import urllib.request
import urllib.parse
from json import loads
from datetime import datetime


def get_token(username, password, server_name):

    params = urllib.parse.urlencode({
        'username': username,
        'password': password,
        'client': 'referer',
        'referer': server_name,
        'expiration': 60,
        'f': 'json'
    })

    params = params.encode('ascii')
    url = server_name + '/portal/sharing/rest/generateToken?'

    try:
        response = urllib.request.urlopen(url, params)
        if response.getcode() != 200:
            print(response.info())
        else:
            response_data = loads(response.read().decode('utf-8'))
            if 'error' in response_data:
                print(response_data['error']['details'])
                return
            else:
                return response_data['token']
    except IOError as e:
        print('Please Ensure URL to Portal is Valid: ', e.__dict__)
        return


def update_service(params, folder_url, service, min_inst, max_inst):

    # Get Service Information
    service_name = service['serviceName']
    service_type = service['type']
    service_url = folder_url + '/' + service_name + '.' + service_type
    response = urllib.request.urlopen(service_url, params)
    service_data = loads(response.read().decode('utf-8'))

    # If Service Min/Max Instances Do Not Match Inputs,
    # Edit Service Data & Pass to Edit REST Operation
    if (service_data['minInstancesPerNode'] != min_inst) or (service_data['maxInstancesPerNode'] != max_inst):

        print('Updating: ', service_name, service_type, ' | ',
              service_data['minInstancesPerNode'], ' | ',
              service_data['maxInstancesPerNode'])

        service_data['minInstancesPerNode'] = min_inst
        service_data['maxInstancesPerNode'] = max_inst

        print('Updating: ', service_name, service_type, ' | ',
              service_data['minInstancesPerNode'], ' | ',
              service_data['maxInstancesPerNode'])

        edit_params = urllib.parse.urlencode({
            'token': token,
            'f': 'json',
            'runAsync': 'true',
            'service': service_data
        })
        edit_params = edit_params.encode('ascii')
        edit_url = (service_url + '/edit')
        response = urllib.request.urlopen(edit_url, edit_params)
        edit_response = loads(response.read().decode('utf-8'))
        print(edit_response)


def get_services(token, server_name, server_port, protected_folders, min_inst, max_inst):

    # Collect Root Services Directory
    params = urllib.parse.urlencode({
        'token': token,
        'f': 'json'
    })
    params = params.encode('ascii')
    url = server_name + ':' + server_port + '/arcgis/admin/services'
    response = urllib.request.urlopen(url, params)
    services_directory = loads(response.read().decode('utf-8'))

    # Get Services in Root Directory & Update Services
    root_services = services_directory['services']
    for service in root_services:
        folder_url = url + '/'
        update_service(params, folder_url, service, min_inst, max_inst)

    # Get Folders in Root Services Directory & Update Services
    folders = (services_directory['folders'])
    for folder in folders:
        if folder not in protected_folders:
            folder_url = url + '/' + folder
            response = urllib.request.urlopen(folder_url, params)
            folder_directory = loads(response.read().decode('utf-8'))
            folder_services = folder_directory['services']
            for service in folder_services:
                update_service(params, folder_url, service, min_inst, max_inst)


if __name__ == "__main__":

    start = datetime.now()
    print('Script Start: ', start)

    username = 'username'
    password = 'password'
    server_name = 'server'
    server_port = 'port'
    min_inst = 0
    max_inst = 1
    protected_folders = ['System', 'Utilities']

    token = get_token(username, password, server_name)

    get_services(token, server_name, server_port, protected_folders, min_inst, max_inst)

    end = datetime.now()
    print('Script End: ', end)
    print('Script Run: ', end-start)