# patch.py - patch file parsing routines

#

# Copyright 2006 Brendan Cully <brendan@kublai.com>

#

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

# of the GNU General Public License, incorporated herein by reference.

from demandload import demandload

from i18n import gettext as _

def extract(ui, fileobj):

    '''extract patch from data read from fileobj.

    patch can be normal patch or contained in email message.

    return tuple (filename, message, user, date). any item in returned

    tuple can be None.  if filename is None, fileobj did not contain

    patch. caller must unlink filename when done.'''

    # attempt to detect the start of a patch

    # (this heuristic is borrowed from quilt)

    diffre = re.compile(r'^(?:Index:[ \t]|diff[ \t]|RCS file: |' +

                        'retrieving revision [0-9]+(\.[0-9]+)*$|' +

                        '(---|\*\*\*)[ \t])', re.MULTILINE)

    fd, tmpname = tempfile.mkstemp(prefix='hg-patch-')

    tmpfp = os.fdopen(fd, 'w')

    try:

        hgpatch = False

        msg = email.Parser.Parser().parse(fileobj)

        message = msg['Subject']

        user = msg['From']

        # should try to parse msg['Date']

        date = None

        if message:

            message = message.replace('\n\t', ' ')

            ui.debug('Subject: %s\n' % message)

        if user:

            ui.debug('From: %s\n' % user)

        diffs_seen = 0

        ok_types = ('text/plain', 'text/x-diff', 'text/x-patch')

        for part in msg.walk():

            content_type = part.get_content_type()

            ui.debug('Content-Type: %s\n' % content_type)

            if content_type not in ok_types:

                continue

            payload = part.get_payload(decode=True)

            m = diffre.search(payload)

            if m:

                ui.debug(_('found patch at byte %d\n') % m.start(0))

                diffs_seen += 1

                cfp = cStringIO.StringIO()

                if message:

                    cfp.write(message)

                    cfp.write('\n')

                for line in payload[:m.start(0)].splitlines():

                    if line.startswith('# HG changeset patch'):

                        ui.debug(_('patch generated by hg export\n'))

                        hgpatch = True

                        # drop earlier commit message content

                        cfp.seek(0)

                        cfp.truncate()

                    elif hgpatch:

                        if line.startswith('# User '):

                            user = line[7:]

                            ui.debug('From: %s\n' % user)

                        elif line.startswith("# Date "):

                            date = line[7:]

                    if not line.startswith('# '):

                        cfp.write(line)

                        cfp.write('\n')

                message = cfp.getvalue()

                if tmpfp:

                    tmpfp.write(payload)

                    if not payload.endswith('\n'):

                        tmpfp.write('\n')

            elif not diffs_seen and message and content_type == 'text/plain':

                message += '\n' + payload

    except:

        tmpfp.close()

        os.unlink(tmpname)

        raise

    tmpfp.close()

    if not diffs_seen:

        os.unlink(tmpname)

        return None, message, user, date

    return tmpname, message, user, date

def readgitpatch(patchname):

    """extract git-style metadata about patches from <patchname>"""

    class gitpatch:

        "op is one of ADD, DELETE, RENAME, MODIFY or COPY"

        def __init__(self, path):

            self.path = path

            self.oldpath = None

            self.mode = None

            self.op = 'MODIFY'

            self.copymod = False

            self.lineno = 0

    # Filter patch for git information

    gitre = re.compile('diff --git a/(.*) b/(.*)')

    pf = file(patchname)

    gp = None

    gitpatches = []

    # Can have a git patch with only metadata, causing patch to complain

    dopatch = False

    lineno = 0

    for line in pf:

        lineno += 1

        if line.startswith('diff --git'):

            m = gitre.match(line)

            if m:

                if gp:

                    gitpatches.append(gp)

                src, dst = m.group(1,2)

                gp = gitpatch(dst)

                gp.lineno = lineno

        elif gp:

            if line.startswith('--- '):

                if gp.op in ('COPY', 'RENAME'):

                    gp.copymod = True

                    dopatch = 'filter'

                gitpatches.append(gp)

                gp = None

                if not dopatch:

                    dopatch = True

                continue

            if line.startswith('rename from '):

                gp.op = 'RENAME'

                gp.oldpath = line[12:].rstrip()

            elif line.startswith('rename to '):

                gp.path = line[10:].rstrip()

            elif line.startswith('copy from '):

                gp.op = 'COPY'

                gp.oldpath = line[10:].rstrip()

            elif line.startswith('copy to '):

                gp.path = line[8:].rstrip()

            elif line.startswith('deleted file'):

                gp.op = 'DELETE'

            elif line.startswith('new file mode '):

                gp.op = 'ADD'

                gp.mode = int(line.rstrip()[-3:], 8)

            elif line.startswith('new mode '):

                gp.mode = int(line.rstrip()[-3:], 8)

    if gp:

        gitpatches.append(gp)

    if not gitpatches:

        dopatch = True

    return (dopatch, gitpatches)

def dogitpatch(patchname, gitpatches):

    """Preprocess git patch so that vanilla patch can handle it"""

    pf = file(patchname)

    pfline = 1

    fd, patchname = tempfile.mkstemp(prefix='hg-patch-')

    tmpfp = os.fdopen(fd, 'w')

    try:

        for i in range(len(gitpatches)):

            p = gitpatches[i]

            if not p.copymod:

                continue

            if os.path.exists(p.path):

                raise util.Abort(_("cannot create %s: destination already exists") %

                            p.path)

            (src, dst) = [os.path.join(os.getcwd(), n)

                          for n in (p.oldpath, p.path)]

            targetdir = os.path.dirname(dst)

            if not os.path.isdir(targetdir):

                os.makedirs(targetdir)

            try:

                shutil.copyfile(src, dst)

                shutil.copymode(src, dst)

            except shutil.Error, inst:

                raise util.Abort(str(inst))

            # rewrite patch hunk

            while pfline < p.lineno:

                tmpfp.write(pf.readline())

                pfline += 1

            tmpfp.write('diff --git a/%s b/%s\n' % (p.path, p.path))

            line = pf.readline()

            pfline += 1

            while not line.startswith('--- a/'):

                tmpfp.write(line)

                line = pf.readline()

                pfline += 1

            tmpfp.write('--- a/%s\n' % p.path)

        line = pf.readline()

        while line:

            tmpfp.write(line)

            line = pf.readline()

    except:

        tmpfp.close()

        os.unlink(patchname)

        raise

    tmpfp.close()

    return patchname

def patch(strip, patchname, ui, cwd=None):

    """apply the patch <patchname> to the working directory.

    a list of patched files is returned"""

    (dopatch, gitpatches) = readgitpatch(patchname)

    files = {}

    if dopatch:

        if dopatch == 'filter':

            patchname = dogitpatch(patchname, gitpatches)

        patcher = util.find_in_path('gpatch', os.environ.get('PATH', ''), 'patch')

        args = []

        if cwd:

            args.append('-d %s' % util.shellquote(cwd))

        fp = os.popen('%s %s -p%d < %s' % (patcher, ' '.join(args), strip,

                                           util.shellquote(patchname)))

        if dopatch == 'filter':

            False and os.unlink(patchname)

        for line in fp:

            line = line.rstrip()

            ui.status("%s\n" % line)

            if line.startswith('patching file '):

                pf = util.parse_patch_output(line)

                files.setdefault(pf, (None, None))

        code = fp.close()

        if code:

            raise util.Abort(_("patch command failed: %s") %

                             util.explain_exit(code)[0])

    for gp in gitpatches:

        files[gp.path] = (gp.op, gp)

    return files