using System.Text;
using SQLInsight.Licensing;
using SQLInsight.Rules.Lifecycle;

namespace SQLInsight.Updates.Tests;

public sealed class UpdateTests : IDisposable
{
    private readonly TestFeed _feed = new();

    public void Dispose() => _feed.Dispose();

    private UpdateApplier Applier(FakeServices services) => new(
        new UpdateApplierOptions
        {
            Channel = "stable",
            PrivateRoot = Path.Combine(_feed.Root, "private"),
            Components = [new UpdateComponent { Name = "Agent", Path = _feed.AgentFolder, Service = "SQLInsight Agent" }],
            HealthCheckDuration = TimeSpan.FromMilliseconds(50),
        },
        _feed.Directories, _feed.Keys, services, TimeProvider.System, _ => { });

    private string AgentFile(string name) => File.ReadAllText(Path.Combine(_feed.AgentFolder, name));

    [Fact]
    public void Manifest_with_valid_signature_is_accepted()
    {
        var token = _feed.Sign(new UpdateManifest { KeyId = TestFeed.KeyId, Channel = "stable", PublishedAt = DateTimeOffset.UtcNow, ExpiresAt = DateTimeOffset.UtcNow.AddDays(1) });

        Assert.Equal("stable", ManifestVerifier.Verify(token, _feed.Keys, "stable", DateTimeOffset.UtcNow).Channel);
    }

    [Fact]
    public void Tampered_or_foreign_manifests_are_refused()
    {
        var now = DateTimeOffset.UtcNow;
        var manifest = new UpdateManifest { KeyId = TestFeed.KeyId, Channel = "stable", PublishedAt = now, ExpiresAt = now.AddDays(1) };
        var token = _feed.Sign(manifest);
        var parts = token.Split('.');
        var forged = Convert.ToBase64String(Encoding.UTF8.GetBytes("{\"keyId\":\"test\",\"channel\":\"preview\",\"publishedAt\":\"2026-01-01T00:00:00Z\",\"expiresAt\":\"2099-01-01T00:00:00Z\"}"))
            .TrimEnd('=').Replace('+', '-').Replace('/', '_');
        using var otherKey = System.Security.Cryptography.ECDsa.Create(System.Security.Cryptography.ECCurve.NamedCurves.nistP256);

        Assert.Throws<UpdateException>(() => ManifestVerifier.Verify($"{parts[0]}.{forged}.{parts[2]}", _feed.Keys, "preview", now));
        Assert.Throws<UpdateException>(() => ManifestVerifier.Verify(SignedDocument.Sign(manifest, otherKey), _feed.Keys, "stable", now));
        Assert.Throws<UpdateException>(() => ManifestVerifier.Verify(token, new TrustedKeys([]), "stable", now));
    }

    [Fact]
    public void Wrong_channel_expired_and_older_manifests_are_refused()
    {
        var now = DateTimeOffset.UtcNow;
        var token = _feed.Sign(new UpdateManifest { KeyId = TestFeed.KeyId, Channel = "preview", PublishedAt = now.AddDays(-2), ExpiresAt = now.AddDays(-1) });
        var fresh = _feed.Sign(new UpdateManifest { KeyId = TestFeed.KeyId, Channel = "stable", PublishedAt = now.AddDays(-2), ExpiresAt = now.AddDays(1) });

        Assert.Contains("kanalen", Assert.Throws<UpdateException>(() => ManifestVerifier.Verify(token, _feed.Keys, "stable", now)).Message, StringComparison.Ordinal);
        Assert.Contains("udløb", Assert.Throws<UpdateException>(() => ManifestVerifier.Verify(token, _feed.Keys, "preview", now)).Message, StringComparison.Ordinal);
        Assert.Contains("ældre", Assert.Throws<UpdateException>(() => ManifestVerifier.Verify(fresh, _feed.Keys, "stable", now, notBefore: now.AddDays(-1))).Message, StringComparison.Ordinal);
    }

    [Theory]
    [InlineData("../secret.zip")]
    [InlineData("/etc/passwd")]
    [InlineData("releases\\x.zip")]
    [InlineData("C:/x.zip")]
    [InlineData("releases//x.zip")]
    public void Paths_outside_the_feed_are_refused(string path)
    {
        var now = DateTimeOffset.UtcNow;
        var token = _feed.Sign(new UpdateManifest
        {
            KeyId = TestFeed.KeyId, Channel = "stable", PublishedAt = now, ExpiresAt = now.AddDays(1),
            RulePack = new RulePackRef("2027.1.1", new FileRef(path, "00", 1)),
        });

        Assert.Throws<UpdateException>(() => ManifestVerifier.Verify(token, _feed.Keys, "stable", now));
    }

    [Theory]
    [InlineData("1.2.0", "1.10.0")]
    [InlineData("1.3.0-preview.2", "1.3.0")]
    [InlineData("1.3.0-preview.2", "1.3.0-preview.10")]
    [InlineData("1.3.0-beta", "1.3.0-rc")]
    [InlineData("0.9.9", "1.0.0-preview.1")]
    public void Versions_are_ordered_like_semver(string lower, string higher)
    {
        Assert.True(AppVersion.Parse(lower) < AppVersion.Parse(higher));
        Assert.True(AppVersion.Parse(higher) > AppVersion.Parse(lower));
    }

    [Fact]
    public void Build_metadata_and_short_versions_compare_equal()
    {
        Assert.Equal(AppVersion.Parse("1.2"), AppVersion.Parse("1.2.0+4f1c2a9"));
        Assert.Equal("1.2.0", AppVersion.Parse("1.2+abc").ToString());
    }

    [Fact]
    public async Task Newer_rule_pack_is_downloaded_stored_and_reloaded()
    {
        var embedded = RulePack.Embedded();
        var newer = new Version(embedded.Version.Major + 1, 1, 1);
        _feed.Publish(rulePack: _feed.RulePack(newer));
        var checker = _feed.Checker();

        var manifest = await checker.FetchAsync(CancellationToken.None);
        var pack = await checker.UpdateRulePackAsync(manifest, embedded, CancellationToken.None);
        var again = await checker.UpdateRulePackAsync(manifest, pack!, CancellationToken.None);
        var reloaded = new RulePackStore(_feed.Directories).Load(_feed.Keys);

        Assert.Equal(newer, pack!.Version);
        Assert.Null(again);
        Assert.Equal(newer, reloaded!.Version);
        Assert.Contains("stable", reloaded.Source, StringComparison.Ordinal);
        Assert.NotNull(reloaded.Builds.Latest(Core.Instances.SqlServerRelease.SqlServer2022));
    }

    [Fact]
    public async Task Rule_pack_changed_on_disk_is_not_loaded()
    {
        var newer = new Version(RulePack.Embedded().Version.Major + 1, 1, 1);
        _feed.Publish(rulePack: _feed.RulePack(newer));
        var checker = _feed.Checker();
        await checker.UpdateRulePackAsync(await checker.FetchAsync(CancellationToken.None), RulePack.Embedded(), CancellationToken.None);

        var file = Path.Combine(_feed.Directories.RulePack, "pack.json");
        File.WriteAllText(file, File.ReadAllText(file).Replace("CU", "XX", StringComparison.Ordinal));

        Assert.Throws<UpdateException>(() => new RulePackStore(_feed.Directories).Load(_feed.Keys));
    }

    [Fact]
    public async Task Rule_pack_that_does_not_match_the_manifest_hash_is_refused()
    {
        var reference = _feed.RulePack(new Version(2099, 1, 1));
        File.AppendAllText(Path.Combine(_feed.FeedDirectory, reference.File.Path), " ");
        _feed.Publish(rulePack: reference);
        var checker = _feed.Checker();

        var manifest = await checker.FetchAsync(CancellationToken.None);

        await Assert.ThrowsAsync<UpdateException>(() => checker.UpdateRulePackAsync(manifest, RulePack.Embedded(), CancellationToken.None));
        Assert.Null(new RulePackStore(_feed.Directories).Load(_feed.Keys));
    }

    [Fact]
    public async Task Older_manifest_is_refused_after_a_newer_one_was_seen()
    {
        var now = DateTimeOffset.UtcNow;
        _feed.Publish(publishedAt: now);
        await _feed.Checker().FetchAsync(CancellationToken.None);
        _feed.Publish(publishedAt: now.AddHours(-1));

        await Assert.ThrowsAsync<UpdateException>(() => _feed.Checker().FetchAsync(CancellationToken.None));
    }

    [Fact]
    public void Plain_http_feed_is_refused()
    {
        using var http = new HttpClient();

        Assert.Throws<UpdateException>(() => new UpdateFeed("http://updates.example.com/", http));
    }

    [Fact]
    public async Task Update_is_staged_applied_and_keeps_the_configuration()
    {
        _feed.Install();
        _feed.Publish(release: _feed.Release("1.1.0"));
        var checker = _feed.Checker();
        var services = new FakeServices(Path.Combine(_feed.AgentFolder, "SQLInsight.Agent.dll"));

        Assert.True(await checker.StageAsync(await checker.FetchAsync(CancellationToken.None), AppVersion.Parse("1.0.0"), CancellationToken.None));
        var result = await Applier(services).ApplyAsync(AppVersion.Parse("1.0.0"), CancellationToken.None);

        Assert.Equal(UpdateOutcome.Applied, result.Outcome);
        Assert.Equal("v2", AgentFile("SQLInsight.Agent.dll"));
        Assert.Equal("new", AgentFile(Path.Combine("runtimes", "new.dll")));
        Assert.Contains("customer", AgentFile("appsettings.json"), StringComparison.Ordinal);
        Assert.Equal(["stop SQLInsight Agent", "start SQLInsight Agent"], services.Calls);
        Assert.False(Directory.Exists(_feed.Directories.Pending));
        Assert.Equal(UpdateOutcome.Applied, _feed.Directories.LastResult()!.Outcome);
    }

    [Fact]
    public async Task Update_that_does_not_start_is_rolled_back()
    {
        _feed.Install();
        _feed.Publish(release: _feed.Release("1.1.0", program: "broken"));
        var checker = _feed.Checker();
        var services = new FakeServices(Path.Combine(_feed.AgentFolder, "SQLInsight.Agent.dll"));
        await checker.StageAsync(await checker.FetchAsync(CancellationToken.None), AppVersion.Parse("1.0.0"), CancellationToken.None);

        var result = await Applier(services).ApplyAsync(AppVersion.Parse("1.0.0"), CancellationToken.None);

        Assert.Equal(UpdateOutcome.RolledBack, result.Outcome);
        Assert.Equal("v1", AgentFile("SQLInsight.Agent.dll"));
        Assert.Contains("customer", AgentFile("appsettings.json"), StringComparison.Ordinal);
        Assert.Equal(["stop SQLInsight Agent", "start SQLInsight Agent", "stop SQLInsight Agent", "start SQLInsight Agent"], services.Calls);
        Assert.Equal("v1", File.ReadAllText(Path.Combine(_feed.Root, "private", "backup", "Agent", "SQLInsight.Agent.dll")));
    }

    [Fact]
    public async Task Applier_refuses_a_package_changed_after_staging()
    {
        _feed.Install();
        _feed.Publish(release: _feed.Release("1.1.0"));
        var checker = _feed.Checker();
        await checker.StageAsync(await checker.FetchAsync(CancellationToken.None), AppVersion.Parse("1.0.0"), CancellationToken.None);
        File.AppendAllText(Path.Combine(_feed.Directories.Pending, "package.zip"), "x");
        var services = new FakeServices(Path.Combine(_feed.AgentFolder, "SQLInsight.Agent.dll"));

        var result = await Applier(services).ApplyAsync(AppVersion.Parse("1.0.0"), CancellationToken.None);

        Assert.Equal(UpdateOutcome.Failed, result.Outcome);
        Assert.Empty(services.Calls);
        Assert.Equal("v1", AgentFile("SQLInsight.Agent.dll"));
    }

    [Fact]
    public async Task Applier_refuses_a_manifest_it_cannot_verify()
    {
        _feed.Install();
        _feed.Publish(release: _feed.Release("1.1.0"));
        var checker = _feed.Checker();
        await checker.StageAsync(await checker.FetchAsync(CancellationToken.None), AppVersion.Parse("1.0.0"), CancellationToken.None);
        var services = new FakeServices(Path.Combine(_feed.AgentFolder, "SQLInsight.Agent.dll"));
        var applier = new UpdateApplier(
            new UpdateApplierOptions { Channel = "stable", PrivateRoot = Path.Combine(_feed.Root, "private"), Components = [new UpdateComponent { Name = "Agent", Path = _feed.AgentFolder, Service = "a" }] },
            _feed.Directories, new TrustedKeys([]), services, TimeProvider.System, _ => { });

        var result = await applier.ApplyAsync(AppVersion.Parse("1.0.0"), CancellationToken.None);

        Assert.Equal(UpdateOutcome.Failed, result.Outcome);
        Assert.Empty(services.Calls);
    }

    [Fact]
    public async Task Nothing_is_staged_or_applied_when_not_newer()
    {
        _feed.Install();
        _feed.Publish(release: _feed.Release("1.0.0"));
        var checker = _feed.Checker();

        Assert.False(await checker.StageAsync(await checker.FetchAsync(CancellationToken.None), AppVersion.Parse("1.0.0"), CancellationToken.None));
        Assert.Equal(UpdateOutcome.NothingToDo, (await Applier(new FakeServices(Path.Combine(_feed.AgentFolder, "SQLInsight.Agent.dll"))).ApplyAsync(AppVersion.Parse("1.0.0"), CancellationToken.None)).Outcome);
    }

    [Fact]
    public async Task Release_without_a_package_for_this_platform_is_reported()
    {
        _feed.Publish(release: _feed.Release("1.1.0", platform: "plan9-mips"));
        var checker = _feed.Checker();

        var error = await Assert.ThrowsAsync<UpdateException>(async () => await checker.StageAsync(await checker.FetchAsync(CancellationToken.None), AppVersion.Parse("1.0.0"), CancellationToken.None));

        Assert.Contains(Platform.Current, error.Message, StringComparison.Ordinal);
    }
}