#!/usr/bin/env python3

# Search for interesting discovery instance

#

#  search-discovery-case REPO [REPO]…

#

# This use a subsetmaker extension (next to this script) to generate a steam of

# random discovery instance. When interesting case are discovered, information

# about them are print on the stdout.

from __future__ import print_function

import json

import os

import queue

import random

import signal

import subprocess

import sys

import threading

this_script = os.path.abspath(sys.argv[0])

this_dir = os.path.dirname(this_script)

hg_dir = os.path.join(this_dir, '..', '..')

HG_REPO = os.path.normpath(hg_dir)

HG_BIN = os.path.join(HG_REPO, 'hg')

JOB = int(os.environ.get('NUMBER_OF_PROCESSORS', 8))

SLICING = ('scratch', 'randomantichain', 'rev')

def nb_revs(repo_path):

    cmd = [

        HG_BIN,

        '--repository',

        repo_path,

        'log',

        '--template',

        '{rev}',

        '--rev',

        'tip',

    ]

    s = subprocess.Popen(cmd, stdout=subprocess.PIPE)

    out, err = s.communicate()

    return int(out)

repos = []

for repo in sys.argv[1:]:

    size = nb_revs(repo)

    repos.append((repo, size))

def pick_one(repo):

    pick = random.choice(SLICING)

    seed = random.randint(0, 100000)

    if pick == 'scratch':

        start = int(repo[1] * 0.3)

        end = int(repo[1] * 0.7)

        nb = random.randint(start, end)

        return ('scratch', nb, seed)

    elif pick == 'randomantichain':

        return ('randomantichain', seed)

    elif pick == 'rev':

        start = int(repo[1] * 0.3)

        end = int(repo[1])

        rev = random.randint(start, end)

        return ('rev', rev)

    else:

        assert False

done = threading.Event()

cases = queue.Queue(maxsize=10 * JOB)

results = queue.Queue()

def worker():

    while not done.is_set():

        c = cases.get()

        if c is None:

            return

        try:

            res = process(c)

            results.put((c, res))

        except Exception as exc:

            print('processing-failed: %s %s' % (c, exc), file=sys.stderr)

        c = (c[0], c[2], c[1])

        try:

            res = process(c)

            results.put((c, res))

        except Exception as exc:

            print('processing-failed: %s %s' % (c, exc), file=sys.stderr)

SUBSET_PATH = os.path.join(HG_REPO, 'contrib', 'perf-utils', 'subsetmaker.py')

CMD_BASE = (

    HG_BIN,

    'debugdiscovery',

    '--template',

    'json',

    '--config',

    'extensions.subset=%s' % SUBSET_PATH,

)

#    '--local-as-revs "$left" --local-as-revs "$right"'

#    > /data/discovery-references/results/disco-mozilla-unified-$1-$2.txt

#        )

def to_revsets(case):

    t = case[0]

    if t == 'scratch':

        return 'not scratch(all(), %d, "%d")' % (case[1], case[2])

    elif t == 'randomantichain':

        return '::randomantichain(all(), "%d")' % case[1]

    elif t == 'rev':

        return '::%d' % case[1]

    else:

        assert False

def process(case):

    (repo, left, right) = case

    cmd = list(CMD_BASE)

    cmd.append('-R')

    cmd.append(repo[0])

    cmd.append('--local-as-revs')

    cmd.append(to_revsets(left))

    cmd.append('--remote-as-revs')

    cmd.append(to_revsets(right))

    s = subprocess.Popen(cmd, stdout=subprocess.PIPE)

    out, err = s.communicate()

    return json.loads(out)[0]

def interesting_boundary(res):

    """check if a case is interesting or not

    For now we are mostly interrested in case were we do multiple roundstrip

    and where the boundary is somewhere in the middle of the undecided set.

    Ideally, we would make this configurable, but this is not a focus for now

    return None or (round-trip, undecided-common, undecided-missing)

    """

    roundtrips = res["total-roundtrips"]

    if roundtrips <= 1:

        return None

    undecided_common = res["nb-ini_und-common"]

    undecided_missing = res["nb-ini_und-missing"]

    if undecided_common == 0:

        return None

    if undecided_missing == 0:

        return None

    return (roundtrips, undecided_common, undecided_missing)

def end(*args, **kwargs):

    done.set()

def format_case(case):

    return '-'.join(str(s) for s in case)

signal.signal(signal.SIGINT, end)

for i in range(JOB):

    threading.Thread(target=worker).start()

nb_cases = 0

while not done.is_set():

    repo = random.choice(repos)

    left = pick_one(repo)

    right = pick_one(repo)

    cases.put((repo, left, right))

    while not results.empty():

        # results has a single reader so this is fine

        c, res = results.get_nowait()

        boundary = interesting_boundary(res)

        if boundary is not None:

            print(c[0][0], format_case(c[1]), format_case(c[2]), *boundary)

            sys.stdout.flush()

    nb_cases += 1

    if not nb_cases % 100:

        print('[%d cases generated]' % nb_cases, file=sys.stderr)

for i in range(JOB):

    try:

        cases.put_nowait(None)

    except queue.Full:

        pass

print('[%d cases generated]' % nb_cases, file=sys.stderr)

print('[ouput generation is over]' % nb_cases, file=sys.stderr)