Continue adding JSON information and also begin working on the aggregation SQL.

Design.md

@@ -8,7 +8,7 @@ To allow users to enter up to 8 locations and have the highs and lows display on
 | SE |  |  | CQ |
 |  | CQ | WS |  |
 
-## Explanation
+## Definitions
 
 The wheel is based on the movement of the sun and determines the seasons of the year.
 
@@ -168,7 +168,7 @@ than half of their latitudes as negatives.
 
 ## 2. Database
 
-### Description
+#: TBD
 
 ### Requirements
 
@@ -255,7 +255,13 @@ access the tables, or a setting / parameter can be set to default to them.
 Today's high and low are accessible when joining to the `LOC_WEATHER` table, which
 is necessary anyways to get to the `WEATHER_DATE` and `ZIP_CODE`.
 
-Extended high and low are for `WEATHER_DATE + 7`, so a week from the date.
+Extended high and low are for the furthest accessible day up to a week out.
+```sql
+SELECT loc_weather_id, max(weather_date)
+  FROM loc_weather
+ WHERE weather_date <= sysdate+7
+ GROUP BY loc_weather_id;
+```
 
 ### Roles
 
@@ -338,6 +344,47 @@ For each `ZIP_CODE`, calculate the following:
 - Weekly Mean
 - Weekly Median
 - Weekly Mode
+- Tomorrow
+    ```sql
+    -- Can be done the same as Extended, just change the sysdate+7 to sysdate+1.
+    ```
+- Extended
+    - Example:
+    ```sql
+    -- Need to get the max(weather_date) per loc_id, identify its loc_weather_id, then use that to join against  the agg table.
+
+    -- Temp view of the latest date that each location has.
+    SELECT lw.loc_id, max(lw.weather_date)
+      FROM loc_weather lw
+     WHERE lw.weather_date <= sysdate + 7
+     GROUP BY lw.loc_id;
+
+    -- Joining the temp view to the table to get the individual records.
+    SELECT lw.loc_weather_id, lw.high, lw.low
+      FROM loc_weather lw
+         , (SELECT lw.loc_id, max(lw.weather_date) as weather_date
+            FROM loc_weather lw
+            WHERE lw.weather_date <= sysdate + 7
+            GROUP BY lw.loc_id) t
+     WHERE lw.loc_id = t.loc_id
+       AND lw.weather_date = t.weather_date;
+
+    -- Merging the data into the agg table.
+    MERGE INTO loc_weather_agg o
+    USING (SELECT lw.loc_weather_id, lw.high, lw.low
+             FROM loc_weather lw
+                , (SELECT lw.loc_id, max(lw.weather_date) as max_weather_date
+                     FROM loc_weather lw
+                    WHERE lw.weather_date <= sysdate + 7
+                    GROUP BY lw.loc_id) t
+            WHERE lw.loc_id = t.loc_id
+              AND lw.weather_date = t.max_weather_date) i
+       ON (o.loc_weather_id = i.loc_weather_id)
+     WHEN MATCHED THEN UPDATE
+      SET o.extended_high = i.high
+        , o.extended_low  = i.low;
+    commit;
+    ```
 
 ## 4. Response API
 
@@ -359,8 +406,33 @@ Listener API which receives requests from the front end and queries the database
 - Program shall post any new zip codes in the `loc` table.
 - program shall update `loc.last_accessed_date` for the zip codes it retrieved data for.
 
+### Flow
+
+1. Initialize.
+1. Parse request. (Appendix #1)
+1. Merge zip codes to `loc`.
+1. Notify `weatherman` if new zip codes exist.
+    - Wait until a continue or error is replied.
+    - If continue, proceed to next steps.
+    - If error, provide error to user (Appendix #8)
+1. Pull weather data from `loc_weather` and `loc_weather_agg`.
+1. Form and deliver response. (Appendix #2)
+
 # Appendix - JSON Requests and Responses
 
+Between the programs being developed there are 3 themes being used regarding message intent.
+
+**data**
+: These messages pass information back and forth.
+
+**command**
+: These are used to notify programs that actions need taken.
+
+**error**
+: These notify that something went wrong and may provide a message with which to return to the front end.
+
+Theintent is passed at the JSON object's root level `"message_type"` attribute. The rest of the payload lies within an attribute named the same as the message type.
+
 ## 1. Request: Front End to Response API
 
 - Data shall be de-duplicated so that any one zip only appears once.
@@ -371,6 +443,7 @@ response to provide, in case the format changes in the future.
 ```json
 {
     "version": "1.0",
+    "message_type": "data",
     "data": [
         "zip_code": "85901",
         "zip_code": "86004",
@@ -389,6 +462,7 @@ response to provide, in case the format changes in the future.
 ```json
 {
     "version": "1.0",
+    "message_type": "data",
     "data": [
         {
             "zip_code": "85901",
@@ -449,25 +523,28 @@ response to provide, in case the format changes in the future.
 
 Notification from the `reporter` for the `weatherman` to kick off an ad hoc run.
 
-This data never leaves the server and cannot come from outside sources, the endpoint will not available to the public, it is accessed via localhost.
+- This data never leaves the server and cannot come from outside sources, the endpoint will not available to the public, it is accessed via localhost.
-
+- Zip codes do not need provided since the `reporter` has already inserted and committed them to `loc`.
-Zip codes do not need provided since the `reporter` has already inserted and committed them to `loc`.
+- `reporter` runs this in a synchronous fashion, waiting for the response before continuing to reply to the user.
 
 ```json
 {
-    "data": "run",
+    "message_type": "command",
+    "command": "run",
 }
 ```
 
 ## 6. Response: ZIP_CODE Data Now Available
 
-Response from `weatherman` program to `reporter`.
+Response from `weatherman` program to `reporter` that the new zip codes inserted into the DB have data.
+
+- If the `reporter` sees this, then it continues with building a response for the front end user.
 
-If the `reporter` sees this, then it continues with building a response for the front end.
 
 ```json
 {
-    "data": "ready",
+    "message_type": "command",
+    "command": "continue",
 }
 ```
 
@@ -479,7 +556,18 @@ If the `reporter` happens to see this, it provides
 
 ```json
 {
-    "data": "error",
+    "message_type": "error",
     "error": "Message about what went wrong, which may get forwarded to the user.",
 }
 ```
+
+## 8. Response: Error to Front End
+
+Sometimes the `reporter` may need to let the user know things did not go as planned.
+
+```json
+{
+    "message_type": "error",
+    "error": "Failed to pull weather information. REASON.",
+}
+```