using System.IdentityModel.Tokens.Jwt;
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text;
using System.Text.Json;
using System.Text.RegularExpressions;
using Api.SeaHavenIndustries.Controllers;
using Api.SeaHavenIndustries.Infrastructure;
using Data.SeaHavenIndustries;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Hosting.Server;
using Microsoft.AspNetCore.Hosting.Server.Features;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc.Controllers;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Logging;
using Microsoft.IdentityModel.Tokens;
using SeaHaven.DataServices.DependencyInjection;
using SeaHaven.Services.DependencyInjection;
using SeaHaven.Services.Interfaces;

namespace SeaHavenIndustries.Tests;

/// <summary>
/// Hosts the real sign-in, user and team member controllers on Kestrel over a SQLite
/// file database, with Identity and bearer authentication registered exactly as the
/// API host registers them. Email goes to an in-memory sender and every log line is
/// captured.
/// </summary>
internal sealed class SessionTestHost : IAsyncDisposable
{
    public static readonly string JwtSecret = new('s', 64);
    public const string Issuer = "issuer";
    public const string Audience = "audience";
    public const string Password = "Harbor-Light-42!";

    private static readonly Regex ResetCode = new(@"Reset Code is: (\d{6})", RegexOptions.CultureInvariant);

    private readonly WebApplication _app;
    private readonly string _databasePath;

    private SessionTestHost(WebApplication app, string databasePath, HttpClient client)
    {
        _app = app;
        _databasePath = databasePath;
        Client = client;
    }

    public HttpClient Client { get; }
    public CapturingEmailSender Sent { get; private set; } = null!;
    public CapturingLoggerProvider Logged { get; private set; } = null!;

    public static async Task<SessionTestHost> StartAsync()
    {
        var databasePath = Path.Combine(Path.GetTempPath(), $"sessions-{Guid.NewGuid():N}.db");
        var connectionString = new SqliteConnectionStringBuilder { DataSource = databasePath, DefaultTimeout = 30 }.ToString();

        var builder = WebApplication.CreateBuilder(new WebApplicationOptions { EnvironmentName = "Testing" });
        builder.WebHost.UseUrls("http://127.0.0.1:0");
        builder.Configuration.AddInMemoryCollection(new Dictionary<string, string?>
        {
            ["JWT:Secret"] = JwtSecret,
            ["JWT:ValidIssuer"] = Issuer,
            ["JWT:ValidAudience"] = Audience
        });

        var sent = new CapturingEmailSender();
        var logged = new CapturingLoggerProvider();
        builder.Logging.ClearProviders();
        builder.Logging.SetMinimumLevel(LogLevel.Trace);
        builder.Logging.AddProvider(logged);

        builder.Services.AddDbContext<ApplicationDbContext>(options => options.UseSqlite(connectionString));
        builder.Services.Replace(ServiceDescriptor.Scoped<ApplicationDbContext>(provider =>
            new SqliteSessionDbContext(provider.GetRequiredService<DbContextOptions<ApplicationDbContext>>())));
        builder.Services.AddSeaHavenIdentity();
        builder.Services.AddSingleton<IEmailSender>(sent);
        builder.Services.AddDataServices();
        builder.Services.AddBusinessServices(builder.Configuration);
        builder.Services.AddSeaHavenJwtAuthentication(builder.Configuration);
        builder.Services.AddControllers()
            .AddApplicationPart(typeof(AuthenticationController).Assembly)
            .ConfigureApplicationPartManager(manager =>
            {
                manager.FeatureProviders.Clear();
                manager.FeatureProviders.Add(new SessionControllers());
            });

        var app = builder.Build();
        app.UseRouting();
        app.UseAuthentication();
        app.UseAuthorization();
        app.MapControllers();

        await using (var scope = app.Services.CreateAsyncScope())
            await scope.ServiceProvider.GetRequiredService<ApplicationDbContext>().Database.EnsureCreatedAsync();

        await app.StartAsync();
        var address = app.Services.GetRequiredService<IServer>().Features
            .Get<IServerAddressesFeature>()!.Addresses.Single();

        var host = new SessionTestHost(app, databasePath, new HttpClient { BaseAddress = new Uri(address) });
        host.Sent = sent;
        host.Logged = logged;
        return host;
    }

    public async Task<ApplicationUser> AddUserAsync(string email, string? role = null)
    {
        await using var scope = _app.Services.CreateAsyncScope();
        var users = scope.ServiceProvider.GetRequiredService<UserManager<ApplicationUser>>();
        var user = new ApplicationUser
        {
            UserName = email,
            Email = email,
            FirstName = "Sam",
            LastName = "Lee",
            EmailConfirmed = true,
            UniqueName = "Active",
            CreatedDate = DateTime.UtcNow
        };
        var created = await users.CreateAsync(user, Password);
        Assert.True(created.Succeeded, string.Join("; ", created.Errors.Select(error => error.Description)));

        if (role != null)
        {
            var roles = scope.ServiceProvider.GetRequiredService<RoleManager<IdentityRole>>();
            if (!await roles.RoleExistsAsync(role))
                await roles.CreateAsync(new IdentityRole(role));
            await users.AddToRoleAsync(user, role);
        }

        return user;
    }

    public async Task<string> SignInAsync(string email, string password = Password)
    {
        using var response = await Client.PostAsJsonAsync("api/Authentication/login", new { username = email, password });
        Assert.Equal(System.Net.HttpStatusCode.OK, response.StatusCode);
        using var payload = JsonDocument.Parse(await response.Content.ReadAsStringAsync());
        return payload.RootElement.GetProperty("token").GetString()!;
    }

    public Task<HttpResponseMessage> SendAsync(HttpMethod method, string path, string? token, object? json = null)
    {
        var request = new HttpRequestMessage(method, path);
        if (token != null)
            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
        if (json != null)
            request.Content = JsonContent.Create(json);
        return Client.SendAsync(request);
    }

    /// <summary>An authorized read that only succeeds for a signed-in, accepted session.</summary>
    public Task<HttpResponseMessage> ProfileAsync(string? token) =>
        SendAsync(HttpMethod.Get, "api/User/UserProfile", token);

    /// <summary>Runs Forgot Password end to end: request a code, read it from the email, reset.</summary>
    public async Task ResetPasswordAsync(string email, string newPassword)
    {
        var before = Sent.Messages.Count;
        using (var requested = await SendAsync(
                   HttpMethod.Post, $"api/Authentication/ForgetPassword?Email={Uri.EscapeDataString(email)}", null, new { email }))
            Assert.Equal(System.Net.HttpStatusCode.OK, requested.StatusCode);

        var deadline = DateTime.UtcNow.AddSeconds(10);
        SentEmail? message;
        while ((message = Sent.Messages.Skip(before).LastOrDefault(sent => sent.To == email && ResetCode.IsMatch(sent.Body))) == null)
        {
            if (DateTime.UtcNow > deadline)
                throw new TimeoutException("No password reset email was sent.");
            await Task.Delay(10);
        }

        var code = ResetCode.Match(message.Body).Groups[1].Value;
        using var reset = await SendAsync(
            HttpMethod.Post, "api/Authentication/ResetPassword", null, new { email, code, password = newPassword });
        Assert.Equal(System.Net.HttpStatusCode.OK, reset.StatusCode);
    }

    public async Task<string?> StoredSecurityStampAsync(string userId)
    {
        await using var scope = _app.Services.CreateAsyncScope();
        return await scope.ServiceProvider.GetRequiredService<ApplicationDbContext>()
            .Users.AsNoTracking().Where(user => user.Id == userId).Select(user => user.SecurityStamp).SingleOrDefaultAsync();
    }

    /// <summary>
    /// Re-signs <paramref name="token"/> with the host's real signing key after letting
    /// <paramref name="edit"/> change its claims, so only the claims differ from a token
    /// the API issued.
    /// </summary>
    public static string Resign(string token, Action<List<System.Security.Claims.Claim>> edit)
    {
        var original = new JwtSecurityTokenHandler().ReadJwtToken(token);
        var claims = original.Claims
            .Where(claim => claim.Type is not (JwtRegisteredClaimNames.Exp or JwtRegisteredClaimNames.Iss or JwtRegisteredClaimNames.Aud or JwtRegisteredClaimNames.Nbf or JwtRegisteredClaimNames.Iat))
            .ToList();
        edit(claims);
        var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(JwtSecret));
        var resigned = new JwtSecurityToken(
            issuer: Issuer,
            audience: Audience,
            claims: claims,
            expires: original.ValidTo,
            signingCredentials: new SigningCredentials(key, SecurityAlgorithms.HmacSha256));
        return new JwtSecurityTokenHandler().WriteToken(resigned);
    }

    public async ValueTask DisposeAsync()
    {
        Client.Dispose();
        await _app.StopAsync();
        await _app.DisposeAsync();
        SqliteConnection.ClearAllPools();
        foreach (var path in new[] { _databasePath, _databasePath + "-wal", _databasePath + "-shm", _databasePath + "-journal" })
        {
            if (File.Exists(path))
                File.Delete(path);
        }
    }

    private sealed class SessionControllers : ControllerFeatureProvider
    {
        protected override bool IsController(System.Reflection.TypeInfo typeInfo) =>
            typeInfo.AsType() == typeof(AuthenticationController)
            || typeInfo.AsType() == typeof(UserController)
            || typeInfo.AsType() == typeof(TeamMemberController);
    }

    private sealed class SqliteSessionDbContext : ApplicationDbContext
    {
        public SqliteSessionDbContext(DbContextOptions<ApplicationDbContext> options)
            : base(options)
        {
        }

        protected override void OnModelCreating(ModelBuilder builder)
        {
            base.OnModelCreating(builder);

            foreach (var index in builder.Model.GetEntityTypes().SelectMany(entity => entity.GetIndexes()))
            {
                // SQL Server filter syntax does not carry over; a filtered unique index
                // without its filter would wrongly reject a second user.
                if (index.GetFilter() is not null)
                {
                    index.SetFilter(null);
                    index.IsUnique = false;
                }
            }

            foreach (var property in builder.Model.GetEntityTypes()
                         .SelectMany(entity => entity.GetProperties())
                         .Where(property => property.Name == "RowVersion" && property.ClrType == typeof(byte[])))
            {
                property.ValueGenerated = ValueGenerated.Never;
                property.IsConcurrencyToken = false;
            }
        }
    }
}