C# debugging and coding

> **They will let me know how to debug, how code is written, C#, and many things — help me in that!**

You're likely getting into a project that includes:
– C# backend code
– Real-world domain understanding (maybe aviation, telecom like Bell.ca, etc.)
– Debugging techniques
– Possibly APIs or weather integration

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### Here's how I’ll help you stay ahead:

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## ✅ Step-by-Step Plan to Prepare Yourself:

### 1. **Understand the Domain (Bell.ca)**
– Bell.ca is a telecom company. Projects might involve:
– Customer portals (MyBell, billing, internet, mobile)
– Service dashboards (plans, upgrades)
– APIs for account management, internet speed, data usage, etc.
– Learn the **business flow**: user login → see plan → upgrade/downgrade → pay bill → track usage.

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### 2. **C# Basics Refresher (for backend code)**
Start with:
– ✔ Classes & Objects
– ✔ Controllers & Services in ASP.NET
– ✔ HTTP Requests (GET/POST)
– ✔ Entity Framework (for DB access)
– ✔ Models, DTOs, and ViewModels

Example:

public class CustomerController : Controller
{
    private readonly ICustomerService _service;

    public CustomerController(ICustomerService service)
    {
        _service = service;
    }

    public IActionResult GetProfile(int id)
    {
        var profile = _service.GetCustomerProfile(id);
        return Ok(profile);
    }
}

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### 3. **Debugging in Visual Studio**
They may show this in the session. Here’s how **you can practice yourself**:

🔹 Set a **Breakpoint** with `F9` on any line of code
🔹 Run with **F5** → execution pauses at the breakpoint
🔹 Use:
– **Locals** window – see current variable values
– **Immediate Window** – run lines of code dynamically
– **Step Into (F11)** – go inside function calls
– **Step Over (F10)** – skip to next line

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### 4. **Reading Existing Code**
Ask these questions when reading:
– What is the controller or class responsible for?
– Are there service layers? How is business logic separated?
– How is the database accessed? Using Entity Framework?
– Are there any configuration files (e.g., `appsettings.json`)?

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### 5. **How You Can Ask Questions in the Session**
If you're confused, try:
> “Could you please walk me through how this function is triggered?”
> “Can you show me where this variable gets its value from?”
> “What’s the role of this API/controller in the full user flow?”

These show you’re serious and observant — not foolish.

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### 6. **Where this METAR Decoder Fits In**
Since you're seeing aviation-related data (METAR), it may be that:
– You're working on a **weather integration or display feature**
– Your team is showing how APIs like this decode structured weather data

Just understand:
– METAR is aviation weather
– The data structure is complex and used in aviation apps
– You may have to **call a weather API**, decode it, and show meaningful data in the UI

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## 💡 Pro Tip for Confidence
You said:
> “They will let me know everything — C#, how to debug, etc.”

✅ Keep a **notepad** with:
– What project/module you're working on
– What they explain (record if allowed)
– Sample data → backend call → output flow
– Tech keywords (like controller, API, debugger, breakpoint)

This helps you recall, ask better questions, and slowly become confident.

—

If you want, I can help you:
– Debug any real C# code
– Understand the structure of a real Bell.ca page you’re working on
– Setup Visual Studio or Visual Studio Code with breakpoints
– Write a small sample project to practice

Just say the word.

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## ✅ 1. What is a Web API in C#?

A **Web API** (in ASP.NET) lets frontend or mobile apps **communicate with backend services** using HTTP requests like `GET`, `POST`, `PUT`, `DELETE`.

### 🧠 Real-Life Use Case at Bell.ca:
– Frontend: React app calls `/api/customer/12345`
– Backend: ASP.NET Web API returns customer info in JSON

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### 🔧 Sample Web API Controller in C#

[Route("api/[controller]")]
[ApiController]
public class CustomerController : ControllerBase
{
    [HttpGet("{id}")]
    public IActionResult GetCustomer(int id)
    {
        var customer = new CustomerService().GetById(id);
        return Ok(customer);
    }
}

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## ✅ 2. What is a Factory Method?

A **Factory Method** is a **design pattern** used to **create objects** without specifying the exact class to be instantiated.

> Useful when object creation is complex or depends on certain conditions.

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### 🧠 Real-Life Use Case:
You want to create different types of plans (Mobile, Internet, TV), but the frontend just says: “Give me a plan object.”

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### 🔧 Simple Factory Method Example in C#

// Step 1: Define Interface
public interface IPlan
{
    string GetPlanDetails();
}

// Step 2: Concrete Classes
public class InternetPlan : IPlan
{
    public string GetPlanDetails() => "Unlimited Internet Plan";
}

public class MobilePlan : IPlan
{
    public string GetPlanDetails() => "5G Mobile Plan";
}

// Step 3: Factory
public static class PlanFactory
{
    public static IPlan CreatePlan(string type)
    {
        switch (type.ToLower())
        {
            case "internet": return new InternetPlan();
            case "mobile": return new MobilePlan();
            default: throw new ArgumentException("Invalid plan type");
        }
    }
}

// Step 4: Usage
var plan = PlanFactory.CreatePlan("internet");
Console.WriteLine(plan.GetPlanDetails()); // Output: Unlimited Internet Plan

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## 🎯 Where You Might Use This in Your Project:
– Creating user roles (`Admin`, `Agent`, `Customer`)
– Generating response models based on plan type
– Handling different payment gateway objects (`Stripe`, `PayPal`, etc.)

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## 🔄 Combine with Web API

You can use the factory in your Web API like this:

[HttpGet("plan/{type}")]
public IActionResult GetPlanDetails(string type)
{
    var plan = PlanFactory.CreatePlan(type);
    return Ok(plan.GetPlanDetails());
}

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## ✅ Summary

| Concept | Use Case | Example |
|—————-|—————————————-|——————————-|
| Web API | Expose backend to frontend via HTTP | `/api/customer/1` |
| Factory Method | Create object based on logic | PlanFactory.CreatePlan("tv") |

—

Would you like:
– A diagram to visualize the factory flow?
– A sample project in Visual Studio to practice?
– Explanation of Factory vs Abstract Factory?

Let me know how deep you want to go.

—

## ✅ What is a Decoder?

In programming, a **decoder** is any logic that takes **raw or encoded input** and **converts** it into a **structured, understandable format**.

> Think of it as:
> **"Incoming data → Decoder → Usable data model"**

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### 🧠 Real-World Examples of Decoders:

| Example | Input | Decoder Converts It To |
|——–|——-|————————-|
| **METAR Decoder** | `"KDEN 262053Z 34006KT…"` | JSON object with fields like `Wind`, `Visibility`, etc. |
| **Base64 Decoder** | `QmVsbENhbmFkYQ==` | `"BellCanada"` |
| **JWT Token Decoder** | `eyJhbGciOiJIUzI1NiIsInR5cCI…` | `{ "user_id": 123, "role": "admin" }` |
| **Custom Telecom Decoder** | Binary data from device | JSON object: `{ plan: "Internet 100 Mbps", usage: "55 GB" }` |

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## 🔧 C# Example: JWT Token Decoder

Let’s say your API uses JWT to authenticate users.

var handler = new JwtSecurityTokenHandler();
var token = handler.ReadJwtToken(jwtString);
Console.WriteLine(token.Payload["user_id"]);

This **decodes** the JWT string into a usable **C# object**.

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## 🔧 C# Example: Custom API Data Decoder

Imagine Bell.ca sends a compressed or encoded API payload. You’ll need to **decode** it into your model.

public class PlanDecoder
{
    public static Plan Decode(string encoded)
    {
        var json = Encoding.UTF8.GetString(Convert.FromBase64String(encoded));
        return JsonConvert.DeserializeObject<Plan>(json);
    }
}

**Usage:**

var planData = PlanDecoder.Decode(encodedPayloadFromApi);

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## 🧠 Bell Canada Project Use Cases for Decoders:
– **METAR Decoder**: Like in your screenshot — weather data decoding.
– **Telecom Plan Decoder**: If the API gives compressed or coded info about plans.
– **Base64 or Binary Decoders**: For image previews or signatures.
– **JWT Decoders**: For user session/token management.

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## 📦 Pro Tip

In enterprise apps, **decoders** are usually:
– Utility or static classes (`TokenDecoder`, `XmlResponseDecoder`, etc.)
– Applied when the **data format from API or device is not directly usable**

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## ✅ Summary

| Term | Role |
|——|——|
| **Decoder** | Converts unreadable/encoded data into usable form |
| **In C#** | Typically a helper class or service |
| **Real Use** | JWT decoding, Base64 decoding, custom format parsing |

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Would you like a **custom decoder demo** project (e.g. decode a sample METAR string or JWT in C#)? Or want to decode data **from your actual project**?

Let me know — I’ll build what fits your need.

**POC** stands for **Proof of Concept**.

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### 📘 Definition:
A **Proof of Concept** is a **small, quick prototype or implementation** built to:

> ✔ Prove that an **idea, technology, or approach** **can work** in a real-world scenario
> ❌ It is **not** the final product
> 🧪 It's just to **test feasibility**, **demonstrate capability**, or **validate assumptions**

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### 🧠 Real-world Examples in Software Development:

| Scenario | POC Example |
|———|————-|
| **New payment gateway** | Integrate just Stripe’s payment flow in a test page to check if it works with your backend |
| **React + .NET project** | Create a simple page with login using React frontend and C# Web API backend |
| **Google Wallet API** | Generate and render 1 ticket dynamically using the API to see if it meets your ticketing needs |
| **Performance test** | Query a large data set from database to check if your architecture supports millions of records |

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### 🏗️ What a POC Usually Includes:
– Minimal code (just to test)
– Hardcoded data or sample input
– No styling or full features
– A single flow (like: API call → decode → show result)

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### 🔄 POC vs Prototype vs MVP

| Term | Purpose | Scope |
|——|———|——-|
| **POC** | Prove that it can work | Technical only, quick |
| **Prototype** | Show how it will look or behave | UI/UX focused, not fully working |
| **MVP** | Minimum version of full product | First release, with essential features only |

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### 💡 In your case:

If someone says:
> “Create a POC for ticket generation using Google Wallet API”

They mean:
– Just create a single API call
– Use dummy ticket data
– Show the wallet link generated
– No need for styling, full database, or UI

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If you want, I can help you:
– Build a small POC with ASP.NET Web API
– Test something new in your current Bell project
– Prepare a POC presentation

Let me know what kind of POC you’re working on.