# Copyright (C) 2009 Jelmer Vernooij <jelmer@samba.org>
#
# 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


"""Git inventory."""


from bzrlib import (
    errors,
    inventory,
    osutils,
    urlutils,
    )


class GitInventoryEntry(inventory.InventoryEntry):

    def __init__(self, inv, parent_id, hexsha, path, name, executable):
        self.name = name
        self.parent_id = parent_id
        self._inventory = inv
        self._object = None
        self.hexsha = hexsha
        self.path = path
        self.revision = self._inventory.revision_id
        self.executable = executable
        self.file_id = self._inventory.mapping.generate_file_id(path.encode('utf-8'))

    @property
    def object(self):
        if self._object is None:
            self._object = self._inventory.store[self.hexsha]
        return self._object


class GitInventoryFile(GitInventoryEntry):

    def __init__(self, inv, parent_id, hexsha, path, basename, executable):
        super(GitInventoryFile, self).__init__(inv, parent_id, hexsha, path, basename, executable)
        self.kind = 'file'
        self.symlink_target = None

    @property
    def text_sha1(self):
        return osutils.sha_string(self.object.data)

    @property
    def text_size(self):
        return len(self.object.data)

    def kind_character(self):
        """See InventoryEntry.kind_character."""
        return ''


class GitInventoryLink(GitInventoryEntry):

    def __init__(self, inv, parent_id, hexsha, path, basename, executable):
        super(GitInventoryLink, self).__init__(inv, parent_id, hexsha, path, basename, executable)
        self.text_sha1 = None
        self.text_size = None
        self.kind = 'symlink'

    @property
    def symlink_target(self):
        return self.object.data

    def kind_character(self):
        """See InventoryEntry.kind_character."""
        return ''


class GitInventoryDirectory(GitInventoryEntry):

    def __init__(self, inv, parent_id, hexsha, path, basename, executable):
        super(GitInventoryDirectory, self).__init__(inv, parent_id, hexsha, path, basename, executable)
        self.text_sha1 = None
        self.text_size = None
        self.symlink_target = None
        self.kind = 'directory'

    def kind_character(self):
        """See InventoryEntry.kind_character."""
        return '/'

    @property
    def children(self):
        ret = {}
        for mode, name, hexsha in self.object.entries():
            basename = name.decode("utf-8")
            child_path = osutils.pathjoin(self.path, basename)
            entry_kind = (mode & 0700000) / 0100000
            fs_mode = mode & 0777
            executable = bool(fs_mode & 0111)
            if entry_kind == 0:
                kind_class = GitInventoryDirectory
            elif entry_kind == 1:
                file_kind = (mode & 070000) / 010000
                if file_kind == 0:
                    kind_class = GitInventoryFile
                elif file_kind == 2:
                    kind_class = GitInventoryLink
                else:
                    raise AssertionError(
                        "Unknown file kind, perms=%o." % (mode,))
            else:
                raise AssertionError(
                    "Unknown blob kind, perms=%r." % (mode,))
            ret[basename] = kind_class(self._inventory, self.file_id, hexsha, child_path, basename, executable)
        return ret


class GitInventory(inventory.Inventory):

    def __init__(self, tree_id, mapping, store, revision_id):
        super(GitInventory, self).__init__(revision_id)
        self.store = store
        self.mapping = mapping
        self.root = GitInventoryDirectory(self, None, tree_id, "", "", False)

    def _get_ie(self, path):
        parts = path.split("/")
        ie = self.root
        for name in parts:
            ie = ie.children[name] 
        return ie

    def has_filename(self, path):
        try:
            self._get_ie(path)
            return True
        except KeyError:
            return False

    def has_id(self, file_id):
        try:
            self.id2path(file_id)
            return True
        except errors.NoSuchId:
            return False

    def id2path(self, file_id):
        path = self.mapping.parse_file_id(file_id)
        try:
            ie = self._get_ie(path)
            assert ie.path == path
        except KeyError:
            raise errors.NoSuchId(None, file_id)

    def path2id(self, path):
        try:
            return self._get_ie(path).file_id
        except KeyError:
            return None

    def __getitem__(self, file_id):
        if file_id == inventory.ROOT_ID:
            return self.root
        path = self.mapping.parse_file_id(file_id)
        return self._get_ie(path)