using AVEVA.Historian.Client.Models;
using Xunit.Abstractions;

namespace AVEVA.Historian.Client.Tests;

/// <summary>
/// Live end-to-end round-trip for <see cref="HistorianSession"/>: open → write → read → status →
/// ping → dispose — ALL on ONE reused session (no re-handshake). Env-gated exactly like
/// <see cref="HandshakeReuseSpikeTests"/> (silent skip without HISTORIAN_GRPC_HOST +
/// HISTORIAN_WRITE_SANDBOX_TAG + HISTORIAN_USER). Bounded write to the sandbox tag only.
/// </summary>
public sealed class HistorianSessionRoundTripTests
{
    private readonly ITestOutputHelper _output;

    public HistorianSessionRoundTripTests(ITestOutputHelper output) => _output = output;

    [Fact]
    public async Task Session_WriteReadStatusPing_AllOnOneSession()
    {
        string? host = Environment.GetEnvironmentVariable("HISTORIAN_GRPC_HOST");
        string? sandboxTag = Environment.GetEnvironmentVariable("HISTORIAN_WRITE_SANDBOX_TAG");
        if (string.IsNullOrWhiteSpace(host) || string.IsNullOrWhiteSpace(sandboxTag)
            || string.IsNullOrEmpty(Environment.GetEnvironmentVariable("HISTORIAN_USER")))
        {
            return; // skip — env not configured
        }

        HistorianClientOptions options = BuildOptions(host);
        await using var client = new HistorianClient(options);
        await using HistorianSession session = await client.OpenSessionAsync(HistorianSessionKind.WriteEnabled, CancellationToken.None);

        // 1) write on the session
        bool wrote = await session.AddHistoricalValuesAsync(sandboxTag,
            new[] { new HistorianHistoricalValue(DateTime.UtcNow, 42.0, OpcQuality: 192) },
            CancellationToken.None);
        Assert.True(wrote);
        _output.WriteLine("1) write -> ok");

        // 2) read on the SAME session
        DateTime end = DateTime.UtcNow, start = end - TimeSpan.FromDays(7);
        var rows = new List<HistorianSample>();
        await foreach (HistorianSample s in session.ReadRawAsync(sandboxTag, start, end, 8, CancellationToken.None))
            rows.Add(s);
        _output.WriteLine($"2) session read rows={rows.Count}");
        Assert.NotEmpty(rows);

        // 3) status + ping on the SAME session
        string? version = await session.GetSystemParameterAsync("HistorianVersion", CancellationToken.None);
        Assert.False(string.IsNullOrWhiteSpace(version));
        _output.WriteLine($"3) HistorianVersion={version}");

        await session.PingAsync(CancellationToken.None); // must not throw
        _output.WriteLine("4) ping -> ok");

        _output.WriteLine("session round-trip OK (write+read+status+ping on one session)");
    }

    // verbatim copy of BuildOptions from HandshakeReuseSpikeTests
    private static HistorianClientOptions BuildOptions(string host)
    {
        string? user = Environment.GetEnvironmentVariable("HISTORIAN_USER");
        string? password = Environment.GetEnvironmentVariable("HISTORIAN_PASSWORD");
        bool explicitCreds = !string.IsNullOrEmpty(user);
        int port = int.TryParse(Environment.GetEnvironmentVariable("HISTORIAN_GRPC_PORT"), out int parsed)
            ? parsed
            : HistorianClientOptions.DefaultGrpcPort;
        bool tls = string.Equals(Environment.GetEnvironmentVariable("HISTORIAN_GRPC_TLS"), "true", StringComparison.OrdinalIgnoreCase);
        TimeSpan timeout = int.TryParse(Environment.GetEnvironmentVariable("HISTORIAN_GRPC_TIMEOUT"), out int secs) && secs > 0
            ? TimeSpan.FromSeconds(secs)
            : new HistorianClientOptions { Host = host }.RequestTimeout;

        return new HistorianClientOptions
        {
            Host = host,
            Port = port,
            Transport = HistorianTransport.RemoteGrpc,
            GrpcUseTls = tls,
            AllowUntrustedServerCertificate = tls,
            ServerDnsIdentity = Environment.GetEnvironmentVariable("HISTORIAN_GRPC_DNSID"),
            IntegratedSecurity = !explicitCreds,
            UserName = user ?? string.Empty,
            Password = password ?? string.Empty,
            RequestTimeout = timeout,
            Compression = true
        };
    }
}