Initial upload: Local Commit Message Generator v0.1.0

app/local_commit_message_generator/src/hooks.py

@@ -0,0 +1,228 @@
+"""Git hook integration for prepare-commit-msg."""
+
+import os
+import shutil
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Optional
+
+
+@dataclass
+class HookResult:
+    """Result of a hook operation."""
+    success: bool
+    message: str
+    backup_path: Optional[str] = None
+
+
+class HookManager:
+    """Manages git prepare-commit-msg hook installation."""
+
+    HOOK_FILENAME = "prepare-commit-msg"
+    HOOK_CONTENT = '''#!/bin/bash
+# prepare-commit-msg hook installed by local-commit-message-generator
+# Generated commit message - edit as needed
+
+exec commit-gen hook "$@"
+'''
+
+    def __init__(self, repo_path: Optional[str] = None):
+        """Initialize hook manager.
+
+        Args:
+            repo_path: Optional path to git repository.
+        """
+        self.repo_path = Path(repo_path) if repo_path else Path.cwd()
+        self.hooks_dir = self.repo_path / ".git" / "hooks"
+
+    def get_hook_path(self) -> Path:
+        """Get the path to the prepare-commit-msg hook.
+
+        Returns:
+            Path to the hook file.
+        """
+        return self.hooks_dir / self.HOOK_FILENAME
+
+    def hook_exists(self) -> bool:
+        """Check if a prepare-commit-msg hook already exists.
+
+        Returns:
+            True if hook exists, False otherwise.
+        """
+        hook_path = self.get_hook_path()
+        return hook_path.exists() and hook_path.stat().st_size > 0
+
+    def has_our_hook(self) -> bool:
+        """Check if our hook is installed.
+
+        Returns:
+            True if our hook is installed, False otherwise.
+        """
+        hook_path = self.get_hook_path()
+        if not hook_path.exists():
+            return False
+        content = hook_path.read_text()
+        return "commit-gen hook" in content
+
+    def backup_existing_hook(self) -> Optional[Path]:
+        """Backup existing hook if it exists.
+
+        Returns:
+            Path to backup file or None if no backup was needed.
+        """
+        hook_path = self.get_hook_path()
+        if not hook_path.exists():
+            return None
+
+        backup_path = hook_path.with_suffix(".backup")
+        shutil.copy2(hook_path, backup_path)
+        return backup_path
+
+    def install_hook(self) -> HookResult:
+        """Install the prepare-commit-msg hook.
+
+        Returns:
+            HookResult with success status and message.
+        """
+        try:
+            hook_path = self.get_hook_path()
+
+            if not self.hooks_dir.exists():
+                return HookResult(
+                    success=False,
+                    message=f"Git hooks directory not found: {self.hooks_dir}"
+                )
+
+            backup_path = None
+            if self.hook_exists() and not self.has_our_hook():
+                backup_path = self.backup_existing_hook()
+                msg = f"Backed up existing hook to {backup_path}"
+            else:
+                msg = ""
+
+            hook_path.write_text(self.HOOK_CONTENT)
+            os.chmod(hook_path, 0o755)
+
+            if msg:
+                msg = f"Hook installed. {msg}"
+            else:
+                msg = "Hook installed successfully."
+
+            return HookResult(
+                success=True,
+                message=msg,
+                backup_path=str(backup_path) if backup_path else None
+            )
+
+        except PermissionError:
+            return HookResult(
+                success=False,
+                message="Permission denied. Check write permissions on .git/hooks/"
+            )
+        except OSError as e:
+            return HookResult(
+                success=False,
+                message=f"Failed to install hook: {e}"
+            )
+
+    def uninstall_hook(self) -> HookResult:
+        """Uninstall the prepare-commit-msg hook.
+
+        Returns:
+            HookResult with success status and message.
+        """
+        try:
+            hook_path = self.get_hook_path()
+
+            if not hook_path.exists():
+                return HookResult(
+                    success=False,
+                    message="No hook file found to uninstall."
+                )
+
+            if self.has_our_hook():
+                backup_path = hook_path.with_suffix(".our_backup")
+                os.rename(hook_path, backup_path)
+                return HookResult(
+                    success=True,
+                    message=f"Hook uninstalled. Backup saved to {backup_path}"
+                )
+            else:
+                return HookResult(
+                    success=False,
+                    message="Our hook was not installed. Not modifying."
+                )
+
+        except OSError as e:
+            return HookResult(
+                success=False,
+                message=f"Failed to uninstall hook: {e}"
+            )
+
+    def restore_hook(self) -> HookResult:
+        """Restore a backed-up hook.
+
+        Returns:
+            HookResult with success status and message.
+        """
+        hook_path = self.get_hook_path()
+        backup_path = hook_path.with_suffix(".backup")
+
+        if not backup_path.exists():
+            return HookResult(
+                success=False,
+                message="No backup file found to restore."
+            )
+
+        try:
+            os.rename(backup_path, hook_path)
+            return HookResult(
+                success=True,
+                message="Restored original hook from backup."
+            )
+        except OSError as e:
+            return HookResult(
+                success=False,
+                message=f"Failed to restore hook: {e}"
+            )
+
+
+def is_hook_mode(args: list) -> bool:
+    """Check if running in hook mode.
+
+    Args:
+        args: Command line arguments.
+
+    Returns:
+        True if running in hook mode.
+    """
+    return len(args) >= 1 and args[0] == "hook"
+
+
+def handle_hook_invocation(args: list, repo_path: Optional[str] = None) -> str:
+    """Handle prepare-commit-msg hook invocation.
+
+    Args:
+        args: Command line arguments from hook.
+        repo_path: Optional repository path.
+
+    Returns:
+        Generated commit message or empty string.
+    """
+    if len(args) < 1:
+        return ""
+
+    commit_msg_file = args[0]
+    commit_source = args[1] if len(args) > 1 else ""
+    sha1 = args[2] if len(args) > 2 else ""
+
+    try:
+        from .generator import generate_commit_message
+        message = generate_commit_message(repo_path)
+
+        if message and commit_source != "merge" and commit_source != "squash":
+            Path(commit_msg_file).write_text(message)
+
+        return message or ""
+    except Exception:
+        return ""