GitAuto: [FEATURE] Preserve original message for merge conflict resolutions +semver: minor

Src/AiCommitMessage/Options/GenerateCommitMessageOptions.cs

@@ -3,36 +3,50 @@
 namespace AiCommitMessage.Options;
 
 /// <summary>
-/// Class GenerateMessageOptions.
+/// Represents the options for generating a commit message based on staged changes.
 /// </summary>
 [Verb("generate-message", HelpText = "Generate a commit message based on staged changes.")]
 public class GenerateCommitMessageOptions
 {
     /// <summary>
-    /// Gets or sets the message.
+    /// Gets or sets the initial commit message provided by the user.
     /// </summary>
-    /// <value>The message.</value>
+    /// <value>The initial commit message used as input for generation.</value>
+    /// <remarks>
+    /// This message serves as the base for generating a refined or enhanced commit message.
+    /// </remarks>
     [Option('m', "message", Required = true, HelpText = "The current commit message.")]
     public string Message { get; set; }
 
     /// <summary>
-    /// Gets or sets the branch.
+    /// Gets or sets the name of the current branch.
     /// </summary>
-    /// <value>The branch.</value>
+    /// <value>The name of the branch where changes are staged.</value>
+    /// <remarks>
+    /// Providing the branch name can help contextualize the commit message for workflows
+    /// or tools that rely on branch-specific details.
+    /// </remarks>
     [Option('b', "branch", Required = false, HelpText = "The current branch name.")]
     public string Branch { get; set; }
 
     /// <summary>
-    /// Gets or sets the difference.
+    /// Gets or sets the staged changes for the commit.
     /// </summary>
-    /// <value>The difference.</value>
+    /// <value>A string representation of the staged changes (e.g., diff output).</value>
+    /// <remarks>
+    /// Including the diff can provide more detailed context for generating a commit message
+    /// tailored to the exact changes being staged.
+    /// </remarks>
     [Option('d', "diff", Required = false, HelpText = "The staged changes.")]
     public string Diff { get; set; }
 
     /// <summary>
-    /// Gets or sets a value indicating whether debug is enabled or not.
+    /// Gets or sets a value indicating whether debug mode is enabled.
     /// </summary>
-    /// <value><c>true</c> if debug is enabled; otherwise, <c>false</c>.</value>
+    /// <value><c>true</c> if debug mode is enabled; otherwise, <c>false</c>.</value>
+    /// <remarks>
+    /// Debug mode enables additional logging and diagnostic output to assist in troubleshooting.
+    /// </remarks>
     [Option('D', "debug", Required = false, HelpText = "Debug mode.")]
     public bool Debug { get; set; }
 }

Src/AiCommitMessage/Program.cs

@@ -1,4 +1,4 @@
-using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.CodeAnalysis;
 using AiCommitMessage.Options;
 using AiCommitMessage.Services;
 using AiCommitMessage.Utility;

Src/AiCommitMessage/Services/GenerateCommitMessageService.cs

@@ -1,6 +1,7 @@
 using System.ClientModel;
 using System.Diagnostics;
 using System.Text.Json;
+using System.Text.RegularExpressions;
 using AiCommitMessage.Options;
 using AiCommitMessage.Utility;
 using OpenAI;
@@ -9,23 +10,41 @@
 namespace AiCommitMessage.Services;
 
 /// <summary>
-/// Class GenerateCommitMessageService.
+/// Service for generating commit messages based on staged changes and contextual information.
 /// </summary>
 public class GenerateCommitMessageService
 {
+    /// <summary>
+    /// Regular expression to detect merge conflict resolution messages.
+    /// </summary>
+    private static readonly Regex MergeConflictPattern = new (
+        @"^Merge branch '.*' into .*$",
+        RegexOptions.Compiled
+    );
+
+    /// <summary>
+    /// Checks whether the given commit message is a merge conflict resolution message.
+    /// </summary>
+    /// <param name="message">The commit message to evaluate.</param>
+    /// <returns><c>true</c> if the message indicates a merge conflict resolution; otherwise, <c>false</c>.</returns>
+    /// <remarks>
+    /// This helper method uses a predefined regular expression to match patterns commonly seen in merge conflict resolutions.
+    /// </remarks>
+    private static bool IsMergeConflictResolution(string message) =>
+        MergeConflictPattern.IsMatch(message);
+
     /// <summary>
     /// Generates a commit message based on the provided options and the OpenAI API.
     /// </summary>
     /// <param name="options">An instance of <see cref="GenerateCommitMessageOptions"/> containing the branch name, original message, and git diff.</param>
     /// <returns>A string containing the generated commit message from the OpenAI API.</returns>
     /// <remarks>
-    /// This method retrieves the OpenAI API URL and API key from the environment variables. If the URL is not set, it defaults to "https://api.openai.com/v1".
-    /// If the API key is not provided, it returns a message prompting the user to set the <c>OPENAI_API_KEY</c> environment variable.
-    /// It constructs a message that includes the branch name, original commit message, and git diff, which is then sent to the OpenAI API using a chat client.
-    /// If debugging is enabled, it serializes the chat completion response to JSON and writes it to a file named "debug.json".
-    /// Finally, it returns the generated commit message from the chat completion response.
+    /// This method retrieves API details (URL and key) from environment variables, constructs a message including the branch name,
+    /// original commit message, and git diff, and sends it to the OpenAI API for processing. It also handles debugging, saving
+    /// API responses to a JSON file if debugging is enabled. If the commit message is a merge conflict resolution, it is returned as-is.
     /// </remarks>
+    /// <exception cref="InvalidOperationException">Thrown if both the branch and diff are empty, as meaningful commit generation is not possible.</exception>
     public string GenerateCommitMessage(GenerateCommitMessageOptions options)
     {
         var model = EnvironmentLoader.LoadOpenAiModel();
         var url = EnvironmentLoader.LoadOpenAiApiUrl();
@@ -44,7 +63,12 @@
         var diff = string.IsNullOrEmpty(options.Diff) ? GitHelper.GetGitDiff() : options.Diff;
 
         // Use the provided message (this will come from the prepare-commit-msg hook)
-        var message = options.Message; // No fallback to GIT, as commit message is passed in the hook
+        var message = options.Message; // No fallback to GIT, as the commit message is passed in the hook
+
+        if (IsMergeConflictResolution(message))
+        {
+            return message;
+        }
 
         if (string.IsNullOrEmpty(branch) && string.IsNullOrEmpty(diff))
         {
@@ -115,21 +139,14 @@
     /// </summary>
     /// <returns>A <see cref="GitProvider"/> enumeration value representing the detected Git provider.</returns>
     /// <remarks>
-    /// This method executes a Git command to fetch the remote origin URL configured for the repository.
-    /// It uses the <c>git config --get remote.origin.url</c> command to obtain the URL, which is then analyzed to determine the Git provider.
-    /// The method checks for specific substrings in the URL to identify the provider:
-    /// - If the URL contains "dev.azure.com", it returns <see cref="GitProvider.AzureDevOps"/>.
-    /// - If the URL contains "bitbucket.org", it returns <see cref="GitProvider.Bitbucket"/>.
-    /// - If the URL contains "github.com", it returns <see cref="GitProvider.GitHub"/>.
-    /// - If the URL contains "gitlab.com", it returns <see cref="GitProvider.GitLab"/>.
-    /// If none of these providers are identified, it returns <see cref="GitProvider.Unidentified"/>.
-    /// This method is useful for determining the source control environment in which the code is hosted.
+    /// This method uses the <c>git config --get remote.origin.url</c> command to determine the Git provider based on substrings in the URL.
+    /// If no known provider is identified, it defaults to <see cref="GitProvider.Unidentified"/>.
     /// </remarks>
     private static GitProvider GetGitProvider()
     {
         var processStartInfo = new ProcessStartInfo
         {
             FileName = "git",
             Arguments = "config --get remote.origin.url",
             RedirectStandardOutput = true,
             UseShellExecute = false,