hitung-jarak.js

const axios = require("axios")

async function getCoordinates(city) {
  try {
    const { data } = await axios.get(
      "https://nominatim.openstreetmap.org/search",
      {
        params: {
          q: city,
          format: "json",
          limit: 1,
          countrycodes: "id",
        },
        headers: {
          "User-Agent": "KawaiiYumeeAPI/1.0",
        },
        timeout: 8000,
      }
    )

    if (!data || !data.length) return null

    return {
      lat: parseFloat(data[0].lat),
      lon: parseFloat(data[0].lon),
      display_name: data[0].display_name,
    }
  } catch {
    return null
  }
}

function haversine(lat1, lon1, lat2, lon2) {
  const R = 6371

  const dLat = ((lat2 - lat1) * Math.PI) / 180
  const dLon = ((lon2 - lon1) * Math.PI) / 180

  const a =
    Math.sin(dLat / 2) ** 2 +
    Math.cos((lat1 * Math.PI) / 180) *
      Math.cos((lat2 * Math.PI) / 180) *
      Math.sin(dLon / 2) ** 2

  const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))
  return R * c
}

function formatJarak(km) {
  if (km < 1) return `${Math.round(km * 1000)} meter`
  return `${km.toFixed(1)} km`
}

function estimasiWaktu(km) {
  const motor = km / 40
  const mobil = km / 60
  const jalan = km / 5

  const fmt = (jam) => {
    const h = Math.floor(jam)
    const m = Math.round((jam - h) * 60)

    if (h === 0) return `${m} menit`
    if (m === 0) return `${h} jam`
    return `${h} jam ${m} menit`
  }

  return {
    motor: fmt(motor),
    mobil: fmt(mobil),
    jalan_kaki: fmt(jalan),
  }
}

async function hitungJarak(kota1, kota2) {
  const [loc1, loc2] = await Promise.all([
    getCoordinates(kota1),
    getCoordinates(kota2),
  ])

  if (!loc1) throw new Error(`Kota '${kota1}' tidak ditemukan`)
  if (!loc2) throw new Error(`Kota '${kota2}' tidak ditemukan`)

  const km = haversine(loc1.lat, loc1.lon, loc2.lat, loc2.lon)

  return {
    dari: {
      nama: kota1,
      lokasi: loc1.display_name,
      koordinat: { lat: loc1.lat, lon: loc1.lon },
    },
    ke: {
      nama: kota2,
      lokasi: loc2.display_name,
      koordinat: { lat: loc2.lat, lon: loc2.lon },
    },
    jarak: formatJarak(km),
    jarak_km: parseFloat(km.toFixed(2)),
    estimasi_waktu: estimasiWaktu(km),
  }
}
;(async () => {
  try {
    const result = await hitungJarak("Solo", "Yogyakarta")
    console.log(result)
  } catch (e) {
    console.log({ status: false, message: e.message })
  }
})()

module.exports = hitungJarak