From 484b96440e432dcdefd6ced42221ef8cc667162c Mon Sep 17 00:00:00 2001
From: Sarah Persov <s.persov@gmail.com>
Date: Sat, 26 Jun 2021 16:25:16 +0100
Subject: [PATCH 1/8] task 2 completed: implemented http client, gets and
 returns all the names as a string

---
 .../PaymentsenseCodingChallengeController.cs       | 14 ++++++++++----
 .../Models/CountryModel.cs                         | 13 +++++++++++++
 .../Models/CurrencyModel.cs                        |  9 +++++++++
 .../Paymentsense.Coding.Challenge.Api.csproj       |  1 -
 4 files changed, 32 insertions(+), 5 deletions(-)
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CurrencyModel.cs

diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/PaymentsenseCodingChallengeController.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/PaymentsenseCodingChallengeController.cs
index d7ced3c..4bf244b 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/PaymentsenseCodingChallengeController.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/PaymentsenseCodingChallengeController.cs
@@ -1,4 +1,6 @@
-using Microsoft.AspNetCore.Mvc;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc;
 
 namespace Paymentsense.Coding.Challenge.Api.Controllers
 {
@@ -7,9 +9,13 @@ namespace Paymentsense.Coding.Challenge.Api.Controllers
     public class PaymentsenseCodingChallengeController : ControllerBase
     {
         [HttpGet]
-        public ActionResult<string> Get()
+        public async Task<ActionResult<string>> Get()
         {
-            return Ok("Paymentsense Coding Challenge!");
+            var client = new HttpClient();
+            var res = await client.GetAsync("https://restcountries.eu/rest/v2/all?fields=name");
+            var resRaw = await res.Content.ReadAsStringAsync();
+
+            return Ok(resRaw);
         }
     }
-}
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
new file mode 100644
index 0000000..115aa13
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
@@ -0,0 +1,13 @@
+namespace Paymentsense.Coding.Challenge.Api.Models
+{
+    public class CountryModel
+    {
+        public CurrencyModel[] currencies { get; set; }
+        public string flag { get; set; }
+        public string name { get; set; }
+        public string capital { get; set; }
+        public int population { get; set; }
+        public string[] timezones { get; set; }
+        public string[] borders { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CurrencyModel.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CurrencyModel.cs
new file mode 100644
index 0000000..86db493
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CurrencyModel.cs
@@ -0,0 +1,9 @@
+namespace Paymentsense.Coding.Challenge.Api.Models
+{
+    public class CurrencyModel
+    {
+        public string code { get; set; }
+        public string name { get; set; }
+        public string symbol { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Paymentsense.Coding.Challenge.Api.csproj b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Paymentsense.Coding.Challenge.Api.csproj
index 1d82fb7..7bde099 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Paymentsense.Coding.Challenge.Api.csproj
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Paymentsense.Coding.Challenge.Api.csproj
@@ -6,7 +6,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Folder Include="Models\" />
     <Folder Include="Services\" />
   </ItemGroup>
 

From e28582f7c8514c359f9484ffb96584112a9e55ba Mon Sep 17 00:00:00 2001
From: Sarah Persov <s.persov@gmail.com>
Date: Sat, 26 Jun 2021 22:30:54 +0100
Subject: [PATCH 2/8] refactored for the get countries to be in its own
 controller

---
 .../Controllers/CountriesController.cs        | 37 +++++++++++++++++++
 .../PaymentsenseCodingChallengeController.cs  | 12 ++----
 .../Models/CountryModel.cs                    | 20 ++++++----
 .../Models/CurrencyModel.cs                   | 10 +++--
 4 files changed, 58 insertions(+), 21 deletions(-)
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs

diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs
new file mode 100644
index 0000000..c3a90a1
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs
@@ -0,0 +1,37 @@
+using Microsoft.AspNetCore.Mvc;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Text.Json;
+using System.Threading.Tasks;
+using Paymentsense.Coding.Challenge.Api.Models;
+
+namespace Paymentsense.Coding.Challenge.Api.Controllers
+{
+    [ApiController]
+    [Route("[controller]")]
+    public class CountriesController : ControllerBase
+    {
+        private static List<CountryModel> Countries { get; set; } = new List<CountryModel>();
+
+        [HttpGet]
+        public async Task<ActionResult<string>> Get()
+        {
+            if (Countries.Count == 0)
+            {
+                await PopulateCountries();
+            }
+
+            return Ok(Countries);
+        }
+
+
+        private static async Task PopulateCountries()
+        {
+            using var client = new HttpClient();
+            var responseStream = client.GetStreamAsync(
+                "https://restcountries.eu/rest/v2/all?fields=name;flag;population;timezones;currencies;language;capital;borders");
+
+            Countries = await JsonSerializer.DeserializeAsync<List<CountryModel>>(await responseStream);
+        }
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/PaymentsenseCodingChallengeController.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/PaymentsenseCodingChallengeController.cs
index 4bf244b..35feee9 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/PaymentsenseCodingChallengeController.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/PaymentsenseCodingChallengeController.cs
@@ -1,6 +1,4 @@
-using System.Net.Http;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc;
 
 namespace Paymentsense.Coding.Challenge.Api.Controllers
 {
@@ -9,13 +7,9 @@ namespace Paymentsense.Coding.Challenge.Api.Controllers
     public class PaymentsenseCodingChallengeController : ControllerBase
     {
         [HttpGet]
-        public async Task<ActionResult<string>> Get()
+        public ActionResult<string> Get()
         {
-            var client = new HttpClient();
-            var res = await client.GetAsync("https://restcountries.eu/rest/v2/all?fields=name");
-            var resRaw = await res.Content.ReadAsStringAsync();
-
-            return Ok(resRaw);
+            return Ok("Paymentsense Coding Challenge!");
         }
     }
 }
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
index 115aa13..0ce0409 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
@@ -1,13 +1,17 @@
-namespace Paymentsense.Coding.Challenge.Api.Models
+using System.Text.Json.Serialization;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Paymentsense.Coding.Challenge.Api.Models
 {
+    [BindProperties(SupportsGet = true)]
     public class CountryModel
     {
-        public CurrencyModel[] currencies { get; set; }
-        public string flag { get; set; }
-        public string name { get; set; }
-        public string capital { get; set; }
-        public int population { get; set; }
-        public string[] timezones { get; set; }
-        public string[] borders { get; set; }
+        [JsonPropertyName("currencies")] public CurrencyModel[] Currencies { get; set; }
+        [JsonPropertyName("flag")] public string Flag { get; set; }
+        [JsonPropertyName("name")] public string Name { get; set; }
+        [JsonPropertyName("capital")] public string Capital { get; set; }
+        [JsonPropertyName("population")] public int Population { get; set; }
+        [JsonPropertyName("timezones")] public string[] Timezones { get; set; }
+        [JsonPropertyName("borders")] public string[] Borders { get; set; }
     }
 }
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CurrencyModel.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CurrencyModel.cs
index 86db493..fb11d2f 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CurrencyModel.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CurrencyModel.cs
@@ -1,9 +1,11 @@
-namespace Paymentsense.Coding.Challenge.Api.Models
+using System.Text.Json.Serialization;
+
+namespace Paymentsense.Coding.Challenge.Api.Models
 {
     public class CurrencyModel
     {
-        public string code { get; set; }
-        public string name { get; set; }
-        public string symbol { get; set; }
+        [JsonPropertyName("code")] public string Code { get; set; }
+        [JsonPropertyName("name")] public string Name { get; set; }
+        [JsonPropertyName("symbol")] public string Symbol { get; set; }
     }
 }
\ No newline at end of file

From 6e1040ef2ae21956d7397c14ef0685a0b8cf9e23 Mon Sep 17 00:00:00 2001
From: Sarah Persov <s.persov@gmail.com>
Date: Sat, 26 Jun 2021 23:30:50 +0100
Subject: [PATCH 3/8] Implemented Clients & Services, added tests

---
 .../Controllers/CountriesControllerTests.cs   | 45 +++++++++++++++++++
 ...entsense.Coding.Challenge.Api.Tests.csproj |  1 +
 .../Clients/CountriesApiClient.cs             | 20 +++++++++
 .../Clients/CountryCache.cs                   | 20 +++++++++
 .../Clients/ICountriesApiClient.cs            | 11 +++++
 .../Clients/ICountryCache.cs                  | 11 +++++
 .../Controllers/CountriesController.cs        | 24 ++++------
 .../Models/CountryModel.cs                    |  1 +
 .../Models/Language.cs                        |  9 ++++
 .../Paymentsense.Coding.Challenge.Api.csproj  |  4 --
 .../Services/CountriesService.cs              | 35 +++++++++++++++
 .../Services/ICountriesService.cs             | 11 +++++
 12 files changed, 172 insertions(+), 20 deletions(-)
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Controllers/CountriesControllerTests.cs
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/ICountriesApiClient.cs
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/ICountryCache.cs
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/Language.cs
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/CountriesService.cs
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/ICountriesService.cs

diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Controllers/CountriesControllerTests.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Controllers/CountriesControllerTests.cs
new file mode 100644
index 0000000..d88708a
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Controllers/CountriesControllerTests.cs
@@ -0,0 +1,45 @@
+using System.Collections.Generic;
+using FluentAssertions;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Moq;
+using Paymentsense.Coding.Challenge.Api.Controllers;
+using Paymentsense.Coding.Challenge.Api.Models;
+using Paymentsense.Coding.Challenge.Api.Services;
+using Xunit;
+
+namespace Paymentsense.Coding.Challenge.Api.Tests.Controllers
+{
+    public class CountriesControllerTests
+    {
+        [Fact]
+        public async void Get_OnInvoke_ReturnsCountries()
+        {
+            var country = new CountryModel
+            {
+                Name = "Test Country",
+                Flag = "flag",
+                Population = 123456,
+                Timezones = new[] {"UTC", "UTC+01:00"},
+                Languages = new[] {new Language() {Name = "English"}},
+                Currencies = new[] {new CurrencyModel() {Name = "GBP"}},
+                Capital = "London",
+                Borders = new[] {"IRL"}
+            };
+
+            var countriesMock = new List<CountryModel>() {country};
+
+            var mockCountriesService = new Mock<ICountriesService>();
+            mockCountriesService.Setup(c => c.GetCountries()).ReturnsAsync(countriesMock);
+
+            var controller = new CountriesController(mockCountriesService.Object);
+
+            var result = (await controller.Get()).Result as OkObjectResult;
+
+            result.StatusCode.Should().Be(StatusCodes.Status200OK);
+            result.Value.Should().BeOfType<List<CountryModel>>();
+            result.Value.Should().Be(countriesMock);
+            mockCountriesService.Verify(c => c.GetCountries(), Times.Once);
+        }
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Paymentsense.Coding.Challenge.Api.Tests.csproj b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Paymentsense.Coding.Challenge.Api.Tests.csproj
index ba38576..773da86 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Paymentsense.Coding.Challenge.Api.Tests.csproj
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Paymentsense.Coding.Challenge.Api.Tests.csproj
@@ -10,6 +10,7 @@
     <PackageReference Include="FluentAssertions" Version="5.9.0" />
     <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="3.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.3.0" />
+    <PackageReference Include="Moq" Version="4.16.1" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1">
       <PrivateAssets>all</PrivateAssets>
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
new file mode 100644
index 0000000..341035e
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Text.Json;
+using System.Threading.Tasks;
+using Paymentsense.Coding.Challenge.Api.Models;
+
+namespace Paymentsense.Coding.Challenge.Api.Clients
+{
+    internal class CountriesApiClient : ICountriesApiClient
+    {
+        public async Task<List<CountryModel>> GetCountries()
+        {
+            using var client = new HttpClient();
+            var responseStream = client.GetStreamAsync(
+                "https://restcountries.eu/rest/v2/all?fields=name;flag;population;timezones;currencies;languages;capital;borders");
+
+            return await JsonSerializer.DeserializeAsync<List<CountryModel>>(await responseStream);
+        }
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
new file mode 100644
index 0000000..a555b7f
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using Paymentsense.Coding.Challenge.Api.Models;
+
+namespace Paymentsense.Coding.Challenge.Api.Clients
+{
+    public class CountryCache : ICountryCache
+    {
+        public static List<CountryModel> Countries { get; private set; } = new List<CountryModel>();
+
+        public List<CountryModel> GetCountries()
+        {
+            return Countries;
+        }
+
+        public void PopulateCountries(List<CountryModel> countries)
+        {
+            Countries = countries;
+        }
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/ICountriesApiClient.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/ICountriesApiClient.cs
new file mode 100644
index 0000000..c9c793a
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/ICountriesApiClient.cs
@@ -0,0 +1,11 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Paymentsense.Coding.Challenge.Api.Models;
+
+namespace Paymentsense.Coding.Challenge.Api.Clients
+{
+    public interface ICountriesApiClient
+    {
+        public Task<List<CountryModel>> GetCountries();
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/ICountryCache.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/ICountryCache.cs
new file mode 100644
index 0000000..42ea196
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/ICountryCache.cs
@@ -0,0 +1,11 @@
+using System.Collections.Generic;
+using Paymentsense.Coding.Challenge.Api.Models;
+
+namespace Paymentsense.Coding.Challenge.Api.Clients
+{
+    public interface ICountryCache
+    {
+        public List<CountryModel> GetCountries();
+        public void PopulateCountries(List<CountryModel> countries);
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs
index c3a90a1..2823316 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs
@@ -1,9 +1,8 @@
 using Microsoft.AspNetCore.Mvc;
 using System.Collections.Generic;
-using System.Net.Http;
-using System.Text.Json;
 using System.Threading.Tasks;
 using Paymentsense.Coding.Challenge.Api.Models;
+using Paymentsense.Coding.Challenge.Api.Services;
 
 namespace Paymentsense.Coding.Challenge.Api.Controllers
 {
@@ -11,27 +10,20 @@ namespace Paymentsense.Coding.Challenge.Api.Controllers
     [Route("[controller]")]
     public class CountriesController : ControllerBase
     {
-        private static List<CountryModel> Countries { get; set; } = new List<CountryModel>();
+        private readonly ICountriesService _countriesService;
 
-        [HttpGet]
-        public async Task<ActionResult<string>> Get()
+        public CountriesController(ICountriesService countriesService)
         {
-            if (Countries.Count == 0)
-            {
-                await PopulateCountries();
-            }
-
-            return Ok(Countries);
+            _countriesService = countriesService;
         }
 
 
-        private static async Task PopulateCountries()
+        [HttpGet]
+        public async Task<ActionResult<List<CountryModel>>> Get()
         {
-            using var client = new HttpClient();
-            var responseStream = client.GetStreamAsync(
-                "https://restcountries.eu/rest/v2/all?fields=name;flag;population;timezones;currencies;language;capital;borders");
+            var countries = await _countriesService.GetCountries();
 
-            Countries = await JsonSerializer.DeserializeAsync<List<CountryModel>>(await responseStream);
+            return Ok(countries);
         }
     }
 }
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
index 0ce0409..c2ae6bb 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/CountryModel.cs
@@ -13,5 +13,6 @@ public class CountryModel
         [JsonPropertyName("population")] public int Population { get; set; }
         [JsonPropertyName("timezones")] public string[] Timezones { get; set; }
         [JsonPropertyName("borders")] public string[] Borders { get; set; }
+        [JsonPropertyName("languages")] public Language[] Languages { get; set; }
     }
 }
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/Language.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/Language.cs
new file mode 100644
index 0000000..1c95547
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/Language.cs
@@ -0,0 +1,9 @@
+using System.Text.Json.Serialization;
+
+public class Language
+{
+    [JsonPropertyName("iso639_1")] public string Iso6391 { get; set; }
+    [JsonPropertyName("iso639_2")] public string Iso6392 { get; set; }
+    [JsonPropertyName("name")] public string Name { get; set; }
+    [JsonPropertyName("nativeName")] public string NativeName { get; set; }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Paymentsense.Coding.Challenge.Api.csproj b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Paymentsense.Coding.Challenge.Api.csproj
index 7bde099..e699224 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Paymentsense.Coding.Challenge.Api.csproj
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Paymentsense.Coding.Challenge.Api.csproj
@@ -5,8 +5,4 @@
     <StartupObject>Paymentsense.Coding.Challenge.Api.Program</StartupObject>
   </PropertyGroup>
 
-  <ItemGroup>
-    <Folder Include="Services\" />
-  </ItemGroup>
-
 </Project>
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/CountriesService.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/CountriesService.cs
new file mode 100644
index 0000000..dfa349d
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/CountriesService.cs
@@ -0,0 +1,35 @@
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Text.Json;
+using System.Threading.Tasks;
+using Paymentsense.Coding.Challenge.Api.Clients;
+using Paymentsense.Coding.Challenge.Api.Models;
+
+namespace Paymentsense.Coding.Challenge.Api.Services
+{
+    public class CountriesService : ICountriesService
+    {
+        private readonly ICountriesApiClient _countriesApiClient;
+        private readonly ICountryCache _countryCache;
+
+        public CountriesService(ICountryCache cache, ICountriesApiClient countriesApiClient)
+        {
+            _countriesApiClient = countriesApiClient;
+            _countryCache = cache;
+        }
+
+        public async Task<List<CountryModel>> GetCountries()
+        {
+            var countries = _countryCache.GetCountries();
+            if (countries.Count != 0)
+            {
+                return countries;
+            }
+
+            countries = await _countriesApiClient.GetCountries();
+            _countryCache.PopulateCountries(countries);
+
+            return countries;
+        }
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/ICountriesService.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/ICountriesService.cs
new file mode 100644
index 0000000..2bb752b
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/ICountriesService.cs
@@ -0,0 +1,11 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Paymentsense.Coding.Challenge.Api.Models;
+
+namespace Paymentsense.Coding.Challenge.Api.Services
+{
+    public interface ICountriesService
+    {
+        Task<List<CountryModel>> GetCountries();
+    }
+}
\ No newline at end of file

From a74972c4fdb18491c7b5ab73c4f40263755b0c58 Mon Sep 17 00:00:00 2001
From: Sarah Persov <s.persov@gmail.com>
Date: Sat, 26 Jun 2021 23:54:23 +0100
Subject: [PATCH 4/8] Service Tests

---
 ...entsense.Coding.Challenge.Api.Tests.csproj |  4 -
 .../Services/CountriesServiceTests.cs         | 86 +++++++++++++++++++
 2 files changed, 86 insertions(+), 4 deletions(-)
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs

diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Paymentsense.Coding.Challenge.Api.Tests.csproj b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Paymentsense.Coding.Challenge.Api.Tests.csproj
index 773da86..8f766be 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Paymentsense.Coding.Challenge.Api.Tests.csproj
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Paymentsense.Coding.Challenge.Api.Tests.csproj
@@ -22,10 +22,6 @@
     </PackageReference>
   </ItemGroup>
 
-  <ItemGroup>
-    <Folder Include="Services\" />
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\Paymentsense.Coding.Challenge.Api\Paymentsense.Coding.Challenge.Api.csproj" />
   </ItemGroup>
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs
new file mode 100644
index 0000000..bdc6eed
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs
@@ -0,0 +1,86 @@
+using System.Collections.Generic;
+using FluentAssertions;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Moq;
+using Paymentsense.Coding.Challenge.Api.Clients;
+using Paymentsense.Coding.Challenge.Api.Controllers;
+using Paymentsense.Coding.Challenge.Api.Models;
+using Paymentsense.Coding.Challenge.Api.Services;
+using Xunit;
+
+namespace Paymentsense.Coding.Challenge.Api.Tests.Services
+{
+    public class CountriesServiceTests
+    {
+        private readonly List<CountryModel> _countriesMock;
+
+        public CountriesServiceTests()
+        {
+            var country = new CountryModel
+            {
+                Name = "Test Country",
+                Flag = "flag",
+                Population = 123456,
+                Timezones = new[] {"UTC", "UTC+01:00"},
+                Languages = new[] {new Language() {Name = "English"}},
+                Currencies = new[] {new CurrencyModel() {Name = "GBP"}},
+                Capital = "London",
+                Borders = new[] {"IRL"}
+            };
+
+            _countriesMock = new List<CountryModel>() {country};
+        }
+
+        [Fact]
+        public async void GetCountries_OnInvoke_ReturnsCountriesFromApiClientFirstCall()
+        {
+            var mockCountriesApiClient = new Mock<ICountriesApiClient>();
+            mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
+
+            var mockCache = new Mock<ICountryCache>();
+            mockCache.Setup(c => c.GetCountries()).Returns(new List<CountryModel>());
+            var countriesService = new CountriesService(mockCache.Object, mockCountriesApiClient.Object);
+
+            var result = await countriesService.GetCountries();
+
+            result.Should().BeOfType<List<CountryModel>>();
+            result.Should().BeSameAs(_countriesMock);
+            mockCountriesApiClient.Verify(c => c.GetCountries(), Times.Once);
+            mockCache.Verify(c => c.GetCountries(), Times.Once);
+        }
+
+        [Fact]
+        public async void GetCountries_OnInvoke_PopulatesCacheOnFirstCall()
+        {
+            var mockCountriesApiClient = new Mock<ICountriesApiClient>();
+            mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
+
+            var mockCache = new Mock<ICountryCache>();
+            mockCache.Setup(c => c.GetCountries()).Returns(new List<CountryModel>());
+            var countriesService = new CountriesService(mockCache.Object, mockCountriesApiClient.Object);
+
+            var result = await countriesService.GetCountries();
+            mockCache.Verify(c => c.PopulateCountries(result), Times.Once);
+
+            mockCache.Verify(c => c.GetCountries(), Times.Once);
+        }
+
+        [Fact]
+        public async void GetCountries_OnInvoke_ReturnsCountriesFromCacheSecondCall()
+        {
+            var mockCountriesApiClient = new Mock<ICountriesApiClient>();
+
+            var mockCache = new Mock<ICountryCache>();
+            mockCache.Setup(c => c.GetCountries()).Returns(_countriesMock);
+            var countriesService = new CountriesService(mockCache.Object, mockCountriesApiClient.Object);
+
+            var result = await countriesService.GetCountries();
+
+            result.Should().BeOfType<List<CountryModel>>();
+            result.Should().BeSameAs(_countriesMock);
+            mockCountriesApiClient.Verify(c => c.GetCountries(), Times.Never);
+            mockCache.Verify(c => c.GetCountries(), Times.Once);
+        }
+    }
+}
\ No newline at end of file

From 4a46a9adb2525fbf8505d4d1d793c47d661b9c4b Mon Sep 17 00:00:00 2001
From: Sarah Persov <s.persov@gmail.com>
Date: Sat, 26 Jun 2021 23:57:14 +0100
Subject: [PATCH 5/8] Added dependency injection

---
 .../Paymentsense.Coding.Challenge.Api/Startup.cs           | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Startup.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Startup.cs
index 623b8b2..17df845 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Startup.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Startup.cs
@@ -3,6 +3,8 @@
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Paymentsense.Coding.Challenge.Api.Clients;
+using Paymentsense.Coding.Challenge.Api.Services;
 
 namespace Paymentsense.Coding.Challenge.Api
 {
@@ -29,6 +31,9 @@ public void ConfigureServices(IServiceCollection services)
                         .AllowAnyHeader();
                 });
             });
+            services.AddScoped<ICountriesService, CountriesService>();
+            services.AddScoped<ICountriesApiClient, CountriesApiClient>();
+            services.AddScoped<ICountryCache, CountryCache>();
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
@@ -54,4 +59,4 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
             });
         }
     }
-}
+}
\ No newline at end of file

From 7a50be8fc1f20b31d0fa07a847cc0027e1ea5cae Mon Sep 17 00:00:00 2001
From: Sarah Persov <s.persov@gmail.com>
Date: Sun, 27 Jun 2021 00:01:26 +0100
Subject: [PATCH 6/8] Switched http client to dependency injected client

---
 .../Clients/CountriesApiClient.cs                        | 9 ++++++++-
 .../Paymentsense.Coding.Challenge.Api/Startup.cs         | 1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
index 341035e..3a8427a 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
@@ -8,9 +8,16 @@ namespace Paymentsense.Coding.Challenge.Api.Clients
 {
     internal class CountriesApiClient : ICountriesApiClient
     {
+        private readonly IHttpClientFactory _clientFactory;
+
+        public CountriesApiClient(IHttpClientFactory clientFactory)
+        {
+            _clientFactory = clientFactory;
+        }
+
         public async Task<List<CountryModel>> GetCountries()
         {
-            using var client = new HttpClient();
+            using var client = _clientFactory.CreateClient();
             var responseStream = client.GetStreamAsync(
                 "https://restcountries.eu/rest/v2/all?fields=name;flag;population;timezones;currencies;languages;capital;borders");
 
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Startup.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Startup.cs
index 17df845..dd78b1a 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Startup.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Startup.cs
@@ -34,6 +34,7 @@ public void ConfigureServices(IServiceCollection services)
             services.AddScoped<ICountriesService, CountriesService>();
             services.AddScoped<ICountriesApiClient, CountriesApiClient>();
             services.AddScoped<ICountryCache, CountryCache>();
+            services.AddHttpClient();
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

From 804c3703ffa8b8a3b550be424057b037e7ecf4e0 Mon Sep 17 00:00:00 2001
From: Sarah Persov <s.persov@gmail.com>
Date: Sun, 27 Jun 2021 00:49:31 +0100
Subject: [PATCH 7/8] Added Pagination, Cache tests

---
 .../Clients/CountryCacheTests.cs              | 58 +++++++++++++++++++
 .../Controllers/CountriesControllerTests.cs   |  6 +-
 .../Services/CountriesServiceTests.cs         | 47 ++++++++++++---
 .../Clients/CountriesApiClient.cs             |  6 +-
 .../Clients/CountryCache.cs                   |  2 +-
 .../Controllers/CountriesController.cs        |  4 +-
 .../Models/Language.cs                        | 13 +++--
 .../Services/CountriesService.cs              | 17 ++++--
 .../Services/ICountriesService.cs             |  2 +-
 9 files changed, 127 insertions(+), 28 deletions(-)
 create mode 100644 paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Clients/CountryCacheTests.cs

diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Clients/CountryCacheTests.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Clients/CountryCacheTests.cs
new file mode 100644
index 0000000..a1ce762
--- /dev/null
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Clients/CountryCacheTests.cs
@@ -0,0 +1,58 @@
+using System.Collections.Generic;
+using System.Linq;
+using FluentAssertions;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Moq;
+using Paymentsense.Coding.Challenge.Api.Clients;
+using Paymentsense.Coding.Challenge.Api.Controllers;
+using Paymentsense.Coding.Challenge.Api.Models;
+using Paymentsense.Coding.Challenge.Api.Services;
+using Xunit;
+
+namespace Paymentsense.Coding.Challenge.Api.Tests.Clients
+{
+    public class CountryCacheTests
+    {
+        private readonly List<CountryModel> _countriesMock;
+
+        public CountryCacheTests()
+        {
+            var country = new CountryModel
+            {
+                Name = "Test Country",
+                Flag = "flag",
+                Population = 123456,
+                Timezones = new[] {"UTC", "UTC+01:00"},
+                Languages = new[] {new Language() {Name = "English"}},
+                Currencies = new[] {new CurrencyModel() {Name = "GBP"}},
+                Capital = "London",
+                Borders = new[] {"IRL"}
+            };
+
+            _countriesMock = Enumerable.Range(1, 100).Select(x => country).ToList();
+        }
+
+        [Fact]
+        public void GetCountries_ReturnsEmptyList()
+        {
+            var cache = new CountryCache();
+            var result = cache.GetCountries();
+
+            result.Should().BeOfType<List<CountryModel>>();
+            result.Should().HaveCount(0);
+        }
+
+        [Fact]
+        public void PopulateCountries_PopulatesCountries()
+        {
+            var cache = new CountryCache();
+            cache.PopulateCountries(_countriesMock);
+            var result = cache.GetCountries();
+
+            result.Should().BeOfType<List<CountryModel>>();
+            result.Should().HaveCount(_countriesMock.Count);
+            result.Should().BeSameAs(_countriesMock);
+        }
+    }
+}
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Controllers/CountriesControllerTests.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Controllers/CountriesControllerTests.cs
index d88708a..9513d96 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Controllers/CountriesControllerTests.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Controllers/CountriesControllerTests.cs
@@ -30,16 +30,16 @@ public async void Get_OnInvoke_ReturnsCountries()
             var countriesMock = new List<CountryModel>() {country};
 
             var mockCountriesService = new Mock<ICountriesService>();
-            mockCountriesService.Setup(c => c.GetCountries()).ReturnsAsync(countriesMock);
+            mockCountriesService.Setup(c => c.GetCountries(null, null)).ReturnsAsync(countriesMock);
 
             var controller = new CountriesController(mockCountriesService.Object);
 
-            var result = (await controller.Get()).Result as OkObjectResult;
+            var result = (await controller.Get(null, null)).Result as OkObjectResult;
 
             result.StatusCode.Should().Be(StatusCodes.Status200OK);
             result.Value.Should().BeOfType<List<CountryModel>>();
             result.Value.Should().Be(countriesMock);
-            mockCountriesService.Verify(c => c.GetCountries(), Times.Once);
+            mockCountriesService.Verify(c => c.GetCountries(null, null), Times.Once);
         }
     }
 }
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs
index bdc6eed..2fcfffc 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs
@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Linq;
 using FluentAssertions;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
@@ -29,11 +30,11 @@ public CountriesServiceTests()
                 Borders = new[] {"IRL"}
             };
 
-            _countriesMock = new List<CountryModel>() {country};
+            _countriesMock = Enumerable.Range(1, 100).Select(x => country).ToList();
         }
 
         [Fact]
-        public async void GetCountries_OnInvoke_ReturnsCountriesFromApiClientFirstCall()
+        public async void GetCountries_OnInvoke_ReturnsCountriesFromApiClientFirstCall_NoPagination()
         {
             var mockCountriesApiClient = new Mock<ICountriesApiClient>();
             mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
@@ -42,7 +43,7 @@ public async void GetCountries_OnInvoke_ReturnsCountriesFromApiClientFirstCall()
             mockCache.Setup(c => c.GetCountries()).Returns(new List<CountryModel>());
             var countriesService = new CountriesService(mockCache.Object, mockCountriesApiClient.Object);
 
-            var result = await countriesService.GetCountries();
+            var result = await countriesService.GetCountries(null, null);
 
             result.Should().BeOfType<List<CountryModel>>();
             result.Should().BeSameAs(_countriesMock);
@@ -51,7 +52,7 @@ public async void GetCountries_OnInvoke_ReturnsCountriesFromApiClientFirstCall()
         }
 
         [Fact]
-        public async void GetCountries_OnInvoke_PopulatesCacheOnFirstCall()
+        public async void GetCountries_OnInvoke_PopulatesCacheOnFirstCall_NoPagination()
         {
             var mockCountriesApiClient = new Mock<ICountriesApiClient>();
             mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
@@ -60,14 +61,14 @@ public async void GetCountries_OnInvoke_PopulatesCacheOnFirstCall()
             mockCache.Setup(c => c.GetCountries()).Returns(new List<CountryModel>());
             var countriesService = new CountriesService(mockCache.Object, mockCountriesApiClient.Object);
 
-            var result = await countriesService.GetCountries();
+            var result = await countriesService.GetCountries(null, null);
             mockCache.Verify(c => c.PopulateCountries(result), Times.Once);
 
             mockCache.Verify(c => c.GetCountries(), Times.Once);
         }
 
         [Fact]
-        public async void GetCountries_OnInvoke_ReturnsCountriesFromCacheSecondCall()
+        public async void GetCountries_OnInvoke_ReturnsCountriesFromCacheSecondCall_NoPagination()
         {
             var mockCountriesApiClient = new Mock<ICountriesApiClient>();
 
@@ -75,12 +76,44 @@ public async void GetCountries_OnInvoke_ReturnsCountriesFromCacheSecondCall()
             mockCache.Setup(c => c.GetCountries()).Returns(_countriesMock);
             var countriesService = new CountriesService(mockCache.Object, mockCountriesApiClient.Object);
 
-            var result = await countriesService.GetCountries();
+            var result = await countriesService.GetCountries(null, null);
 
             result.Should().BeOfType<List<CountryModel>>();
             result.Should().BeSameAs(_countriesMock);
             mockCountriesApiClient.Verify(c => c.GetCountries(), Times.Never);
             mockCache.Verify(c => c.GetCountries(), Times.Once);
         }
+
+        [Fact]
+        public async void GetCountries_OnInvoke_Returns10Countries_Pagination()
+        {
+            var mockCountriesApiClient = new Mock<ICountriesApiClient>();
+            mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
+
+            var mockCache = new Mock<ICountryCache>();
+            mockCache.Setup(c => c.GetCountries()).Returns(new List<CountryModel>());
+            var countriesService = new CountriesService(mockCache.Object, mockCountriesApiClient.Object);
+
+            var result = await countriesService.GetCountries(10, 0);
+
+            result.Should().HaveCount(10);
+        }
+
+        [Fact]
+        public async void GetCountries_OnInvoke_ReturnsDifferent10Countries_Pagination()
+        {
+            var mockCountriesApiClient = new Mock<ICountriesApiClient>();
+            mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
+
+            var mockCache = new Mock<ICountryCache>();
+            mockCache.Setup(c => c.GetCountries()).Returns(new List<CountryModel>());
+            var countriesService = new CountriesService(mockCache.Object, mockCountriesApiClient.Object);
+
+            var result = await countriesService.GetCountries(10, 0);
+            var resultNextPage = await countriesService.GetCountries(10, 1);
+            result.Should().HaveCount(10);
+            resultNextPage.Should().HaveCount(10);
+            resultNextPage.Should().NotBeSameAs(result);
+        }
     }
 }
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
index 3a8427a..b4b1ebc 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountriesApiClient.cs
@@ -8,16 +8,16 @@ namespace Paymentsense.Coding.Challenge.Api.Clients
 {
     internal class CountriesApiClient : ICountriesApiClient
     {
-        private readonly IHttpClientFactory _clientFactory;
+        private readonly HttpClient _clientFactory;
 
         public CountriesApiClient(IHttpClientFactory clientFactory)
         {
-            _clientFactory = clientFactory;
+            _clientFactory = clientFactory.CreateClient();
         }
 
         public async Task<List<CountryModel>> GetCountries()
         {
-            using var client = _clientFactory.CreateClient();
+            using var client = _clientFactory;
             var responseStream = client.GetStreamAsync(
                 "https://restcountries.eu/rest/v2/all?fields=name;flag;population;timezones;currencies;languages;capital;borders");
 
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
index a555b7f..fe5f9fd 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
@@ -5,7 +5,7 @@ namespace Paymentsense.Coding.Challenge.Api.Clients
 {
     public class CountryCache : ICountryCache
     {
-        public static List<CountryModel> Countries { get; private set; } = new List<CountryModel>();
+        private static List<CountryModel> Countries { get; set; } = new List<CountryModel>();
 
         public List<CountryModel> GetCountries()
         {
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs
index 2823316..776bb64 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Controllers/CountriesController.cs
@@ -19,9 +19,9 @@ public CountriesController(ICountriesService countriesService)
 
 
         [HttpGet]
-        public async Task<ActionResult<List<CountryModel>>> Get()
+        public async Task<ActionResult<List<CountryModel>>> Get(int? pageNumber, int? page)
         {
-            var countries = await _countriesService.GetCountries();
+            var countries = await _countriesService.GetCountries(null, null);
 
             return Ok(countries);
         }
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/Language.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/Language.cs
index 1c95547..ca753f2 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/Language.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Models/Language.cs
@@ -1,9 +1,12 @@
 using System.Text.Json.Serialization;
 
-public class Language
+namespace Paymentsense.Coding.Challenge.Api.Models
 {
-    [JsonPropertyName("iso639_1")] public string Iso6391 { get; set; }
-    [JsonPropertyName("iso639_2")] public string Iso6392 { get; set; }
-    [JsonPropertyName("name")] public string Name { get; set; }
-    [JsonPropertyName("nativeName")] public string NativeName { get; set; }
+    public class Language
+    {
+        [JsonPropertyName("iso639_1")] public string Iso6391 { get; set; }
+        [JsonPropertyName("iso639_2")] public string Iso6392 { get; set; }
+        [JsonPropertyName("name")] public string Name { get; set; }
+        [JsonPropertyName("nativeName")] public string NativeName { get; set; }
+    }
 }
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/CountriesService.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/CountriesService.cs
index dfa349d..b569acd 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/CountriesService.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/CountriesService.cs
@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Linq;
 using System.Net.Http;
 using System.Text.Json;
 using System.Threading.Tasks;
@@ -18,18 +19,22 @@ public CountriesService(ICountryCache cache, ICountriesApiClient countriesApiCli
             _countryCache = cache;
         }
 
-        public async Task<List<CountryModel>> GetCountries()
+        public async Task<List<CountryModel>> GetCountries(int? pageNumber, int? page)
         {
             var countries = _countryCache.GetCountries();
-            if (countries.Count != 0)
+            if (countries.Count == 0)
             {
-                return countries;
+                countries = await _countriesApiClient.GetCountries();
+                _countryCache.PopulateCountries(countries);
             }
 
-            countries = await _countriesApiClient.GetCountries();
-            _countryCache.PopulateCountries(countries);
+            if (page == null || pageNumber == null)
+            {
+                return countries;
+            }
 
-            return countries;
+            var numToSkip = page.Value * pageNumber.Value;
+            return countries.Skip(numToSkip).Take(pageNumber.Value).ToList();
         }
     }
 }
\ No newline at end of file
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/ICountriesService.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/ICountriesService.cs
index 2bb752b..7394c11 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/ICountriesService.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Services/ICountriesService.cs
@@ -6,6 +6,6 @@ namespace Paymentsense.Coding.Challenge.Api.Services
 {
     public interface ICountriesService
     {
-        Task<List<CountryModel>> GetCountries();
+        Task<List<CountryModel>> GetCountries(int? pageNumber, int? page);
     }
 }
\ No newline at end of file

From 239f61f9e5ee6b153410087b58a19dfa519fa7ed Mon Sep 17 00:00:00 2001
From: Sarah Persov <s.persov@gmail.com>
Date: Sun, 27 Jun 2021 01:01:42 +0100
Subject: [PATCH 8/8] Added lock

---
 .../Clients/CountryCacheTests.cs                    |  5 -----
 .../Services/CountriesServiceTests.cs               | 13 +++++--------
 .../Clients/CountryCache.cs                         | 11 +++++++++--
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Clients/CountryCacheTests.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Clients/CountryCacheTests.cs
index a1ce762..f4184df 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Clients/CountryCacheTests.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Clients/CountryCacheTests.cs
@@ -1,13 +1,8 @@
 using System.Collections.Generic;
 using System.Linq;
 using FluentAssertions;
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc;
-using Moq;
 using Paymentsense.Coding.Challenge.Api.Clients;
-using Paymentsense.Coding.Challenge.Api.Controllers;
 using Paymentsense.Coding.Challenge.Api.Models;
-using Paymentsense.Coding.Challenge.Api.Services;
 using Xunit;
 
 namespace Paymentsense.Coding.Challenge.Api.Tests.Clients
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs
index 2fcfffc..0004eba 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api.Tests/Services/CountriesServiceTests.cs
@@ -1,11 +1,8 @@
 using System.Collections.Generic;
 using System.Linq;
 using FluentAssertions;
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc;
 using Moq;
 using Paymentsense.Coding.Challenge.Api.Clients;
-using Paymentsense.Coding.Challenge.Api.Controllers;
 using Paymentsense.Coding.Challenge.Api.Models;
 using Paymentsense.Coding.Challenge.Api.Services;
 using Xunit;
@@ -34,7 +31,7 @@ public CountriesServiceTests()
         }
 
         [Fact]
-        public async void GetCountries_OnInvoke_ReturnsCountriesFromApiClientFirstCall_NoPagination()
+        public async void GetCountries_ReturnsCountriesFromApiClientFirstCall_NoPagination()
         {
             var mockCountriesApiClient = new Mock<ICountriesApiClient>();
             mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
@@ -52,7 +49,7 @@ public async void GetCountries_OnInvoke_ReturnsCountriesFromApiClientFirstCall_N
         }
 
         [Fact]
-        public async void GetCountries_OnInvoke_PopulatesCacheOnFirstCall_NoPagination()
+        public async void GetCountries_PopulatesCacheOnFirstCall_NoPagination()
         {
             var mockCountriesApiClient = new Mock<ICountriesApiClient>();
             mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
@@ -68,7 +65,7 @@ public async void GetCountries_OnInvoke_PopulatesCacheOnFirstCall_NoPagination()
         }
 
         [Fact]
-        public async void GetCountries_OnInvoke_ReturnsCountriesFromCacheSecondCall_NoPagination()
+        public async void GetCountries_ReturnsCountriesFromCacheSecondCall_NoPagination()
         {
             var mockCountriesApiClient = new Mock<ICountriesApiClient>();
 
@@ -85,7 +82,7 @@ public async void GetCountries_OnInvoke_ReturnsCountriesFromCacheSecondCall_NoPa
         }
 
         [Fact]
-        public async void GetCountries_OnInvoke_Returns10Countries_Pagination()
+        public async void GetCountries_Returns10Countries_Pagination()
         {
             var mockCountriesApiClient = new Mock<ICountriesApiClient>();
             mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
@@ -100,7 +97,7 @@ public async void GetCountries_OnInvoke_Returns10Countries_Pagination()
         }
 
         [Fact]
-        public async void GetCountries_OnInvoke_ReturnsDifferent10Countries_Pagination()
+        public async void GetCountries_ReturnsDifferent10Countries_Pagination()
         {
             var mockCountriesApiClient = new Mock<ICountriesApiClient>();
             mockCountriesApiClient.Setup(c => c.GetCountries()).ReturnsAsync(_countriesMock);
diff --git a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
index fe5f9fd..242ca59 100644
--- a/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
+++ b/paymentsense-coding-challenge-api/Paymentsense.Coding.Challenge.Api/Clients/CountryCache.cs
@@ -6,15 +6,22 @@ namespace Paymentsense.Coding.Challenge.Api.Clients
     public class CountryCache : ICountryCache
     {
         private static List<CountryModel> Countries { get; set; } = new List<CountryModel>();
+        private static readonly object CountriesLock = new object();
 
         public List<CountryModel> GetCountries()
         {
-            return Countries;
+            lock (CountriesLock)
+            {
+                return Countries;
+            }
         }
 
         public void PopulateCountries(List<CountryModel> countries)
         {
-            Countries = countries;
+            lock (CountriesLock)
+            {
+                Countries = countries;
+            }
         }
     }
 }
\ No newline at end of file