import { describe, expect, it } from 'bun:test';
import {
  formatCurrencyByScale,
  formatFinancialStatementValue,
  formatScaledNumber
} from './format';

describe('formatScaledNumber', () => {
  it('keeps values below one thousand unscaled', () => {
    expect(formatScaledNumber(950)).toBe('950');
    expect(formatScaledNumber(950.44, { maximumFractionDigits: 2 })).toBe('950.44');
  });

  it('scales thousands with K suffix', () => {
    expect(formatScaledNumber(12_345)).toBe('12.3K');
  });

  it('scales millions with M suffix', () => {
    expect(formatScaledNumber(3_250_000)).toBe('3.3M');
  });

  it('scales billions with B suffix', () => {
    expect(formatScaledNumber(7_500_000_000)).toBe('7.5B');
  });

  it('preserves negative sign when scaled', () => {
    expect(formatScaledNumber(-2_750_000)).toBe('-2.8M');
  });

  it('promotes rounded values to the next scale when needed', () => {
    expect(formatScaledNumber(999_950)).toBe('1M');
  });
});

describe('formatCurrencyByScale', () => {
  it('formats values in thousands', () => {
    expect(formatCurrencyByScale(12_345, 'thousands')).toBe('$12.3K');
  });

  it('formats values in millions', () => {
    expect(formatCurrencyByScale(12_345_678, 'millions')).toBe('$12.3M');
  });

  it('formats values in billions', () => {
    expect(formatCurrencyByScale(12_345_678_901, 'billions')).toBe('$12.3B');
  });

  it('keeps sign for negative values', () => {
    expect(formatCurrencyByScale(-2_500_000, 'millions')).toBe('-$2.5M');
  });
});

describe('formatFinancialStatementValue', () => {
  it('renders null statement values as em dashes', () => {
    expect(formatFinancialStatementValue({
      value: null,
      unit: 'currency',
      scale: 'millions',
      rowKey: 'revenue',
      surfaceKind: 'income_statement'
    })).toBe('—');
  });

  it('formats scaled currency values without a currency symbol', () => {
    expect(formatFinancialStatementValue({
      value: 15_940_899_000,
      unit: 'currency',
      scale: 'millions',
      rowKey: 'revenue',
      surfaceKind: 'income_statement'
    })).toBe('15,940.9');
    expect(formatFinancialStatementValue({
      value: 1_100_000_000,
      unit: 'currency',
      scale: 'millions',
      rowKey: 'long_term_debt_issued',
      surfaceKind: 'cash_flow_statement'
    })).toBe('1,100');
  });

  it('keeps extra precision for per-share rows', () => {
    expect(formatFinancialStatementValue({
      value: 14.64,
      unit: 'currency',
      scale: 'millions',
      rowKey: 'diluted_eps',
      surfaceKind: 'income_statement'
    })).toBe('14.64');
  });

  it('formats statement percents and ratios with trimmed precision', () => {
    expect(formatFinancialStatementValue({
      value: 0.233,
      unit: 'percent',
      scale: 'millions',
      rowKey: 'effective_tax_rate',
      surfaceKind: 'income_statement'
    })).toBe('23.3%');
    expect(formatFinancialStatementValue({
      value: 1.5,
      unit: 'ratio',
      scale: 'millions',
      rowKey: 'debt_to_equity',
      surfaceKind: 'ratios'
    })).toBe('1.5x');
  });
});