#!/usr/bin/env python3
"""
Context Monitor Hook - UserPromptSubmit hook
Monitors context usage and triggers backups when needed
"""

import sys
import json
import os
from pathlib import Path

# Add lib directory to path
sys.path.insert(0, str(Path(__file__).parent.parent / "lib"))

from context_monitor import ContextMonitor
from backup_manager import BackupManager  
from session_state import SessionStateManager


def main():
    """Main hook entry point"""
    try:
        # Read input from Claude Code
        input_data = json.loads(sys.stdin.read())
        
        # Initialize components
        context_monitor = ContextMonitor()
        backup_manager = BackupManager()
        session_manager = SessionStateManager()
        
        # Update context estimates from prompt
        context_monitor.update_from_prompt(input_data)
        
        # Check if backup should be triggered
        backup_decision = context_monitor.check_backup_triggers("UserPromptSubmit", input_data)
        
        if backup_decision.should_backup:
            # Execute backup
            session_state = session_manager.get_session_summary()
            backup_result = backup_manager.execute_backup(backup_decision, session_state)
            
            # Record backup in session
            session_manager.add_backup(backup_result.backup_id, {
                "reason": backup_decision.reason,
                "success": backup_result.success
            })
            
            # Add context snapshot
            session_manager.add_context_snapshot({
                "usage_ratio": context_monitor.get_context_usage_ratio(),
                "prompt_count": context_monitor.prompt_count,
                "tool_executions": context_monitor.tool_executions
            })
            
            # Notify about backup
            if backup_result.success:
                message = f"Auto-backup created: {backup_decision.reason} (usage: {context_monitor.get_context_usage_ratio():.1%})"
            else:
                message = f"Backup attempted but failed: {backup_result.error}"
        else:
            message = f"Context usage: {context_monitor.get_context_usage_ratio():.1%}"
        
        # Always allow operation (this is a monitoring hook)
        response = {
            "allow": True,
            "message": message
        }
        
        print(json.dumps(response))
        sys.exit(0)
        
    except Exception as e:
        # Never block on errors - always allow operation
        response = {
            "allow": True,
            "message": f"Context monitor error: {str(e)}"
        }
        print(json.dumps(response))
        sys.exit(0)


if __name__ == "__main__":
    main()