using System;
using System.Collections.Generic;
using Svrnty.CQRS.Sagas.Abstractions;

namespace Svrnty.CQRS.Sagas.Builders;

/// <summary>
/// Implementation of the saga builder for defining saga steps.
/// </summary>
/// <typeparam name="TData">The saga data type.</typeparam>
public class SagaBuilder<TData> : ISagaBuilder<TData>
    where TData : class, ISagaData
{
    private readonly List<SagaStepDefinition> _steps = new();

    /// <summary>
    /// Gets the defined steps.
    /// </summary>
    public IReadOnlyList<SagaStepDefinition> Steps => _steps.AsReadOnly();

    /// <inheritdoc />
    public ISagaStepBuilder<TData> Step(string name)
    {
        return new LocalSagaStepBuilder<TData>(this, name, _steps.Count);
    }

    /// <inheritdoc />
    public ISagaRemoteStepBuilder<TData, TCommand> SendCommand<TCommand>(string name)
        where TCommand : class
    {
        return new RemoteSagaStepBuilder<TData, TCommand>(this, name, _steps.Count);
    }

    /// <inheritdoc />
    public ISagaRemoteStepBuilder<TData, TCommand, TResult> SendCommand<TCommand, TResult>(string name)
        where TCommand : class
    {
        return new RemoteSagaStepBuilderWithResult<TData, TCommand, TResult>(this, name, _steps.Count);
    }

    /// <summary>
    /// Adds a step definition to the builder.
    /// </summary>
    /// <param name="step">The step definition to add.</param>
    internal void AddStep(SagaStepDefinition step)
    {
        _steps.Add(step);
    }
}