cli.py

import argparse
import json
import sys
from reader import JournalReader
from parser import LogParser, LogEntry


def main():
    parser = argparse.ArgumentParser(
        description='Analyze systemd logs and generate a chronological timeline of errors and service failures.'
    )
    parser.add_argument(
        '--boot', 
        type=int, 
        default=0,
        help='Boot number to analyze (0=current, -1=previous boot)'
    )
    parser.add_argument(
        '--service',
        type=str,
        help='Filter by service name (e.g., nginx)'
    )
    parser.add_argument(
        '--json',
        action='store_true',
        help='Output in JSON format'
    )

    args = parser.parse_args()

    try:
        reader = JournalReader()
        log_parser = LogParser()

        lines = reader.read_logs(boot=args.boot, service=args.service)
        
        if not lines:
            print("No errors detected in the specified boot.")
            return 0

        entries = log_parser.parse(lines)

        if not entries:
            print("No errors detected in the specified boot.")
            return 0

        if args.json:
            output = [entry.to_dict() for entry in entries]
            print(json.dumps(output, indent=2))
        else:
            for entry in entries:
                print(entry.to_text())

        return 0

    except RuntimeError as e:
        print(f"Error: {str(e)}", file=sys.stderr)
        return 1
    except KeyboardInterrupt:
        print("\nInterrupted by user", file=sys.stderr)
        return 130
    except Exception as e:
        print(f"Unexpected error: {str(e)}", file=sys.stderr)
        return 1


if __name__ == '__main__':
    sys.exit(main())