# Randomized torture test generation for bdiff

from __future__ import absolute_import, print_function

import random

import sys

from mercurial import (

    mdiff,

)

def reducetest(a, b):

    tries = 0

    reductions = 0

    print("reducing...")

    while tries < 1000:

        a2 = "\n".join(l for l in a.splitlines()

                       if random.randint(0, 100) > 0) + "\n"

        b2 = "\n".join(l for l in b.splitlines()

                       if random.randint(0, 100) > 0) + "\n"

        if a2 == a and b2 == b:

            continue

        if a2 == b2:

            continue

        tries += 1

        try:

            test1(a, b)

        except Exception as inst:

            reductions += 1

            tries = 0

            a = a2

            b = b2

    print("reduced:", reductions, len(a) + len(b),

          repr(a), repr(b))

    try:

        test1(a, b)

    except Exception as inst:

        print("failed:", inst)

    sys.exit(0)

def test1(a, b):

    d = mdiff.textdiff(a, b)

    if not d:

        raise ValueError("empty")

    c = mdiff.patches(a, [d])

    if c != b:

        raise ValueError("bad")

def testwrap(a, b):

    try:

        test1(a, b)

        return

    except Exception as inst:

        pass

    print("exception:", inst)

    reducetest(a, b)

def test(a, b):

    testwrap(a, b)

    testwrap(b, a)

def rndtest(size, noise):

    a = []

    src = "                aaaaaaaabbbbccd"

    for x in xrange(size):

        a.append(src[random.randint(0, len(src) - 1)])

    while True:

        b = [c for c in a if random.randint(0, 99) > noise]

        b2 = []

        for c in b:

            b2.append(c)

            while random.randint(0, 99) < noise:

                b2.append(src[random.randint(0, len(src) - 1)])

        if b2 != a:

            break

    a = "\n".join(a) + "\n"

    b = "\n".join(b2) + "\n"

    test(a, b)

maxvol = 10000

startsize = 2

while True:

    size = startsize

    count = 0

    while size < maxvol:

        print(size)

        volume = 0

        while volume < maxvol:

            rndtest(size, 2)

            volume += size

            count += 2

        size *= 2

    maxvol *= 4

    startsize *= 4