import fcntl
import time
import sys
import os, os.path
import csv
from datetime import datetime

if 'freebsd' in sys.platform.lower() or "darwin" in sys.platform.lower():
    report_file = "/usr/local/panopta-agent/lib/report"
else:
    report_file = '/var/lib/panopta-agent/report'
if not os.path.exists(report_file):
    home = os.path.expanduser("~")
    report_file = os.path.join(home, "lib", "panopta-agent", "report")

unlock_attempts = 10

def report_metric(textkey, value, timestamp):
    csvfile = open(report_file, 'a')

    # Acquire lock
    locked = True
    for i in range(unlock_attempts):
        try:
            fcntl.flock(csvfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
            locked = False
            break
        except:
            time.sleep(1.0)
    if locked:
        print("Could not unlock %s after %s attempts" % (report_file, unlock_attempts))
        sys.exit(1)

    # Append new metric value
    csvwriter = csv.writer(csvfile)
    csvwriter.writerow([textkey, value, timestamp.strftime("%Y-%m-%d %H:%M:%S")])

    # Release lock
    fcntl.flock(csvfile, fcntl.LOCK_UN)
    csvfile.close()

if __name__ == "__main__":
    if len(sys.argv) < 3:
        print("Please specify textkey, value, and optionally UTC timestamp in ISO format")
        print('Example: python report.py metric.key 3.5 "2015-03-24 10:11:12"')
        sys.exit(0)
    else:
        if len(sys.argv) >= 4:
            try: timestamp = datetime.strptime(sys.argv[3], "%Y-%m-%d %H:%M:%S")
            except:
                print("Cannot parse timestamp")
                sys.exit(0)
        else:
            timestamp = datetime.now()
        try: value = float(sys.argv[2])
        except:
            print("Value should be a number")
            sys.exit(0)
        report_metric(sys.argv[1], value, timestamp)