLOGY' | 'REIT' | ...`.
// ──────────────────────────────────────────────────────────────────────────

export const SECTOR = {
  TECHNOLOGY: 'TECHNOLOGY',
  REIT: 'REIT',
  FINANCIAL: 'FINANCIAL',
  ENERGY: 'ENERGY',
  HEALTHCARE: 'HEALTHCARE',
  COMMUNICATION: 'COMMUNICATION',
  CONSUMER_STAPLES: 'CONSUMER_STAPLES',
  CONSUMER_DISCRETIONARY: 'CONSUMER_DISCRETIONARY',
  GENERAL: 'GENERAL',
} as const;

export type Sector = (typeof SECTOR)[keyof typeof SECTOR];

export const SCORE_MODE = {
  FUNDAMENTAL: 'FUNDAMENTAL',
  INFLATED: 'INFLATED',
} as const;

export const REGIME = {
  LOW: 'LOW' as RateRegime,
  NORMAL: 'NORMAL' as RateRegime,
  HIGH: 'HIGH' as RateRegime,
};

export const YAHOO_MODULES: string[] = [
  'assetProfile',
  'financialData',
  'defaultKeyStatistics',
  'price',
  'summaryDetail',
  'fundProfile', // categoryName drives ETF vs bond-fund classification in DataMapper
];

export const SIGNAL_ORDER: Record<string, number> = {
  [SIGNAL.STRONG_BUY]: 0,
  [SIGNAL.MOMENTUM]: 1,
  [SIGNAL.NEUTRAL]: 2,
  [SIGNAL.SPECULATION]: 3,
  [SIGNAL.AVOID]: 4,
};

// ── Market capitalisation tiers ───────────────────────────────────────────
// Thresholds follow institutional convention (MSCI/Russell definitions).
export const CAP_CATEGORY = {
  MEGA: 'Mega Cap', // > $200B
  LARGE: 'Large Cap', // $10B – $200B
  MID: 'Mid Cap', // $2B – $10B
  SMALL: 'Small Cap', // $300M – $2B
  MICRO: 'Micro Cap', // < $300M
} as const;

export type CapCategory = (typeof CAP_CATEGORY)[keyof typeof CAP_CATEGORY];

// ── Growth / style classification ─────────────────────────────────────────
// Derived from revenue growth, earnings growth, and dividend yield.
// Used for display and to contextualise signals within each cap tier.
export const GROWTH_CATEGORY = {
  HIGH_GROWTH: 'High Growth', // rev >15% or earnings >20%
  MODERATE_GROWTH: 'Growth', // rev 5–15%
  STABLE: 'Stable', // low growth, modest or no dividend
  VALUE: 'Value', // low growth + dividend yield ≥ 3%
  TURNAROUND: 'Turnaround', // negative earnings, positive revenue
  DECLINING: 'Declining', // negative revenue growth
} as const;

export type GrowthCategory = (typeof GROWTH_CATEGORY)[keyof typeof GROWTH_CATEGORY];