Assignment 1- HTTP.txt

using Microsoft.Extensions.Primitives;
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.Run(async (HttpContext context) =>
{
    if (context.Request.Method == "GET" && context.Request.Path == "/")
    {
        var queryDict = context.Request.Query;
        var solution = 0.0;
        bool isMissingValue = false;

        if (!queryDict.ContainsKey("firstNumber"))
        {
            context.Response.StatusCode = 400;
            await context.Response.WriteAsync("Invalid input for 'firstNumber'\n");
            isMissingValue = true;
        }
        if (!queryDict.ContainsKey("secondNumber"))
        {
            if (context.Response.StatusCode == 200)
                context.Response.StatusCode = 400;
            await context.Response.WriteAsync($"Invalid input for 'secondNumber'\n");
            isMissingValue = true;
        }
        if (!queryDict.ContainsKey("operation"))
        {
            if (context.Response.StatusCode == 200)
                context.Response.StatusCode = 400;
            await context.Response.WriteAsync($"Invalid input for 'operation'\n");
            isMissingValue = true;
        }
        
        
        if (!isMissingValue && queryDict.Count >= 3)
        {
            int firstNumber = int.Parse(queryDict["firstNumber"]);
            int firstSecondNumber = int.Parse(queryDict["secondNumber"]);
            string operation = queryDict["operation"];

            if (operation == "add")
                solution = firstNumber + firstSecondNumber;
            else if (operation == "subtract")
                solution = firstNumber - firstSecondNumber;
            else if (operation == "multiply")
                solution = firstNumber * firstSecondNumber;
            else if (operation == "divide")
                solution = firstNumber / firstSecondNumber;
            else if (operation == "modulus")
                solution = firstNumber % firstSecondNumber;
            else
            {
                if (context.Response.StatusCode == 200)
                    context.Response.StatusCode = 400;
                await context.Response.WriteAsync($"Invalid input for 'operation'");
                isMissingValue = true;
            }
        }
        
        if (!isMissingValue)   
            await context.Response.WriteAsync($"Solution {solution}");
    }
});

app.Run();