Program.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;
using Microsoft.OpenApi.Models;
using LlrpApi.Data;
using LlrpApi.Middleware;
using LlrpApi.Options;
using LlrpApi.Services;
using LlrpApi.Swagger;
using System.Reflection;

var builder = WebApplication.CreateBuilder(args);

// ── Options ──────────────────────────────────────────────────────────────────
builder.Services.Configure<DatabaseOptions>(builder.Configuration.GetSection(DatabaseOptions.SectionName));
builder.Services.Configure<StorageOptions>(builder.Configuration.GetSection(StorageOptions.SectionName));
builder.Services.Configure<ApiKeyOptions>(builder.Configuration.GetSection(ApiKeyOptions.SectionName));

// ── Database ─────────────────────────────────────────────────────────────────
builder.Services.AddDbContext<AppDbContext>((sp, opt) =>
{
    var dbOptions = sp.GetRequiredService<IOptions<DatabaseOptions>>().Value;
    if (dbOptions.Provider.Equals("sqlite", StringComparison.OrdinalIgnoreCase))
        opt.UseSqlite(dbOptions.BuildConnectionString());
    else
        opt.UseNpgsql(dbOptions.BuildConnectionString());
});

// ── Application services ──────────────────────────────────────────────────────
builder.Services.AddScoped<FileQueryService>();
builder.Services.AddScoped<SeedService>();
builder.Services.AddSingleton<CroissantBuilder>();

// ── File storage (local disk or S3-compatible blob store) ─────────────────────
var storageOptions = builder.Configuration.GetSection(StorageOptions.SectionName).Get<StorageOptions>() ?? new();
if (storageOptions.Provider.Equals("s3", StringComparison.OrdinalIgnoreCase))
    builder.Services.AddSingleton<IFileStorageService, S3FileStorageService>();
else
    builder.Services.AddSingleton<IFileStorageService, LocalFileStorageService>();

// ── Controllers ───────────────────────────────────────────────────────────────
builder.Services.AddControllers();

// ── Swagger / OpenAPI ─────────────────────────────────────────────────────────
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new OpenApiInfo
    {
        Title       = "Low Resource Language Library API",
        Version     = "v1",
        Description = """
            Query the Low Resource Language Library catalogue and receive
            **Croissant 1.0 JSON-LD** responses ready for ML dataset tooling.

            All endpoints require an `X-Api-Key` header.
            Click **Authorize** and enter your key to authenticate within Swagger UI.
            """,
        Contact = new OpenApiContact
        {
            Name  = "DDP Data Access",
            Email = "data@datapartnership.org",
            Url   = new Uri("https://datapartnership.org/contact")
        }
    });

    // Register the X-Api-Key security scheme
    c.AddSecurityDefinition("ApiKey", new OpenApiSecurityScheme
    {
        Type        = SecuritySchemeType.ApiKey,
        In          = ParameterLocation.Header,
        Name        = "X-Api-Key",
        Description = "Enter your API key. Keys are managed in appsettings.json → ApiKeys."
    });

    // Apply the scheme globally so every endpoint shows the lock icon
    c.AddSecurityRequirement(new OpenApiSecurityRequirement
    {
        {
            new OpenApiSecurityScheme
            {
                Reference = new OpenApiReference
                {
                    Type = ReferenceType.SecurityScheme,
                    Id   = "ApiKey"
                }
            },
            []
        }
    });

    // Include XML comments from the project (controllers + DTOs)
    var xmlFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
    var xmlPath = Path.Combine(AppContext.BaseDirectory, xmlFile);
    if (File.Exists(xmlPath))
        c.IncludeXmlComments(xmlPath);

    // Inject realistic Croissant JSON-LD examples into Swagger UI
    c.OperationFilter<CroissantExampleFilter>();
});

// ── Build ─────────────────────────────────────────────────────────────────────
var app = builder.Build();

// ── Middleware pipeline ───────────────────────────────────────────────────────
// Swagger UI is served before the API-key gate so the UI itself is accessible
app.UseSwagger();
app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/v1/swagger.json", "LRLL API v1");
    c.RoutePrefix           = "swagger";
    c.DocumentTitle         = "Low Resource Language Library API";
    c.DefaultModelsExpandDepth(-1);           // hide schema section by default
    c.DisplayRequestDuration();
});

// API key enforcement (Swagger paths are exempt inside the middleware)
app.UseMiddleware<ApiKeyMiddleware>();

//app.UseHttpsRedirection();
app.MapControllers();

// ── Ensure DB exists on startup ───────────────────────────────────────────────
using (var scope = app.Services.CreateScope())
{
    var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
    var logger = scope.ServiceProvider.GetRequiredService<ILogger<Program>>();
    var dbOptions = scope.ServiceProvider.GetRequiredService<IOptions<DatabaseOptions>>().Value;

    db.Database.EnsureCreated();

    try
    {
        var canConnect = await db.Database.CanConnectAsync();
        if (canConnect)
            logger.LogInformation("Database connected successfully (provider: {Provider}).", dbOptions.Provider);
        else
            logger.LogWarning("Database connection check failed (provider: {Provider}).", dbOptions.Provider);
    }
    catch (Exception ex)
    {
        logger.LogError(ex, "Failed to connect to database (provider: {Provider}).", dbOptions.Provider);
    }
}

app.Run();