using System.IdentityModel.Tokens.Jwt;
using System.Text;
using Asp.Versioning;
using Asp.Versioning.ApiExplorer;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;
using Swashbuckle.AspNetCore.SwaggerGen;
using TarninaHub.Application.Abstractions;
using TarninaHub.Application.Security;
using TarninaHub.Configuration;
using TarninaHub.Errors;
using TarninaHub.Infrastructure;
using TarninaHub.Infrastructure.Auth;

var builder = WebApplication.CreateBuilder(args);

// Layered infrastructure: SurrealDB client, settings and persistence services.
builder.Services.AddInfrastructure(builder.Configuration);

// Authentication (JWT bearer) and role-based authorization policies.
var authSettings = builder.Configuration.GetSection("Auth").Get<AuthSettings>() ?? new AuthSettings();

if (!authSettings.HasUsableSigningKey && !builder.Environment.IsDevelopment())
{
    throw new InvalidOperationException(
        "Auth signing key is missing or too short. Configure 'Auth:SigningKey' " +
        "(env 'Auth__SigningKey') with at least 32 characters.");
}

var signingKey = authSettings.HasUsableSigningKey
    ? authSettings.SigningKey
    : "development-only-signing-key-please-override-in-production";

builder.Services
    .AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
    .AddJwtBearer(options =>
    {
        options.MapInboundClaims = false;
        options.TokenValidationParameters = new TokenValidationParameters
        {
            ValidateIssuer = true,
            ValidIssuer = authSettings.Issuer,
            ValidateAudience = true,
            ValidAudience = authSettings.Audience,
            ValidateIssuerSigningKey = true,
            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(signingKey)),
            ValidateLifetime = true,
            ClockSkew = TimeSpan.FromSeconds(30),
            NameClaimType = JwtRegisteredClaimNames.Sub,
            RoleClaimType = "role",
        };
    });

builder.Services.AddAuthorization(options =>
{
    options.AddPolicy(Policies.Staff,
        policy => policy.RequireRole(RoleNames.Operator, RoleNames.Manager, RoleNames.Admin));
    options.AddPolicy(Policies.OperatorOrAdmin,
        policy => policy.RequireRole(RoleNames.Operator, RoleNames.Admin));
    options.AddPolicy(Policies.ManagerOrAbove,
        policy => policy.RequireRole(RoleNames.Manager, RoleNames.Operator, RoleNames.Admin));
    options.AddPolicy(Policies.AdminOnly,
        policy => policy.RequireRole(RoleNames.Admin));
    options.AddPolicy(Policies.JstOrAbove,
        policy => policy.RequireRole(RoleNames.Jst, RoleNames.Operator, RoleNames.Manager, RoleNames.Admin));
});

builder.Services.AddControllers();

// Uniform error responses (RFC 7807) and a global exception handler.
builder.Services.AddProblemDetails();
builder.Services.AddExceptionHandler<GlobalExceptionHandler>();

// API versioning: `?api-version=1.0` or header `X-Api-Version`; default 1.0.
builder.Services
    .AddApiVersioning(options =>
    {
        options.DefaultApiVersion = new ApiVersion(1, 0);
        options.AssumeDefaultVersionWhenUnspecified = true;
        options.ApiVersionReader = ApiVersionReader.Combine(
            new QueryStringApiVersionReader("api-version"),
            new HeaderApiVersionReader("X-Api-Version"));
        options.ReportApiVersions = true;
    })
    .AddMvc()
    .AddApiExplorer(options =>
    {
        options.GroupNameFormat = "'v'VVV";
        options.SubstituteApiVersionInUrl = true;
    });

// OpenAPI document + Swagger UI (Swashbuckle), one document per API version.
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddTransient<IConfigureOptions<SwaggerGenOptions>, ConfigureSwaggerOptions>();
builder.Services.AddSwaggerGen();

var app = builder.Build();

using (var scope = app.Services.CreateScope())
{
    var migrationRunner = scope.ServiceProvider.GetRequiredService<IMigrationRunner>();
    var storageService = scope.ServiceProvider.GetRequiredService<IStorageService>();

    await migrationRunner.ApplyAsync(CancellationToken.None);
    await storageService.InitializeAsync(CancellationToken.None);
}

app.UseExceptionHandler();
app.UseStatusCodePages();

app.UseSwagger();
app.UseSwaggerUI(options =>
{
    var provider = app.Services.GetRequiredService<IApiVersionDescriptionProvider>();

    foreach (var description in provider.ApiVersionDescriptions)
    {
        options.SwaggerEndpoint(
            $"/swagger/{description.GroupName}/swagger.json",
            $"TarninaHub API {description.GroupName.ToUpperInvariant()}");
    }
});

if (!app.Environment.IsDevelopment())
{
    app.UseHttpsRedirection();
}

app.UseDefaultFiles();
app.UseStaticFiles();

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

app.MapControllers();

app.MapFallbackToFile("index.html");

app.Run();