import os
import tempfile
import unittest

import boto3
import botocore
import pandas as pd
from moto import mock_s3

from service.utils.aws_connectors import s3_to_pandas

MY_BUCKET = "fansifter_mock_bucket"


@mock_s3
class TestS3(unittest.TestCase):
    def setUp(self):
        client = boto3.client(
            "s3",
            region_name="eu-west-1",
            aws_access_key_id="fake_access_key",
            aws_secret_access_key="fake_secret_key",
        )
        try:
            s3 = boto3.resource(
                "s3",
                region_name="eu-west-1",
                aws_access_key_id="fake_access_key",
                aws_secret_access_key="fake_secret_key",
            )
            s3.meta.client.head_bucket(Bucket=MY_BUCKET)
        except botocore.exceptions.ClientError:
            pass
        else:
            err = f"{MY_BUCKET} should not exist."
            raise EnvironmentError(err)
        client.create_bucket(Bucket=MY_BUCKET)
        current_dir = os.path.dirname(__file__)
        fixtures_dir = os.path.join(current_dir, "s3_mock_files")
        _upload_fixtures(MY_BUCKET, fixtures_dir)

    def tearDown(self):
        s3 = boto3.resource(
            "s3",
            region_name="eu-west-1",
            aws_access_key_id="fake_access_key",
            aws_secret_access_key="fake_secret_key",
        )
        bucket = s3.Bucket(MY_BUCKET)
        for key in bucket.objects.all():
            key.delete()
        bucket.delete()

    def test_s3_to_pandas(self):
        """Test if s3_to_pandas indeed returns pandas dataframe"""
        with tempfile.TemporaryDirectory():
            df = s3_to_pandas(MY_BUCKET, "data.csv", header=None, file_format="csv")
            self.assertTrue(isinstance(df, pd.DataFrame))


def _upload_fixtures(bucket: str, fixtures_dir: str) -> None:
    client = boto3.client("s3")
    fixtures_paths = [
        os.path.join(path, filename)
        for path, _, files in os.walk(fixtures_dir)
        for filename in files
    ]
    for path in fixtures_paths:
        key = os.path.relpath(path, fixtures_dir)
        client.upload_file(Filename=path, Bucket=bucket, Key=key)


if __name__ == "__main__":
    unittest.main()