#! /usr/bin/env python3
#
# stats-to-csv <stats.log> <meta.dat> <wwwdir>
#
# Reads information from stats log and outputs csv files
# <wwwdir>/<node>.<datatype>.csv.
# If any of these files already exists, we append (without writing the header
# line again).

import os
import sys


# Read the meta.dat file, and extract node names from it.
def readNodes(meta):
    manager = ""
    loggers = set()
    proxies = set()
    workers = set()

    with open(meta) as f:
        for line in f:
            m = line.split()
            if not m:
                continue

            if m[0] == "node":
                if len(m) < 3:
                    print("error: 'node' line in meta.dat is missing some fields")
                    continue

                if m[2] == "worker":
                    workers.add(m[1])

                if m[2] == "proxy":
                    proxies.add(m[1])

                if m[2] == "logger":
                    loggers.add(m[1])

                if m[2] == "manager":
                    manager = m[1]

    return (manager, loggers, proxies, workers)


# Read the stats.log file, and create/append CSV files for one node.
def processNode(stats, wwwdir, node, iface):
    print(f"{node} ...")

    def openFile(tag, columns):
        name = os.path.join(wwwdir, f"{node}.{tag}.csv")

        if os.path.exists(name):
            f = open(name, "a")
        else:
            f = open(name, "w")
            f.write("time,{}\n".format(",".join(columns)))

        return f

    cpu = openFile("cpu", ["CPU"])
    mem = openFile("mem", ["Memory"])
    if iface:
        iface_mbps = openFile("mbps", ["MBits/sec"])
        iface_pkts = openFile("pkts", ["TCP", "UDP", "ICMP", "Other"])

    def printEntry(t, entry):
        if not entry:
            return

        try:
            val = int(entry["parent-cpu"])
            if "child-cpu" in entry:
                val += int(entry["child-cpu"])
            cpu.write(f"{t},{val}\n")
        except (ValueError, KeyError):
            pass

        try:
            val = int(entry["parent-vsize"])
            if "child-vsize" in entry:
                val += int(entry["child-vsize"])
            mem.write(f"{t},{val}\n")
        except (ValueError, KeyError):
            pass

        if iface:
            e = entry.get("interface-mbps")
            if e:
                iface_mbps.write(f"{t},{e}\n")

            try:
                tc = entry["interface-t"]
                ud = entry["interface-u"]
                ic = entry["interface-i"]
                ot = entry["interface-o"]
                iface_pkts.write(f"{t},{tc},{ud},{ic},{ot}\n")

            except KeyError:
                pass

    entry = {}
    first = -1

    with open(stats) as ff:
        for line in ff:
            m = line.split()

            if len(m) < 2:
                print("error: line in stats.log has less than two fields")
                continue

            if m[1] != node:
                continue

            try:
                t = float(m[0])
            except ValueError:
                print("error: line in stats.log has no timestamp")
                continue

            # Write all available data for one time value.
            if t != first and first >= 0:
                printEntry(t, entry)
                entry = {}

            first = t

            if len(m) > 4:
                entry[f"{m[2]}-{m[3]}"] = m[4]

    if first >= 0:
        printEntry(t, entry)

    cpu.close()
    mem.close()
    if iface:
        iface_mbps.close()
        iface_pkts.close()


def main():
    if len(sys.argv) != 4:
        print(f"usage: {sys.argv[0]} <stats.log> <meta.dat> <www-dir>")
        sys.exit(1)

    stats = sys.argv[1]
    meta = sys.argv[2]
    wwwdir = sys.argv[3]

    try:
        if not os.path.exists(wwwdir):
            os.mkdir(wwwdir)
    except OSError as err:
        print(f"Error: failed to create directory: {err}")
        sys.exit(1)

    try:
        manager, loggers, proxies, workers = readNodes(meta)
    except OSError as err:
        print(f"Error: failed to read file: {err}")
        sys.exit(1)

    try:
        for w in workers:
            processNode(stats, wwwdir, w, True)

        for p in proxies:
            processNode(stats, wwwdir, p, False)

        for l in loggers:
            processNode(stats, wwwdir, l, False)

        if manager:
            processNode(stats, wwwdir, manager, False)
    except OSError as err:
        print(f"Error: {err}")
        sys.exit(1)


if __name__ == "__main__":
    main()