using System;
using Microsoft.Extensions.DependencyInjection;

namespace StellaOps.Concelier.Core.Jobs;

public sealed class JobSchedulerBuilder
{
    private readonly IServiceCollection _services;

    public JobSchedulerBuilder(IServiceCollection services)
    {
        _services = services ?? throw new ArgumentNullException(nameof(services));
    }

    public JobSchedulerBuilder AddJob<TJob>(
        string kind,
        string? cronExpression = null,
        TimeSpan? timeout = null,
        TimeSpan? leaseDuration = null,
        bool enabled = true)
        where TJob : class, IJob
    {
        ArgumentException.ThrowIfNullOrEmpty(kind);

        _services.AddTransient<TJob>();
        _services.Configure<JobSchedulerOptions>(options =>
        {
            if (options.Definitions.ContainsKey(kind))
            {
                throw new InvalidOperationException($"Job '{kind}' is already registered.");
            }

            var resolvedTimeout = timeout ?? options.DefaultTimeout;
            var resolvedLease = leaseDuration ?? options.DefaultLeaseDuration;

            options.Definitions.Add(kind, new JobDefinition(
                kind,
                typeof(TJob),
                resolvedTimeout,
                resolvedLease,
                cronExpression,
                enabled));
        });

        return this;
    }
}