from __future__ import absolute_import, print_function

import struct

from mercurial import (

    bdiff,

    mpatch,

)

#issue1295

def showdiff(a, b):

    print('showdiff(\n  %r,\n  %r):' % (a, b))

    bin = bdiff.bdiff(a, b)

    pos = 0

    q = 0

    while pos < len(bin):

        p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12])

        pos += 12

        if p1:

            print('', repr(a[q:p1]))

        print('', p1, p2, repr(a[p1:p2]), '->', repr(bin[pos:pos + l]))

        pos += l

        q = p2

    if q < len(a):

        print('', repr(a[q:]))

showdiff("x\n\nx\n\nx\n\nx\n\nz\n", "x\n\nx\n\ny\n\nx\n\nx\n\nz\n")

showdiff("x\n\nx\n\nx\n\nx\n\nz\n", "x\n\nx\n\ny\n\nx\n\ny\n\nx\n\nz\n")

# we should pick up abbbc. rather than bc.de as the longest match

showdiff("a\nb\nb\nb\nc\n.\nd\ne\n.\nf\n",

         "a\nb\nb\na\nb\nb\nb\nc\n.\nb\nc\n.\nd\ne\nf\n")

print("done")

def testfixws(a, b, allws):

    c = bdiff.fixws(a, allws)

    if c != b:

        print("*** fixws", repr(a), repr(b), allws)

        print("got:")

        print(repr(c))

testfixws(" \ta\r b\t\n", "ab\n", 1)

testfixws(" \ta\r b\t\n", " a b\n", 0)

testfixws("", "", 1)

testfixws("", "", 0)

print("done")

print("Nice diff for a trivial change:")

showdiff(

    ''.join('<%s\n-\n' % i for i in range(5)),

    ''.join('>%s\n-\n' % i for i in range(5)))

print("Diff 1 to 3 lines - preference for appending:")

showdiff('a\n', 'a\n' * 3)

print("Diff 1 to 5 lines - preference for appending:")

showdiff('a\n', 'a\n' * 5)

print("Diff 3 to 1 lines - preference for removing trailing lines:")

showdiff('a\n' * 3, 'a\n')

print("Diff 5 to 1 lines - preference for removing trailing lines:")

showdiff('a\n' * 5, 'a\n')