using System.Net;
using System.Net.Http.Headers;
using System.Net.Http.Json;
using Azaion.Missions.E2E.Fixtures;
using Azaion.Missions.E2E.Helpers;
using Xunit;

namespace Azaion.Missions.E2E.Tests.Security;

/// <summary>
/// NFT-SEC-01..06 + 04b — JWT authn/authz scenarios from
/// <c>_docs/02_document/tests/security-tests.md</c>.
/// Traces: AC-5.2..AC-5.6, AC-5.8, AC-5.11, AC-5.12, AC-9.1, AC-9.2.
/// </summary>
[Collection("SecurityAuthClaims")]
[Trait("Category", "Sec")]
[Trait("db_access", "seed-or-assert-only")]
public sealed class AuthClaimsTests : TestBase, IClassFixture<DbResetFixture>
{
    [Fact]
    [Trait("Traces", "AC-5.4")]
    [Trait("max_ms", "5000")]
    public async Task NFT_SEC_01_missing_authorization_header_rejects_protected_endpoints_with_401_and_no_db_write()
    {
        // Arrange
        DbResetFixture.ResetDatabase(TestEnvironment.DbSideChannel);
        Seeds.Apply(Seeds.OneDefaultVehicle.Sql);
        var anyMissionId = Guid.NewGuid();
        var preCount = DbAssertions.TableRowCount("vehicles");

        // Act
        // Assert — GET /vehicles
        using (var resp = await Missions.GetAsync("/vehicles"))
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);

        using (var resp = await Missions.GetAsync("/missions"))
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);

        using (var resp = await Missions.GetAsync($"/missions/{anyMissionId}/waypoints"))
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);

        var postBody = new
        {
            Type = 0,
            Model = "Bayraktar",
            Name = "BR-noauth",
            FuelType = 1,
            BatteryCapacity = 0,
            EngineConsumption = 5,
            EngineConsumptionIdle = 1,
            IsDefault = false
        };
        using (var post = new HttpRequestMessage(HttpMethod.Post, "/vehicles")
        {
            Content = JsonContent.Create(postBody)
        })
        using (var resp = await Missions.SendAsync(post))
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);

        // Assert — POST 401 did not write a row.
        var postCount = DbAssertions.TableRowCount("vehicles");
        Assert.Equal(preCount, postCount);
    }

    [Fact]
    [Trait("Traces", "AC-5.5")]
    [Trait("max_ms", "5000")]
    public async Task NFT_SEC_02_invalid_signature_rejects_byte_flip_and_foreign_keypair_with_401()
    {
        // Arrange — single-byte-flip uses a mock-signed token; foreign-keypair
        // uses a local ECDSA P-256 (the one in-test signing path the task
        // spec permits).
        var good = await Tokens.MintDefaultAsync();
        var flipped = FlipFirstSignatureChar(good.Jwt);

        using var foreign = new ForeignKeypair();
        var foreignJwt = foreign.Mint(
            TestEnvironment.JwtIssuer, TestEnvironment.JwtAudience, "FL");

        // Act
        // Assert — flipped signature
        using (var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles"))
        {
            req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", flipped);
            using var resp = await Missions.SendAsync(req);
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);
        }

        // (Act+Assert — foreign keypair token (kid not in JWKS).)
        using (var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles"))
        {
            req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", foreignJwt);
            using var resp = await Missions.SendAsync(req);
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);
        }
    }

    [Fact]
    [Trait("Traces", "AC-5.2,AC-5.6")]
    [Trait("max_ms", "5000")]
    public async Task NFT_SEC_03_clock_skew_30s_rejects_minus_60_and_accepts_minus_15()
    {
        // Arrange — both tokens are otherwise identical; only exp differs.
        var expiredBeyondSkew = await Tokens.MintAsync(
            new SignRequest(Permissions: "FL", ExpOffsetSeconds: -60));
        var expiredWithinSkew = await Tokens.MintAsync(
            new SignRequest(Permissions: "FL", ExpOffsetSeconds: -15));

        // Act
        // Assert — outside the 30s skew window.
        using (var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles"))
        {
            req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", expiredBeyondSkew.Jwt);
            using var resp = await Missions.SendAsync(req);
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);
        }

        // Inside the 30s skew window.
        using (var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles"))
        {
            req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", expiredWithinSkew.Jwt);
            using var resp = await Missions.SendAsync(req);
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.OK);
        }
    }

    [Fact]
    [Trait("Traces", "AC-5.3,AC-5.11")]
    [Trait("max_ms", "5000")]
    public async Task NFT_SEC_04_wrong_iss_rejected_default_iss_accepted()
    {
        // Arrange
        var wrongIss = await Tokens.MintAsync(
            new SignRequest(Iss: "https://attacker.example.com", Permissions: "FL"));
        var defaultIss = await Tokens.MintDefaultAsync();

        // Act
        // Assert
        using (var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles"))
        {
            req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", wrongIss.Jwt);
            using var resp = await Missions.SendAsync(req);
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);
        }

        using (var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles"))
        {
            req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", defaultIss.Jwt);
            using var resp = await Missions.SendAsync(req);
            await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.OK);
        }
    }

    [Fact]
    [Trait("Traces", "AC-5.3,AC-5.12")]
    [Trait("max_ms", "5000")]
    public async Task NFT_SEC_04b_wrong_aud_rejected()
    {
        // Arrange
        var wrongAud = await Tokens.MintAsync(
            new SignRequest(Aud: "wrong-audience", Permissions: "FL"));

        // Act
        // Assert
        using var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles");
        req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", wrongAud.Jwt);
        using var resp = await Missions.SendAsync(req);
        await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Unauthorized);
    }

    [Fact]
    [Trait("Traces", "AC-5.8,AC-9.1")]
    [Trait("max_ms", "5000")]
    public async Task NFT_SEC_05_missing_permissions_claim_returns_403()
    {
        // Arrange — Permissions=null + PermissionsArray=null omits the claim.
        var noPermissions = await Tokens.MintAsync(new SignRequest());

        // Act
        using var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles");
        req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", noPermissions.Jwt);
        using var resp = await Missions.SendAsync(req);

        // Assert — authentication succeeds, authorization fails → 403 (NOT 401).
        await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Forbidden);
    }

    [Theory]
    [InlineData("ADMIN")]
    [InlineData("fl")]
    [InlineData("FLight")]
    [Trait("Traces", "AC-9.1,AC-9.2")]
    [Trait("max_ms", "5000")]
    public async Task NFT_SEC_06_wrong_single_permission_value_returns_403(string permissions)
    {
        // Arrange
        var token = await Tokens.MintAsync(new SignRequest(Permissions: permissions));

        // Act
        using var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles");
        req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token.Jwt);
        using var resp = await Missions.SendAsync(req);

        // Assert — RequireClaim("permissions","FL") is case-sensitive exact match.
        await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.Forbidden);
    }

    [Fact]
    [Trait("Traces", "AC-9.1,AC-9.2")]
    [Trait("max_ms", "5000")]
    public async Task NFT_SEC_06_multi_value_permissions_array_accepts_when_FL_is_present()
    {
        // Arrange — array permissions claim; ASP.NET's JWT handler flattens
        // an array claim into multiple per-value claims, so RequireClaim
        // matches if ANY value equals "FL".
        var token = await Tokens.MintAsync(
            new SignRequest(PermissionsArray: new[] { "FL", "ADMIN" }));

        // Act
        using var req = new HttpRequestMessage(HttpMethod.Get, "/vehicles");
        req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token.Jwt);
        using var resp = await Missions.SendAsync(req);

        // Assert
        await HttpAssertions.AssertStatusAsync(resp, HttpStatusCode.OK);
    }

    private static string FlipFirstSignatureChar(string jwt)
    {
        var parts = jwt.Split('.');
        if (parts.Length != 3)
            throw new InvalidOperationException(
                "expected a JWS-compact JWT with exactly 3 segments");
        var sig = parts[2].ToCharArray();
        // Toggle the first char between two base64url-valid letters so the
        // result is still parseable but signature verification fails.
        sig[0] = sig[0] == 'A' ? 'B' : 'A';
        return $"{parts[0]}.{parts[1]}.{new string(sig)}";
    }
}