Add time calculation diagram and render images

docs/source/diagrams.md

@@ -9,29 +9,56 @@ The Diagrams are drawn using [draw.io](https://.wwww.draw.io). You can download
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 **Deployment Diagram:**
-![Deployment Diagram](/_static/img/deployment_diagram.png)
+![Deployment Diagram](_static/img/deployment_diagram.png)
 
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 **Proposed Data Structure Project Type 1 - Firebase:**
-![Data Structure - Firebase](/_static/img/data_structure-firebase-1.svg)
+![Data Structure - Firebase](_static/img/data_structure-firebase-1.svg)
 
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 **Proposed Data Structure Project Type 2 - Firebase:**
-![Data Structure - Firebase](/_static/img/data_structure-firebase-2.svg)
+![Data Structure - Firebase](_static/img/data_structure-firebase-2.svg)
 
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 **Database Scheme - Postgres:**
-![Database Schema - Postgres](/_static/img/database_schema-postgres.png)
+![Database Schema - Postgres](_static/img/database_schema-postgres.png)
 
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 **Entity Relationship Diagram - Postgres:**
-![Entity Relationship Diagram- Postgres](/_static/img/entity_relationship_diagram-postgres.png)
+![Entity Relationship Diagram- Postgres](_static/img/entity_relationship_diagram-postgres.png)
 
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 **Database Schema - Analytics:**
-![Database Schema - Analytics](/_static/img/database_schema-analytics.png)
+![Database Schema - Analytics](_static/img/database_schema-analytics.png)
+
+---
+
+**Mapping Sessions - Time Calculation**
+
+The diagram below is a visual representation of how time is calculated in MapSwipe. 
+
+Step 1: User Mapping Session **sends data** to Firebase
+- When a user completes a mapping session in the mobile/web app, the session payload (including start/end timestamps, user ID, session metadata, etc.) is sent in real time to Firebase.
+
+Step 2: Cron job **fetches data** from the firebase 
+- Every 3 minutes, a cron job syncs data for any new session records and pulls them into the backend.
+
+Step 3: Cron job **saves raw data** to Postgres database
+- The cron job sends new session data to the Postgres database.
+
+Step 4: Cron job **reads raw data** from Postgres database
+- Another cron job reads the raw data from Postgres database.
+
+Step 5: Cron job **saves aggregates** to Postgres database
+- The cron job aggregates previous 24 hours data (end date - start date), sends back, and saves processed aggregated data to the Postgres database.
+
+Step 6: Community dashboard **queries aggregate data** from Postgres database 
+- The Community dashboard pulls the processed data from the Postgres database and updates the dashbaord with up-to-date stats.
+
+
+![MapSwipe Time Calculation](_static/img/mapswipe-time-calculation.png)