chore: import upstream snapshot with attribution

2026-07-13 13:02:50 +08:00
commit 0fc60fdcb1
5008 changed files with 910633 additions and 0 deletions
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+/*
+ * QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
+ * Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+
+using System.Globalization;
+using System.Text.RegularExpressions;
+
+namespace QuantConnect.Util
+{
+    /// <summary>
+    /// Provides methods for validating strings following a certain format, such as an email address
+    /// </summary>
+    public static class Validate
+    {
+        /// <summary>
+        /// Validates the provided email address
+        /// </summary>
+        /// <remarks>
+        /// Implementation taken from msdn (with slight refactoring for readability and C#6 compliance):
+        /// https://docs.microsoft.com/en-us/dotnet/standard/base-types/how-to-verify-that-strings-are-in-valid-email-format
+        /// </remarks>
+        /// <param name="emailAddress">The email address to be validated</param>
+        /// <returns>True if the provided email address is valid</returns>
+        public static bool EmailAddress(string emailAddress)
+        {
+            if (emailAddress == null)
+            {
+                return true;
+            }
+
+            if (string.IsNullOrWhiteSpace(emailAddress))
+            {
+                return false;
+            }
+
+            emailAddress = NormalizeEmailAddressDomainName(emailAddress);
+            if (emailAddress == null)
+            {
+                // an error occurred during domain name normalization
+                return false;
+            }
+
+            try
+            {
+                return RegularExpression.Email.IsMatch(emailAddress);
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
+        private static string NormalizeEmailAddressDomainName(string emailAddress)
+        {
+            try
+            {
+                // Normalize the domain
+                emailAddress = RegularExpression.EmailDomainName.Replace(emailAddress, match =>
+                {
+                    // Use IdnMapping class to convert Unicode domain names.
+                    var idn = new IdnMapping();
+
+                    // Pull out and process domain name (throws ArgumentException on invalid)
+                    var domainName = idn.GetAscii(match.Groups[2].Value);
+
+                    return match.Groups[1].Value + domainName;
+                });
+            }
+            catch
+            {
+                return null;
+            }
+
+            return emailAddress;
+        }
+
+        /// <summary>
+        /// Provides static storage of compiled regular expressions to preclude parsing on each invocation
+        /// </summary>
+        public static class RegularExpression
+        {
+            /// <summary>
+            /// Matches the domain name in an email address ignored@[domain.com]
+            /// Pattern sourced via msdn:
+            /// https://docs.microsoft.com/en-us/dotnet/standard/base-types/how-to-verify-that-strings-are-in-valid-email-format
+            /// </summary>
+            public static readonly Regex EmailDomainName = new Regex(@"(@)(.+)$", RegexOptions.Compiled);
+
+            /// <summary>
+            /// Matches a valid email address address@sub.domain.com
+            /// Pattern sourced via msdn:
+            /// https://docs.microsoft.com/en-us/dotnet/standard/base-types/how-to-verify-that-strings-are-in-valid-email-format
+            /// </summary>
+            public static readonly Regex Email = new Regex(@"^(?("")("".+?(?<!\\)""@)|(([0-9a-z]((\.(?!\.))|[-!#\$%&'\*\+/=\?\^`\{\}\|~\w])*)(?<=[0-9a-z])@))(?(\[)(\[(\d{1,3}\.){3}\d{1,3}\])|(([0-9a-z][-0-9a-z]*[0-9a-z]*\.)+[a-z0-9][\-a-z0-9]{0,22}[a-z0-9]))$", RegexOptions.IgnoreCase | RegexOptions.Compiled);
+        }
+    }
+}