# Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
#     http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.
"""Placeholder docstring"""
from __future__ import absolute_import

from botocore import exceptions

from sagemaker.job import _Job
from sagemaker.session import Session
from sagemaker.utils import base_name_from_image, name_from_base


class Transformer(object):
    """A class for handling creating and interacting with Amazon SageMaker
    transform jobs.
    """

    def __init__(
        self,
        model_name,
        instance_count,
        instance_type,
        strategy=None,
        assemble_with=None,
        output_path=None,
        output_kms_key=None,
        accept=None,
        max_concurrent_transforms=None,
        max_payload=None,
        tags=None,
        env=None,
        base_transform_job_name=None,
        sagemaker_session=None,
        volume_kms_key=None,
    ):
        """Initialize a ``Transformer``.

        Args:
            model_name (str): Name of the SageMaker model being used for the
                transform job.
            instance_count (int): Number of EC2 instances to use.
            instance_type (str): Type of EC2 instance to use, for example,
                'ml.c4.xlarge'.
            strategy (str): The strategy used to decide how to batch records in
                a single request (default: None). Valid values: 'MultiRecord'
                and 'SingleRecord'.
            assemble_with (str): How the output is assembled (default: None).
                Valid values: 'Line' or 'None'.
            output_path (str): S3 location for saving the transform result. If
                not specified, results are stored to a default bucket.
            output_kms_key (str): Optional. KMS key ID for encrypting the
                transform output (default: None).
            accept (str): The content type accepted by the endpoint deployed
                during the transform job.
            max_concurrent_transforms (int): The maximum number of HTTP requests
                to be made to each individual transform container at one time.
            max_payload (int): Maximum size of the payload in a single HTTP
                request to the container in MB.
            tags (list[dict]): List of tags for labeling a transform job
                (default: None). For more, see
                https://docs.aws.amazon.com/sagemaker/latest/dg/API_Tag.html.
            env (dict): Environment variables to be set for use during the
                transform job (default: None).
            base_transform_job_name (str): Prefix for the transform job when the
                :meth:`~sagemaker.transformer.Transformer.transform` method
                launches. If not specified, a default prefix will be generated
                based on the training image name that was used to train the
                model associated with the transform job.
            sagemaker_session (sagemaker.session.Session): Session object which
                manages interactions with Amazon SageMaker APIs and any other
                AWS services needed. If not specified, the estimator creates one
                using the default AWS configuration chain.
            volume_kms_key (str): Optional. KMS key ID for encrypting the volume
                attached to the ML compute instance (default: None).
        """
        self.model_name = model_name
        self.strategy = strategy
        self.env = env

        self.output_path = output_path
        self.output_kms_key = output_kms_key
        self.accept = accept
        self.assemble_with = assemble_with

        self.instance_count = instance_count
        self.instance_type = instance_type
        self.volume_kms_key = volume_kms_key

        self.max_concurrent_transforms = max_concurrent_transforms
        self.max_payload = max_payload
        self.tags = tags

        self.base_transform_job_name = base_transform_job_name
        self._current_job_name = None
        self.latest_transform_job = None
        self._reset_output_path = False

        self.sagemaker_session = sagemaker_session or Session()

    def transform(
        self,
        data,
        data_type="S3Prefix",
        content_type=None,
        compression_type=None,
        split_type=None,
        job_name=None,
        input_filter=None,
        output_filter=None,
        join_source=None,
    ):
        """Start a new transform job.

        Args:
            data (str): Input data location in S3.
            data_type (str): What the S3 location defines (default: 'S3Prefix').
                Valid values:

                * 'S3Prefix' - the S3 URI defines a key name prefix. All objects with this prefix
                    will be used as inputs for the transform job.

                * 'ManifestFile' - the S3 URI points to a single manifest file listing each S3
                    object to use as an input for the transform job.
            content_type (str): MIME type of the input data (default: None).
            compression_type (str): Compression type of the input data, if
                compressed (default: None). Valid values: 'Gzip', None.
            split_type (str): The record delimiter for the input object
                (default: 'None'). Valid values: 'None', 'Line', 'RecordIO', and
                'TFRecord'.
            job_name (str): job name (default: None). If not specified, one will
                be generated.
            input_filter (str): A JSONPath to select a portion of the input to
                pass to the algorithm container for inference. If you omit the
                field, it gets the value '$', representing the entire input.
                For more information, see https://docs.aws.amazon.com/sagemaker/latest/dg/API_CreateTransformJob.html.
                Some examples: "$[1:]", "$.features" (default: None).
            output_filter (str): A JSONPath to select a portion of the
                joined/original output to return as the output.
                For more information, see https://docs.aws.amazon.com/sagemaker/latest/dg/API_CreateTransformJob.html.
                Some examples: "$[1:]", "$.prediction" (default: None).
            join_source (str): The source of data to be joined to the transform
                output. It can be set to 'Input' meaning the entire input record
                will be joined to the inference result. You can use OutputFilter
                to select the useful portion before uploading to S3. (default:
                None). Valid values: Input, None.
        """
        local_mode = self.sagemaker_session.local_mode
        if not local_mode and not data.startswith("s3://"):
            raise ValueError("Invalid S3 URI: {}".format(data))

        if job_name is not None:
            self._current_job_name = job_name
        else:
            base_name = self.base_transform_job_name

            if base_name is None:
                base_name = self._retrieve_base_name()

            self._current_job_name = name_from_base(base_name)

        if self.output_path is None or self._reset_output_path is True:
            self.output_path = "s3://{}/{}".format(
                self.sagemaker_session.default_bucket(), self._current_job_name
            )
            self._reset_output_path = True

        self.latest_transform_job = _TransformJob.start_new(
            self,
            data,
            data_type,
            content_type,
            compression_type,
            split_type,
            input_filter,
            output_filter,
            join_source,
        )

    def delete_model(self):
        """Delete the corresponding SageMaker model for this Transformer."""
        self.sagemaker_session.delete_model(self.model_name)

    def _retrieve_base_name(self):
        """Placeholder docstring"""
        image_name = self._retrieve_image_name()

        if image_name:
            return base_name_from_image(image_name)

        return self.model_name

    def _retrieve_image_name(self):
        """Placeholder docstring"""
        try:
            model_desc = self.sagemaker_session.sagemaker_client.describe_model(
                ModelName=self.model_name
            )

            primary_container = model_desc.get("PrimaryContainer")
            if primary_container:
                return primary_container.get("Image")

            containers = model_desc.get("Containers")
            if containers:
                return containers[0].get("Image")

            return None

        except exceptions.ClientError:
            raise ValueError(
                "Failed to fetch model information for %s. "
                "Please ensure that the model exists. "
                "Local instance types require locally created models." % self.model_name
            )

    def wait(self):
        """Placeholder docstring"""
        self._ensure_last_transform_job()
        self.latest_transform_job.wait()

    def _ensure_last_transform_job(self):
        """Placeholder docstring"""
        if self.latest_transform_job is None:
            raise ValueError("No transform job available")

    @classmethod
    def attach(cls, transform_job_name, sagemaker_session=None):
        """Attach an existing transform job to a new Transformer instance

        Args:
            transform_job_name (str): Name for the transform job to be attached.
            sagemaker_session (sagemaker.session.Session): Session object which
                manages interactions with Amazon SageMaker APIs and any other
                AWS services needed. If not specified, one will be created using
                the default AWS configuration chain.

        Returns:
            sagemaker.transformer.Transformer: The Transformer instance with the
            specified transform job attached.
        """
        sagemaker_session = sagemaker_session or Session()

        job_details = sagemaker_session.sagemaker_client.describe_transform_job(
            TransformJobName=transform_job_name
        )
        init_params = cls._prepare_init_params_from_job_description(job_details)
        transformer = cls(sagemaker_session=sagemaker_session, **init_params)
        transformer.latest_transform_job = _TransformJob(
            sagemaker_session=sagemaker_session, job_name=init_params["base_transform_job_name"]
        )

        return transformer

    @classmethod
    def _prepare_init_params_from_job_description(cls, job_details):
        """Convert the transform job description to init params that can be
        handled by the class constructor

        Args:
            job_details (dict): the returned job details from a
                describe_transform_job API call.

        Returns:
            dict: The transformed init_params
        """
        init_params = dict()

        init_params["model_name"] = job_details["ModelName"]
        init_params["instance_count"] = job_details["TransformResources"]["InstanceCount"]
        init_params["instance_type"] = job_details["TransformResources"]["InstanceType"]
        init_params["volume_kms_key"] = job_details["TransformResources"].get("VolumeKmsKeyId")
        init_params["strategy"] = job_details.get("BatchStrategy")
        init_params["assemble_with"] = job_details["TransformOutput"].get("AssembleWith")
        init_params["output_path"] = job_details["TransformOutput"]["S3OutputPath"]
        init_params["output_kms_key"] = job_details["TransformOutput"].get("KmsKeyId")
        init_params["accept"] = job_details["TransformOutput"].get("Accept")
        init_params["max_concurrent_transforms"] = job_details.get("MaxConcurrentTransforms")
        init_params["max_payload"] = job_details.get("MaxPayloadInMB")
        init_params["base_transform_job_name"] = job_details["TransformJobName"]

        return init_params


class _TransformJob(_Job):
    """Placeholder docstring"""

    @classmethod
    def start_new(
        cls,
        transformer,
        data,
        data_type,
        content_type,
        compression_type,
        split_type,
        input_filter,
        output_filter,
        join_source,
    ):
        """
        Args:
            transformer:
            data:
            data_type:
            content_type:
            compression_type:
            split_type:
            input_filter:
            output_filter:
            join_source:
        """
        config = _TransformJob._load_config(
            data, data_type, content_type, compression_type, split_type, transformer
        )
        data_processing = _TransformJob._prepare_data_processing(
            input_filter, output_filter, join_source
        )

        transformer.sagemaker_session.transform(
            job_name=transformer._current_job_name,
            model_name=transformer.model_name,
            strategy=transformer.strategy,
            max_concurrent_transforms=transformer.max_concurrent_transforms,
            max_payload=transformer.max_payload,
            env=transformer.env,
            input_config=config["input_config"],
            output_config=config["output_config"],
            resource_config=config["resource_config"],
            tags=transformer.tags,
            data_processing=data_processing,
        )

        return cls(transformer.sagemaker_session, transformer._current_job_name)

    def wait(self):
        self.sagemaker_session.wait_for_transform_job(self.job_name)

    @staticmethod
    def _load_config(data, data_type, content_type, compression_type, split_type, transformer):
        """
        Args:
            data:
            data_type:
            content_type:
            compression_type:
            split_type:
            transformer:
        """
        input_config = _TransformJob._format_inputs_to_input_config(
            data, data_type, content_type, compression_type, split_type
        )

        output_config = _TransformJob._prepare_output_config(
            transformer.output_path,
            transformer.output_kms_key,
            transformer.assemble_with,
            transformer.accept,
        )

        resource_config = _TransformJob._prepare_resource_config(
            transformer.instance_count, transformer.instance_type, transformer.volume_kms_key
        )

        return {
            "input_config": input_config,
            "output_config": output_config,
            "resource_config": resource_config,
        }

    @staticmethod
    def _format_inputs_to_input_config(data, data_type, content_type, compression_type, split_type):
        """
        Args:
            data:
            data_type:
            content_type:
            compression_type:
            split_type:
        """
        config = {"DataSource": {"S3DataSource": {"S3DataType": data_type, "S3Uri": data}}}

        if content_type is not None:
            config["ContentType"] = content_type

        if compression_type is not None:
            config["CompressionType"] = compression_type

        if split_type is not None:
            config["SplitType"] = split_type

        return config

    @staticmethod
    def _prepare_output_config(s3_path, kms_key_id, assemble_with, accept):
        """
        Args:
            s3_path:
            kms_key_id:
            assemble_with:
            accept:
        """
        config = super(_TransformJob, _TransformJob)._prepare_output_config(s3_path, kms_key_id)

        if assemble_with is not None:
            config["AssembleWith"] = assemble_with

        if accept is not None:
            config["Accept"] = accept

        return config

    @staticmethod
    def _prepare_resource_config(instance_count, instance_type, volume_kms_key):
        """
        Args:
            instance_count:
            instance_type:
            volume_kms_key:
        """
        config = {"InstanceCount": instance_count, "InstanceType": instance_type}

        if volume_kms_key is not None:
            config["VolumeKmsKeyId"] = volume_kms_key

        return config

    @staticmethod
    def _prepare_data_processing(input_filter, output_filter, join_source):
        """
        Args:
            input_filter:
            output_filter:
            join_source:
        """
        config = {}

        if input_filter is not None:
            config["InputFilter"] = input_filter

        if output_filter is not None:
            config["OutputFilter"] = output_filter

        if join_source is not None:
            config["JoinSource"] = join_source

        if len(config) == 0:
            return None

        return config
