import csv
import datetime
import uuid
import os
import requests
from google.cloud import bigquery
from google.cloud import storage
from itertools import islice
from datetime import timedelta
from dateutil.relativedelta import relativedelta

query_range = 5
now = datetime.datetime.now()
delta = now - relativedelta(days=query_range)
year = now.strftime("%Y")
month = now.strftime("%m")
day = now.strftime("%d")

# Finalized data
# Appends finalized data to the last day of the previous month
# month_end = now.replace(day=1) - timedelta(days=1)
# delta = now.replace(day=1) - timedelta(days=query_range)
# year = month_end.strftime("%Y")
# month = month_end.strftime("%m")
# day = month_end.strftime("%d")

report_prefix=f"{year}/{month}/{day}/{uuid.uuid4()}"

# Required vars to update
CLIENT_ID = os.getenv('client_id')          # C.R.C service account client_id
CLIENT_SECRET = os.getenv('client_secret')  # C.R.C service account client secret
INTEGRATION_ID = "CHANGE-ME"                # Cost management integration_id
BUCKET = "CHANGE-ME"                        # Filtered data GCP Bucket
PROJECT_ID = "CHANGE-ME"                    # Your project ID
DATASET = "CHANGE-ME"                       # Your dataset name
TABLE_ID = "CHANGE-ME"                      # Your table ID

gcp_big_query_columns = [
    "billing_account_id",
    "service.id",
    "service.description",
    "sku.id",
    "sku.description",
    "usage_start_time",
    "usage_end_time",
    "project.id",
    "project.name",
    "project.labels",
    "project.ancestry_numbers",
    "labels",
    "system_labels",
    "location.location",
    "location.country",
    "location.region",
    "location.zone",
    "export_time",
    "cost",
    "currency",
    "currency_conversion_rate",
    "usage.amount",
    "usage.unit",
    "usage.amount_in_pricing_units",
    "usage.pricing_unit",
    "credits",
    "invoice.month",
    "cost_type",
    "resource.name",
    "resource.global_name",
]
table_name = ".".join([PROJECT_ID, DATASET, TABLE_ID])

BATCH_SIZE = 200000

def batch(iterable, n):
    """Yields successive n-sized chunks from iterable"""
    it = iter(iterable)
    while chunk := tuple(islice(it, n)):
        yield chunk

def build_query_select_statement():
    """Helper to build query select statement."""
    columns_list = gcp_big_query_columns.copy()
    columns_list = [
        f"TO_JSON_STRING({col})" if col in ("labels", "system_labels", "project.labels", "credits") else col
        for col in columns_list
    ]
    columns_list.append("DATE(_PARTITIONTIME) as partition_date")
    return ",".join(columns_list)

def get_service_account_token():
    """Get correct authentication token for your C.R.C service account"""
    token_url = 'https://sso.redhat.com/auth/realms/redhat-external/protocol/openid-connect/token'
    token_headers = {
        'Content-Type': 'application/x-www-form-urlencoded'
    }
    token_data = {
        "client_id": CLIENT_ID,
        "client_secret": CLIENT_SECRET,
        "grant_type": "client_credentials"
    }
    return requests.post(token_url, headers=token_headers, data=token_data)

def create_reports(query_date):
    query = f"SELECT {build_query_select_statement()} FROM {table_name} WHERE DATE(_PARTITIONTIME) = {query_date} AND sku.description LIKE '%RedHat%' OR sku.description LIKE '%Red Hat%' OR sku.description LIKE '%RHEL%' OR  service.description LIKE '%Red Hat%' ORDER BY usage_start_time"
    client = bigquery.Client()
    query_job = client.query(query).result()
    column_list = gcp_big_query_columns.copy()
    column_list.append("partition_date")
    daily_files = []
    storage_client = storage.Client()
    bucket = storage_client.bucket(BUCKET)
    for i, rows in enumerate(batch(query_job, BATCH_SIZE)):
        csv_file = f"{report_prefix}/{query_date}_part_{str(i)}.csv"
        daily_files.append(csv_file)
        blob = bucket.blob(csv_file)
        with blob.open(mode='w') as f:
            writer = csv.writer(f)
            writer.writerow(column_list)
            writer.writerows(rows)
    return daily_files

def post_data(files_list):
    # Post CSV's to console.redhat.com API
    url = "https://console.redhat.com/api/cost-management/v1/ingress/reports/"
    json_data = {"source": INTEGRATION_ID, "reports_list": files_list, "bill_year": year, "bill_month": month}
    token_response = get_service_account_token()
    headers = {
        'Authorization': f'Bearer {token_response.json().get("access_token")}',
        'Accept': 'application/json'
    }
    resp = requests.post(url, json=json_data, headers=headers)
    return resp

def get_filtered_data(request):
    files_list = []
    query_dates = [delta + datetime.timedelta(days=x) for x in range(query_range)]
    for query_date in query_dates:
        files_list += create_reports(query_date.date())
    resp = post_data(files_list)
    return f'Files posted! {resp}'