# patch.py - patch file parsing routines

#

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

# Copyright 2007 Chris Mason <chris.mason@oracle.com>

#

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

# GNU General Public License version 2, incorporated herein by reference.

from i18n import _

from node import hex, nullid, short

import base85, cmdutil, mdiff, util, diffhelpers, copies

import cStringIO, email.Parser, os, re

import sys, tempfile, zlib

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

class PatchError(Exception):

    pass

class NoHunks(PatchError):

    pass

# helper functions

def copyfile(src, dst, basedir):

    abssrc, absdst = [util.canonpath(basedir, basedir, x) for x in [src, dst]]

    if os.path.exists(absdst):

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

                         dst)

    dstdir = os.path.dirname(absdst)

    if dstdir and not os.path.isdir(dstdir):

        try:

            os.makedirs(dstdir)

        except IOError:

            raise util.Abort(

                _("cannot create %s: unable to create destination directory")

                % dst)

    util.copyfile(abssrc, absdst)

# public functions

def extract(ui, fileobj):

    '''extract patch from data read from fileobj.

    patch can be a normal patch or contained in an email message.

    return tuple (filename, message, user, date, node, p1, p2).

    Any item in the returned tuple can be None. If filename is None,

    fileobj did not contain a 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: |'

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

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

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

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

    try:

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

        subject = msg['Subject']

        user = msg['From']

        if not subject and not user:

            # Not an email, restore parsed headers if any

            subject = '\n'.join(': '.join(h) for h in msg.items()) + '\n'

        gitsendmail = 'git-send-email' in msg.get('X-Mailer', '')

        # should try to parse msg['Date']

        date = None

        nodeid = None

        branch = None

        parents = []

        if subject:

            if subject.startswith('[PATCH'):

                pend = subject.find(']')

                if pend >= 0:

                    subject = subject[pend+1:].lstrip()

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

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

        if user:

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

        diffs_seen = 0

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

        message = ''

        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:

                hgpatch = False

                ignoretext = False

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

                diffs_seen += 1

                cfp = cStringIO.StringIO()

                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()

                        subject = None

                    elif hgpatch:

                        if line.startswith('# User '):

                            user = line[7:]

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

                        elif line.startswith("# Date "):

                            date = line[7:]

                        elif line.startswith("# Branch "):

                            branch = line[9:]

                        elif line.startswith("# Node ID "):

                            nodeid = line[10:]

                        elif line.startswith("# Parent "):

                            parents.append(line[10:])

                    elif line == '---' and gitsendmail:

                        ignoretext = True

                    if not line.startswith('# ') and not ignoretext:

                        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

    if subject and not message.startswith(subject):

        message = '%s\n%s' % (subject, message)

    tmpfp.close()

    if not diffs_seen:

        os.unlink(tmpname)

        return None, message, user, date, branch, None, None, None

    p1 = parents and parents.pop(0) or None

    p2 = parents and parents.pop(0) or None

    return tmpname, message, user, date, branch, nodeid, p1, p2

GP_PATCH  = 1 << 0  # we have to run patch

GP_FILTER = 1 << 1  # there's some copy/rename operation

GP_BINARY = 1 << 2  # there's a binary patch

class patchmeta(object):

    """Patched file metadata

    'op' is the performed operation within ADD, DELETE, RENAME, MODIFY

    or COPY.  'path' is patched file path. 'oldpath' is set to the

    origin file when 'op' is either COPY or RENAME, None otherwise. If

    file mode is changed, 'mode' is a tuple (islink, isexec) where

    'islink' is True if the file is a symlink and 'isexec' is True if

    the file is executable. Otherwise, 'mode' is None.

    """

    def __init__(self, path):

        self.path = path

        self.oldpath = None

        self.mode = None

        self.op = 'MODIFY'

        self.lineno = 0

        self.binary = False

    def setmode(self, mode):

        islink = mode & 020000

        isexec = mode & 0100

        self.mode = (islink, isexec)

def readgitpatch(lr):

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

    # Filter patch for git information

    gp = None

    gitpatches = []

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

    dopatch = 0

    lineno = 0

    for line in lr:

        lineno += 1

        line = line.rstrip(' \r\n')

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

            m = gitre.match(line)

            if m:

                if gp:

                    gitpatches.append(gp)

                dst = m.group(2)

                gp = patchmeta(dst)

                gp.lineno = lineno

        elif gp:

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

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

                    dopatch |= GP_FILTER

                gitpatches.append(gp)

                gp = None

                dopatch |= GP_PATCH

                continue

            if line.startswith('rename from '):

                gp.op = 'RENAME'

                gp.oldpath = line[12:]

            elif line.startswith('rename to '):

                gp.path = line[10:]

            elif line.startswith('copy from '):

                gp.op = 'COPY'

                gp.oldpath = line[10:]

            elif line.startswith('copy to '):

                gp.path = line[8:]

            elif line.startswith('deleted file'):

                gp.op = 'DELETE'

                # is the deleted file a symlink?

                gp.setmode(int(line[-6:], 8))

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

                gp.op = 'ADD'

                gp.setmode(int(line[-6:], 8))

            elif line.startswith('new mode '):

                gp.setmode(int(line[-6:], 8))

            elif line.startswith('GIT binary patch'):

                dopatch |= GP_BINARY

                gp.binary = True

    if gp:

        gitpatches.append(gp)

    if not gitpatches:

        dopatch = GP_PATCH

    return (dopatch, gitpatches)

class linereader(object):

    # simple class to allow pushing lines back into the input stream

    def __init__(self, fp, textmode=False):

        self.fp = fp

        self.buf = []

        self.textmode = textmode

    def push(self, line):

        if line is not None:

            self.buf.append(line)

    def readline(self):

        if self.buf:

            l = self.buf[0]

            del self.buf[0]

            return l

        l = self.fp.readline()

        if self.textmode and l.endswith('\r\n'):

            l = l[:-2] + '\n'

        return l

    def __iter__(self):

        while 1:

            l = self.readline()

            if not l:

                break

            yield l

# @@ -start,len +start,len @@ or @@ -start +start @@ if len is 1

unidesc = re.compile('@@ -(\d+)(,(\d+))? \+(\d+)(,(\d+))? @@')

contextdesc = re.compile('(---|\*\*\*) (\d+)(,(\d+))? (---|\*\*\*)')

class patchfile(object):

    def __init__(self, ui, fname, opener, missing=False, eolmode='strict'):

        self.fname = fname

        self.eolmode = eolmode

        self.opener = opener

        self.ui = ui

        self.lines = []

        self.exists = False

        self.missing = missing

        if not missing:

            try:

                self.lines = self.readlines(fname)

                self.exists = True

            except IOError:

                pass

        else:

            self.ui.warn(_("unable to find '%s' for patching\n") % self.fname)

        self.hash = {}

        self.dirty = 0

        self.offset = 0

        self.rej = []

        self.fileprinted = False

        self.printfile(False)

        self.hunks = 0

    def readlines(self, fname):

        if os.path.islink(fname):

            return [os.readlink(fname)]

        fp = self.opener(fname, 'r')

        try:

        finally:

            fp.close()

    def writelines(self, fname, lines):

        # Ensure supplied data ends in fname, being a regular file or

        # a symlink. updatedir() will -too magically- take care of

        # setting it to the proper type afterwards.

        islink = os.path.islink(fname)

        if islink:

            fp = cStringIO.StringIO()

        else:

            fp = self.opener(fname, 'w')

        try:

                for l in lines:

                    if l and l[-1] == '\n':

                    fp.write(l)

            else:

                fp.writelines(lines)

            if islink:

                self.opener.symlink(fp.getvalue(), fname)

        finally:

            fp.close()

    def unlink(self, fname):

        os.unlink(fname)

    def printfile(self, warn):

        if self.fileprinted:

            return

        if warn or self.ui.verbose:

            self.fileprinted = True

        s = _("patching file %s\n") % self.fname

        if warn:

            self.ui.warn(s)

        else:

            self.ui.note(s)

    def findlines(self, l, linenum):

        # looks through the hash and finds candidate lines.  The

        # result is a list of line numbers sorted based on distance

        # from linenum

        cand = self.hash.get(l, [])

        if len(cand) > 1:

            # resort our list of potentials forward then back.

            cand.sort(key=lambda x: abs(x - linenum))

        return cand

    def hashlines(self):

        self.hash = {}

        for x, s in enumerate(self.lines):

            self.hash.setdefault(s, []).append(x)

    def write_rej(self):

        # our rejects are a little different from patch(1).  This always

        # creates rejects in the same form as the original patch.  A file

        # header is inserted so that you can run the reject through patch again

        # without having to type the filename.

        if not self.rej:

            return

        fname = self.fname + ".rej"

        self.ui.warn(

            _("%d out of %d hunks FAILED -- saving rejects to file %s\n") %

            (len(self.rej), self.hunks, fname))

        def rejlines():

            base = os.path.basename(self.fname)

            yield "--- %s\n+++ %s\n" % (base, base)

            for x in self.rej:

                for l in x.hunk:

                    yield l

                    if l[-1] != '\n':

                        yield "\n\ No newline at end of file\n"

        self.writelines(fname, rejlines())

    def write(self, dest=None):

        if not self.dirty:

            return

        if not dest:

            dest = self.fname

        self.writelines(dest, self.lines)

    def close(self):

        self.write()

        self.write_rej()

    def apply(self, h):

        if not h.complete():

            raise PatchError(_("bad hunk #%d %s (%d %d %d %d)") %

                            (h.number, h.desc, len(h.a), h.lena, len(h.b),

                            h.lenb))

        self.hunks += 1

        if self.missing:

            self.rej.append(h)

            return -1

        if self.exists and h.createfile():

            self.ui.warn(_("file %s already exists\n") % self.fname)

            self.rej.append(h)

            return -1

        if isinstance(h, binhunk):

            if h.rmfile():

                self.unlink(self.fname)

            else:

                self.lines[:] = h.new()

                self.offset += len(h.new())

                self.dirty = 1

            return 0

        # fast case first, no offsets, no fuzz

        old = h.old()

        # patch starts counting at 1 unless we are adding the file

        if h.starta == 0:

            start = 0

        else:

            start = h.starta + self.offset - 1

        orig_start = start

        if diffhelpers.testhunk(old, self.lines, start) == 0:

            if h.rmfile():

                self.unlink(self.fname)

            else:

                self.lines[start : start + h.lena] = h.new()

                self.offset += h.lenb - h.lena

                self.dirty = 1

            return 0

        # ok, we couldn't match the hunk.  Lets look for offsets and fuzz it

        self.hashlines()

        if h.hunk[-1][0] != ' ':

            # if the hunk tried to put something at the bottom of the file

            # override the start line and use eof here

            search_start = len(self.lines)

        else:

            search_start = orig_start

        for fuzzlen in xrange(3):

            for toponly in [ True, False ]:

                old = h.old(fuzzlen, toponly)

                cand = self.findlines(old[0][1:], search_start)

                for l in cand:

                    if diffhelpers.testhunk(old, self.lines, l) == 0:

                        newlines = h.new(fuzzlen, toponly)

                        self.lines[l : l + len(old)] = newlines

                        self.offset += len(newlines) - len(old)

                        self.dirty = 1

                        if fuzzlen:

                            fuzzstr = "with fuzz %d " % fuzzlen

                            f = self.ui.warn

                            self.printfile(True)

                        else:

                            fuzzstr = ""

                            f = self.ui.note

                        offset = l - orig_start - fuzzlen

                        if offset == 1:

                            msg = _("Hunk #%d succeeded at %d %s"

                                    "(offset %d line).\n")

                        else:

                            msg = _("Hunk #%d succeeded at %d %s"

                                    "(offset %d lines).\n")

                        f(msg % (h.number, l+1, fuzzstr, offset))