# Copyright (C) 2008 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""UI helper for the push command."""

from bzrlib import (
    builtins,
    branch,
    bzrdir,
    errors,
    revision as _mod_revision,
    transport,
    )
from bzrlib.trace import (
    note,
    warning,
    )


class PushResult(object):
    """Result of a push operation.

    :ivar branch_push_result: Result of a push between branches
    :ivar target_branch: The target branch
    :ivar stacked_on: URL of the branch on which the result is stacked
    :ivar workingtree_updated: Whether or not the target workingtree was updated.
    """

    def __init__(self):
        self.branch_push_result = None
        self.stacked_on = None
        self.workingtree_updated = None
        self.target_branch = None

    def report(self, to_file):
        """Write a human-readable description of the result."""
        if self.branch_push_result is None:
            if self.stacked_on is not None:
                note('Created new stacked branch referring to %s.' %
                    self.stacked_on)
            else:
                note('Created new branch.')
        else:
            self.branch_push_result.report(to_file)


def _show_push_branch(br_from, revision_id, location, to_file, verbose=False,
    overwrite=False, remember=False, stacked_on=None, create_prefix=False,
    use_existing_dir=False):
    """Push a branch to a location.

    :param br_from: the source branch
    :param revision_id: the revision-id to push up to
    :param location: the url of the destination
    :param to_file: the output stream
    :param verbose: if True, display more output than normal
    :param overwrite: if False, a current branch at the destination may not
        have diverged from the source, otherwise the push fails
    :param remember: if True, store the location as the push location for
        the source branch
    :param stacked_on: the url of the branch, if any, to stack on;
        if set, only the revisions not in that branch are pushed
    :param create_prefix: if True, create the necessary parent directories
        at the destination if they don't already exist
    :param use_existing_dir: if True, proceed even if the destination
        directory exists without a current .bzr directory in it
    """
    to_transport = transport.get_transport(location)
    try:
        dir_to = bzrdir.BzrDir.open_from_transport(to_transport)
    except errors.NotBranchError:
        # Didn't find anything
        dir_to = None

    if dir_to is None:
        try:
            br_to = br_from.create_clone_on_transport(to_transport,
                revision_id=revision_id, stacked_on=stacked_on,
                create_prefix=create_prefix, use_existing_dir=use_existing_dir)
        except errors.FileExists, err:
            if err.path.endswith('/.bzr'):
                raise errors.BzrCommandError(
                    "Target directory %s already contains a .bzr directory, "
                    "but it is not valid." % (location,))
            if not use_existing_dir:
                raise errors.BzrCommandError("Target directory %s"
                     " already exists, but does not have a .bzr"
                     " directory. Supply --use-existing-dir to push"
                     " there anyway." % location)
            # This shouldn't occur, but if it does the FileExists error will be
            # more informative than an UnboundLocalError for br_to.
            raise
        except errors.NoSuchFile:
            if not create_prefix:
                raise errors.BzrCommandError("Parent directory of %s"
                    " does not exist."
                    "\nYou may supply --create-prefix to create all"
                    " leading parent directories."
                    % location)
        except errors.TooManyRedirections:
            raise errors.BzrCommandError("Too many redirections trying "
                                         "to make %s." % location)
        push_result = PushResult()
        # TODO: Some more useful message about what was copied
        try:
            push_result.stacked_on = br_to.get_stacked_on_url()
        except (errors.UnstackableBranchFormat,
                errors.UnstackableRepositoryFormat,
                errors.NotStacked):
            push_result.stacked_on = None
        push_result.target_branch = br_to
        push_result.old_revid = _mod_revision.NULL_REVISION
        push_result.old_revno = 0
        if br_from.get_push_location() is None or remember:
            br_from.set_push_location(br_to.base)
    else:
        if stacked_on is not None:
            warning("Ignoring request for a stacked branch as repository "
                    "already exists at the destination location.")
        try:
            push_result = dir_to.push_branch(br_from, revision_id, overwrite, 
                remember, create_prefix)
        except errors.DivergedBranches:
            raise errors.BzrCommandError('These branches have diverged.'
                                    '  See "bzr help diverged-branches"'
                                    ' for more information.')
        except errors.NoRepositoryPresent:
            # we have a bzrdir but no branch or repository
            # XXX: Figure out what to do other than complain.
            raise errors.BzrCommandError("At %s you have a valid .bzr"
                " control directory, but not a branch or repository. This"
                " is an unsupported configuration. Please move the target"
                " directory out of the way and try again." % location)
        if push_result.workingtree_updated == False:
            warning("This transport does not update the working " 
                    "tree of: %s. See 'bzr help working-trees' for "
                    "more information." % push_result.target_branch.base)
    push_result.report(to_file)
    if verbose:
        br_to = push_result.target_branch
        br_to.lock_read()
        try:
            from bzrlib.log import show_branch_change
            show_branch_change(br_to, to_file, push_result.old_revno, 
                               push_result.old_revid)
        finally:
            br_to.unlock()


