import { describe, expect, it } from 'vitest'
import { haversineKm, legKm, summarize } from '../../server/utils/transitous'

const PARIS = { lat: 48.8566, lon: 2.3522 }
const LYON = { lat: 45.764, lon: 4.8357 }

describe('haversineKm', () => {
  it('mesure Paris-Lyon a environ 392 km a vol d oiseau', () => {
    const km = haversineKm(PARIS, LYON)
    expect(km).toBeGreaterThan(388)
    expect(km).toBeLessThan(396)
  })

  it('renvoie zero entre un point et lui-meme', () => {
    expect(haversineKm(PARIS, PARIS)).toBe(0)
  })
})

describe('legKm', () => {
  const base = { mode: 'RAIL', startTime: '', endTime: '', from: PARIS, to: LYON }

  it('utilise la distance fournie quand elle existe', () => {
    expect(legKm({ ...base, distance: 465000 })).toBe(465)
  })

  it('retombe sur le calcul geometrique quand la distance manque', () => {
    expect(legKm(base)).toBeCloseTo(haversineKm(PARIS, LYON), 5)
  })
})

describe('summarize', () => {
  const leg = (mode: string, distance: number) => ({
    mode,
    distance,
    startTime: '',
    endTime: '',
    from: PARIS,
    to: PARIS,
  })

  it('applique a chaque troncon son propre facteur d emission', () => {
    // 10 km de metro a 4,1 g + 400 km de TGV a 2,4 g
    const r = summarize({ duration: 7200, transfers: 1, legs: [leg('SUBWAY', 10000), leg('HIGHSPEED_RAIL', 400000)] }, 'train')
    expect(r.co2Grams).toBe(1001)
    expect(r.distanceKm).toBe(410)
    expect(r.durationMin).toBe(120)
  })

  it('ne compte pas la marche dans les emissions', () => {
    const r = summarize({ duration: 600, transfers: 0, legs: [leg('WALK', 2000)] }, 'bus')
    expect(r.co2Grams).toBe(0)
  })

  it('prend le facteur le plus penalisant pour un mode inconnu', () => {
    // Mieux vaut surestimer que de laisser croire a un trajet propre.
    const r = summarize({ duration: 600, transfers: 0, legs: [leg('TELEPORTATION', 10000)] }, 'bus')
    expect(r.co2Grams).toBe(1130)
  })
})