# 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, incorporated herein by reference.

'''

The `extdiff' Mercurial extension allows you to use external programs

to compare revisions, or revision with working dir.  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.

To enable this extension:

  [extensions]

  hgext.extdiff =

The `extdiff' extension also allows 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" argv(0) argv(1)'

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 import cmdutil, util, commands

import os, shlex, shutil, tempfile

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

    '''snapshot files as of some revision'''

    mf = repo.changectx(node).manifest()

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

    if dirname == "":

        dirname = "root"

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

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

    os.mkdir(base)

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

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

    for fn in files:

        if not fn in mf:

            # skipping new file after a merge ?

            continue

        wfn = util.pconvert(fn)

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

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

        destdir = os.path.dirname(dest)

        if not os.path.isdir(destdir):

            os.makedirs(destdir)

        data = repo.wwritedata(wfn, repo.file(wfn).read(mf[wfn]))

        open(dest, 'wb').write(data)

    return dirname

def snapshot_wdir(ui, repo, files, tmproot):

    '''snapshot files from working directory.

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

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

    repo_root = repo.root

    dirname = os.path.basename(repo_root)

    if dirname == "":

        dirname = "root"

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

    os.mkdir(base)

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

            (len(files)))

    fns_and_mtime = []

    for fn in files:

        wfn = util.pconvert(fn)

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

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

        destdir = os.path.dirname(dest)

        if not os.path.isdir(destdir):

            os.makedirs(destdir)

        fp = open(dest, 'wb')

        for chunk in util.filechunkiter(repo.wopener(wfn)):

            fp.write(chunk)

        fp.close()

        fns_and_mtime.append((dest, os.path.join(repo_root, fn),

            os.path.getmtime(dest)))

    return dirname, fns_and_mtime

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

    '''Do the actuall 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

    '''

    node1, node2 = cmdutil.revpair(repo, opts['rev'])

    files, matchfn, anypats = cmdutil.matchpats(repo, pats, opts)

    modified, added, removed, deleted, unknown = repo.status(

        node1, node2, files, match=matchfn)[:5]

    if not (modified or added or removed):

        return 0

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

    dir2root = ''

    try:

        # Always make a copy of node1

        dir1 = snapshot_node(ui, repo, modified + removed, node1, tmproot)

        changes = len(modified) + len(removed) + len(added)

        fns_and_mtime = []

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

        if node2:

            dir2 = snapshot_node(ui, repo, modified + added, node2, tmproot)

        elif changes > 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_wdir(ui, repo, modified + added, tmproot)

        else:

            # This lets the diff tool open the changed file directly

            dir2 = ''

            dir2root = repo.root

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

        if changes == 1 :

            if len(modified):

                dir1 = os.path.join(dir1, util.localpath(modified[0]))

                dir2 = os.path.join(dir2root, dir2, util.localpath(modified[0]))

            elif len(removed) :

                dir1 = os.path.join(dir1, util.localpath(removed[0]))

                dir2 = os.devnull

            else:

                dir1 = os.devnull

                dir2 = os.path.join(dir2root, dir2, util.localpath(added[0]))

        cmdline = ('%s %s %s %s' %

                   (util.shellquote(diffcmd), ' '.join(diffopts),

                    util.shellquote(dir1), util.shellquote(dir2)))

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

        util.system(cmdline, cwd=tmproot)

        for copy_fn, working_fn, mtime in fns_and_mtime:

            if os.path.getmtime(copy_fn) != 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)

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 option.  The program

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

    additional options to the program, use the -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['program'] or 'diff'

    if opts['program']:

        option = opts['option']

    else:

        option = opts['option'] or ['-Npru']

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

cmdtable = {

    "extdiff":

    (extdiff,

     [('p', 'program', '', _('comparison program to run')),

      ('o', 'option', [], _('pass option to comparison program')),

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

     ] + commands.walkopts,

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

    }

def uisetup(ui):

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

        if cmd.startswith('cmd.'):

            cmd = cmd[4:]

            if not path: path = cmd

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

            diffopts = diffopts and [diffopts] or []

        elif cmd.startswith('opts.'):

            continue

        else:

            # command = path opts

            if path:

                diffopts = shlex.split(path)

                path = diffopts.pop(0)

            else:

                path, diffopts = cmd, []

        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, pats, opts)

            mydiff.__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),

                }

            return mydiff

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

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

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