using System.Net;
using System.Text.RegularExpressions;
using Microsoft.Extensions.DependencyInjection;
using ZB.MOM.WW.ScadaBridge.CentralUI.Auth;
using ZB.MOM.WW.ScadaBridge.Security;

namespace ZB.MOM.WW.ScadaBridge.IntegrationTests;

/// <summary>
/// Auth flow integration tests.
/// Tests that require a running LDAP server are marked with Integration trait.
/// </summary>
public class AuthFlowTests : IClassFixture<ScadaBridgeWebApplicationFactory>
{
    private readonly ScadaBridgeWebApplicationFactory _factory;

    /// <summary>Initializes the test with the shared web application factory.</summary>
    /// <param name="factory">The web application factory hosting the app under test.</param>
    public AuthFlowTests(ScadaBridgeWebApplicationFactory factory)
    {
        _factory = factory;
    }

    /// <summary>Verifies that the login endpoint with empty credentials redirects to the login page with an error.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task LoginEndpoint_WithEmptyCredentials_RedirectsToLoginWithError()
    {
        var client = _factory.CreateClient(new Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactoryClientOptions
        {
            AllowAutoRedirect = false
        });

        using var content = await CreateLoginFormAsync(client, "", "");

        var response = await client.PostAsync("/auth/login", content);

        Assert.Equal(HttpStatusCode.Redirect, response.StatusCode);
        var location = response.Headers.Location?.ToString() ?? "";
        Assert.Contains("/login", location);
        Assert.Contains("error", location, StringComparison.OrdinalIgnoreCase);
    }

    /// <summary>Verifies that the logout endpoint clears the cookie and redirects.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task LogoutEndpoint_ClearsCookieAndRedirects()
    {
        var client = _factory.CreateClient(new Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactoryClientOptions
        {
            AllowAutoRedirect = false
        });

        var response = await client.PostAsync("/auth/logout", null);

        Assert.Equal(HttpStatusCode.Redirect, response.StatusCode);
        var location = response.Headers.Location?.ToString() ?? "";
        Assert.Contains("/login", location);
    }

    /// <summary>Verifies that the JWT token service round-trips a generated token through validation.</summary>
    [Fact]
    public void JwtTokenService_GenerateAndValidate_RoundTrips()
    {
        using var scope = _factory.Services.CreateScope();
        var jwtService = scope.ServiceProvider.GetRequiredService<JwtTokenService>();

        var token = jwtService.GenerateToken(
            displayName: "Test User",
            username: "testuser",
            roles: new[] { "Administrator", "Designer" },
            permittedSiteIds: null);

        Assert.NotNull(token);

        var principal = jwtService.ValidateToken(token);
        Assert.NotNull(principal);

        var displayName = principal!.FindFirst(JwtTokenService.DisplayNameClaimType)?.Value;
        var username = principal.FindFirst(JwtTokenService.UsernameClaimType)?.Value;
        var roles = principal.FindAll(JwtTokenService.RoleClaimType).Select(c => c.Value).ToList();

        Assert.Equal("Test User", displayName);
        Assert.Equal("testuser", username);
        Assert.Contains("Administrator", roles);
        Assert.Contains("Designer", roles);
    }

    /// <summary>Verifies that tokens generated with site scopes include site id claims.</summary>
    [Fact]
    public void JwtTokenService_WithSiteScopes_IncludesSiteIdClaims()
    {
        using var scope = _factory.Services.CreateScope();
        var jwtService = scope.ServiceProvider.GetRequiredService<JwtTokenService>();

        var token = jwtService.GenerateToken(
            displayName: "Deployer",
            username: "deployer1",
            roles: new[] { "Deployer" },
            permittedSiteIds: new[] { "1", "3" });

        var principal = jwtService.ValidateToken(token);
        Assert.NotNull(principal);

        var siteIds = principal!.FindAll(JwtTokenService.SiteIdClaimType).Select(c => c.Value).ToList();
        Assert.Contains("1", siteIds);
        Assert.Contains("3", siteIds);
    }

    /// <summary>Verifies that the login endpoint with valid LDAP credentials sets the cookie and redirects.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Trait("Category", "Integration")]
    [Fact]
    public async Task LoginEndpoint_WithValidLdapCredentials_SetsCookieAndRedirects()
    {
        // Requires a local GLAuth on localhost:3893 — the redundant test pair:
        //   cd ~/Desktop/scadaproj/infra/glauth-redundant && docker compose up -d
        // (baseDN dc=zb,dc=local, user passwords "password"; the old infra/docker-compose.yml
        // glauth service no longer exists — LDAP moved out of that stack.)
        if (!await IsLdapAvailableAsync())
        {
            // Skip gracefully if GLAuth not running — not a test failure
            return;
        }

        var client = _factory.CreateClient(new Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactoryClientOptions
        {
            AllowAutoRedirect = false
        });

        using var content = await CreateLoginFormAsync(client, "admin", "password");

        var response = await client.PostAsync("/auth/login", content);

        Assert.Equal(HttpStatusCode.Redirect, response.StatusCode);
        var location = response.Headers.Location?.ToString() ?? "";
        Assert.Equal("/", location);

        // Verify auth cookie was set
        var setCookieHeader = response.Headers.GetValues("Set-Cookie").FirstOrDefault();
        Assert.NotNull(setCookieHeader);
        Assert.Contains("ZB.MOM.WW.ScadaBridge.Auth", setCookieHeader);
    }

    /// <summary>Verifies that the login endpoint without an antiforgery token is rejected without an auth cookie.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task LoginEndpoint_WithoutAntiforgeryToken_RejectsWithoutAuthCookie()
    {
        using var client = _factory.CreateClient(new Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactoryClientOptions
        {
            AllowAutoRedirect = false
        });
        using var content = new FormUrlEncodedContent(new Dictionary<string, string>
        {
            ["username"] = "admin", ["password"] = "password"
        });
        using var response = await client.PostAsync("/auth/login", content);
        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
        if (response.Headers.TryGetValues("Set-Cookie", out var cookies))
            Assert.DoesNotContain(cookies, cookie => cookie.StartsWith(SecurityOptions.DefaultCookieName + "=", StringComparison.Ordinal));
    }

    private static async Task<FormUrlEncodedContent> CreateLoginFormAsync(HttpClient client, string username, string password)
    {
        // Fetch the actual rendered form. WebApplicationFactory's cookie handler retains
        // its antiforgery cookie, so the POST exercises the same pair as a browser login.
        using var page = await client.GetAsync("/login");
        Assert.Equal(HttpStatusCode.OK, page.StatusCode);
        var html = await page.Content.ReadAsStringAsync();
        var input = Regex.Match(html, """<input\b[^>]*name="__RequestVerificationToken"[^>]*>""", RegexOptions.IgnoreCase);
        Assert.True(input.Success, "The login form must render an antiforgery input.");
        var value = Regex.Match(input.Value, "\\bvalue=\"([^\"]+)\"", RegexOptions.IgnoreCase);
        Assert.True(value.Success, "The login form must provide a nonempty antiforgery token.");
        return new FormUrlEncodedContent(new Dictionary<string, string>
        {
            ["username"] = username,
            ["password"] = password,
            ["__RequestVerificationToken"] = WebUtility.HtmlDecode(value.Groups[1].Value)
        });
    }

    private static async Task<bool> IsLdapAvailableAsync()
    {
        try
        {
            using var tcp = new System.Net.Sockets.TcpClient();
            await tcp.ConnectAsync("localhost", 3893).WaitAsync(TimeSpan.FromSeconds(2));
            return true;
        }
        catch
        {
            return false;
        }
    }
}