#!/usr/bin/env python3
"""
Network configuration validator for ICS-SimLab.

Checks for common network configuration issues that cause docker-compose failures:
1. Duplicate IPs within the same docker_network ("Address already in use")
2. docker_network not declared in ip_networks[]
3. IP address outside the declared subnet

Usage:
    python3 -m tools.check_networking --config <path> [--strict]

Exit codes:
    0: No issues found
    1: Issues found (or --strict and warnings exist)
    2: Configuration file error
"""

import argparse
import json
import sys
from pathlib import Path
from typing import List

from models.ics_simlab_config_v2 import Config
from tools.semantic_validation import validate_network_config, SemanticError


def format_issues(errors: List[SemanticError]) -> str:
    """Format errors for human-readable output."""
    lines = []
    for err in errors:
        lines.append(f"  - {err.entity}: {err.message}")
    return "\n".join(lines)


def main() -> int:
    parser = argparse.ArgumentParser(
        description="Validate ICS-SimLab network configuration"
    )
    parser.add_argument(
        "--config",
        required=True,
        help="Path to configuration.json"
    )
    parser.add_argument(
        "--strict",
        action="store_true",
        help="Exit non-zero on any issue (not just errors)"
    )
    parser.add_argument(
        "--json",
        action="store_true",
        help="Output in JSON format"
    )
    args = parser.parse_args()

    config_path = Path(args.config)
    if not config_path.exists():
        print(f"ERROR: Config file not found: {config_path}", file=sys.stderr)
        return 2

    # Load and validate config
    try:
        raw_data = json.loads(config_path.read_text(encoding="utf-8"))
        config = Config.model_validate(raw_data)
    except json.JSONDecodeError as e:
        print(f"ERROR: Invalid JSON in {config_path}: {e}", file=sys.stderr)
        return 2
    except Exception as e:
        print(f"ERROR: Config validation failed: {e}", file=sys.stderr)
        return 2

    # Run network validation
    errors = validate_network_config(config)

    if args.json:
        output = {
            "config": str(config_path),
            "issues": [{"entity": e.entity, "message": e.message} for e in errors],
            "status": "error" if errors else "ok"
        }
        print(json.dumps(output, indent=2))
    else:
        if errors:
            print(f"NETWORK VALIDATION ISSUES ({len(errors)}):")
            print(format_issues(errors))
            print()
            print("FIX: Each device must have a unique IP within its docker_network.")
            print("     Check for copy-paste errors or IP assignment overlap.")
        else:
            print(f"OK: Network configuration valid ({config_path})")

    # Return appropriate exit code
    if errors:
        return 1
    return 0


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