Program.cs

using LabManagementBackend.Helpers;
using LabManagementBackend.Services;
using LabManagementBackend.Filters;
using LabManagementBackend.Hubs;
using LabManagementBackend.Models;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using Microsoft.OpenApi.Models;
using System.Reflection;
using System.Security.Claims;
using System.Text;
using Microsoft.Extensions.FileProviders;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container
builder.Services.AddControllers();

// Register CORS policy
builder.Services.AddCors(options =>
{
    options.AddPolicy("AllowViteFrontend", policy =>
    {
        policy.WithOrigins("http://localhost:5173")
              .AllowAnyHeader()
              .AllowAnyMethod()
              .AllowCredentials();
    });
});

// Configure MongoDB settings
builder.Services.Configure<MongoDbSettings>(
    builder.Configuration.GetSection("MongoDbSettings"));

// Configure Cloudinary settings
builder.Services.Configure<CloudinarySettings>(
    builder.Configuration.GetSection("CloudinarySettings"));

// Register your services
builder.Services.AddSingleton<AuthService>();
builder.Services.AddSingleton<LabService>();
builder.Services.AddSingleton<UserService>();
builder.Services.AddSingleton<NotificationService>();
builder.Services.AddSingleton<SubjectService>();
builder.Services.AddSingleton<AttendanceService>();
builder.Services.AddSingleton<CloudinaryService>();
builder.Services.AddSingleton<SubmissionService>();
builder.Services.AddSingleton<NotificationPreferenceService>();

// Add SignalR
builder.Services.AddSignalR();

// JWT Authentication configuration
var jwtSettings = builder.Configuration.GetSection("JwtSettings");
var secretKey = jwtSettings["SecretKey"];

builder.Services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
    options.TokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuer = true,
        ValidateAudience = true,
        ValidateLifetime = true,
        ValidateIssuerSigningKey = true,
        ValidIssuer = jwtSettings["Issuer"],
        ValidAudience = jwtSettings["Audience"],
        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(secretKey)),

        // Map role and name claims correctly
        RoleClaimType = ClaimTypes.Role,
        NameClaimType = ClaimTypes.NameIdentifier
    };
});

// Swagger configuration
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new OpenApiInfo
    {
        Title = "Lab Management API",
        Version = "v1",
        Description = "API for managing lab attendance, submissions, and user authentication for MSU FoTE MCA department."
    });

    // JWT Bearer Authentication in Swagger
    c.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme
    {
        Description = "JWT Authorization header using the Bearer scheme. Enter 'Bearer' [space] and then your token.\r\n\r\nExample: \"Bearer 12345abcdef\"",
        Name = "Authorization",
        In = ParameterLocation.Header,
        Type = SecuritySchemeType.ApiKey,
        Scheme = "Bearer",
        BearerFormat = "JWT"
    });

    c.AddSecurityRequirement(new OpenApiSecurityRequirement
    {
        {
            new OpenApiSecurityScheme
            {
                Reference = new OpenApiReference { Type = ReferenceType.SecurityScheme, Id = "Bearer" }
            },
            new string[] { }
        }
    });

    // XML comments if available
    var xmlFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
    var xmlPath = Path.Combine(AppContext.BaseDirectory, xmlFile);
    if (File.Exists(xmlPath))
    {
        c.IncludeXmlComments(xmlPath);
    }

    // File upload schema and operation filter
    c.MapType<IFormFile>(() => new OpenApiSchema { Type = "string", Format = "binary" });
    c.OperationFilter<FileUploadOperationFilter>();
});

var app = builder.Build();

// Middleware pipeline
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseCors("AllowViteFrontend");

app.UseAuthentication();
app.UseAuthorization();

app.MapControllers();

app.MapHub<NotificationHub>("/hubs/notifications");

// -------------------
// Serve Frontend dist
// -------------------
var frontendPath = Path.Combine(Directory.GetCurrentDirectory(), "Frontend", "dist");
app.UseDefaultFiles(new DefaultFilesOptions
{
    FileProvider = new PhysicalFileProvider(frontendPath),
    DefaultFileNames = new List<string> { "index.html" }
});
app.UseStaticFiles(new StaticFileOptions
{
    FileProvider = new PhysicalFileProvider(frontendPath),
    RequestPath = ""
});

// SPA fallback -> always return index.html for unknown routes
app.MapFallbackToFile("index.html", new StaticFileOptions
{
    FileProvider = new PhysicalFileProvider(frontendPath)
});

app.Run();