from django.db import models
from django_filters import rest_framework as filters
from urllib.parse import urlsplit


class DataLocation(models.Model):
    name = models.CharField(max_length=50, primary_key=True)
    uri = models.CharField(max_length=200)

    @staticmethod
    def insert_location_from_string(location_string):
        """
        Insert a datalocation from a srm string (e.g. srm://surm:4321/path.tar)

        :param str location_string: SRM url
        :return: DataLocation object
        rtype: DataLocations
        """
        _, netloc, *_ = urlsplit(location_string)

        dataloc = DataLocation(name=netloc, uri=location_string.rstrip('/'))
        dataloc.save()
        return dataloc


class DataProduct(models.Model):
    obs_id = models.CharField(verbose_name="OBS_ID", max_length=15)
    oid_source = models.CharField(verbose_name='OBS_ID_SOURCE', max_length=15)
    dataproduct_source = models.CharField(max_length=20)
    dataproduct_type = models.CharField(max_length=50)
    project = models.CharField(max_length=15)
    location = models.ForeignKey(DataLocation, on_delete=models.DO_NOTHING)
    activity = models.CharField(max_length=50)
    surl = models.CharField(max_length=200)
    filesize = models.PositiveBigIntegerField()
    additional_meta = models.JSONField()

    @staticmethod
    def insert_dataproduct(obs_id,
                           oid_source,
                           dataproduct_source,
                           dataproduct_type,
                           project,
                           activity,
                           surl,
                           filesize,
                           additional_meta):
        scheme, netloc, *_ = urlsplit(surl)

        dp = DataProduct(obs_id=obs_id,
                         oid_source=oid_source,
                         dataproduct_source=dataproduct_source,
                         dataproduct_type=dataproduct_type,
                         project=project,
                         location=DataLocation.insert_location_from_string('://'.join((scheme, netloc))),
                         activity=activity,
                         filesize=filesize,
                         additional_meta=additional_meta,
                         surl=surl
                         )
        dp.save()
        return dp


class DataProductFilter(models.Model):
    field = models.CharField(max_length=20)
    name = models.CharField(max_length=20)
    lookup_type = models.CharField(max_length=100)