import boto3
from botocore import UNSIGNED
from botocore.client import Config
from botocore.exceptions import ClientError
from botocore.handlers import disable_signing
import configparser
import datetime
import time
import os
import munch
import random
import string
import itertools
import urllib3

config = munch.Munch

# this will be assigned by setup()
prefix = None

def get_prefix():
    assert prefix is not None
    return prefix

def choose_bucket_prefix(template, max_len=30):
    """
    Choose a prefix for our test buckets, so they're easy to identify.

    Use template and feed it more and more random filler, until it's
    as long as possible but still below max_len.
    """
    rand = ''.join(
        random.choice(string.ascii_lowercase + string.digits)
        for c in range(255)
        )

    while rand:
        s = template.format(random=rand)
        if len(s) <= max_len:
            return s
        rand = rand[:-1]

    raise RuntimeError(
        'Bucket prefix template is impossible to fulfill: {template!r}'.format(
            template=template,
            ),
        )

def get_buckets_list(client=None, prefix=None):
    if client == None:
        client = get_client()
    if prefix == None:
        prefix = get_prefix()
    response = client.list_buckets()
    bucket_dicts = response['Buckets']
    buckets_list = []
    for bucket in bucket_dicts:
        if prefix in bucket['Name']:
            buckets_list.append(bucket['Name'])

    return buckets_list

def get_objects_list(bucket, client=None, prefix=None):
    if client == None:
        client = get_client()

    if prefix == None:
        response = client.list_objects(Bucket=bucket)
    else:
        response = client.list_objects(Bucket=bucket, Prefix=prefix)
    objects_list = []

    if 'Contents' in response:
        contents = response['Contents']
        for obj in contents:
            objects_list.append(obj['Key'])

    return objects_list

# generator function that returns object listings in batches, where each
# batch is a list of dicts compatible with delete_objects()
def list_versions(client, bucket, batch_size):
    key_marker = ''
    version_marker = ''
    truncated = True
    while truncated:
        listing = client.list_object_versions(
                Bucket=bucket,
                KeyMarker=key_marker,
                VersionIdMarker=version_marker,
                MaxKeys=batch_size)

        key_marker = listing.get('NextKeyMarker')
        version_marker = listing.get('NextVersionIdMarker')
        truncated = listing['IsTruncated']

        objs = listing.get('Versions', []) + listing.get('DeleteMarkers', [])
        if len(objs):
            yield [{'Key': o['Key'], 'VersionId': o['VersionId']} for o in objs]

def nuke_bucket(client, bucket):
    batch_size = 128
    max_retain_date = None

    # list and delete objects in batches
    for objects in list_versions(client, bucket, batch_size):
        delete = client.delete_objects(Bucket=bucket,
                Delete={'Objects': objects, 'Quiet': True},
                BypassGovernanceRetention=True)

        # check for object locks on 403 AccessDenied errors
        for err in delete.get('Errors', []):
            if err.get('Code') != 'AccessDenied':
                continue
            try:
                res = client.get_object_retention(Bucket=bucket,
                        Key=err['Key'], VersionId=err['VersionId'])
                retain_date = res['Retention']['RetainUntilDate']
                if not max_retain_date or max_retain_date < retain_date:
                    max_retain_date = retain_date
            except ClientError:
                pass

    if max_retain_date:
        # wait out the retention period (up to 60 seconds)
        now = datetime.datetime.now(max_retain_date.tzinfo)
        if max_retain_date > now:
            delta = max_retain_date - now
            if delta.total_seconds() > 60:
                raise RuntimeError('bucket {} still has objects \
locked for {} more seconds, not waiting for \
bucket cleanup'.format(bucket, delta.total_seconds()))
            print('nuke_bucket', bucket, 'waiting', delta.total_seconds(),
                    'seconds for object locks to expire')
            time.sleep(delta.total_seconds())

        for objects in list_versions(client, bucket, batch_size):
            client.delete_objects(Bucket=bucket,
                    Delete={'Objects': objects, 'Quiet': True},
                    BypassGovernanceRetention=True)

    client.delete_bucket(Bucket=bucket)

def nuke_prefixed_buckets(prefix, client=None):
    if client == None:
        client = get_client()

    buckets = get_buckets_list(client, prefix)

    err = None
    for bucket_name in buckets:
        try:
            nuke_bucket(client, bucket_name)
        except Exception as e:
            # The exception shouldn't be raised when doing cleanup. Pass and continue
            # the bucket cleanup process. Otherwise left buckets wouldn't be cleared
            # resulting in some kind of resource leak. err is used to hint user some
            # exception once occurred.
            err = e
            pass
    if err:
        raise err

    print('Done with cleanup of buckets in tests.')

def setup():
    cfg = configparser.RawConfigParser()
    try:
        path = os.environ['S3TEST_CONF']
    except KeyError:
        raise RuntimeError(
            'To run tests, point environment '
            + 'variable S3TEST_CONF to a config file.',
            )
    cfg.read(path)

    if not cfg.defaults():
        raise RuntimeError('Your config file is missing the DEFAULT section!')
    if not cfg.has_section("s3 main"):
        raise RuntimeError('Your config file is missing the "s3 main" section!')
    if not cfg.has_section("s3 alt"):
        raise RuntimeError('Your config file is missing the "s3 alt" section!')
    if not cfg.has_section("s3 tenant"):
        raise RuntimeError('Your config file is missing the "s3 tenant" section!')

    global prefix

    defaults = cfg.defaults()

    # vars from the DEFAULT section
    config.default_host = defaults.get("host")
    config.default_port = int(defaults.get("port"))
    config.default_is_secure = cfg.getboolean('DEFAULT', "is_secure")

    proto = 'https' if config.default_is_secure else 'http'
    config.default_endpoint = "%s://%s:%d" % (proto, config.default_host, config.default_port)

    try:
        config.default_ssl_verify = cfg.getboolean('DEFAULT', "ssl_verify")
    except configparser.NoOptionError:
        config.default_ssl_verify = False

    # Disable InsecureRequestWarning reported by urllib3 when ssl_verify is False
    if not config.default_ssl_verify:
        urllib3.disable_warnings()

    # vars from the main section
    config.main_access_key = cfg.get('s3 main',"access_key")
    config.main_secret_key = cfg.get('s3 main',"secret_key")
    config.main_display_name = cfg.get('s3 main',"display_name")
    config.main_user_id = cfg.get('s3 main',"user_id")
    config.main_email = cfg.get('s3 main',"email")
    try:
        config.main_kms_keyid = cfg.get('s3 main',"kms_keyid")
    except (configparser.NoSectionError, configparser.NoOptionError):
        config.main_kms_keyid = 'testkey-1'

    try:
        config.main_kms_keyid2 = cfg.get('s3 main',"kms_keyid2")
    except (configparser.NoSectionError, configparser.NoOptionError):
        config.main_kms_keyid2 = 'testkey-2'

    try:
        config.main_api_name = cfg.get('s3 main',"api_name")
    except (configparser.NoSectionError, configparser.NoOptionError):
        config.main_api_name = ""
        pass

    config.alt_access_key = cfg.get('s3 alt',"access_key")
    config.alt_secret_key = cfg.get('s3 alt',"secret_key")
    config.alt_display_name = cfg.get('s3 alt',"display_name")
    config.alt_user_id = cfg.get('s3 alt',"user_id")
    config.alt_email = cfg.get('s3 alt',"email")

    config.tenant_access_key = cfg.get('s3 tenant',"access_key")
    config.tenant_secret_key = cfg.get('s3 tenant',"secret_key")
    config.tenant_display_name = cfg.get('s3 tenant',"display_name")
    config.tenant_user_id = cfg.get('s3 tenant',"user_id")
    config.tenant_email = cfg.get('s3 tenant',"email")

    # vars from the fixtures section
    try:
        template = cfg.get('fixtures', "bucket prefix")
    except (configparser.NoOptionError):
        template = 'test-{random}-'
    prefix = choose_bucket_prefix(template=template)

    alt_client = get_alt_client()
    tenant_client = get_tenant_client()
    nuke_prefixed_buckets(prefix=prefix)
    nuke_prefixed_buckets(prefix=prefix, client=alt_client)
    nuke_prefixed_buckets(prefix=prefix, client=tenant_client)


def teardown():
    alt_client = get_alt_client()
    tenant_client = get_tenant_client()
    nuke_prefixed_buckets(prefix=prefix)
    nuke_prefixed_buckets(prefix=prefix, client=alt_client)
    nuke_prefixed_buckets(prefix=prefix, client=tenant_client)
    try:
        iam_client = get_iam_client()
        list_roles_resp = iam_client.list_roles()
        for role in list_roles_resp['Roles']:
            list_policies_resp = iam_client.list_role_policies(RoleName=role['RoleName'])
            for policy in list_policies_resp['PolicyNames']:
                del_policy_resp = iam_client.delete_role_policy(
                                         RoleName=role['RoleName'],
                                         PolicyName=policy
                                        )
            del_role_resp = iam_client.delete_role(RoleName=role['RoleName'])
        list_oidc_resp = iam_client.list_open_id_connect_providers()
        for oidcprovider in list_oidc_resp['OpenIDConnectProviderList']:
            del_oidc_resp = iam_client.delete_open_id_connect_provider(
                        OpenIDConnectProviderArn=oidcprovider['Arn']
                    )
    except:
        pass

def check_webidentity():
    cfg = configparser.RawConfigParser()
    try:
        path = os.environ['S3TEST_CONF']
    except KeyError:
        raise RuntimeError(
            'To run tests, point environment '
            + 'variable S3TEST_CONF to a config file.',
            )
    cfg.read(path)
    if not cfg.has_section("webidentity"):
        raise RuntimeError('Your config file is missing the "webidentity" section!')

    config.webidentity_thumbprint = cfg.get('webidentity', "thumbprint")
    config.webidentity_aud = cfg.get('webidentity', "aud")
    config.webidentity_token = cfg.get('webidentity', "token")
    config.webidentity_realm = cfg.get('webidentity', "KC_REALM")
    config.webidentity_sub = cfg.get('webidentity', "sub")
    config.webidentity_azp = cfg.get('webidentity', "azp")
    config.webidentity_user_token = cfg.get('webidentity', "user_token")

def get_client(client_config=None):
    if client_config == None:
        client_config = Config(signature_version='s3v4')

    client = boto3.client(service_name='s3',
                        aws_access_key_id=config.main_access_key,
                        aws_secret_access_key=config.main_secret_key,
                        endpoint_url=config.default_endpoint,
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=client_config)
    return client

def get_v2_client():
    client = boto3.client(service_name='s3',
                        aws_access_key_id=config.main_access_key,
                        aws_secret_access_key=config.main_secret_key,
                        endpoint_url=config.default_endpoint,
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=Config(signature_version='s3'))
    return client

def get_sts_client(client_config=None):
    if client_config == None:
        client_config = Config(signature_version='s3v4')

    client = boto3.client(service_name='sts',
                        aws_access_key_id=config.alt_access_key,
                        aws_secret_access_key=config.alt_secret_key,
                        endpoint_url=config.default_endpoint,
                        region_name='',
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=client_config)
    return client

def get_iam_client(client_config=None):
    cfg = configparser.RawConfigParser()
    try:
        path = os.environ['S3TEST_CONF']
    except KeyError:
        raise RuntimeError(
            'To run tests, point environment '
            + 'variable S3TEST_CONF to a config file.',
            )
    cfg.read(path)
    if not cfg.has_section("iam"):
        raise RuntimeError('Your config file is missing the "iam" section!')

    config.iam_access_key = cfg.get('iam',"access_key")
    config.iam_secret_key = cfg.get('iam',"secret_key")
    config.iam_display_name = cfg.get('iam',"display_name")
    config.iam_user_id = cfg.get('iam',"user_id")
    config.iam_email = cfg.get('iam',"email")    

    if client_config == None:
        client_config = Config(signature_version='s3v4')
    
    client = boto3.client(service_name='iam',
                        aws_access_key_id=config.iam_access_key,
                        aws_secret_access_key=config.iam_secret_key,
                        endpoint_url=config.default_endpoint,
                        region_name='',
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=client_config)
    return client

def get_alt_client(client_config=None):
    if client_config == None:
        client_config = Config(signature_version='s3v4')

    client = boto3.client(service_name='s3',
                        aws_access_key_id=config.alt_access_key,
                        aws_secret_access_key=config.alt_secret_key,
                        endpoint_url=config.default_endpoint,
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=client_config)
    return client

def get_tenant_client(client_config=None):
    if client_config == None:
        client_config = Config(signature_version='s3v4')

    client = boto3.client(service_name='s3',
                        aws_access_key_id=config.tenant_access_key,
                        aws_secret_access_key=config.tenant_secret_key,
                        endpoint_url=config.default_endpoint,
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=client_config)
    return client

def get_tenant_iam_client():

    client = boto3.client(service_name='iam',
                          region_name='us-east-1',
                          aws_access_key_id=config.tenant_access_key,
                          aws_secret_access_key=config.tenant_secret_key,
                          endpoint_url=config.default_endpoint,
                          verify=config.default_ssl_verify,
                          use_ssl=config.default_is_secure)
    return client

def get_unauthenticated_client():
    client = boto3.client(service_name='s3',
                        aws_access_key_id='',
                        aws_secret_access_key='',
                        endpoint_url=config.default_endpoint,
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=Config(signature_version=UNSIGNED))
    return client

def get_bad_auth_client(aws_access_key_id='badauth'):
    client = boto3.client(service_name='s3',
                        aws_access_key_id=aws_access_key_id,
                        aws_secret_access_key='roflmao',
                        endpoint_url=config.default_endpoint,
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=Config(signature_version='s3v4'))
    return client

def get_svc_client(client_config=None, svc='s3'):
    if client_config == None:
        client_config = Config(signature_version='s3v4')

    client = boto3.client(service_name=svc,
                        aws_access_key_id=config.main_access_key,
                        aws_secret_access_key=config.main_secret_key,
                        endpoint_url=config.default_endpoint,
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify,
                        config=client_config)
    return client

bucket_counter = itertools.count(1)

def get_new_bucket_name():
    """
    Get a bucket name that probably does not exist.

    We make every attempt to use a unique random prefix, so if a
    bucket by this name happens to exist, it's ok if tests give
    false negatives.
    """
    name = '{prefix}{num}'.format(
        prefix=prefix,
        num=next(bucket_counter),
        )
    return name

def get_new_bucket_resource(name=None):
    """
    Get a bucket that exists and is empty.

    Always recreates a bucket from scratch. This is useful to also
    reset ACLs and such.
    """
    s3 = boto3.resource('s3',
                        aws_access_key_id=config.main_access_key,
                        aws_secret_access_key=config.main_secret_key,
                        endpoint_url=config.default_endpoint,
                        use_ssl=config.default_is_secure,
                        verify=config.default_ssl_verify)
    if name is None:
        name = get_new_bucket_name()
    bucket = s3.Bucket(name)
    bucket_location = bucket.create()
    return bucket

def get_new_bucket(client=None, name=None):
    """
    Get a bucket that exists and is empty.

    Always recreates a bucket from scratch. This is useful to also
    reset ACLs and such.
    """
    if client is None:
        client = get_client()
    if name is None:
        name = get_new_bucket_name()

    client.create_bucket(Bucket=name)
    return name

def get_parameter_name():
    parameter_name=""
    rand = ''.join(
        random.choice(string.ascii_lowercase + string.digits)
        for c in range(255)
        )
    while rand:
        parameter_name = '{random}'.format(random=rand)
        if len(parameter_name) <= 10:
            return parameter_name
        rand = rand[:-1]
    return parameter_name

def get_sts_user_id():
    return config.alt_user_id

def get_config_is_secure():
    return config.default_is_secure

def get_config_host():
    return config.default_host

def get_config_port():
    return config.default_port

def get_config_endpoint():
    return config.default_endpoint

def get_config_ssl_verify():
    return config.default_ssl_verify

def get_main_aws_access_key():
    return config.main_access_key

def get_main_aws_secret_key():
    return config.main_secret_key

def get_main_display_name():
    return config.main_display_name

def get_main_user_id():
    return config.main_user_id

def get_main_email():
    return config.main_email

def get_main_api_name():
    return config.main_api_name

def get_main_kms_keyid():
    return config.main_kms_keyid

def get_secondary_kms_keyid():
    return config.main_kms_keyid2

def get_alt_aws_access_key():
    return config.alt_access_key

def get_alt_aws_secret_key():
    return config.alt_secret_key

def get_alt_display_name():
    return config.alt_display_name

def get_alt_user_id():
    return config.alt_user_id

def get_alt_email():
    return config.alt_email

def get_tenant_aws_access_key():
    return config.tenant_access_key

def get_tenant_aws_secret_key():
    return config.tenant_secret_key

def get_tenant_display_name():
    return config.tenant_display_name

def get_tenant_user_id():
    return config.tenant_user_id

def get_tenant_email():
    return config.tenant_email

def get_thumbprint():
    return config.webidentity_thumbprint

def get_aud():
    return config.webidentity_aud

def get_sub():
    return config.webidentity_sub

def get_azp():
    return config.webidentity_azp

def get_token():
    return config.webidentity_token

def get_realm_name():
    return config.webidentity_realm

def get_iam_access_key():
    return config.iam_access_key

def get_iam_secret_key():
    return config.iam_secret_key

def get_user_token():
    return config.webidentity_user_token