#!/usr/bin/env python
# Copyright (c) 2014, Intel Corporation
# Author: Andi Kleen
#
# This program is free software; you can redistribute it and/or modify it
# under the terms and conditions of the GNU General Public License,
# version 2, as published by the Free Software Foundation.
#
# This program is distributed in the hope it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
# more details.
#
# Automatic event list downloader
#
# event_download.py         download for current cpu
# event_download.py -a      download all
# event_download.py cpustr...  Download for specific CPU
from __future__ import absolute_import
from __future__ import print_function
import sys

import re
import os
import string
from fnmatch import fnmatch
from shutil import copyfile

try:
    from urllib2 import URLError
except ImportError:
    # python 3
    from urllib.error import URLError


urlpath = 'https://download.01.org/perfmon'
localpath = 'pmu_local_mirror/download.01.org/perfmon'
mapfile = 'mapfile.csv'
modelpath = localpath + "/" + mapfile
NSB_JSON = os.environ.get("PMU_EVENTS_PATH", "/tmp/pmu_event.json")


def get_cpustr():
    with open('/proc/cpuinfo', 'r') as f:
        cpu = [None, None, None]
        for j in f:
            n = j.split()
            if n[0] == 'vendor_id':
                cpu[0] = n[2]
            elif n[0] == 'model' and n[1] == ':':
                cpu[2] = int(n[2])
            elif n[0] == 'cpu' and n[1] == 'family':
                cpu[1] = int(n[3])
            if all(cpu):
                break
    return "%s-%d-%X" % (cpu[0], cpu[1], cpu[2])


def sanitize(s, a):
    o = ""
    for j in s:
        if j in a:
            o += j
    return o


def getdir():
    try:
        d = os.getenv("XDG_CACHE_HOME")
        xd = d
        if not d:
            home = os.getenv("HOME")
            d = "%s/.cache" % home
        d += "/pmu-events"
        if not os.path.isdir(d):
            # try to handle the sudo case
            if not xd:
                user = os.getenv("SUDO_USER")
                if user:
                    nd = os.path.expanduser("~" + user) + "/.cache/pmu-events"
                    if os.path.isdir(nd):
                        return nd
            os.makedirs(d)
        return d
    except OSError:
        raise Exception('Cannot access ' + d)


NUM_TRIES = 3


def getfile(url, dir, fn):
    tries = 0
    print("Downloading", url, "to", fn)
    while True:
        try:
            f = open(url)
            data = f.read()
        except IOError:
            tries += 1
            if tries >= NUM_TRIES:
                raise
            print("retrying download")
            continue
        break
    with open(os.path.join(dir, fn), "w") as o:
        o.write(data)
    f.close()


allowed_chars = string.ascii_letters + '_-.' + string.digits


def download(match, key=None, link=True):
    found = 0
    dir = getdir()
    try:
        getfile(modelpath, dir, "mapfile.csv")
        models = open(os.path.join(dir, "mapfile.csv"))
        for j in models:
            n = j.rstrip().split(",")
            if len(n) < 4:
                if len(n) > 0:
                    print("Cannot parse", n)
                continue
            cpu, version, name, type = n
            if not fnmatch(cpu, match) or (key is not None and type not in key) or type.startswith("EventType"):
                continue
            cpu = sanitize(cpu, allowed_chars)
            url = localpath + name
            fn = "%s-%s.json" % (cpu, sanitize(type, allowed_chars))
            try:
                os.remove(os.path.join(dir, fn))
            except OSError:
                pass
            getfile(url, dir, fn)
            if link:
                lname = re.sub(r'.*/', '', name)
                lname = sanitize(lname, allowed_chars)
                try:
                    os.remove(os.path.join(dir, lname))
                except OSError:
                    pass
                try:
                    os.symlink(fn, os.path.join(dir, lname))
                except OSError as e:
                    print("Cannot link %s to %s:" % (name, lname), e, file=sys.stderr)
            found += 1
        models.close()
        getfile(localpath + "/readme.txt", dir, "readme.txt")
    except URLError as e:
        print("Cannot access event server:", e, file=sys.stderr)
        print("If you need a proxy to access the internet please set it with:", file=sys.stderr)
        print("\texport https_proxy=http://proxyname...", file=sys.stderr)
        print("If you are not connected to the internet please run this on a connected system:", file=sys.stderr)
        print("\tevent_download.py '%s'" % match, file=sys.stderr)
        print("and then copy ~/.cache/pmu-events to the system under test", file=sys.stderr)
        print("To get events for all possible CPUs use:", file=sys.stderr)
        print("\tevent_download.py -a", file=sys.stderr)
    except OSError as e:
        print("Cannot write events file:", e, file=sys.stderr)
    return found


def download_current(link=False):
    """Download JSON event list for current cpu.
       Returns >0 when a event list is found"""
    return download(get_cpustr(), link=link)


def eventlist_name(name=None, key="core"):
    if not name:
        name = get_cpustr()
    cache = getdir()
    return "%s/%s-%s.json" % (cache, name, key)


if __name__ == '__main__':
    # only import argparse when actually called from command line
    # this makes ocperf work on older python versions without it.
    import argparse
    p = argparse.ArgumentParser(usage='download Intel event files')
    p.add_argument('--all', '-a', help='Download all available event files', action='store_true')
    p.add_argument('--verbose', '-v', help='Be verbose', action='store_true')
    p.add_argument('--mine', help='Print name of current CPU', action='store_true')
    p.add_argument('--link', help='Create links with the original event file name',
                   action='store_true', default=True)
    p.add_argument('cpus', help='CPU identifiers to download', nargs='*')
    args = p.parse_args()

    cpustr = get_cpustr()
    if args.verbose or args.mine:
        print("My CPU", cpustr)
    if args.mine:
        sys.exit(0)
    d = getdir()
    if args.all:
        found = download('*', link=args.link)
    elif len(args.cpus) == 0:
        found = download_current(link=args.link)
    else:
        found = 0
        for j in args.cpus:
            found += download(j, link=args.link)

    if found == 0:
        print("Nothing found", file=sys.stderr)

    el = eventlist_name()
    if os.path.exists(el):
        print("my event list", el)
        copyfile(el, NSB_JSON)
        print("File copied to ", NSB_JSON)