// Copyright (c) Microsoft. All rights reserved.

using System.Diagnostics;
using System.Threading.Tasks;
using Microsoft.Shared.Diagnostics;

namespace Microsoft.Agents.Workflows.Execution;

internal class InputEdgeRunner(IRunnerContext runContext, string sinkId)
    : EdgeRunner<string>(runContext, sinkId)
{
    public IWorkflowContext WorkflowContext { get; } = runContext.Bind(sinkId);

    public static InputEdgeRunner ForPort(IRunnerContext runContext, InputPort port)
    {
        Throw.IfNull(port);

        // The port is an input port, so we can use the port's ID as the sink ID.
        return new InputEdgeRunner(runContext, port.Id);
    }

    private async ValueTask<Executor> FindExecutorAsync()
    {
        return await this.RunContext.EnsureExecutorAsync(this.EdgeData).ConfigureAwait(false);
    }

    public async ValueTask<object?> ChaseAsync(MessageEnvelope envelope)
    {
        Executor target = await this.FindExecutorAsync().ConfigureAwait(false);
        if (target.CanHandle(envelope.MessageType))
        {
            return await target.ExecuteAsync(envelope.Message, envelope.MessageType, this.WorkflowContext)
                               .ConfigureAwait(false);
        }

        // TODO: Throw instead? / Log
        Debug.WriteLine($"Executor {target.Id} cannot handle message of type {envelope.MessageType.FullName}. Dropping.");

        return null;
    }
}