proposal-system/api/src/ProposalSystem.Api/Program.cs

using Amazon.S3;
using Amazon.SecretsManager;
using Amazon.SQS;
using FluentValidation;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.EntityFrameworkCore;
using Microsoft.IdentityModel.Tokens;
using ProposalSystem.Api.Middleware;
using ProposalSystem.Api.Services;
using ProposalSystem.Application.Interfaces;
using ProposalSystem.Application.Validators;
using ProposalSystem.Infrastructure.Data;
using ProposalSystem.Infrastructure.Services;

var builder = WebApplication.CreateBuilder(args);

// AWS SDK clients
builder.Services.AddDefaultAWSOptions(builder.Configuration.GetAWSOptions());
builder.Services.AddAWSService<IAmazonS3>();
builder.Services.AddAWSService<IAmazonSQS>();
builder.Services.AddAWSService<IAmazonSecretsManager>();

// Database
var dbSecretArn = builder.Configuration["DB_SECRET_ARN"];
if (!string.IsNullOrEmpty(dbSecretArn))
{
    var smClient = new AmazonSecretsManagerClient();
    var connectionString = SecretsManagerConnectionString.ResolveAsync(smClient, dbSecretArn).GetAwaiter().GetResult();
    builder.Services.AddDbContext<ProposalDbContext>(options =>
        options.UseNpgsql(connectionString));
}
else
{
    builder.Services.AddDbContext<ProposalDbContext>(options =>
        options.UseNpgsql(builder.Configuration.GetConnectionString("DefaultConnection")));
}

// Authentication
var cognitoAuthority = builder.Configuration["Auth:Authority"];
if (!string.IsNullOrEmpty(cognitoAuthority))
{
    builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
        .AddJwtBearer(options =>
        {
            options.Authority = cognitoAuthority;
            options.TokenValidationParameters = new TokenValidationParameters
            {
                ValidateIssuerSigningKey = true,
                ValidateIssuer = true,
                ValidateAudience = false,
                ValidateLifetime = true,
            };
        });
}
else
{
    builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
        .AddJwtBearer();
}

builder.Services.AddAuthorization();

// Services
builder.Services.AddHttpContextAccessor();
builder.Services.AddScoped<ICurrentUserService, CurrentUserService>();
builder.Services.AddScoped<IProposalService, ProposalService>();
builder.Services.AddScoped<ILineItemService, LineItemService>();
builder.Services.AddScoped<ICustomerService, CustomerService>();
builder.Services.AddScoped<IAuditService, AuditService>();
builder.Services.AddScoped<IProposalNumberGenerator, ProposalNumberGenerator>();
builder.Services.AddScoped<IS3Service, S3Service>();
builder.Services.AddScoped<IJobPublisher>(sp =>
{
    var sqsClient = sp.GetRequiredService<IAmazonSQS>();
    var queueUrl = builder.Configuration["JOBS_QUEUE_URL"] ?? "";
    return new SqsJobPublisher(sqsClient, queueUrl);
});

// Validation
builder.Services.AddValidatorsFromAssemblyContaining<CreateProposalValidator>();

// Controllers
builder.Services.AddControllers(options =>
{
    options.Filters.Add<ValidationFilter>();
});

// Middleware
builder.Services.AddTransient<GlobalExceptionHandler>();

// Health checks
builder.Services.AddHealthChecks()
    .AddDbContextCheck<ProposalDbContext>();

// CORS
builder.Services.AddCors(options =>
{
    options.AddDefaultPolicy(policy =>
    {
        policy.WithOrigins(
                "https://proposals.seahaven.com",
                "http://localhost:5173")
            .AllowAnyMethod()
            .AllowAnyHeader();
    });
});

// Lambda hosting
builder.Services.AddAWSLambdaHosting(LambdaEventSource.HttpApi);

var app = builder.Build();

app.UseMiddleware<GlobalExceptionHandler>();
app.UseCors();
app.UseAuthentication();
app.UseAuthorization();
app.MapControllers();
app.MapHealthChecks("/api/health");

app.Run();