// <copyright file="ITestEvidenceService.cs" company="StellaOps">
// Copyright (c) StellaOps. Licensed under BUSL-1.1.
// </copyright>
// Sprint: SPRINT_20260105_002_002_TEST_trace_replay_evidence
// Task: TREP-013, TREP-014

using System.Collections.Immutable;

namespace StellaOps.Testing.Evidence;

/// <summary>
/// Links test executions to EvidenceLocker for audit-grade storage.
/// </summary>
public interface ITestEvidenceService
{
    /// <summary>
    /// Begin a test evidence session.
    /// </summary>
    /// <param name="metadata">Session metadata.</param>
    /// <param name="ct">Cancellation token.</param>
    /// <returns>The created session.</returns>
    Task<TestEvidenceSession> BeginSessionAsync(
        TestSessionMetadata metadata,
        CancellationToken ct = default);

    /// <summary>
    /// Record a test result within a session.
    /// </summary>
    /// <param name="session">The active session.</param>
    /// <param name="result">The test result to record.</param>
    /// <param name="ct">Cancellation token.</param>
    Task RecordTestResultAsync(
        TestEvidenceSession session,
        TestResultRecord result,
        CancellationToken ct = default);

    /// <summary>
    /// Finalize session and store in EvidenceLocker.
    /// </summary>
    /// <param name="session">The session to finalize.</param>
    /// <param name="ct">Cancellation token.</param>
    /// <returns>The evidence bundle.</returns>
    Task<TestEvidenceBundle> FinalizeSessionAsync(
        TestEvidenceSession session,
        CancellationToken ct = default);

    /// <summary>
    /// Retrieve test evidence bundle for audit.
    /// </summary>
    /// <param name="bundleId">The bundle identifier.</param>
    /// <param name="ct">Cancellation token.</param>
    /// <returns>The evidence bundle, or null if not found.</returns>
    Task<TestEvidenceBundle?> GetBundleAsync(
        string bundleId,
        CancellationToken ct = default);
}

/// <summary>
/// Metadata about a test session.
/// </summary>
/// <param name="SessionId">Unique session identifier.</param>
/// <param name="TestSuiteId">Identifier for the test suite.</param>
/// <param name="GitCommit">Git commit hash.</param>
/// <param name="GitBranch">Git branch name.</param>
/// <param name="RunnerEnvironment">Description of the runner environment.</param>
/// <param name="StartedAt">When the session started.</param>
/// <param name="Labels">Additional labels.</param>
public sealed record TestSessionMetadata(
    string SessionId,
    string TestSuiteId,
    string GitCommit,
    string GitBranch,
    string RunnerEnvironment,
    DateTimeOffset StartedAt,
    ImmutableDictionary<string, string> Labels);

/// <summary>
/// A recorded test result.
/// </summary>
/// <param name="TestId">Unique test identifier.</param>
/// <param name="TestName">Test method name.</param>
/// <param name="TestClass">Test class name.</param>
/// <param name="Outcome">Test outcome.</param>
/// <param name="Duration">Test duration.</param>
/// <param name="FailureMessage">Failure message, if failed.</param>
/// <param name="StackTrace">Stack trace, if failed.</param>
/// <param name="Categories">Test categories.</param>
/// <param name="BlastRadiusAnnotations">Blast radius annotations.</param>
/// <param name="Attachments">Attached file references.</param>
public sealed record TestResultRecord(
    string TestId,
    string TestName,
    string TestClass,
    TestOutcome Outcome,
    TimeSpan Duration,
    string? FailureMessage,
    string? StackTrace,
    ImmutableArray<string> Categories,
    ImmutableArray<string> BlastRadiusAnnotations,
    ImmutableDictionary<string, string> Attachments);

/// <summary>
/// Test outcome.
/// </summary>
public enum TestOutcome
{
    Passed,
    Failed,
    Skipped,
    Inconclusive
}

/// <summary>
/// A finalized test evidence bundle.
/// </summary>
/// <param name="BundleId">Unique bundle identifier.</param>
/// <param name="MerkleRoot">Merkle root for integrity verification.</param>
/// <param name="Metadata">Session metadata.</param>
/// <param name="Summary">Test summary.</param>
/// <param name="Results">All test results.</param>
/// <param name="FinalizedAt">When the bundle was finalized.</param>
/// <param name="EvidenceLockerRef">Reference to EvidenceLocker storage.</param>
public sealed record TestEvidenceBundle(
    string BundleId,
    string MerkleRoot,
    TestSessionMetadata Metadata,
    TestSummary Summary,
    ImmutableArray<TestResultRecord> Results,
    DateTimeOffset FinalizedAt,
    string EvidenceLockerRef);

/// <summary>
/// Summary of test results.
/// </summary>
/// <param name="TotalTests">Total number of tests.</param>
/// <param name="Passed">Number of passed tests.</param>
/// <param name="Failed">Number of failed tests.</param>
/// <param name="Skipped">Number of skipped tests.</param>
/// <param name="TotalDuration">Total test duration.</param>
/// <param name="ResultsByCategory">Results grouped by category.</param>
/// <param name="ResultsByBlastRadius">Results grouped by blast radius.</param>
public sealed record TestSummary(
    int TotalTests,
    int Passed,
    int Failed,
    int Skipped,
    TimeSpan TotalDuration,
    ImmutableDictionary<string, int> ResultsByCategory,
    ImmutableDictionary<string, int> ResultsByBlastRadius);

/// <summary>
/// An active test evidence session.
/// </summary>
public sealed class TestEvidenceSession
{
    private readonly List<TestResultRecord> _results = [];
    private readonly object _lock = new();

    /// <summary>
    /// Gets the session metadata.
    /// </summary>
    public TestSessionMetadata Metadata { get; }

    /// <summary>
    /// Gets whether the session is finalized.
    /// </summary>
    public bool IsFinalized { get; private set; }

    /// <summary>
    /// Initializes a new instance of the <see cref="TestEvidenceSession"/> class.
    /// </summary>
    /// <param name="metadata">Session metadata.</param>
    public TestEvidenceSession(TestSessionMetadata metadata)
    {
        Metadata = metadata;
    }

    /// <summary>
    /// Add a test result to the session.
    /// </summary>
    /// <param name="result">The result to add.</param>
    public void AddResult(TestResultRecord result)
    {
        if (IsFinalized)
        {
            throw new InvalidOperationException("Cannot add results to a finalized session.");
        }

        lock (_lock)
        {
            _results.Add(result);
        }
    }

    /// <summary>
    /// Get all results recorded in this session.
    /// </summary>
    /// <returns>Immutable array of results.</returns>
    public ImmutableArray<TestResultRecord> GetResults()
    {
        lock (_lock)
        {
            return [.. _results];
        }
    }

    /// <summary>
    /// Mark the session as finalized.
    /// </summary>
    internal void MarkAsFinalized()
    {
        IsFinalized = true;
    }
}