import subprocess
import re
import csv
import os
import time

# Define your shell command
command = ["iostat", "-n", "0"]

headerRow = [
    "timestamp",
    "name",
    "tty_in",
    "tty_out",
    "cpu_user",
    "cpu_user_niced",
    "cpu_system",
    "cpu_interrupt",
    "cpu_idle",
]

filename = "cpuStat.csv"


def runIostat():
    # Run the command and capture output
    result = subprocess.run(command, capture_output=True, text=True)

    timestamp = time.time()
    local_time = time.localtime(timestamp)
    # Format the time components for a more readable output
    timestamp = time.strftime("%Y-%m-%d %H:%M:%S", local_time)

    # Check the return code (0 for success)
    if result.returncode == 0:
        # Check if the file exists
        if not os.path.exists(filename):
            # Create the file in write mode ('w') if it doesn't exist
            with open(filename, "w", newline="") as csvfile:
                csv_writer = csv.writer(csvfile)
                # Write the header row (optional)
                csv_writer.writerow(headerRow)

        # Access the captured output as a string
        output = result.stdout
        byline = re.split("\n", output)
        data = byline[2]
        lineData = data.split()

        if lineData:
            with open(filename, "a", newline="") as csvfile:
                csv_writer = csv.writer(csvfile)
                lineData.insert(0, "cpu")
                lineData.insert(0, timestamp)
                csv_writer.writerow(lineData)

    else:
        print(f"Error running command: {result.stderr}")


def main():
    runIostat()


if __name__ == "__main__":
    main()