# extdiff.py - external diff program support for mercurial

#

# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

'''command to allow external programs to compare revisions

The extdiff Mercurial extension allows you to use external programs

to compare revisions, or revision with working directory. The external

diff programs are called with a configurable set of options and two

non-option arguments: paths to directories containing snapshots of

files to compare.

The extdiff extension also allows you to configure new diff commands, so

you do not need to type :hg:`extdiff -p kdiff3` always. ::

  [extdiff]

  # add new command that runs GNU diff(1) in 'context diff' mode

  cdiff = gdiff -Nprc5

  ## or the old way:

  #cmd.cdiff = gdiff

  #opts.cdiff = -Nprc5

  # add new command called vdiff, runs kdiff3

  vdiff = kdiff3

  # add new command called meld, runs meld (no need to name twice)

  meld =

  # add new command called vimdiff, runs gvimdiff with DirDiff plugin

  # (see http://www.vim.org/scripts/script.php?script_id=102) Non

  # English user, be sure to put "let g:DirDiffDynamicDiffText = 1" in

  # your .vimrc

  vimdiff = gvim -f "+next" \\

            "+execute 'DirDiff' fnameescape(argv(0)) fnameescape(argv(1))"

Tool arguments can include variables that are expanded at runtime::

  $parent1, $plabel1 - filename, descriptive label of first parent

  $child,   $clabel  - filename, descriptive label of child revision

  $parent2, $plabel2 - filename, descriptive label of second parent

  $root              - repository root

  $parent is an alias for $parent1.

The extdiff extension will look in your [diff-tools] and [merge-tools]

sections for diff tool arguments, when none are specified in [extdiff].

::

  [extdiff]

  kdiff3 =

  [diff-tools]

  kdiff3.diffargs=--L1 '$plabel1' --L2 '$clabel' $parent $child

You can use -I/-X and list of file or directory names like normal

:hg:`diff` command. The extdiff extension makes snapshots of only

needed files, so running the external diff program will actually be

pretty fast (at least faster than having to compare the entire tree).

'''

from mercurial.i18n import _

from mercurial.node import short, nullid

from mercurial import cmdutil, scmutil, util, commands, encoding

import os, shlex, shutil, tempfile, re

cmdtable = {}

command = cmdutil.command(cmdtable)

testedwith = 'internal'

def snapshot(ui, repo, files, node, tmproot):

    '''snapshot files as of some revision

    if not using snapshot, -I/-X does not work and recursive diff

    in tools like kdiff3 and meld displays too many files.'''

    dirname = os.path.basename(repo.root)

    if dirname == "":

        dirname = "root"

    if node is not None:

        dirname = '%s.%s' % (dirname, short(node))

    base = os.path.join(tmproot, dirname)

    os.mkdir(base)

    if node is not None:

        ui.note(_('making snapshot of %d files from rev %s\n') %

                (len(files), short(node)))

    else:

        ui.note(_('making snapshot of %d files from working directory\n') %

            (len(files)))

    wopener = scmutil.opener(base)

    fns_and_mtime = []

    ctx = repo[node]

    for fn in files:

        wfn = util.pconvert(fn)

        if wfn not in ctx:

            # File doesn't exist; could be a bogus modify

            continue

        ui.note('  %s\n' % wfn)

        dest = os.path.join(base, wfn)

        fctx = ctx[wfn]

        data = repo.wwritedata(wfn, fctx.data())

        if 'l' in fctx.flags():

            wopener.symlink(data, wfn)

        else:

            wopener.write(wfn, data)

            if 'x' in fctx.flags():

                util.setflags(dest, False, True)

        if node is None:

            fns_and_mtime.append((dest, repo.wjoin(fn),

                                  os.lstat(dest).st_mtime))

    return dirname, fns_and_mtime

def dodiff(ui, repo, diffcmd, diffopts, pats, opts):

    '''Do the actual diff:

    - copy to a temp structure if diffing 2 internal revisions

    - copy to a temp structure if diffing working revision with

      another one and more than 1 file is changed

    - just invoke the diff for a single file in the working dir

    '''

    revs = opts.get('rev')

    change = opts.get('change')

    args = ' '.join(map(util.shellquote, diffopts))

    do3way = '$parent2' in args

    if revs and change:

        msg = _('cannot specify --rev and --change at the same time')

        raise util.Abort(msg)

    elif change:

        node2 = scmutil.revsingle(repo, change, None).node()

        node1a, node1b = repo.changelog.parents(node2)

    else:

        node1a, node2 = scmutil.revpair(repo, revs)

        if not revs:

            node1b = repo.dirstate.p2()

        else:

            node1b = nullid

    # Disable 3-way merge if there is only one parent

    if do3way:

        if node1b == nullid:

            do3way = False

    matcher = scmutil.match(repo[node2], pats, opts)

    mod_a, add_a, rem_a = map(set, repo.status(node1a, node2, matcher)[:3])

    if do3way:

        mod_b, add_b, rem_b = map(set, repo.status(node1b, node2, matcher)[:3])

    else:

        mod_b, add_b, rem_b = set(), set(), set()

    modadd = mod_a | add_a | mod_b | add_b

    common = modadd | rem_a | rem_b

    if not common:

        return 0

    tmproot = tempfile.mkdtemp(prefix='extdiff.')

    try:

        # Always make a copy of node1a (and node1b, if applicable)

        dir1a_files = mod_a | rem_a | ((mod_b | add_b) - add_a)

        dir1a = snapshot(ui, repo, dir1a_files, node1a, tmproot)[0]

        rev1a = '@%d' % repo[node1a].rev()

        if do3way:

            dir1b_files = mod_b | rem_b | ((mod_a | add_a) - add_b)

            dir1b = snapshot(ui, repo, dir1b_files, node1b, tmproot)[0]

            rev1b = '@%d' % repo[node1b].rev()

        else:

            dir1b = None

            rev1b = ''

        fns_and_mtime = []

        # If node2 in not the wc or there is >1 change, copy it

        dir2root = ''

        rev2 = ''

        if node2:

            dir2 = snapshot(ui, repo, modadd, node2, tmproot)[0]

            rev2 = '@%d' % repo[node2].rev()

        elif len(common) > 1:

            #we only actually need to get the files to copy back to

            #the working dir in this case (because the other cases

            #are: diffing 2 revisions or single file -- in which case

            #the file is already directly passed to the diff tool).

            dir2, fns_and_mtime = snapshot(ui, repo, modadd, None, tmproot)

        else:

            # This lets the diff tool open the changed file directly

            dir2 = ''

            dir2root = repo.root

        label1a = rev1a

        label1b = rev1b

        label2 = rev2

        # If only one change, diff the files instead of the directories

        # Handle bogus modifies correctly by checking if the files exist

        if len(common) == 1:

            common_file = util.localpath(common.pop())

            dir1a = os.path.join(tmproot, dir1a, common_file)

            label1a = common_file + rev1a

            if not os.path.isfile(dir1a):

                dir1a = os.devnull

            if do3way:

                dir1b = os.path.join(tmproot, dir1b, common_file)

                label1b = common_file + rev1b

                if not os.path.isfile(dir1b):

                    dir1b = os.devnull

            dir2 = os.path.join(dir2root, dir2, common_file)

            label2 = common_file + rev2

        # Function to quote file/dir names in the argument string.

        # When not operating in 3-way mode, an empty string is

        # returned for parent2

        replace = {'parent': dir1a, 'parent1': dir1a, 'parent2': dir1b,

                   'plabel1': label1a, 'plabel2': label1b,

                   'clabel': label2, 'child': dir2,

                   'root': repo.root}

        def quote(match):

            key = match.group()[1:]

            if not do3way and key == 'parent2':

                return ''

            return util.shellquote(replace[key])

        # Match parent2 first, so 'parent1?' will match both parent1 and parent

        regex = '\$(parent2|parent1?|child|plabel1|plabel2|clabel|root)'

        if not do3way and not re.search(regex, args):

            args += ' $parent1 $child'

        args = re.sub(regex, quote, args)

        cmdline = util.shellquote(diffcmd) + ' ' + args

        ui.debug('running %r in %s\n' % (cmdline, tmproot))

        util.system(cmdline, cwd=tmproot, out=ui.fout)

        for copy_fn, working_fn, mtime in fns_and_mtime:

            if os.lstat(copy_fn).st_mtime != mtime:

                ui.debug('file changed while diffing. '

                         'Overwriting: %s (src: %s)\n' % (working_fn, copy_fn))

                util.copyfile(copy_fn, working_fn)

        return 1

    finally:

        ui.note(_('cleaning up temp directory\n'))

        shutil.rmtree(tmproot)

@command('extdiff',

    [('p', 'program', '',

     _('comparison program to run'), _('CMD')),

    ('o', 'option', [],

     _('pass option to comparison program'), _('OPT')),

    ('r', 'rev', [], _('revision'), _('REV')),

    ('c', 'change', '', _('change made by revision'), _('REV')),

    ] + commands.walkopts,

    _('hg extdiff [OPT]... [FILE]...'),

    inferrepo=True)

def extdiff(ui, repo, *pats, **opts):

    '''use external program to diff repository (or selected files)

    Show differences between revisions for the specified files, using

    an external program. The default program used is diff, with

    default options "-Npru".

    To select a different program, use the -p/--program option. The

    program will be passed the names of two directories to compare. To

    pass additional options to the program, use -o/--option. These

    will be passed before the names of the directories to compare.

    When two revision arguments are given, then changes are shown

    between those revisions. If only one revision is specified then

    that revision is compared to the working directory, and, when no

    revisions are specified, the working directory files are compared

    to its parent.'''

    program = opts.get('program')

    option = opts.get('option')

    if not program:

        program = 'diff'

        option = option or ['-Npru']

    return dodiff(ui, repo, program, option, pats, opts)

def uisetup(ui):

    for cmd, path in ui.configitems('extdiff'):

        if cmd.startswith('cmd.'):

            cmd = cmd[4:]

            if not path:

                path = cmd

            diffopts = shlex.split(ui.config('extdiff', 'opts.' + cmd, ''))

        elif cmd.startswith('opts.'):

            continue

        else:

            # command = path opts

            if path:

                diffopts = shlex.split(path)

                path = diffopts.pop(0)

            else:

                path, diffopts = cmd, []

        # look for diff arguments in [diff-tools] then [merge-tools]

        if diffopts == []:

            args = ui.config('diff-tools', cmd+'.diffargs') or \

                   ui.config('merge-tools', cmd+'.diffargs')

            if args:

                diffopts = shlex.split(args)

        def save(cmd, path, diffopts):

            '''use closure to save diff command to use'''

            def mydiff(ui, repo, *pats, **opts):

                return dodiff(ui, repo, path, diffopts + opts['option'],

                              pats, opts)

            doc = _('''\

use %(path)s to diff repository (or selected files)

    Show differences between revisions for the specified files, using

    the %(path)s program.

    When two revision arguments are given, then changes are shown

    between those revisions. If only one revision is specified then

    that revision is compared to the working directory, and, when no

    revisions are specified, the working directory files are compared

    to its parent.\

''') % {'path': util.uirepr(path)}

            # We must translate the docstring right away since it is

            # used as a format string. The string will unfortunately

            # be translated again in commands.helpcmd and this will

            # fail when the docstring contains non-ASCII characters.

            # Decoding the string to a Unicode string here (using the

            # right encoding) prevents that.

            mydiff.__doc__ = doc.decode(encoding.encoding)

            return mydiff

        cmdtable[cmd] = (save(cmd, path, diffopts),

                         cmdtable['extdiff'][1][1:],

                         _('hg %s [OPTION]... [FILE]...') % cmd)