# Copyright 2010-2011 Fog Creek Software
# Copyright 2010-2011 Unity Technologies
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''remote largefile store; the base class for wirestore'''

from mercurial import util, wireproto, error
from mercurial.i18n import _

urlerr = util.urlerr
urlreq = util.urlreq

import lfutil
import basestore

class remotestore(basestore.basestore):
    '''a largefile store accessed over a network'''
    def __init__(self, ui, repo, url):
        super(remotestore, self).__init__(ui, repo, url)

    def put(self, source, hash):
        if self.sendfile(source, hash):
            raise error.Abort(
                _('remotestore: could not put %s to remote store %s')
                % (source, util.hidepassword(self.url)))
        self.ui.debug(
            _('remotestore: put %s to remote store %s\n')
            % (source, util.hidepassword(self.url)))

    def exists(self, hashes):
        return dict((h, s == 0) for (h, s) in # dict-from-generator
                    self._stat(hashes).iteritems())

    def sendfile(self, filename, hash):
        self.ui.debug('remotestore: sendfile(%s, %s)\n' % (filename, hash))
        fd = None
        try:
            fd = lfutil.httpsendfile(self.ui, filename)
            return self._put(hash, fd)
        except IOError as e:
            raise error.Abort(
                _('remotestore: could not open file %s: %s')
                % (filename, str(e)))
        finally:
            if fd:
                fd.close()

    def _getfile(self, tmpfile, filename, hash):
        try:
            chunks = self._get(hash)
        except urlerr.httperror as e:
            # 401s get converted to error.Aborts; everything else is fine being
            # turned into a StoreError
            raise basestore.StoreError(filename, hash, self.url, str(e))
        except urlerr.urlerror as e:
            # This usually indicates a connection problem, so don't
            # keep trying with the other files... they will probably
            # all fail too.
            raise error.Abort('%s: %s' %
                             (util.hidepassword(self.url), e.reason))
        except IOError as e:
            raise basestore.StoreError(filename, hash, self.url, str(e))

        return lfutil.copyandhash(chunks, tmpfile)

    def _verifyfiles(self, contents, filestocheck):
        failed = False
        expectedhashes = [expectedhash
                          for cset, filename, expectedhash in filestocheck]
        stats = self._stat(expectedhashes)
        for cset, filename, expectedhash in filestocheck:
            stat = stats[expectedhash]
            if stat:
                if stat == 1:
                    self.ui.warn(
                        _('changeset %s: %s: contents differ\n')
                        % (cset, filename))
                    failed = True
                elif stat == 2:
                    self.ui.warn(
                        _('changeset %s: %s missing\n')
                        % (cset, filename))
                    failed = True
                else:
                    raise RuntimeError('verify failed: unexpected response '
                                       'from statlfile (%r)' % stat)
        return failed

    def batch(self):
        '''Support for remote batching.'''
        return wireproto.remotebatch(self)

    def _put(self, hash, fd):
        '''Put file with the given hash in the remote store.'''
        raise NotImplementedError('abstract method')

    def _get(self, hash):
        '''Get file with the given hash from the remote store.'''
        raise NotImplementedError('abstract method')

    def _stat(self, hashes):
        '''Get information about availability of files specified by
        hashes in the remote store. Return dictionary mapping hashes
        to return code where 0 means that file is available, other
        values if not.'''
        raise NotImplementedError('abstract method')