bytelyst-devops-tools/Slack Message/slack_poster.py

#!/usr/bin/env python3
"""
Slack Message Poster CLI Tool

A command-line tool that posts messages to Slack channels using the Slack Web API.
"""

import argparse
import os
import sys
from datetime import datetime
from typing import Optional

try:
    from slack_sdk import WebClient
    from slack_sdk.errors import SlackApiError, SlackClientError
except ImportError:
    print("Error: slack_sdk not installed. Run: pip install slack_sdk")
    sys.exit(1)

# Try to load environment variables from .env file
try:
    from dotenv import load_dotenv
    load_dotenv()
except ImportError:
    # dotenv not installed, continue without it
    pass


class SlackPoster:
    """Main class for posting messages to Slack."""
    
    def __init__(self, token: str):
        """Initialize the Slack client with the provided token."""
        self.client = WebClient(token=token)
    
    def post_message(self, channel: str, message: str) -> dict:
        """
        Post a message to the specified Slack channel.
        
        Args:
            channel: Slack channel ID (e.g., C04ABC123)
            message: Message text to post
            
        Returns:
            dict: Response from Slack API
            
        Raises:
            SlackApiError: If the API call fails
            SlackClientError: If there's a client error
        """
        try:
            response = self.client.chat_postMessage(
                channel=channel,
                text=message
            )
            return response
        except SlackApiError as e:
            raise e
        except SlackClientError as e:
            raise e


def get_user_input(prompt: str, required: bool = True) -> str:
    """
    Get user input with optional validation.
    
    Args:
        prompt: The prompt to display to the user
        required: Whether the input is required
        
    Returns:
        str: User input
    """
    while True:
        value = input(prompt).strip()
        if value or not required:
            return value
        print("This field is required. Please try again.")


def validate_token(token: str) -> bool:
    """
    Basic validation for Slack token format.
    
    Args:
        token: The token to validate
        
    Returns:
        bool: True if token format looks valid
    """
    if not token:
        return False
    
    # Basic format validation for Slack tokens
    valid_prefixes = ['xoxb-', 'xoxp-', 'xoxa-', 'xoxr-']
    return any(token.startswith(prefix) for prefix in valid_prefixes)


def validate_channel(channel: str) -> bool:
    """
    Basic validation for Slack channel ID format.
    
    Args:
        channel: The channel ID to validate
        
    Returns:
        bool: True if channel format looks valid
    """
    if not channel:
        return False
    
    # Slack channel IDs typically start with C, D, or G
    return channel.startswith(('C', 'D', 'G')) and len(channel) > 1


def main():
    """Main function to handle CLI arguments and execute the message posting."""
    parser = argparse.ArgumentParser(
        description="Post a message to a Slack channel",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Examples:
  python slack_poster.py -t xoxb-1234567890-1234567890-abcdefghijklmnopqrstuvwx -c C04ABC123 -m "Hello World!"
  python slack_poster.py --token xoxb-1234567890-1234567890-abcdefghijklmnopqrstuvwx --channel C04ABC123 --message "Hello World!"
  python slack_poster.py  # Interactive mode - will prompt for missing parameters
        """
    )
    
    parser.add_argument(
        '--token', '-t',
        type=str,
        help='Slack Bot/User OAuth token (e.g., xoxb-...)'
    )
    
    parser.add_argument(
        '--channel', '-c',
        type=str,
        help='Slack channel ID (e.g., C04ABC123)'
    )
    
    parser.add_argument(
        '--message', '-m',
        type=str,
        help='Message text to post'
    )
    
    args = parser.parse_args()
    
    # Get token (try environment variable first, then command line, then interactive)
    token = args.token or os.getenv('SLACK_BOT_TOKEN')
    if not token:
        print("Slack Token not provided. Please enter it interactively:")
        token = get_user_input("Enter your Slack token: ")
    
    # Validate token format
    if not validate_token(token):
        print("Error: Invalid token format. Slack tokens typically start with 'xoxb-', 'xoxp-', 'xoxa-', or 'xoxr-'")
        sys.exit(1)
    
    # Get channel (try environment variable first, then command line, then interactive)
    channel = args.channel or os.getenv('SLACK_CHANNEL_ID')
    if not channel:
        print("Channel ID not provided. Please enter it interactively:")
        channel = get_user_input("Enter Slack channel ID (e.g., C04ABC123): ")
    
    # Validate channel format
    if not validate_channel(channel):
        print("Error: Invalid channel format. Channel IDs typically start with 'C', 'D', or 'G'")
        sys.exit(1)
    
    # Get message
    message = args.message
    if not message:
        print("Message not provided. Please enter it interactively:")
        message = get_user_input("Enter message text: ")
    
    # Validate message
    if not message.strip():
        print("Error: Message cannot be empty")
        sys.exit(1)
    
    # Initialize Slack poster and send message
    try:
        poster = SlackPoster(token)
        response = poster.post_message(channel, message)
        
        # Extract timestamp from response
        timestamp = response.get('ts', 'unknown')
        channel_name = response.get('channel', channel)
        
        # Convert timestamp to readable format
        try:
            dt = datetime.fromtimestamp(float(timestamp))
            formatted_time = dt.strftime('%Y-%m-%d %H:%M:%S UTC')
        except (ValueError, TypeError):
            formatted_time = timestamp
        
        print(f"[SUCCESS] Message posted to channel {channel_name}")
        print(f"[TIMESTAMP] {formatted_time}")
        print(f"[MESSAGE] {message}")
        
    except SlackApiError as e:
        error_msg = str(e)
        if "invalid_auth" in error_msg.lower():
            print("[ERROR] Invalid token. Please check your Slack token.")
        elif "channel_not_found" in error_msg.lower():
            print(f"[ERROR] Channel '{channel}' not found. Please check the channel ID.")
        elif "not_in_channel" in error_msg.lower():
            print(f"[ERROR] Bot is not a member of channel '{channel}'. Please add the bot to the channel.")
        elif "rate_limited" in error_msg.lower():
            print("[ERROR] Rate limited. Please wait before trying again.")
        else:
            print(f"[ERROR] Slack API Error: {error_msg}")
        sys.exit(1)
        
    except SlackClientError as e:
        print(f"[ERROR] Slack Client Error: {e}")
        sys.exit(1)
        
    except Exception as e:
        print(f"[ERROR] Unexpected error: {e}")
        sys.exit(1)


if __name__ == "__main__":
    main()