Program.cs

using Microsoft.AspNetCore.Components.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using BlazorLearnSite.Components;
using BlazorLearnSite.Components.Account;
using BlazorLearnSite.Data;
using BlazorLearnSite.Services;

var builder = WebApplication.CreateBuilder(args);

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

builder.Services.AddCascadingAuthenticationState();
builder.Services.AddScoped<IdentityRedirectManager>();
builder.Services.AddScoped<AuthenticationStateProvider, IdentityRevalidatingAuthenticationStateProvider>();

builder.Services.AddAuthentication(options =>
    {
        options.DefaultScheme = IdentityConstants.ApplicationScheme;
        options.DefaultSignInScheme = IdentityConstants.ExternalScheme;
    })
    .AddIdentityCookies();

var connectionString = builder.Configuration.GetConnectionString("DefaultConnection") ?? throw new InvalidOperationException("Connection string 'DefaultConnection' not found.");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlite(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddIdentityCore<ApplicationUser>(options =>
    {
        // 学习站场景：注册即可用，不强制邮箱确认（无 SMTP 配置时避免卡住注册流程）
        options.SignIn.RequireConfirmedAccount = false;
        options.Stores.SchemaVersion = IdentitySchemaVersions.Version3;
    })
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddSignInManager()
    .AddDefaultTokenProviders();

builder.Services.AddSingleton<IEmailSender<ApplicationUser>, IdentityNoOpEmailSender>();

// 学习进度服务：每个用户会话（Circuit）一个实例，底层共享 Scoped 的 DbContext
builder.Services.AddScoped<LearningProgressService>();

// 健康检查：/health 用于部署探活（含数据库连通性检查）
builder.Services.AddHealthChecks()
    .AddDbContextCheck<ApplicationDbContext>();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseMigrationsEndPoint();
}
else
{
    app.UseExceptionHandler("/Error", createScopeForErrors: true);
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}
app.UseStatusCodePagesWithReExecute("/not-found", createScopeForStatusCodePages: true);
app.UseHttpsRedirection();

app.UseAntiforgery();

// 启动时自动应用迁移：简化部署（生产环境请确保数据库文件可写，或改用发布脚本迁移）
using (var scope = app.Services.CreateScope())
{
    var db = scope.ServiceProvider.GetRequiredService<ApplicationDbContext>();
    db.Database.Migrate();
}

app.MapStaticAssets();
app.MapRazorComponents<App>()
    .AddInteractiveServerRenderMode();
app.MapHealthChecks("/health");

// Add additional endpoints required by the Identity /Account Razor components.
app.MapAdditionalIdentityEndpoints();

app.Run();