using System.Linq.Expressions;
using System.Reflection;
using Dlhis.ScheduledTask.Attributes;
using Hangfire;
using Hangfire.Common;
using Kurisu.AspNetCore.Startup;
using Kurisu.AspNetCore.Utils.Extensions;

namespace Dlhis.ScheduledTask.Packs;

public class JobPack : BaseAppPack
{
    public override int Order => 999;

    public override void Invoke(IServiceProvider serviceProvider)
    {
        var logger = serviceProvider.GetService<ILogger<JobPack>>();

        var jobs = Assembly.GetEntryAssembly().GetTypes()
            .Where(x => x.IsAssignableTo(typeof(BaseJob)) && x != typeof(BaseJob))
            .Where(x => x.IsDefined(typeof(RecurringJobAttribute)))
            .ToList();

        var setJob = typeof(Job).GetMethod(nameof(Job.FromExpression), BindingFlags.NonPublic | BindingFlags.Static, new[] { typeof(LambdaExpression), typeof(Type), typeof(string) });
        var m = (Lazy<RecurringJobManager>)typeof(RecurringJob).GetField("Instance", BindingFlags.NonPublic | BindingFlags.Static).GetValue(null);

        (jobs.Select(job => job.GetCustomAttribute<RecurringJobAttribute>().UniqueJobKey).Distinct().Count() != jobs.Count).ThrowIfTrue("任务key重复");

        logger.LogDebug("一共获取{count}个调度任务", jobs.Count);

        foreach (var job in jobs)
        {
            var recurringSetting = job.GetCustomAttribute<RecurringJobAttribute>()!;
            recurringSetting.Cron.IsEmpty().ThrowIfTrue(job.Name + "尚未定义Cron");

            var parameterExpression = Expression.Parameter(job);
            var todo = job.GetMethod(nameof(BaseJob.TodoAsync));
            var todoExp = Expression.Call(parameterExpression, todo);

            var nJob = (Job)setJob.Invoke(null, new object[] { Expression.Lambda(todoExp), job, recurringSetting.Queue });
            m.Value.AddOrUpdate(recurringSetting.UniqueJobKey, nJob, recurringSetting.Cron, new RecurringJobOptions
            {
                TimeZone = TimeZoneInfo.Local
            });
        }
    }
}