# Copyright 2018 TrilioData Inc.
# All Rights Reserved.

import copy

from dmapi.api.openstack import common


def get_view_builder(req):
    base_url = req.application_url
    return ViewBuilder(base_url)


class ViewBuilder(common.ViewBuilder):

    def __init__(self, base_url):
        """:param base_url: url of the root wsgi application."""
        self.prefix = self._update_dmapi_link_prefix(base_url)
        self.base_url = base_url

    def build_choices(self, VERSIONS, req):
        version_objs = []
        for version in sorted(VERSIONS):
            version = VERSIONS[version]
            version_objs.append({
                "id": version['id'],
                "status": version['status'],
                "links": [
                    {
                        "rel": "self",
                        "href": self.generate_href(version['id'], req.path),
                    },
                ],
                "media-types": version['media-types'],
            })

        return dict(choices=version_objs)

    def build_versions(self, versions):
        version_objs = []
        for version in sorted(versions.keys()):
            version = versions[version]
            version_objs.append({
                "id": version['id'],
                "status": version['status'],
                "version": version['version'],
                "min_version": version['min_version'],
                "updated": version['updated'],
                "links": self._build_links(version),
            })

        return dict(versions=version_objs)

    def build_version(self, version):
        reval = copy.deepcopy(version)
        reval['links'].insert(0, {
            "rel": "self",
            "href": self.prefix.rstrip('/') + '/',
        })
        return dict(version=reval)

    def _build_links(self, version_data):
        """Generate a container of links that refer to the provided version."""
        href = self.generate_href(version_data['id'])

        links = [
            {
                "rel": "self",
                "href": href,
            },
        ]

        return links

    def generate_href(self, version, path=None):
        """Create an url that refers to a specific version_number."""
        version_number = 'v2'

        path = path or ''
        return common.url_join(self.prefix, version_number, path)