abstracted service functionality to extensible services in anticipation for future use

app/services/base.py

@@ -0,0 +1,4 @@
+class Base:
+  def __init__(self, source, ingest_type='message'):
+    self.ingest_type = ingest_type
+    self.source = source

app/services/loft.py

@@ -0,0 +1,63 @@
+import os
+import json
+import random
+import io
+import time
+
+from helpers import aws_helper, tar_helper, csv_helper, service_helper
+
+from models.solver_run import SolverRun
+from models.solution import Solution
+from models.form import Form
+
+from services.base import Base
+
+class Loft(Base):
+  def process(self):
+    self.solver_run = SolverRun.parse_obj(self.retreive_attributes_from_message())
+    self.solution = self.generate_solution()
+    self.result = self.stream_to_s3_bucket()
+
+  def retreive_attributes_from_message(self):
+    # get s3 object
+    key = aws_helper.get_key_from_message(self.source)
+    s3_object = aws_helper.get_object(key, os.environ['SOLVER_INGEST_BUCKET'])
+
+    # convert to tar
+    tar = tar_helper.raw_to_tar(s3_object)
+
+    # get attributes file and convert to dict
+    attributes = json.loads(tar_helper.extract_file_from_tar(tar, 'solver_run_attributes.json').read())
+
+    # get items file and convert to dict
+    items_csv = tar_helper.extract_file_from_tar(tar, 'items.csv')
+    items_csv_reader = csv_helper.file_stream_reader(items_csv)
+
+    # add items to attributes dict
+    attributes['items'] = service_helper.items_csv_to_dict(items_csv_reader)
+
+    return attributes
+
+  def generate_solution(self):
+    # temporary data for mocks
+    form_count = 10
+
+    # items will be generated from real solver process, this is for mock purposes
+    # real solver will return N forms and process a cut score, this is for mock purposes
+    return Solution(
+      response_id=random.randint(100,5000),
+      forms=[
+        Form(
+          items=[item.id for item in random.sample(self.solver_run.items, self.solver_run.total_form_items)],
+          cut_score=120
+        ) for x in range(form_count)
+      ]
+    )
+
+  def stream_to_s3_bucket(self):
+    # setup writer buffer and write processed forms to file
+    buffer = io.StringIO()
+    solution_file = service_helper.solution_to_file(buffer, self.solver_run.total_form_items, self.solution.forms)
+
+    # upload generated file to s3 and return result
+    return aws_helper.file_stream_upload(solution_file, f'test_solution_{time.time()}.csv', os.environ['MEASURE_PROCESSED_BUCKET'])