from os.path import splitext
from .resource import List
from .resource import Find
from .resource import Create
from .resource import Post
from .resource import Update
from .resource import Delete
from .resource import Replace

from . import utils

class File(List, Find, Create, Post, Update, Delete, Replace):
    """Node class wrapping the REST nodes endpoint
    """
    path = "files"
    file_server_path = "file_storage/file"
    build_previews_server_path = "file_storage/build_previews"

    def post_file(self, file_path, name=None, api=None):
        """Stores a file on the database or static folder.
        :param file: A file object
        """
        api = api or self.api
        url = utils.join_url(self.file_server_path)
        file_ = open(file_path, 'rb')
        files = {'data': file_}
        api.post(url, {"name": name}, {}, files)
        file_.close()
        # self.error = None
        # self.merge(new_attributes)
        return self.success()

    def build_previews(self, path, api=None):
        """Stores a file on the database or static folder.
        :param path: A file path
        """
        api = api or self.api
        url = utils.join_url(self.build_previews_server_path, path)
        api.get(url)
        return self.success()

    def children(self, api=None):
        """Collect children (variations) of the current file. Used to connect
        different resolutions of the same picture, or multiple versions of the
        same video in different formats/containers.

        TODO: add params to support pagination.
        """
        api = api or self.api
        files = self.all({'where': '{"parent": "%s"}' % self._id}, api=api)
        if not files._items:
            return None
        return files

    def thumbnail(self, size):
        """Utility to replace a component of an image link so that it points to
        a thumbnail, without querying the database.
        """
        if size in ['s', 'b', 't', 'm', 'l', 'h']:
            root, ext = splitext(self.link)
            return "{0}-{1}.jpg".format(root, size)
        else:
            raise ValueError("Size should be (s, b, t, m, l, h)")

    def thumbnail_file(self, size, api=None):
        """Delivers a single thumbnail (child) file for an image. Before returning
        we check that the parent is actually an image.
        :param path: the size (s, b, t, m, l, h)
        """
        api = api or self.api
        if size in ['s', 'b', 't', 'm', 'l', 'h']:
            # We chack from the content_type if the file is an image
            if self.content_type.split('/')[0] == 'image':
                thumbnail = self.find_first({
                    'where': '{"parent" : "%s", "size" : "%s"}'\
                        % (self._id, size),
                    }, api=api)
                return thumbnail
            else:
                return None
        else:
            raise ValueError("Size should be (s, b, t, m, l, h)")