using System;
using System.Linq;
using System.Threading.Tasks;
using Elsa.Activities.Console.Extensions;
using Elsa.Activities.Primitives;
using Elsa.Activities.UserTask.Extensions;
using Elsa.Extensions;
using Elsa.Models;
using Elsa.Persistence.Memory;
using Elsa.Runtime;
using Elsa.Services;
using Elsa.Services.Extensions;
using Microsoft.Extensions.DependencyInjection;

namespace Sample12
{
    /// <summary>
    /// Demonstrates workflow correlation.
    /// </summary>
    public class Program
    {
        public static async Task Main(string[] args)
        {
            var services = BuildServices();
            var registry = services.GetService<IWorkflowRegistry>();
            var workflowDefinition = registry.RegisterWorkflow<UserTaskWorkflow>();
            var invoker = services.GetRequiredService<IWorkflowInvoker>();

            // Invoke the workflow.
            var executionContext = await invoker.InvokeAsync(workflowDefinition);

            do
            {
                // Workflow is now halted on the user task activity. Ask user for input:
                Console.WriteLine("What action will you take? Choose one of: Accept, Reject, Needs Work");
                var userAction = Console.ReadLine();

                // Resume the workflow with the received stimulus.
                var blockingActivities = executionContext.Workflow.BlockingActivities.Select(x => x.Id);
                executionContext = await invoker.ResumeAsync(executionContext.Workflow.ToInstance(), new Variables { ["UserAction"] = userAction }, blockingActivities);
                
            } while (executionContext.Workflow.IsHalted());
        }

        private static IServiceProvider BuildServices()
        {
            return new ServiceCollection()
                .AddWorkflows()
                .AddConsoleActivities()
                .AddUserTaskActivities()
                .AddMemoryWorkflowDefinitionStore()
                .AddMemoryWorkflowInstanceStore()
                .BuildServiceProvider();
        }
    }
}