import { describe, it, expect } from 'vitest'
import { parseQuery } from '@/lib/utm'

function params(obj: Record<string, string>): URLSearchParams {
  return new URLSearchParams(obj)
}

describe('parseQuery', () => {
  it('extracts all whitelisted UTM params', () => {
    const result = parseQuery(
      params({
        utm_source: 'google',
        utm_medium: 'cpc',
        utm_campaign: 'summer',
        utm_content: 'banner',
        utm_term: 'shoes',
        gclid: 'abc123',
      })
    )
    expect(result).toEqual({
      utm_source: 'google',
      utm_medium: 'cpc',
      utm_campaign: 'summer',
      utm_content: 'banner',
      utm_term: 'shoes',
      gclid: 'abc123',
    })
  })

  it('returns empty object when no UTM params are present', () => {
    expect(parseQuery(params({ page: '1', foo: 'bar' }))).toEqual({})
  })

  it('ignores non-whitelisted params', () => {
    const result = parseQuery(params({ utm_source: 'fb', referrer: 'https://example.com' }))
    expect(result).toEqual({ utm_source: 'fb' })
    expect(result).not.toHaveProperty('referrer')
  })

  it('omits params with empty string values', () => {
    // URLSearchParams.get returns '' for empty value — the lib checks `if (value)` so it skips
    const result = parseQuery(params({ utm_source: '', utm_medium: 'email' }))
    expect(result).not.toHaveProperty('utm_source')
    expect(result.utm_medium).toBe('email')
  })

  it('handles only gclid present', () => {
    expect(parseQuery(params({ gclid: 'Cj0KCQ' }))).toEqual({ gclid: 'Cj0KCQ' })
  })

  it('handles empty URLSearchParams', () => {
    expect(parseQuery(new URLSearchParams())).toEqual({})
  })

  it('returns a partial object when only some UTM params are present', () => {
    const result = parseQuery(params({ utm_source: 'newsletter', utm_campaign: 'may' }))
    expect(result).toEqual({ utm_source: 'newsletter', utm_campaign: 'may' })
    expect(Object.keys(result)).toHaveLength(2)
  })
})