# This is the file that implements a flask server to do inferences. It's the file that you will modify to
# implement the scoring for your own algorithm.

import os
import json
import pickle
from io import StringIO
import sys
import signal
import traceback

import flask

from transformscript import *

prefix = "/opt/ml/"
model_path = os.path.join(prefix, "model")

# A singleton for holding the model. This simply loads the model and holds it.
# It has a predict function that does a prediction based on the model and the input data.


class ScoringService(object):
    model = None  # Where we keep the model when it's loaded

    @classmethod
    def get_model(cls):
        """Get the model object for this instance, loading it if it's not already loaded."""
        if cls.model == None:
            cls.model = load_model(model_path)
        return cls.model

    @classmethod
    def predict(cls, input):
        """For the input, do the predictions and return them.

        Args:
            input (a pandas dataframe): The data on which to do the predictions. There will be
                one prediction per row in the dataframe"""
        clf = cls.get_model()

        return predict(clf, input)


# The flask app for serving predictions
app = flask.Flask(__name__)


@app.route("/ping", methods=["GET"])
def ping():
    """Determine if the container is working and healthy. In this sample container, we declare
    it healthy if we can load the model successfully."""
    health = (
        ScoringService.get_model() is not None
    )  # You can insert a health check here

    status = 200 if health else 404
    return flask.Response(response="\n", status=status, mimetype="application/json")


@app.route("/invocations", methods=["POST"])
def transformation():
    data = None

    data = flask.request.data

    print("received input data")
    print(data)

    # Do the prediction
    predictions = ScoringService.predict(data)
    print("predictions from model")
    print(predictions)

    return flask.Response(response=predictions, status=200, mimetype="text/csv")