Readme update

README.md

@@ -10,4 +10,75 @@ pinned: false
 hf_oauth: true
 ---
 
-Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
+# Database structure
+2 main endpoints: Videos and video_captions.
+
+### Videos
+Contains a json object with YouTube links to the videos.
+
+Example entry: 
+```
+0: "https://www.youtube.com/watch?v=tkMg8g8vVUo"
+```
+
+Keys are `integers`. 
+They define the order in which the videos show up on the page. 
+Keys must start with zero and have no gaps.
+
+Values are video link `strings`.
+Format is flexible, can optionally include `https://` or a query string.
+
+All data is read only.
+Editing/uploading new entries requires changing access rules. 
+
+### video_captions
+Contains a json object with video information, namely captions.
+
+Example entry:
+```
+tkMg8g8vVUo:
+    captions:
+        0:
+            start_time: 0
+            text: "text"         # first caption line
+            end_time: 1
+        1:
+            start_time: 1
+            text: "text 2"       # second caption line
+            end_time: 1.5
+    username: "user"            # user who last edited captions
+    signer: 1                   # (optional) signer in the video
+```
+
+Keys are video id `strings`.
+
+Contains a json object. All keys are optional.
+Relevant endpoints are `captions` and `username`, although any number of other objects can be added.
+
+`captions` contains a json object with the captions to the video. 
+Keys are `integers`. 
+Values are json objects with `start_time`, `text` and `end_time` endpoints.
+All keys are mandatory.
+`start_time` and `end_time` must have a numeric value type.
+`text` is a string.
+
+`username` contains a `string` value.
+It is the HuggingFace username of the person who last edited/saved captions for this video.
+
+By default, data is read only.
+The `username` endpoint is writable.
+The `captions` endpoint is writable, as long as:
+- written data has children
+- all children have the required `start_time`, `text` and `end_time` children
+- `start_time` and `end_time` are numeric
+
+# Database connection
+
+Connecting a Space to the database:
+- Go to `Firebase` > `Project settings` > `General` > `Your apps` > `Caption_editor`
+- In "SDK setup and configuration" select `Config`
+- Copy only the config object value
+- Go to space `Settings` > `Variables and secrets` > `Secrets` > `New secret`
+- Add a secret with the name `FIREBASE_CONFIG` and value of the config object copied previously.
+Note that it must be a valid json object, so the key names must be in double quotes.
+- Done!