From 7ca7ae49a598e8d3bbd506e5deb6180c83003e0c Mon Sep 17 00:00:00 2001
From: Stefano Pigozzi <me@steffo.eu>
Date: Sat, 22 May 2021 03:50:04 +0200
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Add=20Coordinates=20class=20and=20s?=
 =?UTF-8?q?ome=20tests?=
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---
 nest_frontend/objects/Condition.test.js |  6 ++--
 nest_frontend/objects/Coordinates.js    | 42 +++++++++++++++++++++++++
 nest_frontend/objects/MapArea.js        | 39 ++++++++++++++++-------
 nest_frontend/objects/MapArea.test.js   | 13 ++++++++
 4 files changed, 85 insertions(+), 15 deletions(-)
 create mode 100644 nest_frontend/objects/Coordinates.js
 create mode 100644 nest_frontend/objects/MapArea.test.js

diff --git a/nest_frontend/objects/Condition.test.js b/nest_frontend/objects/Condition.test.js
index 7fe651b..ee838af 100644
--- a/nest_frontend/objects/Condition.test.js
+++ b/nest_frontend/objects/Condition.test.js
@@ -1,7 +1,7 @@
-import "@testing-library/jest-dom/extend-expect"
 import { Condition, ConditionHashtag, ConditionLocation, ConditionTime, ConditionUser } from "./Condition"
 import TimeRay from "./TimeRay"
 import MapArea from "./MapArea"
+import Coordinates from "./Coordinates"
 
 
 test("Condition can be constructed", () => {
@@ -28,7 +28,7 @@ test("ConditionTime can be constructed", () => {
 })
 
 test("ConditionLocation can be constructed", () => {
-    const mapArea = new MapArea(1000, 0.000, 0.000)
+    const mapArea = new MapArea(1000, new Coordinates(0.000, 0.000))
 
     expect(new ConditionLocation(mapArea)).toBeTruthy()
     expect(new ConditionLocation(mapArea, 1)).toBeTruthy()
@@ -50,7 +50,7 @@ test("ConditionTime has the correct type", () => {
 })
 
 test("ConditionLocation has the correct type", () => {
-    const mapArea = new MapArea(1000, 0.000, 0.000)
+    const mapArea = new MapArea(1000, new Coordinates(0.000, 0.000))
 
     expect(new ConditionLocation(mapArea).type).toBe(3)
 })
diff --git a/nest_frontend/objects/Coordinates.js b/nest_frontend/objects/Coordinates.js
new file mode 100644
index 0000000..9f4868a
--- /dev/null
+++ b/nest_frontend/objects/Coordinates.js
@@ -0,0 +1,42 @@
+/**
+ * A pair of coordinates, latitude `lat` and longitude `lng`.
+ */
+export default class Coordinates {
+    lat
+    lng
+
+    /**
+     * @param lat - Latitude.
+     * @param lng - Longitude.
+     */
+    constructor(lat, lng) {
+        this.lat = lat
+        this.lng = lng
+    }
+
+    /**
+     * @returns {string}
+     */
+    toString() {
+        return `${this.lat.toFixed(7)} ${this.lng.toFixed(7)}`
+    }
+
+    /**
+     * Render the Coordinates as an human-readable string.
+     *
+     * @returns {string}
+     */
+    toHumanString() {
+        return `${this.lat.toFixed(3)} ${this.lng.toFixed(3)}`
+    }
+
+    /**
+     * Transform the object in a Geolib compatible-one.
+     */
+    toGeolib() {
+        return {
+            latitude: this.lat,
+            longitude: this.lng,
+        }
+    }
+}
diff --git a/nest_frontend/objects/MapArea.js b/nest_frontend/objects/MapArea.js
index 4d23de4..9bd5b9e 100644
--- a/nest_frontend/objects/MapArea.js
+++ b/nest_frontend/objects/MapArea.js
@@ -1,23 +1,27 @@
+import {getDistance} from "geolib"
+
+
 /**
- * An area on a map, defined by a latitude `lat`, a longitude `lng` and a radius `rad` in meters.
+ * An area on a map, defined by a `center` and a `radius` in meters.
  */
 export default class MapArea {
+    radius
+    center
+
     /**
-     * @param rad - Radius of the area in meters.
-     * @param lat - Latitude of the center of the radius.
-     * @param lng - Longitude of the center of the radius.
+     * @param radius - The radius of the area in meters.
+     * @param center - The center of the area.
      */
-    constructor(rad, lat, lng) {
-        this.rad = rad
-        this.lat = lat
-        this.lng = lng
+    constructor(radius, center) {
+        this.radius = radius
+        this.center = center
     }
 
     /**
      * @returns {string}
      */
     toString() {
-        return `${this.rad} ${this.lat.toFixed(7)} ${this.lng.toFixed(7)}`
+        return `${this.radius} ${this.center.toString()}`
     }
 
     /**
@@ -26,9 +30,20 @@ export default class MapArea {
      * @returns {string}
      */
     toHumanString() {
-        if(this.rad >= 2000) {
-            const kmRadius = Math.round(this.rad / 1000)
-            return `${kmRadius}km ${this.lat.toFixed(3)} ${this.lng.toFixed(3)}`
+        if(this.radius >= 2000) {
+            const kmRadius = Math.round(this.radius / 1000)
+            return `${kmRadius}km ${this.center.toHumanString()}`
         }
+        return `${this.radius}m ${this.center.toHumanString()}`
+    }
+
+    /**
+     * Check if a pair of coordinates is included in the area.
+     *
+     * @param coords - The coordinates to check.
+     * @returns {boolean}
+     */
+    includes(coords) {
+        return getDistance(this.center.toGeolib(), coords.toGeolib()) <= this.radius
     }
 }
diff --git a/nest_frontend/objects/MapArea.test.js b/nest_frontend/objects/MapArea.test.js
new file mode 100644
index 0000000..409f015
--- /dev/null
+++ b/nest_frontend/objects/MapArea.test.js
@@ -0,0 +1,13 @@
+import Coordinates from "./Coordinates"
+import MapArea from "./MapArea"
+
+
+test("MapArea can be constructed", () => {
+    const mapArea = new MapArea(1000, new Coordinates(0.0, 0.0))
+    expect(mapArea).toBeTruthy()
+})
+
+test("MapArea can be rendered to a spec-compatible string", () => {
+    const mapArea = new MapArea(1000, new Coordinates(0.0, 0.0))
+    expect(mapArea.toString()).toBe("1000 0.0000000 0.0000000")
+})