using Microsoft.Extensions.DependencyInjection;
using System;
using System.Collections.Generic;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks;

namespace Pole.Sagas.Core
{
    public class ActivityWapper
    {
        public string Id { get; set; }
        public Type ActivityType { get; set; }
        public Type ActivityDataType { get; set; }
        public object DataObj { get; set; }
        public int Order { get; set; }
        public ActivityStatus ActivityState { get; set; }
        public IServiceProvider ServiceProvider { get; set; }
        public DateTime TimeOut { get; set; }
        public Task<ActivityExecuteResult> InvokeExecute()
        {
            var activityObjParams = Expression.Parameter(typeof(object), "activity");
            var activityParams = Expression.Convert(activityObjParams, ActivityType);
            var dataObjParams = Expression.Parameter(typeof(object), "data");
            var dataParams = Expression.Convert(dataObjParams, ActivityDataType);
            var method = ActivityType.GetMethod("Execute", new Type[] { ActivityDataType });
            var body = Expression.Call(activityObjParams, method, activityObjParams, dataParams);
            var func = Expression.Lambda<Func<object, object, Task<ActivityExecuteResult>>>(body, activityObjParams, dataObjParams).Compile();

            using (var scope = ServiceProvider.CreateScope())
            {
                var activity = scope.ServiceProvider.GetRequiredService(ActivityType);
                return func(activity, DataObj);
            }
        }
        public Task InvokeCompensate()
        {
            var activityObjParams = Expression.Parameter(typeof(object), "activity");
            var activityParams = Expression.Convert(activityObjParams, ActivityType);
            var dataObjParams = Expression.Parameter(typeof(object), "data");
            var dataParams = Expression.Convert(dataObjParams, ActivityDataType);
            var method = ActivityType.GetMethod("Compensate", new Type[] { ActivityDataType });
            var body = Expression.Call(activityObjParams, method, activityObjParams, dataParams);
            var func = Expression.Lambda<Func<object, object, Task>>(body, activityObjParams, dataObjParams).Compile();
            using (var scope = ServiceProvider.CreateScope())
            {
                var activity = scope.ServiceProvider.GetRequiredService(ActivityType);
                return func(activity, DataObj);
            }
        }
    }
}