import { describe, it, expect } from 'vitest'
import { validateCurrencyCode, validateAmount, validateConvertParams, validateExchangeRatesParams } from '../utils/validation'
import { ValidationError, InvalidCurrencyError } from '../errors'

describe('Validation', () => {
  describe('validateCurrencyCode', () => {
    it('should pass for valid currency codes', () => {
      expect(() => validateCurrencyCode('USD')).not.toThrow()
      expect(() => validateCurrencyCode('EUR')).not.toThrow()
      expect(() => validateCurrencyCode('GBP')).not.toThrow()
    })

    it('should throw for invalid currency codes', () => {
      expect(() => validateCurrencyCode('INVALID')).toThrow(InvalidCurrencyError)
      expect(() => validateCurrencyCode('')).toThrow(ValidationError)
      expect(() => validateCurrencyCode('12345')).toThrow(InvalidCurrencyError)
    })
  })

  describe('validateAmount', () => {
    it('should pass for valid amounts', () => {
      expect(() => validateAmount(100)).not.toThrow()
      expect(() => validateAmount(0)).not.toThrow()
      expect(() => validateAmount(99.99)).not.toThrow()
    })

    it('should throw for invalid amounts', () => {
      expect(() => validateAmount(-100)).toThrow(ValidationError)
      expect(() => validateAmount(NaN)).toThrow(ValidationError)
    })
  })

  describe('validateConvertParams', () => {
    it('should pass for valid parameters', () => {
      expect(() =>
        validateConvertParams({
          amount: 100,
          from: 'USD',
          to: 'EUR',
        })
      ).not.toThrow()
    })

    it('should throw for invalid parameters', () => {
      expect(() =>
        validateConvertParams({
          amount: -100,
          from: 'USD',
          to: 'EUR',
        })
      ).toThrow(ValidationError)

      expect(() =>
        validateConvertParams({
          amount: 100,
          from: 'INVALID',
          to: 'EUR',
        })
      ).toThrow(InvalidCurrencyError)

      expect(() =>
        validateConvertParams({
          amount: 100,
          from: 'USD',
          to: 'USD',
        })
      ).toThrow(ValidationError)
    })
  })

  describe('validateExchangeRatesParams', () => {
    it('should pass for valid parameters', () => {
      expect(() =>
        validateExchangeRatesParams({
          base: 'USD',
          codes: ['EUR', 'GBP'],
        })
      ).not.toThrow()

      expect(() => validateExchangeRatesParams()).not.toThrow()
    })

    it('should throw for invalid parameters', () => {
      expect(() =>
        validateExchangeRatesParams({
          base: 'INVALID',
        })
      ).toThrow(InvalidCurrencyError)

      expect(() =>
        validateExchangeRatesParams({
          base: 'USD',
          codes: ['INVALID'],
        })
      ).toThrow(InvalidCurrencyError)
    })
  })
})