"""
Real-time log file monitor for debug mode
Displays log file content in a visible CMD window
"""
import sys
import time
import os
from pathlib import Path

def monitor_log_file(log_path: str, job_name: str):
    """Monitor log file and display content in real-time"""

    # Set console title
    os.system(f'title Job Debug - {job_name}')

    print("=" * 80)
    print(f"JOB DEBUG MONITOR - {job_name}")
    print("=" * 80)
    print(f"Log file: {log_path}")
    print("=" * 80)
    print()
    print("Waiting for log file to be created...")
    print()

    # Wait for log file to exist
    max_wait = 30  # seconds
    waited = 0
    while not os.path.exists(log_path) and waited < max_wait:
        time.sleep(0.5)
        waited += 0.5

    if not os.path.exists(log_path):
        print(f"ERROR: Log file not created after {max_wait} seconds")
        print(f"Expected path: {log_path}")
        input("\nPress Enter to close...")
        return

    print(f"Log file found! Monitoring output...\n")
    print("=" * 80)
    print()

    # Open file and start tailing
    with open(log_path, 'r', encoding='utf-8', errors='replace') as f:
        # Read existing content
        content = f.read()
        if content:
            print(content, end='')

        # Monitor for new content
        last_position = f.tell()
        no_change_count = 0
        max_no_change = 600  # 60 seconds with 0.1s sleep = 600 iterations

        while True:
            # Check if file still exists (job might have finished and cleaned up)
            if not os.path.exists(log_path):
                break

            # Read new content
            f.seek(last_position)
            new_content = f.read()

            if new_content:
                print(new_content, end='', flush=True)
                last_position = f.tell()
                no_change_count = 0
            else:
                no_change_count += 1

                # If no changes for a while, check if parent process still exists
                if no_change_count >= max_no_change:
                    # Assume job has finished
                    break

            time.sleep(0.1)  # Check every 100ms

    print()
    print("=" * 80)
    print("MONITORING COMPLETE - Job finished or log file closed")
    print("=" * 80)
    input("\nPress Enter to close this window...")

if __name__ == '__main__':
    if len(sys.argv) != 3:
        print("Usage: python log_monitor.py <log_file_path> <job_name>")
        sys.exit(1)

    log_file_path = sys.argv[1]
    job_name = sys.argv[2]

    try:
        monitor_log_file(log_file_path, job_name)
    except KeyboardInterrupt:
        print("\n\nMonitoring interrupted by user")
    except Exception as e:
        print(f"\n\nERROR: {e}")
        import traceback
        traceback.print_exc()
        input("\nPress Enter to close...")