"""
Defines ResourceSet objects that can be used to represent a set of resources.
"""

import operator
import functools
import itertools

from . import lookups, exceptions


class BaseResourceSet(object):
    """
    Defines basic functionality for a ResourceSet object.
    """
    def __init__(self, manager, resources=None, limit=0, offset=0, total_count=None):
        """
        :param managers.ResourceManager manager: (required). ResourceManager object.
        :param resources: (optional). Iterable of resources.
        :type resources: list or tuple
        :param int limit: (optional). Resource limit.
        :param int offset: (optional). Resource offset.
        :param int total_count: (optional). How many resources are there available in Redmine.
        """
        self.manager = manager
        self.limit = limit
        self.offset = offset
        self._resources = resources
        self._total_count = total_count
        self._is_sliced = False

    @property
    def total_count(self):
        """
        Returns total count of available resources in Redmine, this is known only after ResourceSet evaluation.
        """
        if self._total_count is None:
            if self._resources is None:
                raise exceptions.ResultSetTotalCountError
            else:
                self._total_count = len(self)

        return self._total_count

    def export(self, fmt, savepath=None, filename=None, columns=None):
        """
        Exports all resources from resource set to requested format if Resource supports that.

        :param string fmt: (required). Format to use for export, e.g. atom, csv, txt, pdf, html etc.
        :param string savepath: (optional). Path where to save the file.
        :param string filename: (optional). Name that will be used for the file.
        :param columns: (optional). Iterable of column names or "all" for all columns.
        :type columns: iterable or string
        """
        if self.manager.resource_class.query_all_export is None:
            raise exceptions.ExportNotSupported

        url = self.manager.redmine.url + self.manager.resource_class.query_all_export.format(
                format=fmt, **self.manager.params)

        params = self.manager.resource_class.query_all_export.formatter.unused_kwargs

        if columns is not None:
            if columns == 'all':
                columns = 'all_inline'

            params.update({'c[]': columns, 'encoding': 'UTF-8'})

        try:
            return self.manager.redmine.download(url, savepath, filename, params=params)
        except exceptions.UnknownError as e:
            if e.status_code == 406:
                raise exceptions.ExportFormatNotSupportedError
            raise e

    def _resource_cls(self, cls, resources, **kwargs):
        """
        Returns a new resource set class instance defined by cls, filled with resources and loaded with kwargs.

        :param any cls: (required). Resource set class.
        :param resources: (required). Iterable of resources.
        :type resources: list or tuple
        :param dict kwargs: (optional). Additional keyword arguments if any.
        """
        return cls(self.manager, resources=resources, limit=self.limit, offset=self.offset,
                   total_count=self._total_count, **kwargs)

    def __getitem__(self, item):
        """
        Sets limit and offset or returns a Resource by requested index.
        """
        if isinstance(item, slice):
            self.limit = item.stop
            self.offset = item.start
            self._is_sliced = True
        elif isinstance(item, int):
            try:
                return next(itertools.islice(self, item, item + 1))
            except StopIteration:
                raise exceptions.ResourceSetIndexError

        if self._resources is not None and self._is_sliced:
            return self._resource_cls(self.__class__, [resource for resource in BaseResourceSet.__iter__(self)])

        return self

    def __iter__(self):
        """
        Returns requested resources in a lazy fashion.
        """
        # If this is the first time we are evaluating the ResourceSet
        # all the hard part will be done by the active Engine object
        if self._resources is None:
            self.manager.params.setdefault('limit', self.limit)
            self.manager.params.setdefault('offset', self.offset)

            try:
                self._resources, self._total_count = self.manager.redmine.engine.bulk_request(
                    'get', self.manager.url, self.manager.container, **self.manager.params)
            except exceptions.ResourceNotFoundError as e:
                if self.manager.resource_class.requirements:
                    raise exceptions.ResourceRequirementsError(self.manager.resource_class.requirements)
                raise e

            resources = self._resources
        # Otherwise ResourceSet object should handle slicing by itself
        elif self._is_sliced:
            offset = self.offset or None

            if not self.limit:
                limit = None
            elif self.limit and not self.offset:
                limit = self.limit
            else:
                limit = self.limit + self.offset

            resources = self._resources[offset:limit]
        else:
            resources = self._resources

        self._is_sliced = False
        return (resource for resource in resources)

    def __len__(self):
        """
        Allows len() to be called on a ResourceSet object.
        """
        return sum(1 for _ in self)

    def __repr__(self):
        """
        Official representation of a ResourceSet object.
        """
        return '<{0}.{1} object with {2} resources>'.format(
            self.__class__.__module__, self.__class__.__name__, self.manager.resource_class.__name__)


class ResourceSet(BaseResourceSet):
    """
    Represents a set of Redmine resources as objects.
    """
    def get(self, resource_id, default=None):
        """
        Returns a single Resource from a ResourceSet by resource id.

        :param resource_id: (required). Resource id.
        :type resource_id: int or string
        :param none default: (optional). What to return if Resource wasn't found.
        """
        for resource in super(ResourceSet, self).__iter__():
            if resource_id == resource[self.manager.resource_class.internal_id_key]:
                return self.manager.to_resource(resource)

        return default

    def filter(self, **filters):
        """
        Returns a new filtered ResourceSet with requested filters applied.

        :param dict filters: (required). Filters used for resources retrieval.
        """
        if not filters:
            raise exceptions.ResourceNoFiltersProvidedError

        reducers = []

        for f in filters:
            fields = f.split('__')
            lookup = fields[-1]

            reducer = {
                'fields': fields,
                'value': filters[f],
                'lookup': lookups.registry['exact'],
                'lookup_name': lookup,
                'filter_name': f,
            }

            if lookup in lookups.registry:
                reducer['fields'] = fields[:-1]
                reducer['lookup'] = lookups.registry[lookup]

            reducers.append(reducer)

        resources = []

        for resource in super(ResourceSet, self).__iter__():
            for r in reducers:
                try:
                    if not r['lookup'](functools.reduce(operator.getitem, r['fields'], resource), r['value']):
                        break
                except KeyError:
                    break
                except TypeError:
                    raise exceptions.ResourceSetFilterLookupError(r['lookup_name'], r['filter_name'])
            else:
                resources.append(resource)

        return self._resource_cls(ResourceSet, resources)

    def update(self, **fields):
        """
        Updates fields of all resources in a ResourceSet with the given values.

        :param dict fields: (optional). Fields in resources that will be updated.
        """
        resources = []

        for resource in self:
            for field in fields:
                setattr(resource, field, fields[field])

            resources.append(resource.save().raw())

        return self._resource_cls(ResourceSet, resources)

    def delete(self):
        """
        Deletes all resources in a ResourceSet.
        """
        for resource in self:
            resource.delete()

        self._resources = None
        return True

    def values(self, *fields):
        """
        Returns ResourceSet as an iterable of dictionaries.

        :param fields: (optional). Iterable which sets field names each resource will contain.
        :type fields: list or tuple
        """
        if fields:
            for resource in super(ResourceSet, self).__iter__():
                yield {field: resource[field] for field in fields if field in resource}
        else:
            for resource in super(ResourceSet, self).__iter__():
                yield resource

    def values_list(self, *fields, **kwargs):
        """
        Returns ResourceSet as an iterable of tuples with Resource values or single values if flattened.

        :param fields: (optional). Iterable which sets field names each resource will contain.
        :type fields: list or tuple
        :param dict kwargs: (optional). If fields contain single field, setting flat=True will flatten the result.
        """
        flat = kwargs.pop('flat', False)

        if fields:
            if flat and len(fields) == 1:
                for resource in super(ResourceSet, self).__iter__():
                    yield resource.get(fields[0])
            else:
                for resource in super(ResourceSet, self).__iter__():
                    yield tuple(resource[field] for field in fields if field in resource)
        else:
            for resource in super(ResourceSet, self).__iter__():
                yield tuple(resource.values())

    def __iter__(self):
        """
        Returns requested resources in a lazy fashion.
        """
        return (self.manager.to_resource(resource) for resource in super(ResourceSet, self).__iter__())

"""
Defines ResourceSet objects that can be used to represent a set of resources.
"""

import operator
import functools
import itertools

from . import lookups, exceptions


class BaseResourceSet(object):
    """
    Defines basic functionality for a ResourceSet object.
    """
    def __init__(self, manager, resources=None, limit=0, offset=0, total_count=None):
        """
        :param managers.ResourceManager manager: (required). ResourceManager object.
        :param resources: (optional). Iterable of resources.
        :type resources: list or tuple
        :param int limit: (optional). Resource limit.
        :param int offset: (optional). Resource offset.
        :param int total_count: (optional). How many resources are there available in Redmine.
        """
        self.manager = manager
        self.limit = limit
        self.offset = offset
        self._resources = resources
        self._total_count = total_count
        self._is_sliced = False

    @property
    def total_count(self):
        """
        Returns total count of available resources in Redmine, this is known only after ResourceSet evaluation.
        """
        if self._total_count is None:
            if self._resources is None:
                raise exceptions.ResultSetTotalCountError
            else:
                self._total_count = len(self)

        return self._total_count

    def export(self, fmt, savepath=None, filename=None, columns=None):
        """
        Exports all resources from resource set to requested format if Resource supports that.

        :param string fmt: (required). Format to use for export, e.g. atom, csv, txt, pdf, html etc.
        :param string savepath: (optional). Path where to save the file.
        :param string filename: (optional). Name that will be used for the file.
        :param columns: (optional). Iterable of column names or "all" for all columns.
        :type columns: iterable or string
        """
        if self.manager.resource_class.query_all_export is None:
            raise exceptions.ExportNotSupported

        url = self.manager.redmine.url + self.manager.resource_class.query_all_export.format(
                format=fmt, **self.manager.params)

        params = self.manager.resource_class.query_all_export.formatter.unused_kwargs

        if columns is not None:
            if columns == 'all':
                columns = 'all_inline'

            params.update({'c[]': columns, 'encoding': 'UTF-8'})

        try:
            return self.manager.redmine.download(url, savepath, filename, params=params)
        except exceptions.UnknownError as e:
            if e.status_code == 406:
                raise exceptions.ExportFormatNotSupportedError
            raise e

    def _resource_cls(self, cls, resources, **kwargs):
        """
        Returns a new resource set class instance defined by cls, filled with resources and loaded with kwargs.

        :param any cls: (required). Resource set class.
        :param resources: (required). Iterable of resources.
        :type resources: list or tuple
        :param dict kwargs: (optional). Additional keyword arguments if any.
        """
        return cls(self.manager, resources=resources, limit=self.limit, offset=self.offset,
                   total_count=self._total_count, **kwargs)

    def __getitem__(self, item):
        """
        Sets limit and offset or returns a Resource by requested index.
        """
        if isinstance(item, slice):
            self.limit = item.stop
            self.offset = item.start
            self._is_sliced = True
        elif isinstance(item, int):
            try:
                return next(itertools.islice(self, item, item + 1))
            except StopIteration:
                raise exceptions.ResourceSetIndexError

        if self._resources is not None and self._is_sliced:
            return self._resource_cls(self.__class__, [resource for resource in BaseResourceSet.__iter__(self)])

        return self

    def __iter__(self):
        """
        Returns requested resources in a lazy fashion.
        """
        # If this is the first time we are evaluating the ResourceSet
        # all the hard part will be done by the active Engine object
        if self._resources is None:
            self.manager.params.setdefault('limit', self.limit)
            self.manager.params.setdefault('offset', self.offset)

            try:
                self._resources, self._total_count = self.manager.redmine.engine.bulk_request(
                    'get', self.manager.url, self.manager.container, **self.manager.params)
            except exceptions.ResourceNotFoundError as e:
                if self.manager.resource_class.requirements:
                    raise exceptions.ResourceRequirementsError(self.manager.resource_class.requirements)
                raise e

            resources = self._resources
        # Otherwise ResourceSet object should handle slicing by itself
        elif self._is_sliced:
            offset = self.offset or None

            if not self.limit:
                limit = None
            elif self.limit and not self.offset:
                limit = self.limit
            else:
                limit = self.limit + self.offset

            resources = self._resources[offset:limit]
        else:
            resources = self._resources

        self._is_sliced = False
        return (resource for resource in resources)

    def __len__(self):
        """
        Allows len() to be called on a ResourceSet object.
        """
        return sum(1 for _ in self)

    def __repr__(self):
        """
        Official representation of a ResourceSet object.
        """
        return '<{0}.{1} object with {2} resources>'.format(
            self.__class__.__module__, self.__class__.__name__, self.manager.resource_class.__name__)


class ResourceSet(BaseResourceSet):
    """
    Represents a set of Redmine resources as objects.
    """
    def get(self, resource_id, default=None):
        """
        Returns a single Resource from a ResourceSet by resource id.

        :param resource_id: (required). Resource id.
        :type resource_id: int or string
        :param none default: (optional). What to return if Resource wasn't found.
        """
        for resource in super(ResourceSet, self).__iter__():
            if resource_id == resource[self.manager.resource_class.internal_id_key]:
                return self.manager.to_resource(resource)

        return default

    def filter(self, **filters):
        """
        Returns a new filtered ResourceSet with requested filters applied.

        :param dict filters: (required). Filters used for resources retrieval.
        """
        if not filters:
            raise exceptions.ResourceNoFiltersProvidedError

        reducers = []

        for f in filters:
            fields = f.split('__')
            lookup = fields[-1]

            reducer = {
                'fields': fields,
                'value': filters[f],
                'lookup': lookups.registry['exact'],
                'lookup_name': lookup,
                'filter_name': f,
            }

            if lookup in lookups.registry:
                reducer['fields'] = fields[:-1]
                reducer['lookup'] = lookups.registry[lookup]

            reducers.append(reducer)

        resources = []

        for resource in super(ResourceSet, self).__iter__():
            for r in reducers:
                try:
                    if not r['lookup'](functools.reduce(operator.getitem, r['fields'], resource), r['value']):
                        break
                except KeyError:
                    break
                except TypeError:
                    raise exceptions.ResourceSetFilterLookupError(r['lookup_name'], r['filter_name'])
            else:
                resources.append(resource)

        return self._resource_cls(ResourceSet, resources)

    def update(self, **fields):
        """
        Updates fields of all resources in a ResourceSet with the given values.

        :param dict fields: (optional). Fields in resources that will be updated.
        """
        resources = []

        for resource in self:
            for field in fields:
                setattr(resource, field, fields[field])

            resources.append(resource.save().raw())

        return self._resource_cls(ResourceSet, resources)

    def delete(self):
        """
        Deletes all resources in a ResourceSet.
        """
        for resource in self:
            resource.delete()

        self._resources = None
        return True

    def values(self, *fields):
        """
        Returns ResourceSet as an iterable of dictionaries.

        :param fields: (optional). Iterable which sets field names each resource will contain.
        :type fields: list or tuple
        """
        if fields:
            for resource in super(ResourceSet, self).__iter__():
                yield {field: resource[field] for field in fields if field in resource}
        else:
            for resource in super(ResourceSet, self).__iter__():
                yield resource

    def values_list(self, *fields, **kwargs):
        """
        Returns ResourceSet as an iterable of tuples with Resource values or single values if flattened.

        :param fields: (optional). Iterable which sets field names each resource will contain.
        :type fields: list or tuple
        :param dict kwargs: (optional). If fields contain single field, setting flat=True will flatten the result.
        """
        flat = kwargs.pop('flat', False)

        if fields:
            if flat and len(fields) == 1:
                for resource in super(ResourceSet, self).__iter__():
                    yield resource.get(fields[0])
            else:
                for resource in super(ResourceSet, self).__iter__():
                    yield tuple(resource[field] for field in fields if field in resource)
        else:
            for resource in super(ResourceSet, self).__iter__():
                yield tuple(resource.values())

    def __iter__(self):
        """
        Returns requested resources in a lazy fashion.
        """
        return (self.manager.to_resource(resource) for resource in super(ResourceSet, self).__iter__())

Defines ResourceSet objects that can be used to represent a set of resources. Defines basic functionality for a ResourceSet object. :param managers.ResourceManager manager: (required). ResourceManager object.         :param resources: (optional). Iterable of resources.         :type resources: list or tuple         :param int limit: (optional). Resource limit.         :param int offset: (optional). Resource offset.         :param int total_count: (optional). How many resources are there available in Redmine. Returns total count of available resources in Redmine, this is known only after ResourceSet evaluation. Exports all resources from resource set to requested format if Resource supports that.          :param string fmt: (required). Format to use for export, e.g. atom, csv, txt, pdf, html etc.         :param string savepath: (optional). Path where to save the file.         :param string filename: (optional). Name that will be used for the file.         :param columns: (optional). Iterable of column names or "all" for all columns.         :type columns: iterable or string Returns a new resource set class instance defined by cls, filled with resources and loaded with kwargs.          :param any cls: (required). Resource set class.         :param resources: (required). Iterable of resources.         :type resources: list or tuple         :param dict kwargs: (optional). Additional keyword arguments if any. Sets limit and offset or returns a Resource by requested index. Returns requested resources in a lazy fashion. # If this is the first time we are evaluating the ResourceSet # all the hard part will be done by the active Engine object # Otherwise ResourceSet object should handle slicing by itself Allows len() to be called on a ResourceSet object. Official representation of a ResourceSet object. Represents a set of Redmine resources as objects. Returns a single Resource from a ResourceSet by resource id.          :param resource_id: (required). Resource id.         :type resource_id: int or string         :param none default: (optional). What to return if Resource wasn't found. Returns a new filtered ResourceSet with requested filters applied.          :param dict filters: (required). Filters used for resources retrieval. Updates fields of all resources in a ResourceSet with the given values.          :param dict fields: (optional). Fields in resources that will be updated. Deletes all resources in a ResourceSet. Returns ResourceSet as an iterable of dictionaries.          :param fields: (optional). Iterable which sets field names each resource will contain.         :type fields: list or tuple Returns ResourceSet as an iterable of tuples with Resource values or single values if flattened.          :param fields: (optional). Iterable which sets field names each resource will contain.         :type fields: list or tuple         :param dict kwargs: (optional). If fields contain single field, setting flat=True will flatten the result. Returns requested resources in a lazy fashion.