import boto3
import csv
from datetime import datetime

client = boto3.client('ecs')

def get_clusters():
    clusters = []
    response = client.list_clusters()
    clusters.extend(response['clusterArns'])
    while 'nextToken' in response:
        response = client.list_clusters(nextToken=response['nextToken'])
        clusters.extend(response['clusterArns'])
    return clusters


def get_clusters_with_services(clusters):
    i = 0
    clusters_with_services = []
    while i < len(clusters):
        response = client.list_services(cluster=clusters[i])
        if response['serviceArns']:
            clusters_with_services.append({'cluster': clusters[i],
                                           'service': response['serviceArns'][0]})
        i += 1
    return clusters_with_services


def get_services_info(clusters_with_services):
    service_info = []
    for each_service in clusters_with_services:
        response = client.describe_services(
            cluster=each_service['cluster'],
            services=[each_service['service']]
        )
        response_tags = client.list_tags_for_resource(
            resourceArn=each_service['service']
        )
        i = 0
        tags = 'None'
        while i < len(response_tags['tags']):
            if 'application_family' in response_tags['tags'][i].values():
                tags = response_tags['tags'][i]
            i += 1
        service_info.append({'Service Name': response['services'][0]['serviceName'],
                             'Tags': tags})
    return service_info


def create_services_list(service_info):
    now = datetime.now()
    dt_string = now.strftime('%d-%m-%Y-%H:%M:%S')
    service_columns = ['Service Name', 'Tags']
    with open('services_ecs_{date_time}.csv'.format(date_time=dt_string), 'w') as csvfile:
        writer = csv.DictWriter(csvfile, fieldnames=service_columns)
        writer.writeheader()
        writer.writerows(service_info)


def main():
    """Start script."""
    ecs_clusters = get_clusters()
    ecs_clusters_with_services = get_clusters_with_services(ecs_clusters)
    services_info = get_services_info(ecs_clusters_with_services)
    create_services_list(services_info)



if __name__ == '__main__':
    main()