"""
Bigquery setup related functions
"""
import os
import argparse
from os import listdir
from google.cloud import bigquery
from google.api_core.exceptions import BadRequest
# disabling for linting to pass
# pylint: disable = broad-exception-raised
DATABASE_PREFIX = os.getenv("DATABASE_PREFIX", "")

GCP_PROJECT = os.getenv("PROJECT_ID", None)

BQ_REGION = os.getenv("BQ_REGION", "US")

BQ_DATASET = DATABASE_PREFIX + os.getenv("BQ_DATASET", "lms_analytics")

bq_client = bigquery.Client(location=BQ_REGION)
# Print statements are being used in this file to debug in the Github actions


def create_bigquery_dataset(dataset):
  """Create a dataset in the bigquery"""
  dataset_id = f"{GCP_PROJECT}.{dataset}"
  print("Dataset_id", dataset_id)
  dataset = bigquery.Dataset(dataset_id)
  try:
    bq_client.create_dataset(dataset, timeout=30)
    print(f"{dataset} dataset created")
  except Exception as e:  # pylint: disable = broad-except
    print("Error raised", e)


def create_table_using_sql_file(dataset, file_name):
  """Create a table using the query from the given file in the BQ dataset"""
  dataset_id = f"{GCP_PROJECT}.{dataset}"
  print("Dataset_id", dataset_id)
  old_dataset = os.getenv("BQ_DATASET", "lms_analytics")
  job_config = bigquery.QueryJobConfig(default_dataset=dataset_id)
  with open(file_name, "r", encoding="utf-8") as file:
    query = file.read()
  query = query.replace(old_dataset, dataset)
  query_job = bq_client.query(query,
                              project=GCP_PROJECT,
                              job_config=job_config)
  error = ""
  try:
    query_job.result()
    print("Completed for the file: ", file_name)
  except BadRequest as e:
    for e in query_job.errors:
      error = f"ERROR: {e['message']}"
      raise Exception(error) from e


def get_sql_files_list(bq_dataset_name, folder_name):
  """Returns the set of files in the folder named by the given  dataset name"""
  file_path = os.path.join(folder_name,bq_dataset_name)
  if not os.path.exists(file_path):
    return []
  sql_files = listdir(file_path)
  return [file_path + "/" + i for i in sql_files]

def create_tables(dataset):
  """Create tables in the bigquery"""
  print("dataset", dataset)
  sql_file_list = get_sql_files_list(os.getenv("BQ_DATASET"),"tables_sql")
  if sql_file_list:
    for each_file in sql_file_list:
      print(f"Running ddl_file: {each_file}")
      create_table_using_sql_file(dataset, each_file)
  else:
    print("No files exist at the given path")


def create_views(dataset):
  """Create tables in the bigquery """
  print("dataset", dataset)
  sql_file_list = get_sql_files_list(os.getenv("BQ_DATASET"),"views_sql")
  if sql_file_list:
    sql_file_list.sort(key=lambda x: x[-7:])
    for each_file in sql_file_list:
      print(f"Running ddl_file: {each_file}")
      create_table_using_sql_file(dataset, each_file)
  else:
    print("No files exist at the given path")


def alter_table_using_sql_file(dataset, file_name):
  """Alter a table using the query from the given file in the BQ dataset"""
  dataset_id = f"{GCP_PROJECT}.{dataset}"
  print("Dataset_id", dataset_id)
  old_dataset = os.getenv("BQ_DATASET", "lms_analytics")
  job_config = bigquery.QueryJobConfig(default_dataset=dataset_id)
  with open(file_name, "r", encoding="utf-8") as file:
    query = file.read()
  query = query.replace(old_dataset, dataset)
  query_job = bq_client.query(query,
                              project=GCP_PROJECT,
                              job_config=job_config)
  error = ""
  try:
    query_job.result()
    print("Completed for the file: ", file_name)
  except BadRequest as e:
    for e in query_job.errors:
      error = f"ERROR: {e['message']}"
      raise Exception(error) from e


def alter_tables(dataset):
  """Alter tables in the bigquery"""
  print("dataset", dataset)
  sql_file_list = get_sql_files_list(os.getenv("BQ_DATASET"),"alter_tables_sql")
  if sql_file_list:
    for each_file in sql_file_list:
      print(f"Running ddl_file: {each_file}")
      alter_table_using_sql_file(dataset, each_file)
  else:
    print("No files exist at the given path")


def parse_arguments():
  """Parse the given arguments"""
  parser = argparse.ArgumentParser()

  parser.add_argument("--create-dataset",
                      dest="create_dataset",
                      type=str,
                      default="false",
                      choices=["true", "false"],
                      help="Create dataset for lms_analytics? true or false")

  parser.add_argument(
      "--create-tables",
      dest="create_tables",
      type=str,
      default="true",
      choices=["true", "false"],
      help="Create table for logs in lms_analytics dataset? true or false")

  parser.add_argument(
      "--alter-tables",
      dest="alter_tables",
      type=str,
      default="false",
      choices=["true", "false"],
      help="Alter tables in lms_analytics dataset? true or false")

  parser.add_argument(
      "--create-views",
      dest="create_views",
      type=str,
      default="true",
      choices=["true", "false"],
      help="Create Views for logs in lms_analytics dataset? true or false")
  return parser.parse_args()


if __name__ == "__main__":
  # To run locally, appropriate BQ permissions should be there and
  # be logged in to the respective GCP project using google sdk

  # Set the following environment variables
  # BQ_DATASET -<dataset-name> (default -> lms_analytics),
  # GCP_PROJECT -<project_id>
  # Run the following command with the required arguments to trigger the script
  # cd utils
  # PYTHONPATH=../common/src python3 bq_setup.py
  # For altering the tables pass these as args:
  # --create-tables=false --create-views=false --alter-tables=true

  args = parse_arguments()

  if not GCP_PROJECT:
    raise Exception("Please set 'GCP_PROJECT' environment variable")

  if args.create_dataset == "true":
    create_bigquery_dataset(BQ_DATASET)
  if args.create_tables == "true":
    create_tables(BQ_DATASET)
  if args.create_views == "true":
    create_views(BQ_DATASET)
  if args.alter_tables == "true":
    alter_tables(BQ_DATASET)