# Copyright 2022 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# --------------------------------------------------------------------------------
# Load The Dependencies
# --------------------------------------------------------------------------------

import csv
import datetime
import io
import json
import logging
import os

from airflow import models
from airflow.providers.google.cloud.operators.dataflow import DataflowTemplatedJobStartOperator
from airflow.operators import dummy
from airflow.providers.google.cloud.operators.bigquery import  BigQueryInsertJobOperator, BigQueryUpsertTableOperator, BigQueryUpdateTableSchemaOperator
from airflow.utils.task_group import TaskGroup

# --------------------------------------------------------------------------------
# Set variables - Needed for the DEMO
# --------------------------------------------------------------------------------
BQ_LOCATION = os.environ.get("BQ_LOCATION")
DATA_CAT_TAGS = json.loads(os.environ.get("DATA_CAT_TAGS"))
DWH_LAND_PRJ = os.environ.get("DWH_LAND_PRJ")
DWH_LAND_BQ_DATASET = os.environ.get("DWH_LAND_BQ_DATASET")
DWH_LAND_GCS = os.environ.get("DWH_LAND_GCS")
DWH_CURATED_PRJ = os.environ.get("DWH_CURATED_PRJ")
DWH_CURATED_BQ_DATASET = os.environ.get("DWH_CURATED_BQ_DATASET")
DWH_CURATED_GCS = os.environ.get("DWH_CURATED_GCS")
DWH_CONFIDENTIAL_PRJ = os.environ.get("DWH_CONFIDENTIAL_PRJ")
DWH_CONFIDENTIAL_BQ_DATASET = os.environ.get("DWH_CONFIDENTIAL_BQ_DATASET")
DWH_CONFIDENTIAL_GCS = os.environ.get("DWH_CONFIDENTIAL_GCS")
DWH_PLG_PRJ = os.environ.get("DWH_PLG_PRJ")
DWH_PLG_BQ_DATASET = os.environ.get("DWH_PLG_BQ_DATASET")
DWH_PLG_GCS = os.environ.get("DWH_PLG_GCS")
GCP_REGION = os.environ.get("GCP_REGION")
DRP_PRJ = os.environ.get("DRP_PRJ")
DRP_BQ = os.environ.get("DRP_BQ")
DRP_GCS = os.environ.get("DRP_GCS")
DRP_PS = os.environ.get("DRP_PS")
LOD_PRJ = os.environ.get("LOD_PRJ")
LOD_GCS_STAGING = os.environ.get("LOD_GCS_STAGING")
LOD_NET_VPC = os.environ.get("LOD_NET_VPC")
LOD_NET_SUBNET = os.environ.get("LOD_NET_SUBNET")
LOD_SA_DF = os.environ.get("LOD_SA_DF")
ORC_PRJ = os.environ.get("ORC_PRJ")
ORC_GCS = os.environ.get("ORC_GCS")
TRF_PRJ = os.environ.get("TRF_PRJ")
TRF_GCS_STAGING = os.environ.get("TRF_GCS_STAGING")
TRF_NET_VPC = os.environ.get("TRF_NET_VPC")
TRF_NET_SUBNET = os.environ.get("TRF_NET_SUBNET")
TRF_SA_DF = os.environ.get("TRF_SA_DF")
TRF_SA_BQ = os.environ.get("TRF_SA_BQ")
DF_KMS_KEY = os.environ.get("DF_KMS_KEY", "")
DF_REGION = os.environ.get("GCP_REGION")
DF_ZONE = os.environ.get("GCP_REGION") + "-b"

# --------------------------------------------------------------------------------
# Set default arguments
# --------------------------------------------------------------------------------

# If you are running Airflow in more than one time zone
# see https://airflow.apache.org/docs/apache-airflow/stable/timezone.html
# for best practices
yesterday = datetime.datetime.now() - datetime.timedelta(days=1)

default_args = {
  'owner': 'airflow',
  'start_date': yesterday,
  'depends_on_past': False,
  'email': [''],
  'email_on_failure': False,
  'email_on_retry': False,
  'retries': 1,
  'retry_delay': datetime.timedelta(minutes=5),
  'dataflow_default_options': {
    'location': DF_REGION,
    'zone': DF_ZONE,
    'stagingLocation': LOD_GCS_STAGING,
    'tempLocation': LOD_GCS_STAGING + "/tmp",
    'serviceAccountEmail': LOD_SA_DF,
    'subnetwork': LOD_NET_SUBNET,
    'ipConfiguration': "WORKER_IP_PRIVATE",
    'kmsKeyName' : DF_KMS_KEY
  },
}

# --------------------------------------------------------------------------------
# Main DAG
# --------------------------------------------------------------------------------

with models.DAG(
    'data_pipeline_dag',
    default_args=default_args,
    schedule_interval=None) as dag:
  start = dummy.DummyOperator(
    task_id='start',
    trigger_rule='all_success'
  )

  end = dummy.DummyOperator(
    task_id='end',
    trigger_rule='all_success'
  )

  # Bigquery Tables automatically created for demo porpuse. 
  # Consider a dedicated pipeline or tool for a real life scenario.
  customers_import = DataflowTemplatedJobStartOperator(
    task_id="dataflow_customers_import",
    template="gs://dataflow-templates/latest/GCS_Text_to_BigQuery",
    project_id=LOD_PRJ,
    location=DF_REGION,
    parameters={
      "javascriptTextTransformFunctionName": "transform",
      "JSONPath": ORC_GCS + "/customers_schema.json",
      "javascriptTextTransformGcsPath": ORC_GCS + "/customers_udf.js",
      "inputFilePattern": DRP_GCS + "/customers.csv",
      "outputTable": DWH_LAND_PRJ + ":" + DWH_LAND_BQ_DATASET + ".customers",
      "bigQueryLoadingTemporaryDirectory": LOD_GCS_STAGING + "/tmp/bq/",
    },
  )

  purchases_import = DataflowTemplatedJobStartOperator(
    task_id="dataflow_purchases_import",
    template="gs://dataflow-templates/latest/GCS_Text_to_BigQuery",
    project_id=LOD_PRJ,
    location=DF_REGION,
    parameters={
      "javascriptTextTransformFunctionName": "transform",
      "JSONPath": ORC_GCS + "/purchases_schema.json",
      "javascriptTextTransformGcsPath": ORC_GCS + "/purchases_udf.js",
      "inputFilePattern": DRP_GCS + "/purchases.csv",
      "outputTable": DWH_LAND_PRJ + ":" + DWH_LAND_BQ_DATASET + ".purchases",
      "bigQueryLoadingTemporaryDirectory": LOD_GCS_STAGING + "/tmp/bq/",
    },
  )

  join_customer_purchase = BigQueryInsertJobOperator(
    task_id='bq_join_customer_purchase',
    gcp_conn_id='bigquery_default',
    project_id=TRF_PRJ,
    location=BQ_LOCATION,
    configuration={
      'jobType':'QUERY',
      'query':{
        'query':"""SELECT
                  c.id as customer_id,
                  p.id as purchase_id,
                  p.item as item,
                  p.price as price,
                  p.timestamp as timestamp
                FROM `{dwh_0_prj}.{dwh_0_dataset}.customers` c
                JOIN `{dwh_0_prj}.{dwh_0_dataset}.purchases` p ON c.id = p.customer_id
              """.format(dwh_0_prj=DWH_LAND_PRJ, dwh_0_dataset=DWH_LAND_BQ_DATASET, ),
        'destinationTable':{
          'projectId': DWH_CURATED_PRJ,
          'datasetId': DWH_CURATED_BQ_DATASET,
          'tableId': 'customer_purchase'
        },
        'writeDisposition':'WRITE_TRUNCATE',
        "useLegacySql": False
      }
    },
    impersonation_chain=[TRF_SA_BQ]
  )

  confidential_customer_purchase = BigQueryInsertJobOperator(
    task_id='bq_confidential_customer_purchase',
    gcp_conn_id='bigquery_default',
    project_id=TRF_PRJ,
    location=BQ_LOCATION,
    configuration={
      'jobType':'QUERY',
      'query':{
        'query':"""SELECT
                  c.id as customer_id,
                  p.id as purchase_id,
                  c.name as name,
                  c.surname as surname,
                  p.item as item,
                  p.price as price,
                  p.timestamp as timestamp
                FROM `{dwh_0_prj}.{dwh_0_dataset}.customers` c
                JOIN `{dwh_0_prj}.{dwh_0_dataset}.purchases` p ON c.id = p.customer_id
              """.format(dwh_0_prj=DWH_LAND_PRJ, dwh_0_dataset=DWH_LAND_BQ_DATASET, ),
        'destinationTable':{
          'projectId': DWH_CONFIDENTIAL_PRJ,
          'datasetId': DWH_CONFIDENTIAL_BQ_DATASET,
          'tableId': 'customer_purchase'
        },
        'writeDisposition':'WRITE_TRUNCATE',
        "useLegacySql": False
      }
    },
    impersonation_chain=[TRF_SA_BQ]
  )

  start >> [customers_import, purchases_import] >> join_customer_purchase >> confidential_customer_purchase >> end