// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System.Collections.Immutable;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.EditAndContinue;
using Microsoft.CodeAnalysis.Host;
using Microsoft.VisualStudio.Debugger.Contracts.HotReload;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.ExternalAccess.Debugger;
 
internal sealed class GlassTestsHotReloadService
{
    private static readonly ActiveStatementSpanProvider s_noActiveStatementSpanProvider =
       (_, _, _) => ValueTaskFactory.FromResult(ImmutableArray<ActiveStatementSpan>.Empty);
 
    private readonly IManagedHotReloadService _debuggerService;
 
    private readonly IEditAndContinueService _encService;
    private DebuggingSessionId _sessionId;
 
    public GlassTestsHotReloadService(HostWorkspaceServices services, IManagedHotReloadService debuggerService)
    {
        _encService = services.GetRequiredService<IEditAndContinueWorkspaceService>().Service;
        _debuggerService = debuggerService;
    }
 
    public async Task StartSessionAsync(Solution solution, CancellationToken cancellationToken)
    {
        var newSessionId = await _encService.StartDebuggingSessionAsync(
            solution,
            new ManagedHotReloadServiceBridge(_debuggerService),
            NullPdbMatchingSourceTextProvider.Instance,
            captureMatchingDocuments: [],
            captureAllMatchingDocuments: true,
            reportDiagnostics: false,
            cancellationToken).ConfigureAwait(false);
 
        Contract.ThrowIfFalse(_sessionId == default, "Session already started");
        _sessionId = newSessionId;
    }
 
    private DebuggingSessionId GetSessionId()
    {
        var sessionId = _sessionId;
        Contract.ThrowIfFalse(sessionId != default, "Session has not started");
 
        return sessionId;
    }
 
    public void EnterBreakState()
    {
        _encService.BreakStateOrCapabilitiesChanged(GetSessionId(), inBreakState: true);
    }
 
    public void ExitBreakState()
    {
        _encService.BreakStateOrCapabilitiesChanged(GetSessionId(), inBreakState: false);
    }
 
    public void OnCapabilitiesChanged()
    {
        _encService.BreakStateOrCapabilitiesChanged(GetSessionId(), inBreakState: null);
    }
 
    public void CommitSolutionUpdate()
    {
        _encService.CommitSolutionUpdate(GetSessionId());
    }
 
    public void DiscardSolutionUpdate()
    {
        _encService.DiscardSolutionUpdate(GetSessionId());
    }
 
    public void EndDebuggingSession()
    {
        _encService.EndDebuggingSession(GetSessionId());
        _sessionId = default;
    }
 
    public async ValueTask<ManagedHotReloadUpdates> GetUpdatesAsync(Solution solution, CancellationToken cancellationToken)
    {
        var results = (await _encService.EmitSolutionUpdateAsync(GetSessionId(), solution, runningProjects: [], s_noActiveStatementSpanProvider, cancellationToken).ConfigureAwait(false)).Dehydrate();
        return new ManagedHotReloadUpdates(results.ModuleUpdates.Updates.FromContract(), results.GetAllDiagnostics().FromContract(), [], []);
    }
}