#!/usr/bin/python3

import argparse
import re

ap = argparse.ArgumentParser()
ap.add_argument("files", nargs="+")

args = ap.parse_args()

sessions = {}
summary = {}
for fn in args.files:
    with open(fn) as fh:
        for ln in fh:
            if m := re.match(r".*user=\[unknown\],db=\[unknown\],pid=(\d+) LOG:  connection received: host=(\S+)", ln):
                pid = int(m.group(1))
                host = m.group(2)
                sessions[pid] = { "host": host }
            elif m := re.match(r".*user=(.*?),db=(.*?),pid=(\d+) LOG:  connection authorized:", ln):
                user = m.group(1)
                db = m.group(2)
                pid = int(m.group(3))
                sessions[pid]["user"] = user
                sessions[pid]["db"] = db
                if m := re.match(r".*application_name=(\S+)", ln):
                    sessions[pid]["application_name"] = m.group(1)
                else:
                    sessions[pid]["application_name"] = "-"
            elif m := re.match(r".*user=(.*?),db=(.*?),pid=(\d+) LOG:  disconnection: session time: ([0-9:.]+) user=\S+ database=\S+ host=(\S+)", ln):
                user = m.group(1)
                db = m.group(2)
                pid = int(m.group(3))
                time_str = m.group(4)
                host = m.group(5)
                m = re.match("(\d+):(\d{2}):(\d{2})\.(\d{3})", time_str)
                time = int(m.group(1)) * 3600 + int(m.group(2)) * 60 + int(m.group(3)) * 1 + int(m.group(4)) * 0.001

                assert user == sessions[pid]["user"]
                assert db == sessions[pid]["db"]
                assert host == sessions[pid]["host"]

                s = summary.setdefault((db, user, host, sessions[pid]["application_name"]), { "n_sessions": 0, "session_time": 0 })
                s["n_sessions"] += 1
                s["session_time"] += time
                del sessions[pid]

print("Database", "User", "Client", "Application", "#Sessions", "Session time (s)", sep="\t")
for k, v in summary.items():
    print(k[0], k[1], k[2], k[3], v["n_sessions"], v["session_time"], sep="\t")

# vim: tw=0