/*
Copyright 2023 The KubeSphere Authors.

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.
*/

package modules

import (
	"context"

	utilruntime "k8s.io/apimachinery/pkg/util/runtime"

	"github.com/kubesphere/kubekey/v4/pkg/variable"
)

/*
The Command module executes shell commands on remote hosts and returns their output.
This module allows users to run arbitrary shell commands and capture their output.

Configuration:
Users can specify the command to execute:

command: "ls -l"    # The shell command to execute

Usage Examples in Playbook Tasks:
1. Basic command execution:
   ```yaml
   - name: List directory contents
     command: ls -l
     register: ls_result
   ```

2. Command with variables:
   ```yaml
   - name: Check service status
     command: systemctl status {{ service_name }}
     register: service_status
   ```

3. Complex command:
   ```yaml
   - name: Get disk usage
     command: df -h | grep /dev/sda1
     register: disk_usage
   ```

Return Values:
- On success: Returns command output in stdout
- On failure: Returns error message in stderr
*/

// ModuleCommand handles the "command" module, executing shell commands on remote hosts
func ModuleCommand(ctx context.Context, options ExecOptions) (string, string, error) {
	// get host variable
	ha, err := options.getAllVariables()
	if err != nil {
		return StdoutFailed, StderrGetHostVariable, err
	}
	// get connector
	conn, err := options.getConnector(ctx)
	if err != nil {
		return StdoutFailed, StderrGetConnector, err
	}
	defer conn.Close(ctx)
	// command string
	command, err := variable.Extension2String(ha, options.Args)
	if err != nil {
		return StdoutFailed, StderrParseArgument, err
	}
	// execute command
	stdout, stderr, err := conn.ExecuteCommand(ctx, string(command))
	return string(stdout), string(stderr), err
}

func init() {
	utilruntime.Must(RegisterModule("command", ModuleCommand))
	utilruntime.Must(RegisterModule("shell", ModuleCommand))
}
