#!/usr/bin/env python3
import sys

def compare_logs(file1, file2, N):
    marker = "Local Time-Stepping Loop"
    lines1, lines2 = [], []

    # Find section in file1
    with open(file1, "r") as f1:
        for line in f1:
            if marker in line:
                # Skip marker line and break
                break
        # Read next N lines
        for _ in range(N):
            l = f1.readline()
            if not l:
                break
            lines1.append(l.strip())

    # Find section in file2
    with open(file2, "r") as f2:
        for line in f2:
            if marker in line:
                break
        for _ in range(N):
            l = f2.readline()
            if not l:
                break
            lines2.append(l.strip())

    # Compare
    print(f"Comparing {len(lines1)} lines from {file1} with {len(lines2)} lines from {file2}:\n")
    for i, (l1, l2) in enumerate(zip(lines1, lines2), start=1):
        if l1 == l2:
            print(f"Line {i}: SAME")
        else:
            print(f"Line {i}: DIFFERENT")
            print(f"  {file1}: {l1}")
            print(f"  {file2}: {l2}")

if __name__ == "__main__":
    if len(sys.argv) != 4:
        print(f"Usage: {sys.argv[0]} <file1> <file2> <N>")
        sys.exit(1)
    file1, file2, N = sys.argv[1], sys.argv[2], int(sys.argv[3])
    compare_logs(file1, file2, N)