# Copyright (C) 2007 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""An adapter between a Git Repository and a Bazaar Branch"""

from bzrlib import (
    deprecated_graph,
    repository,
    urlutils,
    )

from bzrlib.plugins.git.gitlib import (
    ids,
    model,
    )


class GitRepository(repository.Repository):
    """An adapter to git repositories for bzr."""

    def __init__(self, gitdir, lockfiles):
        self.bzrdir = gitdir
        self.control_files = lockfiles
        gitdirectory = gitdir.transport.local_abspath('.')
        self._git = model.GitModel(gitdirectory)
        self._revision_cache = {}

    def _ancestor_revisions(self, revision_ids):
        if revision_ids is not None:
            git_revisions = [gitrevid_from_bzr(r) for r in revision_ids]
        else:
            git_revisions = None
        for lines in self._git.ancestor_lines(git_revisions):
            yield self.parse_rev(lines)

    def is_shared(self):
        return True

    def get_revision_graph(self, revision_id=None):
        result = {}
        if revision_id is not None:
            param = [ids.convert_revision_id_bzr_to_git(revision_id)]
        else:
            param = None
        for node, parents in self._git.ancestry(param).iteritems():
            bzr_node = ids.convert_revision_id_git_to_bzr(node)
            bzr_parents = [ids.convert_revision_id_git_to_bzr(n)
                           for n in parents]
            result[bzr_node] = bzr_parents
        return result

    def get_revision_graph_with_ghosts(self, revision_ids=None):
        graph = deprecated_graph.Graph()
        if revision_ids is not None:
            revision_ids = [ids.convert_revision_id_bzr_to_git(r)
                            for r in revision_ids]
        for node, parents in self._git.ancestry(revision_ids).iteritems():
            bzr_node = ids.convert_revision_id_git_to_bzr(node)
            bzr_parents = [ids.convert_revision_id_git_to_bzr(n)
                           for n in parents]

            graph.add_node(bzr_node, bzr_parents)
        return graph

    def get_revision(self, revision_id):
        if revision_id in self._revision_cache:
            return self._revision_cache[revision_id]
        raw = self._git.rev_list([gitrevid_from_bzr(revision_id)], max_count=1,
                                 header=True)
        return self.parse_rev(raw)

    def has_revision(self, revision_id):
        try:
            self.get_revision(revision_id)
        except NoSuchRevision:
            return False
        else:
            return True

    def get_revisions(self, revisions):
        return [self.get_revision(r) for r in revisions]

    def parse_rev(self, raw):
        # first field is the rev itself.
        # then its 'field value'
        # until the EOF??
        parents = []
        log = []
        in_log = False
        committer = None
        revision_id = bzrrevid_from_git(raw[0][:-1])
        for field in raw[1:]:
            #if field.startswith('author '):
            #    committer = field[7:]
            if field.startswith('parent '):
                parents.append(bzrrevid_from_git(field.split()[1]))
            elif field.startswith('committer '):
                commit_fields = field.split()
                if committer is None:
                    committer = ' '.join(commit_fields[1:-3])
                timestamp = commit_fields[-2]
                timezone = commit_fields[-1]
            elif field.startswith('tree '):
                tree_id = field.split()[1]
            elif in_log:
                log.append(field[4:])
            elif field == '\n':
                in_log = True

        log = ''.join(log)
        result = Revision(revision_id)
        result.parent_ids = parents
        result.message = log
        result.inventory_sha1 = ""
        result.timezone = timezone and int(timezone)
        result.timestamp = float(timestamp)
        result.committer = committer
        result.properties['git-tree-id'] = tree_id
        return result

    def revision_trees(self, revids):
        for revid in revids:
            yield self.revision_tree(revid)

    def revision_tree(self, revision_id):
        return GitRevisionTree(self, revision_id)

    def get_inventory(self, revision_id):
        revision = self.get_revision(revision_id)
        inventory = GitInventory(revision_id)
        tree_id = revision.properties['git-tree-id']
        type_map = {'blob': 'file', 'tree': 'directory' }
        def get_inventory(tree_id, prefix):
            for perms, type, obj_id, name in self._git.get_inventory(tree_id):
                full_path = prefix + name
                if type == 'blob':
                    text_sha1 = obj_id
                else:
                    text_sha1 = None
                executable = (perms[-3] in ('1', '3', '5', '7'))
                entry = GitEntry(full_path, type_map[type], revision_id,
                                 text_sha1, executable)
                inventory.entries[full_path] = entry
                if type == 'tree':
                    get_inventory(obj_id, full_path+'/')
        get_inventory(tree_id, '')
        return inventory


class GitRevisionTree(object):

    def __init__(self, repository, revision_id):
        self.repository = repository
        self.revision_id = revision_id
        self.inventory = repository.get_inventory(revision_id)

    def get_file(self, file_id):
        return iterablefile.IterableFile(self.get_file_lines(file_id))

    def get_file_lines(self, file_id):
        obj_id = self.inventory[file_id].text_sha1
        return self.repository._git.cat_file('blob', obj_id)

    def is_executable(self, file_id):
        return self.inventory[file_id].executable


class GitInventory(object):

    def __init__(self, revision_id):
        self.entries = {}
        self.root = GitEntry('', 'directory', revision_id)
        self.entries[''] = self.root

    def __getitem__(self, key):
        return self.entries[key]

    def iter_entries(self):
        return iter(sorted(self.entries.items()))

    def iter_entries_by_dir(self):
        return self.iter_entries()

    def __len__(self):
        return len(self.entries)


class GitEntry(object):

    def __init__(self, path, kind, revision, text_sha1=None, executable=False,
                 text_size=None):
        self.path = path
        self.file_id = path
        self.kind = kind
        self.executable = executable
        self.name = osutils.basename(path)
        if path == '':
            self.parent_id = None
        else:
            self.parent_id = osutils.dirname(path)
        self.revision = revision
        self.symlink_target = None
        self.text_sha1 = text_sha1
        self.text_size = None

    def __repr__(self):
        return "GitEntry(%r, %r, %r, %r)" % (self.path, self.kind,
                                             self.revision, self.parent_id)


