"""Headless CLI for IoT PreTester 4.6 Demo.

Exit codes: 0 no high/critical findings, 2 at least one, 1 runtime error.
"""

from __future__ import annotations

import argparse
import logging
import sys

from . import __version__
from .engine import AnalysisEngine
from .findings import Severity
from .reporting import render, FORMATS
from . import logutil


def build_parser() -> argparse.ArgumentParser:
    p = argparse.ArgumentParser(
        prog="analyzer",
        description="Analyze the security of a PCAP or PCAPNG network capture.",
    )
    p.add_argument("capture", help="Path to a .pcap or .pcapng file")
    p.add_argument("-f", "--format", choices=FORMATS, default="md",
                   help="Output format (default: md)")
    p.add_argument("-o", "--output", default=None,
                   help="Output file (default: standard output)")
    p.add_argument("--packet-limit", type=int, default=None,
                   help="Maximum packets to read from a large capture")
    p.add_argument("--device-ip", default=None,
                   help="IP address of the device under test (focuses and attributes findings)")
    p.add_argument("-v", "--verbose", action="store_true", help="Debug logging on stderr")
    p.add_argument("--log-file", default=None, help="Write the analysis log to this file")
    p.add_argument(
        "--version",
        action="version",
        version=f"IoT PreTester 4.6 Demo analyzer {__version__}",
    )
    return p


def main(argv=None) -> int:
    args = build_parser().parse_args(argv)
    logutil.configure_console("DEBUG" if args.verbose else "WARNING")

    try:
        with logutil.run_log(args.log_file):
            result = AnalysisEngine().analyze_pcap(args.capture, packet_limit=args.packet_limit,
                                                   device_ip=args.device_ip)
    except FileNotFoundError as exc:
        print(f"Error: {exc}", file=sys.stderr)
        return 1
    except RuntimeError as exc:
        print(f"Error: {exc}", file=sys.stderr)
        return 1
    except Exception as exc:
        logging.getLogger("analyzer.cli").exception("Unexpected failure")
        print(f"Error: {exc!r}", file=sys.stderr)
        return 1

    report = render(result, args.format)

    if args.output:
        with open(args.output, "w", encoding="utf-8") as fh:
            fh.write(report)
        print(f"Report written: {args.output} "
              f"({result.meta.get('finding_count', 0)} Findings)", file=sys.stderr)
    else:
        print(report)

    worst = max((f.severity.rank for f in result.findings), default=0)
    return 2 if worst >= Severity.HIGH.rank else 0


if __name__ == "__main__":  # pragma: no cover
    raise SystemExit(main())