# -*- coding: utf-8 -*-
#
# Copyright (C) 2013-2017 Gauvain Pocentek <gauvain@pocentek.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import copy
import importlib
import itertools
import json
import sys

import six

import gitlab
from gitlab.exceptions import *  # noqa


class jsonEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, GitlabObject):
            return obj.as_dict()
        elif isinstance(obj, gitlab.Gitlab):
            return {'url': obj._url}
        return json.JSONEncoder.default(self, obj)


class BaseManager(object):
    """Base manager class for API operations.

    Managers provide method to manage GitLab API objects, such as retrieval,
    listing, creation.

    Inherited class must define the ``obj_cls`` attribute.

    Attributes:
        obj_cls (class): class of objects wrapped by this manager.
    """

    obj_cls = None

    def __init__(self, gl, parent=None, args=[]):
        """Constructs a manager.

        Args:
            gl (gitlab.Gitlab): Gitlab object referencing the GitLab server.
            parent (Optional[Manager]): A parent manager.
            args (list): A list of tuples defining a link between the
                parent/child attributes.

        Raises:
            AttributeError: If `obj_cls` is None.
        """
        self.gitlab = gl
        self.args = args
        self.parent = parent

        if self.obj_cls is None:
            raise AttributeError("obj_cls must be defined")

    def _set_parent_args(self, **kwargs):
        args = copy.copy(kwargs)
        if self.parent is not None:
            for attr, parent_attr in self.args:
                args.setdefault(attr, getattr(self.parent, parent_attr))

        return args

    def get(self, id=None, **kwargs):
        """Get a GitLab object.

        Args:
            id: ID of the object to retrieve.
            **kwargs: Additional arguments to send to GitLab.

        Returns:
            object: An object of class `obj_cls`.

        Raises:
            NotImplementedError: If objects cannot be retrieved.
            GitlabGetError: If the server fails to perform the request.
        """
        args = self._set_parent_args(**kwargs)
        if not self.obj_cls.canGet:
            raise NotImplementedError
        if id is None and self.obj_cls.getRequiresId is True:
            raise ValueError('The id argument must be defined.')
        return self.obj_cls.get(self.gitlab, id, **args)

    def list(self, **kwargs):
        """Get a list of GitLab objects.

        Args:
            **kwargs: Additional arguments to send to GitLab.

        Returns:
            list[object]: A list of `obj_cls` objects.

        Raises:
            NotImplementedError: If objects cannot be listed.
            GitlabListError: If the server fails to perform the request.
        """
        args = self._set_parent_args(**kwargs)
        if not self.obj_cls.canList:
            raise NotImplementedError
        return self.obj_cls.list(self.gitlab, **args)

    def create(self, data, **kwargs):
        """Create a new object of class `obj_cls`.

        Args:
            data (dict): The parameters to send to the GitLab server to create
                the object. Required and optional arguments are defined in the
                `requiredCreateAttrs` and `optionalCreateAttrs` of the
                `obj_cls` class.
            **kwargs: Additional arguments to send to GitLab.

        Returns:
            object: A newly create `obj_cls` object.

        Raises:
            NotImplementedError: If objects cannot be created.
            GitlabCreateError: If the server fails to perform the request.
        """
        args = self._set_parent_args(**kwargs)
        if not self.obj_cls.canCreate:
            raise NotImplementedError
        return self.obj_cls.create(self.gitlab, data, **args)

    def delete(self, id, **kwargs):
        """Delete a GitLab object.

        Args:
            id: ID of the object to delete.

        Raises:
            NotImplementedError: If objects cannot be deleted.
            GitlabDeleteError: If the server fails to perform the request.
        """
        args = self._set_parent_args(**kwargs)
        if not self.obj_cls.canDelete:
            raise NotImplementedError
        self.gitlab.delete(self.obj_cls, id, **args)


class GitlabObject(object):
    """Base class for all classes that interface with GitLab."""
    #: Url to use in GitLab for this object
    _url = None
    # Some objects (e.g. merge requests) have different urls for singular and
    # plural
    _urlPlural = None
    _id_in_delete_url = True
    _id_in_update_url = True
    _constructorTypes = None

    #: Tells if GitLab-api allows retrieving single objects.
    canGet = True
    #: Tells if GitLab-api allows listing of objects.
    canList = True
    #: Tells if GitLab-api allows creation of new objects.
    canCreate = True
    #: Tells if GitLab-api allows updating object.
    canUpdate = True
    #: Tells if GitLab-api allows deleting object.
    canDelete = True
    #: Attributes that are required for constructing url.
    requiredUrlAttrs = []
    #: Attributes that are required when retrieving list of objects.
    requiredListAttrs = []
    #: Attributes that are optional when retrieving list of objects.
    optionalListAttrs = []
    #: Attributes that are optional when retrieving single object.
    optionalGetAttrs = []
    #: Attributes that are required when retrieving single object.
    requiredGetAttrs = []
    #: Attributes that are required when deleting object.
    requiredDeleteAttrs = []
    #: Attributes that are required when creating a new object.
    requiredCreateAttrs = []
    #: Attributes that are optional when creating a new object.
    optionalCreateAttrs = []
    #: Attributes that are required when updating an object.
    requiredUpdateAttrs = []
    #: Attributes that are optional when updating an object.
    optionalUpdateAttrs = []
    #: Whether the object ID is required in the GET url.
    getRequiresId = True
    #: List of managers to create.
    managers = []
    #: Name of the identifier of an object.
    idAttr = 'id'
    #: Attribute to use as ID when displaying the object.
    shortPrintAttr = None

    def _data_for_gitlab(self, extra_parameters={}, update=False,
                         as_json=True):
        data = {}
        if update and (self.requiredUpdateAttrs or self.optionalUpdateAttrs):
            attributes = itertools.chain(self.requiredUpdateAttrs,
                                         self.optionalUpdateAttrs)
        else:
            attributes = itertools.chain(self.requiredCreateAttrs,
                                         self.optionalCreateAttrs)
        attributes = list(attributes) + ['sudo', 'page', 'per_page']
        for attribute in attributes:
            if hasattr(self, attribute):
                value = getattr(self, attribute)
                # labels need to be sent as a comma-separated list
                if attribute == 'labels' and isinstance(value, list):
                    value = ", ".join(value)
                elif attribute == 'sudo':
                    value = str(value)
                data[attribute] = value

        data.update(extra_parameters)

        return json.dumps(data) if as_json else data

    @classmethod
    def list(cls, gl, **kwargs):
        """Retrieve a list of objects from GitLab.

        Args:
            gl (gitlab.Gitlab): Gitlab object referencing the GitLab server.
            per_page (int): Maximum number of items to return.
            page (int): ID of the page to return when using pagination.

        Returns:
            list[object]: A list of objects.

        Raises:
            NotImplementedError: If objects can't be listed.
            GitlabListError: If the server cannot perform the request.
        """
        if not cls.canList:
            raise NotImplementedError

        if not cls._url:
            raise NotImplementedError

        return gl.list(cls, **kwargs)

    @classmethod
    def get(cls, gl, id, **kwargs):
        """Retrieve a single object.

        Args:
            gl (gitlab.Gitlab): Gitlab object referencing the GitLab server.
            id (int or str): ID of the object to retrieve.

        Returns:
            object: The found GitLab object.

        Raises:
            NotImplementedError: If objects can't be retrieved.
            GitlabGetError: If the server cannot perform the request.
        """

        if cls.canGet is False:
            raise NotImplementedError
        elif cls.canGet is True:
            return cls(gl, id, **kwargs)
        elif cls.canGet == 'from_list':
            for obj in cls.list(gl, **kwargs):
                obj_id = getattr(obj, obj.idAttr)
                if str(obj_id) == str(id):
                    return obj

            raise GitlabGetError("Object not found")

    def _get_object(self, k, v, **kwargs):
        if self._constructorTypes and k in self._constructorTypes:
            cls = getattr(self._module, self._constructorTypes[k])
            return cls(self.gitlab, v, **kwargs)
        else:
            return v

    def _set_from_dict(self, data, **kwargs):
        if not hasattr(data, 'items'):
            return

        for k, v in data.items():
            # If a k attribute already exists and is a Manager, do nothing (see
            # https://github.com/python-gitlab/python-gitlab/issues/209)
            if isinstance(getattr(self, k, None), BaseManager):
                continue

            if isinstance(v, list):
                self.__dict__[k] = []
                for i in v:
                    self.__dict__[k].append(self._get_object(k, i, **kwargs))
            elif v is None:
                self.__dict__[k] = None
            else:
                self.__dict__[k] = self._get_object(k, v, **kwargs)

    def _create(self, **kwargs):
        if not self.canCreate:
            raise NotImplementedError

        json = self.gitlab.create(self, **kwargs)
        self._set_from_dict(json)
        self._from_api = True

    def _update(self, **kwargs):
        if not self.canUpdate:
            raise NotImplementedError

        json = self.gitlab.update(self, **kwargs)
        self._set_from_dict(json)

    def save(self, **kwargs):
        if self._from_api:
            self._update(**kwargs)
        else:
            self._create(**kwargs)

    def delete(self, **kwargs):
        if not self.canDelete:
            raise NotImplementedError

        if not self._from_api:
            raise GitlabDeleteError("Object not yet created")

        return self.gitlab.delete(self, **kwargs)

    @classmethod
    def create(cls, gl, data, **kwargs):
        """Create an object.

        Args:
            gl (gitlab.Gitlab): Gitlab object referencing the GitLab server.
            data (dict): The data used to define the object.

        Returns:
            object: The new object.

        Raises:
            NotImplementedError: If objects can't be created.
            GitlabCreateError: If the server cannot perform the request.
        """
        if not cls.canCreate:
            raise NotImplementedError

        obj = cls(gl, data, **kwargs)
        obj.save()

        return obj

    def __init__(self, gl, data=None, **kwargs):
        """Constructs a new object.

        Do not use this method. Use the `get` or `create` class methods
        instead.

        Args:
            gl (gitlab.Gitlab): Gitlab object referencing the GitLab server.
            data: If `data` is a dict, create a new object using the
                information. If it is an int or a string, get a GitLab object
                from an API request.
            **kwargs: Additional arguments to send to GitLab.
        """
        self._from_api = False
        #: (gitlab.Gitlab): Gitlab connection.
        self.gitlab = gl

        # store the module in which the object has been created (v3/v4) to be
        # able to reference other objects from the same module
        self._module = importlib.import_module(self.__module__)

        if (data is None or isinstance(data, six.integer_types) or
           isinstance(data, six.string_types)):
            if not self.canGet:
                raise NotImplementedError
            data = self.gitlab.get(self.__class__, data, **kwargs)
            self._from_api = True

            # the API returned a list because custom kwargs where used
            # instead of the id to request an object. Usually parameters
            # other than an id return ambiguous results. However in the
            # gitlab universe iids together with a project_id are
            # unambiguous for merge requests and issues, too.
            # So if there is only one element we can use it as our data
            # source.
            if 'iid' in kwargs and isinstance(data, list):
                if len(data) < 1:
                    raise GitlabGetError('Not found')
                elif len(data) == 1:
                    data = data[0]
                else:
                    raise GitlabGetError('Impossible! You found multiple'
                                         ' elements with the same iid.')

        self._set_from_dict(data, **kwargs)

        if kwargs:
            for k, v in kwargs.items():
                # Don't overwrite attributes returned by the server (#171)
                if k not in self.__dict__ or not self.__dict__[k]:
                    self.__dict__[k] = v

        # Special handling for api-objects that don't have id-number in api
        # responses. Currently only Labels and Files
        if not hasattr(self, "id"):
            self.id = None

    def _set_manager(self, var, cls, attrs):
        manager = cls(self.gitlab, self, attrs)
        setattr(self, var, manager)

    def __getattr__(self, name):
        # build a manager if it doesn't exist yet
        for var, cls, attrs in self.managers:
            if var != name:
                continue
            # Build the full class path if needed
            if isinstance(cls, six.string_types):
                cls = getattr(self._module, cls)
            self._set_manager(var, cls, attrs)
            return getattr(self, var)

        raise AttributeError(name)

    def __str__(self):
        return '%s => %s' % (type(self), str(self.__dict__))

    def __repr__(self):
        return '<%s %s:%s>' % (self.__class__.__name__,
                               self.idAttr,
                               getattr(self, self.idAttr))

    def display(self, pretty):
        if pretty:
            self.pretty_print()
        else:
            self.short_print()

    def short_print(self, depth=0):
        """Print the object on the standard output (verbose).

        Args:
            depth (int): Used internaly for recursive call.
        """
        id = self.__dict__[self.idAttr]
        print("%s%s: %s" % (" " * depth * 2, self.idAttr, id))
        if self.shortPrintAttr:
            print("%s%s: %s" % (" " * depth * 2,
                                self.shortPrintAttr.replace('_', '-'),
                                self.__dict__[self.shortPrintAttr]))

    @staticmethod
    def _get_display_encoding():
        return sys.stdout.encoding or sys.getdefaultencoding()

    @staticmethod
    def _obj_to_str(obj):
        if isinstance(obj, dict):
            s = ", ".join(["%s: %s" %
                          (x, GitlabObject._obj_to_str(y))
                          for (x, y) in obj.items()])
            return "{ %s }" % s
        elif isinstance(obj, list):
            s = ", ".join([GitlabObject._obj_to_str(x) for x in obj])
            return "[ %s ]" % s
        elif six.PY2 and isinstance(obj, six.text_type):
            return obj.encode(GitlabObject._get_display_encoding(), "replace")
        else:
            return str(obj)

    def pretty_print(self, depth=0):
        """Print the object on the standard output (verbose).

        Args:
            depth (int): Used internaly for recursive call.
        """
        id = self.__dict__[self.idAttr]
        print("%s%s: %s" % (" " * depth * 2, self.idAttr, id))
        for k in sorted(self.__dict__.keys()):
            if k in (self.idAttr, 'id', 'gitlab'):
                continue
            if k[0] == '_':
                continue
            v = self.__dict__[k]
            pretty_k = k.replace('_', '-')
            if six.PY2:
                pretty_k = pretty_k.encode(
                    GitlabObject._get_display_encoding(), "replace")
            if isinstance(v, GitlabObject):
                if depth == 0:
                    print("%s:" % pretty_k)
                    v.pretty_print(1)
                else:
                    print("%s: %s" % (pretty_k, v.id))
            elif isinstance(v, BaseManager):
                continue
            else:
                if hasattr(v, __name__) and v.__name__ == 'Gitlab':
                    continue
                v = GitlabObject._obj_to_str(v)
                print("%s%s: %s" % (" " * depth * 2, pretty_k, v))

    def json(self):
        """Dump the object as json.

        Returns:
            str: The json string.
        """
        return json.dumps(self, cls=jsonEncoder)

    def as_dict(self):
        """Dump the object as a dict."""
        return {k: v for k, v in six.iteritems(self.__dict__)
                if (not isinstance(v, BaseManager) and not k[0] == '_')}

    def __eq__(self, other):
        if type(other) is type(self):
            return self.as_dict() == other.as_dict()
        return False

    def __ne__(self, other):
        return not self.__eq__(other)
