feat: Add headless CLI mode for AI code review and comment workflows (#193)

Co-authored-by: Claude Haiku 4.5 <noreply@anthropic.com>

Author: finxo

.github/workflows/ci.yml

@@ -134,6 +134,8 @@ venv.bak/
 # IDE settings
 .idea/
 .vscode/
+.codex
+.titan/worktrees/
 *.swp
 *.swo
 

.gitignore

@@ -6,6 +6,7 @@
 
 from titan_plugin_git.operations.diff_operations import (
     parse_diff_stat_output,
+    expand_rename_path,
     get_max_filename_length,
     colorize_diff_stats,
     colorize_diff_summary,
@@ -185,3 +186,32 @@ def test_format_real_git_output(self):
         assert "diff.py" in files[0]
         assert "commit.py" in files[1]
         assert "77 insertions" in summary[0]
+
+
+class TestExpandRenamePath:
+    """Tests for expand_rename_path function."""
+
+    def test_no_rename_unchanged(self):
+        assert expand_rename_path("titan_cli/core/models.py") == "titan_cli/core/models.py"
+
+    def test_rename_with_prefix(self):
+        result = expand_rename_path("titan_cli/core/{models.py => models/__init__.py}")
+        assert result == "titan_cli/core/models/__init__.py"
+
+    def test_rename_at_root(self):
+        result = expand_rename_path("{old_file.py => new_file.py}")
+        assert result == "new_file.py"
+
+    def test_rename_with_suffix(self):
+        result = expand_rename_path("{old_dir => new_dir}/file.py")
+        assert result == "new_dir/file.py"
+
+    def test_rename_with_prefix_and_suffix(self):
+        result = expand_rename_path("pkg/{old => new}/module.py")
+        assert result == "pkg/new/module.py"
+
+    def test_simple_filename_unchanged(self):
+        assert expand_rename_path("file.py") == "file.py"
+
+    def test_path_without_rename_unchanged(self):
+        assert expand_rename_path("a/b/c/file.py") == "a/b/c/file.py"

plugins/titan-plugin-git/tests/operations/test_diff_operations.py

@@ -309,9 +309,20 @@ def get_file_diff(self, file_path: str) -> ClientResult[str]:
         """Get diff for a specific file."""
         return self.diff_service.get_file_diff(file_path)
 
-    def get_branch_diff(self, base_branch: str, head_branch: str) -> ClientResult[str]:
-        """Get diff between two branches."""
-        return self.diff_service.get_branch_diff(base_branch, head_branch)
+    def get_branch_diff(self, base_branch: str, head_branch: str, context_lines: int = 3, use_remote: bool = False) -> ClientResult[str]:
+        """
+        Get diff between two branches.
+
+        Args:
+            base_branch: Base branch name
+            head_branch: Head branch name
+            context_lines: Number of context lines (default: 3)
+            use_remote: If True, both branches are treated as remote refs (default: False)
+
+        Returns:
+            ClientResult[str] with diff output
+        """
+        return self.diff_service.get_branch_diff(base_branch, head_branch, context_lines, use_remote)
 
     def get_diff_stat(self, base_ref: str, head_ref: str = "HEAD") -> ClientResult[str]:
         """Get diff stat summary."""

plugins/titan-plugin-git/titan_plugin_git/clients/git_client.py

@@ -5,6 +5,7 @@
 Business logic for Git commit operations.
 Uses network layer to execute commands, parses to network models, maps to view models.
 """
+import os
 from typing import List, Optional, Sequence
 
 from titan_cli.core.result import ClientResult, ClientSuccess, ClientError
@@ -86,7 +87,33 @@ def commit_files(
             ClientResult[str] with commit hash
         """
         try:
-            self.git.run_command(["git", "add", "--"] + list(files))
+            # Separate existing files from deleted ones
+            # Only include files that exist in the filesystem OR are tracked in git
+            existing_files = []
+            deleted_files = []
+
+            for f in files:
+                if os.path.exists(f):
+                    # File exists in filesystem
+                    existing_files.append(f)
+                else:
+                    # File doesn't exist - check if it's tracked in git
+                    # If it's tracked, we can use git rm; if not, skip it
+                    try:
+                        self.git.run_command(["git", "ls-files", "--error-unmatch", f])
+                        # File is tracked, mark for deletion
+                        deleted_files.append(f)
+                    except GitCommandError:
+                        # File not tracked in git, skip it
+                        pass
+
+            # Stage existing files with git add
+            if existing_files:
+                self.git.run_command(["git", "add", "--"] + existing_files)
+
+            # Stage deleted files with git rm
+            if deleted_files:
+                self.git.run_command(["git", "rm", "--"] + deleted_files)
 
             args = ["git", "commit", "-m", message]
             if no_verify:

plugins/titan-plugin-git/titan_plugin_git/clients/services/commit_service.py

@@ -141,20 +141,34 @@ def get_file_diff(self, file_path: str) -> ClientResult[str]:
             return ClientError(error_message=str(e), error_code="DIFF_ERROR")
 
     @log_client_operation()
-    def get_branch_diff(self, base_branch: str, head_branch: str) -> ClientResult[str]:
+    def get_branch_diff(self, base_branch: str, head_branch: str, context_lines: int = 3, use_remote: bool = False) -> ClientResult[str]:
         """
         Get diff between two branches.
 
         Args:
             base_branch: Base branch name
             head_branch: Head branch name
+            context_lines: Number of unchanged context lines around each change (default: 3).
+                When called from code review with context_lines=20, provides extended context
+                for AI analysis. The higher value gives better code understanding for review
+                quality, while still keeping token usage reasonable compared to reading entire files.
+            use_remote: If True, both branches are prefixed with the configured default_remote.
+                Used for PR reviews where branches are remote refs only (not checked out locally).
 
         Returns:
             ClientResult[str] with diff output
         """
         try:
+            # Build branch references using configured default_remote if use_remote=True
+            if use_remote:
+                base_ref = f"{self.default_remote}/{base_branch}"
+                head_ref = f"{self.default_remote}/{head_branch}"
+            else:
+                base_ref = f"{self.default_remote}/{base_branch}"
+                head_ref = head_branch
+
             diff = self.git.run_command(
-                ["git", "diff", f"{self.default_remote}/{base_branch}...{head_branch}"],
+                ["git", "diff", f"-U{context_lines}", f"{base_ref}...{head_ref}"],
                 check=False
             )
             return ClientSuccess(

plugins/titan-plugin-git/titan_plugin_git/clients/services/diff_service.py

@@ -20,6 +20,7 @@
 
 from .diff_operations import (
     parse_diff_stat_output,
+    expand_rename_path,
     get_max_filename_length,
     colorize_diff_stats,
     colorize_diff_summary,
@@ -42,6 +43,7 @@
 
     # Diff operations
     "parse_diff_stat_output",
+    "expand_rename_path",
     "get_max_filename_length",
     "colorize_diff_stats",
     "colorize_diff_summary",

plugins/titan-plugin-git/titan_plugin_git/operations/__init__.py

@@ -5,8 +5,36 @@
 These functions can be used by any step and are easily testable.
 """
 
+import re
 from typing import List, Tuple
 
+# Matches git rename notation: prefix{old => new}suffix
+# Examples:
+#   titan_cli/core/{models.py => models/__init__.py}  →  titan_cli/core/models/__init__.py
+#   {old_dir => new_dir}/file.py                      →  new_dir/file.py
+_RENAME_PATTERN = re.compile(r'^(.*?)\{[^}]*\s*=>\s*([^}]*)\}(.*)$')
+
+
+def expand_rename_path(path: str) -> str:
+    """
+    Expand a git rename notation path to the actual new file path.
+
+    Git diff --stat uses {old => new} notation for renames.
+    This function converts it to a real file path usable by git add.
+
+    Args:
+        path: A file path, possibly containing git rename notation.
+
+    Returns:
+        Expanded path with the rename resolved to the new name.
+        If no rename notation is present, returns the path unchanged.
+    """
+    match = _RENAME_PATTERN.match(path)
+    if not match:
+        return path
+    prefix, new_part, suffix = match.groups()
+    return prefix + new_part.strip() + suffix
+
 
 def parse_diff_stat_output(stat_output: str) -> Tuple[List[Tuple[str, str]], List[str]]:
     """
@@ -155,6 +183,7 @@ def format_diff_stat_display(stat_output: str) -> Tuple[List[str], List[str]]:
 
 __all__ = [
     "parse_diff_stat_output",
+    "expand_rename_path",
     "get_max_filename_length",
     "colorize_diff_stats",
     "colorize_diff_summary",

plugins/titan-plugin-git/titan_plugin_git/operations/diff_operations.py

@@ -3,7 +3,7 @@
 from titan_cli.core.result import ClientSuccess, ClientError
 from titan_cli.ui.tui.widgets import SelectionOption
 from titan_plugin_git.messages import msg
-from ..operations import parse_diff_stat_output, colorize_diff_stats, colorize_diff_summary, format_diff_stat_display
+from ..operations import parse_diff_stat_output, expand_rename_path, colorize_diff_stats, colorize_diff_summary, format_diff_stat_display
 
 
 def show_uncommitted_diff_summary(ctx: WorkflowContext) -> WorkflowResult:
@@ -42,7 +42,7 @@ def show_uncommitted_diff_summary(ctx: WorkflowContext) -> WorkflowResult:
                 max_len = max(len(filename) for filename, _ in file_lines)
                 options = [
                     SelectionOption(
-                        value=filename,
+                        value=expand_rename_path(filename),
                         label=f"{filename.ljust(max_len)} |{colorize_diff_stats(stats)}",
                         selected=True,
                     )