The ledger repo aims to achieve the following:

+-------------------+          HTTPS          +---------------------+
|                   | <------------------->  |                     |
|   Android App     |    (API Requests)      |   Flask Web Server  |
|  (Kotlin, XML/    |      (JSON)           |   (Python)          |
|  Jetpack Compose) |                       |                     |
+-------------------+                       +---------------------+
        |                                             |
        |                                             |
        |   1. User enters credentials (coming soon)  |
        |-------------------------------------------->|
        |   2. Flask authenticates (JWT/Session)      |
        |        (coming soon)                        |
        |<--------------------------------------------|
        |   3. Receives token/session (coming soon)   |
        |                                             |
        |   4. User fills input form (Up && Running?) |
        |-------------------------------------------->|
        |   5. Flask validates & stores data          |
        |      (Up && Running?)                       |
        |<--------------------------------------------|
        |   6. Success/failure response               |
        |    (Up && Running?)                         |
        |                                             |
        |                                             |
        |                                    +------------------+
        |                                    |                  |
        |                                    |   Database       |
        |                                    | (SQLAlchemy)     |                                   
        |                                    |                  |
        |                                    +------------------+
        |
+-------------------+ 
|                   | 
|    User Device    |
|                   |
+-------------------+ 

Languages and frameworks I intend to use:

• Frontend (Android App):

  • Language: Java
  • UI: XML layouts
  • Networking: Retrofit/OkHttp for API calls
  • Auth: Store JWT securely (EncryptedSharedPreferences)

• Backend (Web Server):

  • Language: Python
  • Framework: Flask
  • ORM: SQLAlchemy
  • Database: SQLite
  • Auth: JWT or session cookies
  • Input validation: Marshmallow

Architecture Flow Explained

---

i. Input & Data Upload

• User fills out input fields in the Android app.
• App sends the data to the Flask backend via a POST request.
• Flask validates, processes, and stores the data in the database using SQLAlchemy.

---

ii. Response

• Flask sends a JSON response (success/failure) to the Android app.
• App updates the UI accordingly.

---