chore: Finalize API surface

backend/.gitignore

@@ -0,0 +1,2 @@
+data/
+env/

backend/main.py

@@ -8,6 +8,7 @@
 REQUEST_ARG_POST_ID = 'postId'
 REQUEST_ARG_IMAGE_URL = 'imageUrl'
 
+
 def posts(request: Request) -> Response:
     """Return data related to posts.
 
@@ -34,24 +35,24 @@ def posts(request: Request) -> Response:
                 'Content-Length': len(posts_json)
             }
             response = make_response((posts_json, status, headers))
-        except GetPostQueryException:
-            error_body = {
-                'errorCode': 'unknown',
-                'message': 'An unknown server error occured. Try again later.'
-            }
-            response = make_response((error_body, 500))
         except UnknownPostIdException:
             error_body = {
                 'errorCode': 'unknownPostId',
                 'message': 'The provided post does not exist.'
             }
             response = make_response((error_body, 404))
+        except GetPostException:
+            error_body = {
+                'errorCode': 'unknown',
+                'message': 'An unknown server error occurred. Try again later.'
+            }
+            response = make_response((error_body, 500))
         except:
             response = _generate_server_error()
-    elif request.method === 'POST':
+    elif request.method == 'POST':
         try:
-            imageUrl = request.args.get(REQUEST_ARG_IMAGE_URL)
-            if imageUrl is None or imageUrl == ''
+            image_url = request.args.get(REQUEST_ARG_IMAGE_URL)
+            if image_url is None or image_url == '':
                 add_post_metadata = AddPostMetadata()
             # TODO: Handle uploads
         except CreatePostException:

backend/ml/models.py

@@ -0,0 +1,55 @@
+from typing import List
+
+
+class HashtagPrediction:
+    """A single prediction for a hashtag; a mapping of a hashtag to its confidence.
+
+    Attributes:
+        hashtag (str): A possibly relevant hashtag for a piece of content
+        confidence (float): The probability that the hashtag is relevant
+    """
+
+    def __init__(self, hashtag: str, confidence: float):
+        self.hashtag = hashtag
+        self.confidence = confidence
+
+
+class ClassPrediction:
+    """A single prediction for an object's class; a mapping of a class to its confidence.
+
+    Attributes:
+        object_class (str): The category of
+        confidence (float): The probability that the hashtag is relevant
+    """
+
+    def __init__(self, object_class: str, confidence: float):
+        self.object_class = object_class
+        self.confidence = confidence
+
+
+class TextPostPredictionResult:
+    def __init__(self, hashtags: List[HashtagPrediction], entities: List[str]):
+        pass
+
+
+class ImagePostPredictionResult:
+    """
+    Attributes:
+        hashtags (List[HashtagPrediction]): A list of eight relevant hashtags
+        classes (List[str])
+    """
+
+    def __init__(self, hashtags: List[HashtagPrediction], classes: List[str]):
+        pass
+
+
+class PredictionSuggestion:
+    """A suggestion to re-tag a data point.
+
+    Attributes:
+        prediction_id (str):
+        new_value (dict): A json payload containing new data
+    """
+
+    def __init__(self, prediction_id: str, new_value: dict):
+        pass

backend/posts/intelligence.py

@@ -2,7 +2,6 @@
 import os
 import base64
 from typing import List
-from models import PostMetadata
 
 API_BASE = 'https://api.imagga.com/v2'
 
@@ -45,11 +44,11 @@ def generate_image_metadata(image_url: str) -> List[PostPredictionData]:
     Returns:
         A list of PostPredictionData containing results from hashtag generation.
     """
-    result_json = _get_imagga_data(imageUrl)
+    result_json = _get_imagga_data(image_url)
     predictions = []
     for json_object in result_json.result.tags:
         tag = json_object['tag']['en']
         confidence = json_object['confidence']
         prediction = PostPredictionData(confidence, tag)
-        predictions.add(prediction)
+        predictions.append(prediction)
     return predictions

backend/posts/models.py

@@ -1,19 +1,59 @@
+"""Domain-layer abstractions for data models that the client will accept."""
 
-class PostMetadata:
+from typing import List, Dict, Tuple
+
+
+class ImagePost:
     """A data container for post attributes.
 
     This is used to store post data after being generated using
     machine learning.
+
+    Attributes:
+        uid (str): A unique identifier for this post
+        image_url (str): The downloadable location
+        hashtags (List[Dict[str, int]]): A list of hashtags and their confidence ratings
+        captions (List[Dict[str, int]]): A list of captions and their confidence ratings
     """
 
-    def __init__(self, id: str, image_url: str, hashtags: list, caption: str):
-        self.id = id
+    def __init__(self, uid: str, image_url: str, hashtags: List[Dict[str, int]],
+                 captions: List[Dict[str, int]], upload_timestamp: int, segments: List[Tuple[int, int]]):
+        self.uid = uid
         self.image_url = image_url
         self.hashtags = hashtags
-        self.caption = caption
+        self.captions = captions
+        self.upload_timestamp = upload_timestamp
+
+
+class TextPost:
+    """A data container for text post attributes."""
+
+    def __init__(self, uid: str, content: str, hashtags: List[Dict[str, int]],
+                 captions: List[Dict[str, int]], upload_timestamp: int):
+        self.uid = uid
+        self.content = content
+        self.hashtags = hashtags
+        self.captions = captions
+        self.upload_timestamp = upload_timestamp
 
 
-class AddPostMetadata:
+class AddTextPostMetadata:
+    """Metadata needed to upload a new text post to the backend.
+
+    Attributes:
+        text (str): The contents of the post
+    """
+
+    def __init__(self, text: str):
+        self.text = text
+
+
+class AddImagePostMetadata:
+    """Metadata needed to upload a new image post to the database.
+
+    Attributes:
+        image_url (str): A URL to this image stored in Cloud Storage
+    """
 
     def ___init__(self, image_url: str):
         self.image_url = image_url

backend/posts/posts.py

@@ -61,12 +61,13 @@ def get_post_by_id(post_id: str) -> PostMetadata:
         A PostMetadata object containing post data.
     """
     try:
-        doc = db.collection(COLLECTION_POSTS) \
+        posts = db.collection(COLLECTION_POSTS) \
             .document(post_id) \
             .get()
+        # TODO: Validate that this post is text
         if len(posts) < 1:
             raise UnknownPostIdException()
-        return
+        return posts[0]
     except NotFound:
         raise UnknownPostIdException()
     except: