#!/usr/bin/env python3
"""Line counter utility - counts lines in a file."""

import sys

def count_lines(filepath):
    """Count lines in a file, return -1 if file doesn't exist or is unreadable."""
    try:
        with open(filepath, 'r') as f:
            return sum(1 for _ in f)
    except (FileNotFoundError, PermissionError, IOError):
        return -1

def count_comma_separated(filepath):
    """Count items in a comma-separated file (first row, count commas + 1)."""
    try:
        with open(filepath, 'r') as f:
            first_line = f.readline().strip()
            if not first_line:
                return 0
            return len(first_line.split(','))
    except (FileNotFoundError, PermissionError, IOError):
        return -1

if __name__ == '__main__':
    if len(sys.argv) != 3:
        print(f"Usage: {sys.argv[0]} <filepath> <mode>", file=sys.stderr)
        print("Modes: count (lines), csv (fields)", file=sys.stderr)
        sys.exit(1)
    
    filepath = sys.argv[1]
    mode = sys.argv[2]
    
    if mode == 'count':
        result = count_lines(filepath)
        if result == -1:
            print(f"ERROR: Cannot read file '{filepath}'", file=sys.stderr)
            sys.exit(2)
        print(result)
    elif mode == 'csv':
        result = count_comma_separated(filepath)
        if result == -1:
            print(f"ERROR: Cannot read file '{filepath}'", file=sys.stderr)
            sys.exit(2)
        print(result)
    else:
        print(f"Unknown mode: {mode}", file=sys.stderr)
        sys.exit(1)