Self-contained export (#321)

DiscordChatExporter.Domain/Internal/UrlBuilder.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Text;
+
+namespace DiscordChatExporter.Domain.Internal
+{
+    internal class UrlBuilder
+    {
+        private string _path = "";
+
+        private readonly Dictionary<string, string?> _queryParameters =
+            new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase);
+
+        public UrlBuilder SetPath(string path)
+        {
+            _path = path;
+            return this;
+        }
+
+        public UrlBuilder SetQueryParameter(string key, string? value, bool ignoreUnsetValue = true)
+        {
+            if (ignoreUnsetValue && string.IsNullOrWhiteSpace(value))
+                return this;
+
+            var keyEncoded = WebUtility.UrlEncode(key);
+            var valueEncoded = WebUtility.UrlEncode(value);
+            _queryParameters[keyEncoded] = valueEncoded;
+
+            return this;
+        }
+
+        public string Build()
+        {
+            var buffer = new StringBuilder();
+
+            buffer.Append(_path);
+
+            if (_queryParameters.Any())
+                buffer.Append('?').AppendJoin('&', _queryParameters.Select(kvp => $"{kvp.Key}={kvp.Value}"));
+
+            return buffer.ToString();
+        }
+    }
+}