using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using System.Reflection;
using System.Runtime.CompilerServices;
using Foodsoft.Alpm;

// ReSharper disable once UnusedType.Global
namespace Samples
{
    [Example("installed")]
    internal class Installed : IExample
    {
        public int Run(string[] args)
        {
            using var h = new Handle("/", "/var/lib/pacman");
            using var db = h.LocalDB;

            foreach (var pkg in db.PackageCache)
                using (pkg)
                {
                    Console.WriteLine("{0} {1}", pkg.Name, pkg.Version);
                }

            return 0;
        }
    }

    [Example("search")]
    internal class Search : IExample
    {
        public int Run(string[] args)
        {
            using var h = new Handle("/", "/var/lib/pacman");
            using var db = h.RegisterSyncDB("core");
            db.Servers = new[]{"http://www.google.com"};
            db.Update(true);

            foreach (var pkg in db.PackageCache)
                using (pkg)
                {
                    Console.WriteLine("{0} {1} {2}", pkg.Name, pkg.Version, pkg.Description);
                }

            return 0;
        }
    }
}

namespace Samples
{
    internal static class Program
    {
        private static int Main(string[] args)
        {
            var examples = (from t in Assembly.GetExecutingAssembly().GetTypes()
                let attribute = (Example?) t.GetCustomAttribute(typeof(Example))
                where attribute != null
                select new {Name = attribute.Name, Type = t}).ToImmutableDictionary((e) => e.Name);

            if (args.Length < 1)
            {
                Console.Error.WriteLine("Sample");
                foreach (var example in examples.Values)
                {
                    Console.Error.WriteLine("{0}", example.Name);
                }

                return 1;
            }

            int ret;
            try
            {
                ret = ((IExample) Activator.CreateInstance(examples[args[0]].Type)!).Run(args);
            }
            catch (AlpmException e)
            {
                Console.Error.WriteLine("{0}", e.Message);
                return 1;
            }

            return ret;
        }
    }

    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct, AllowMultiple = false)]
    public class Example : Attribute
    {
        public string Name { get; }

        public Example(string name)
        {
            Name = name;
        }
    }

    public interface IExample
    {
        public int Run(string[] args);
    }
}