# Copyright 2011 Fog Creek Software

#

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

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

from __future__ import absolute_import

import os

import re

from mercurial.i18n import _

from mercurial import (

    error,

    exthelper,

    httppeer,

    util,

    wireprototypes,

    wireprotov1peer,

    wireprotov1server,

)

from . import lfutil

urlerr = util.urlerr

urlreq = util.urlreq

LARGEFILES_REQUIRED_MSG = (

    b'\nThis repository uses the largefiles extension.'

    b'\n\nPlease enable it in your Mercurial config '

    b'file.\n'

)

eh = exthelper.exthelper()

# these will all be replaced by largefiles.uisetup

ssholdcallstream = None

httpoldcallstream = None

def putlfile(repo, proto, sha):

    '''Server command for putting a largefile into a repository's local store

    and into the user cache.'''

    with proto.mayberedirectstdio() as output:

        path = lfutil.storepath(repo, sha)

        util.makedirs(os.path.dirname(path))

        tmpfp = util.atomictempfile(path, createmode=repo.store.createmode)

        try:

            for p in proto.getpayload():

                tmpfp.write(p)

            tmpfp._fp.seek(0)

            if sha != lfutil.hexsha1(tmpfp._fp):

                raise IOError(0, _(b'largefile contents do not match hash'))

            tmpfp.close()

            lfutil.linktousercache(repo, sha)

        except IOError as e:

            repo.ui.warn(

                _(b'largefiles: failed to put %s into store: %s\n')

                % (sha, e.strerror)

            )

            return wireprototypes.pushres(

                1, output.getvalue() if output else b''

            )

        finally:

            tmpfp.discard()

    return wireprototypes.pushres(0, output.getvalue() if output else b'')

def getlfile(repo, proto, sha):

    '''Server command for retrieving a largefile from the repository-local

    cache or user cache.'''

    filename = lfutil.findfile(repo, sha)

    if not filename:

        raise error.Abort(

            _(b'requested largefile %s not present in cache') % sha

        )

    f = open(filename, b'rb')

    length = os.fstat(f.fileno())[6]

    # Since we can't set an HTTP content-length header here, and

    # Mercurial core provides no way to give the length of a streamres

    # (and reading the entire file into RAM would be ill-advised), we

    # just send the length on the first line of the response, like the

    # ssh proto does for string responses.

    def generator():

        yield b'%d\n' % length

        for chunk in util.filechunkiter(f):

            yield chunk

    return wireprototypes.streamreslegacy(gen=generator())

def statlfile(repo, proto, sha):

    '''Server command for checking if a largefile is present - returns '2\n' if

    the largefile is missing, '0\n' if it seems to be in good condition.

    The value 1 is reserved for mismatched checksum, but that is too expensive

    to be verified on every stat and must be caught be running 'hg verify'

    server side.'''

    filename = lfutil.findfile(repo, sha)

    if not filename:

        return wireprototypes.bytesresponse(b'2\n')

    return wireprototypes.bytesresponse(b'0\n')

def wirereposetup(ui, repo):

    class lfileswirerepository(repo.__class__):

        def putlfile(self, sha, fd):

            # unfortunately, httprepository._callpush tries to convert its

            # input file-like into a bundle before sending it, so we can't use

            # it ...

            if issubclass(self.__class__, httppeer.httppeer):

                res = self._call(

                    b'putlfile',

                    data=fd,

                    sha=sha,

                    headers={r'content-type': r'application/mercurial-0.1'},

                )

                try:

                    d, output = res.split(b'\n', 1)

                    for l in output.splitlines(True):

                        self.ui.warn(_(b'remote: '), l)  # assume l ends with \n

                    return int(d)

                except ValueError:

                    self.ui.warn(_(b'unexpected putlfile response: %r\n') % res)

                    return 1

            # ... but we can't use sshrepository._call because the data=

            # argument won't get sent, and _callpush does exactly what we want

            # in this case: send the data straight through

            else:

                try:

                    ret, output = self._callpush(b"putlfile", fd, sha=sha)

                    if ret == b"":

                        raise error.ResponseError(

                            _(b'putlfile failed:'), output

                        )

                    return int(ret)

                except IOError:

                    return 1

                except ValueError:

                    raise error.ResponseError(

                        _(b'putlfile failed (unexpected response):'), ret

                    )

        def getlfile(self, sha):

            """returns an iterable with the chunks of the file with sha sha"""

            stream = self._callstream(b"getlfile", sha=sha)

            length = stream.readline()

            try:

                length = int(length)

            except ValueError:

                self._abort(

                    error.ResponseError(_(b"unexpected response:"), length)

                )

            # SSH streams will block if reading more than length

            for chunk in util.filechunkiter(stream, limit=length):

                yield chunk

            # HTTP streams must hit the end to process the last empty

            # chunk of Chunked-Encoding so the connection can be reused.

            if issubclass(self.__class__, httppeer.httppeer):

                chunk = stream.read(1)

                if chunk:

                    self._abort(

                        error.ResponseError(_(b"unexpected response:"), chunk)

                    )

        @wireprotov1peer.batchable

        def statlfile(self, sha):

            f = wireprotov1peer.future()

            result = {b'sha': sha}

            yield result, f

            try:

                yield int(f.value)

            except (ValueError, urlerr.httperror):

                # If the server returns anything but an integer followed by a

                # newline, newline, it's not speaking our language; if we get

                # an HTTP error, we can't be sure the largefile is present;

                # either way, consider it missing.

                yield 2

    repo.__class__ = lfileswirerepository

# advertise the largefiles=serve capability

@eh.wrapfunction(wireprotov1server, b'_capabilities')

def _capabilities(orig, repo, proto):

    '''announce largefile server capability'''

    caps = orig(repo, proto)

    caps.append(b'largefiles=serve')

    return caps

def heads(orig, repo, proto):

    '''Wrap server command - largefile capable clients will know to call

    lheads instead'''

    if lfutil.islfilesrepo(repo):

        return wireprototypes.ooberror(LARGEFILES_REQUIRED_MSG)

    return orig(repo, proto)

def sshrepocallstream(self, cmd, **args):

    if cmd == b'heads' and self.capable(b'largefiles'):

        cmd = b'lheads'

    if cmd == b'batch' and self.capable(b'largefiles'):

        args[r'cmds'] = args[r'cmds'].replace(b'heads ', b'lheads ')

    return ssholdcallstream(self, cmd, **args)

headsre = re.compile(br'(^|;)heads\b')

def httprepocallstream(self, cmd, **args):

    if cmd == b'heads' and self.capable(b'largefiles'):

        cmd = b'lheads'

    if cmd == b'batch' and self.capable(b'largefiles'):

        args[r'cmds'] = headsre.sub(b'lheads', args[r'cmds'])

    return httpoldcallstream(self, cmd, **args)