Untuk **ambil alamat dari longitude–latitude** itu namanya **reverse geocoding**.
Ada beberapa cara, tergantung mau **pakai API online** atau **offline**.

---

## ✅ Cara PALING UMUM: Google Maps Reverse Geocoding

### Contoh koordinat

```
lat = -6.200000
lng = 106.816666
```

---

### 🔹 JavaScript (fetch)

```js
const lat = -6.2;
const lng = 106.816666;
const apiKey = "API_KEY_KAMU";

fetch(`https://maps.googleapis.com/maps/api/geocode/json?latlng=${lat},${lng}&key=${apiKey}`)
  .then(res => res.json())
  .then(data => {
    console.log(data.results[0].formatted_address);
  });
```

📌 Output contoh:

```
Jakarta, Daerah Khusus Ibukota Jakarta, Indonesia
```

---

### 🔹 Response penting dari Google

```json
{
  "formatted_address": "Jl. MH Thamrin No.1, Jakarta Pusat, Indonesia",
  "address_components": [
    { "long_name": "Jakarta Pusat", "types": ["administrative_area_level_2"] }
  ]
}
```

---

## ✅ Alternatif GRATIS (tanpa API key): OpenStreetMap (Nominatim)

⚠️ Ada rate limit (jangan spam)

### JavaScript

```js
fetch(`https://nominatim.openstreetmap.org/reverse?lat=-6.2&lon=106.816666&format=json`)
  .then(res => res.json())
  .then(data => {
    console.log(data.display_name);
  });
```

📌 Output:

```
Jakarta Pusat, DKI Jakarta, Indonesia
```

---

## ✅ Flutter (sering dipakai di mobile)

### Pakai `geocoding` package

```dart
import 'package:geocoding/geocoding.dart';

List<Placemark> placemarks =
    await placemarkFromCoordinates(-6.2, 106.816666);

Placemark place = placemarks.first;

print(place.street);
print(place.locality);
print(place.country);
```

---

## ✅ Golang (pakai OpenStreetMap)

```go
resp, _ := http.Get(
  "https://nominatim.openstreetmap.org/reverse?lat=-6.2&lon=106.816666&format=json",
)
defer resp.Body.Close()

var result map[string]interface{}
json.NewDecoder(resp.Body).Decode(&result)

fmt.Println(result["display_name"])
```

---

## ⚠️ Penting diketahui

* Reverse geocoding **tidak 100% presisi**
* Bisa beda hasil antar provider
* Google = paling akurat, tapi **berbayar**
* OSM = gratis, tapi **lebih lambat**

---

## 🔥 Mau hasil lebih detail?

Kamu bisa ambil:

* Jalan
* Kecamatan
* Kota
* Provinsi
* Kode pos

Tinggal bilang:

* **pakai bahasa apa** (JS / Flutter / Go)
* **provider** (Google / OSM / Mapbox)
* mau **online atau offline**

Nanti aku bikinin contoh **siap copy–paste** 👍