feat: Add BaseCommand class for command handling

.gitignore

@@ -121,6 +121,9 @@ ipython_config.py
 # PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
 __pypackages__/
 
+# Helm Values Manager specific
+.helm-values.lock
+
 # Celery stuff
 celerybeat-schedule
 celerybeat.pid

docs/Development/tasks.md

@@ -74,18 +74,90 @@
   - [ ] Add better validation
 
 ### Command System
-- [ ] Implement BaseCommand improvements
-  - [ ] Add file locking mechanism
-  - [ ] Implement backup strategy
-  - [ ] Add better error handling
-- [ ] Add new commands
+
+#### Phase 1: Core Infrastructure & Essential Commands
+- [x] Basic Command Framework
+  - [x] Create commands directory structure
+  - [x] Implement BaseCommand class with basic flow
+    - [x] Add configuration loading/saving
+    - [x] Add error handling and logging
+  - [ ] Add command registration in CLI
+  - [ ] Add basic command discovery
+
+- [ ] Configuration Setup Commands
+  - [ ] Implement init command
+    - [ ] Add empty config initialization
+    - [ ] Add config file creation
+    - [ ] Add schema template generation
   - [ ] Implement add-value-config command
+    - [ ] Add basic path validation
+    - [ ] Add metadata validation
+    - [ ] Add config update
+  - [ ] Implement add-deployment command
+    - [ ] Add basic deployment validation
+    - [ ] Add backend validation
+    - [ ] Add deployment registration
+  - [ ] Implement generate command
+    - [ ] Add template generation
+    - [ ] Add basic value substitution
+
+- [ ] Value Management Commands
+  - [ ] Implement get-value command
+    - [ ] Add basic path validation
+    - [ ] Add value retrieval
+  - [ ] Implement set-value command
+    - [ ] Add basic path validation
+    - [ ] Add value storage
+
+#### Phase 2: Enhanced Safety & Management
+- [ ] Enhanced Command Infrastructure
+  - [ ] Add file locking mechanism
+  - [ ] Add atomic writes
+  - [ ] Add basic backup strategy
+
+- [ ] Configuration Management
   - [ ] Implement remove-value-config command
-  - [ ] Update existing commands for new structure
-- [ ] Update command validation
-  - [ ] Add input validation
-  - [ ] Improve error messages
-  - [ ] Add command-specific validation
+    - [ ] Add path validation
+    - [ ] Add basic cleanup
+  - [ ] Enhance add-value-config
+    - [ ] Add conflict detection
+    - [ ] Add dependency validation
+
+- [ ] Basic Validation System
+  - [ ] Add PathValidator class
+    - [ ] Add path format validation
+    - [ ] Add existence checks
+
+#### Phase 3: Advanced Features
+- [ ] Enhanced Security & Recovery
+  - [ ] Add comprehensive backup strategy
+  - [ ] Add rollback support
+  - [ ] Improve error handling
+
+- [ ] Deployment Management
+  - [ ] Add DeploymentValidator class
+
+- [ ] Advanced Validation
+  - [ ] Add ValueValidator class
+  - [ ] Add conflict detection
+  - [ ] Add dependency checking
+
+#### Phase 4: Polish & Documentation
+- [ ] Command Documentation
+  - [ ] Add command documentation generation
+  - [ ] Add help text improvements
+  - [ ] Add usage examples
+
+- [ ] Testing Infrastructure
+  - [ ] Add command test fixtures
+  - [ ] Add mock file system
+  - [ ] Add mock backend
+  - [ ] Add integration tests
+
+- [ ] Final Touches
+  - [ ] Add command output formatting
+  - [ ] Add progress indicators
+  - [ ] Add interactive mode support
 
 ### Testing Infrastructure
 - [x] Set up test infrastructure

helm_values_manager/commands/__init__.py

@@ -0,0 +1 @@
+"""Commands package containing command implementations for the helm-values-manager."""

helm_values_manager/commands/base_command.py

@@ -0,0 +1,150 @@
+"""Base command class for helm-values plugin."""
+
+import fcntl
+import json
+import os
+from typing import Any, Optional
+
+from jsonschema.exceptions import ValidationError
+
+from helm_values_manager.models.helm_values_config import HelmValuesConfig
+from helm_values_manager.utils.logger import HelmLogger
+
+
+class BaseCommand:
+    """Base class for all helm-values commands.
+
+    This class provides common functionality for all commands including:
+    - Configuration loading and saving
+    - Error handling and logging
+    - Lock management for concurrent access
+    """
+
+    def __init__(self) -> None:
+        """Initialize the base command."""
+        self.config_file = "helm-values.json"
+        self.lock_file = ".helm-values.lock"
+        self._lock_fd: Optional[int] = None
+
+    def _load_config_file(self) -> dict:
+        """Load and parse the configuration file.
+
+        Returns:
+            dict: The parsed configuration data
+
+        Raises:
+            FileNotFoundError: If the config file doesn't exist
+            json.JSONDecodeError: If the file contains invalid JSON
+        """
+        if not os.path.exists(self.config_file):
+            HelmLogger.error("Configuration file %s not found", self.config_file)
+            raise FileNotFoundError(f"Configuration file {self.config_file} not found")
+
+        try:
+            with open(self.config_file, "r", encoding="utf-8") as f:
+                return json.load(f)
+        except json.JSONDecodeError as e:
+            HelmLogger.error("Failed to parse configuration file: %s", e)
+            raise
+
+    def load_config(self) -> HelmValuesConfig:
+        """Load the helm-values configuration from disk.
+
+        Returns:
+            HelmValuesConfig: The loaded configuration.
+
+        Raises:
+            FileNotFoundError: If the config file doesn't exist.
+            json.JSONDecodeError: If the file contains invalid JSON.
+            ValidationError: If the configuration format is invalid.
+        """
+        data = self._load_config_file()
+        try:
+            return HelmValuesConfig.from_dict(data)
+        except ValidationError as e:
+            HelmLogger.error("Invalid configuration format: %s", e)
+            raise
+
+    def save_config(self, config: HelmValuesConfig) -> None:
+        """Save the helm-values configuration to disk.
+
+        Args:
+            config: The configuration to save.
+
+        Raises:
+            IOError: If unable to write to the file.
+        """
+        try:
+            with open(self.config_file, "w", encoding="utf-8") as f:
+                json.dump(config.to_dict(), f, indent=2)
+        except IOError as e:
+            HelmLogger.error("Failed to save configuration: %s", e)
+            raise
+
+    def acquire_lock(self) -> None:
+        """Acquire an exclusive lock for file operations.
+
+        This ensures thread-safe operations when multiple commands
+        are trying to modify the configuration.
+
+        Raises:
+            IOError: If unable to acquire the lock.
+        """
+        self._lock_fd = os.open(self.lock_file, os.O_CREAT | os.O_RDWR)
+        try:
+            fcntl.flock(self._lock_fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            HelmLogger.debug("Acquired lock on file %s", self.lock_file)
+        except IOError:
+            os.close(self._lock_fd)
+            self._lock_fd = None
+            HelmLogger.error("Unable to acquire lock. Another command may be running.")
+            raise IOError("Unable to acquire lock. Another command may be running.")
+
+    def release_lock(self) -> None:
+        """Release the exclusive lock."""
+        if self._lock_fd is not None:
+            fcntl.flock(self._lock_fd, fcntl.LOCK_UN)
+            os.close(self._lock_fd)
+            self._lock_fd = None
+            HelmLogger.debug("Released lock on file %s", self.lock_file)
+
+    def execute(self) -> Any:
+        """Execute the command.
+
+        This is the main entry point for running a command.
+        It handles:
+        1. Lock acquisition
+        2. Configuration loading
+        3. Command execution via run()
+        4. Lock release
+
+        Returns:
+            Any: The result of the command execution.
+
+        Raises:
+            Exception: If any error occurs during command execution.
+        """
+        try:
+            self.acquire_lock()
+            config = self.load_config()
+            result = self.run(config)
+            return result
+        finally:
+            self.release_lock()
+
+    def run(self, config: HelmValuesConfig) -> Any:
+        """Run the command-specific logic.
+
+        This method should be implemented by each specific command subclass
+        to perform its unique functionality.
+
+        Args:
+            config: The loaded configuration.
+
+        Returns:
+            Any: The result of running the command.
+
+        Raises:
+            NotImplementedError: This method must be implemented by subclasses.
+        """
+        raise NotImplementedError("Subclasses must implement run()")

tests/unit/commands/__init__.py

@@ -0,0 +1 @@
+"""Unit tests for the commands package."""