using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using TLang.Common;

namespace TLang.VM
{
    public class DefaultDependencyPool : IDependencyPool
    {
        List<(TLangDependency Dependency,TVMFile File)> items = new List<(TLangDependency Dependency, TVMFile File)>();
        public bool AddDependency(TLangDependency dependency,RootEnvironment env)
        {
            string fileName = $"{dependency.Name}-{dependency.Version}.tvm";
            if(File.Exists(fileName))
            {
                using(var f = File.OpenRead(fileName))
                {
                    TVMFile file = new TVMFile(f,env);
                    items.Add((dependency,file));
                    return file.LoadDependencies(this);
                }
            }
            return false;         
        }
        private static TLangDependencyResponse DefaultDependencyCheck(TLangDependency dep)
        {
            string fileName = $"{dep.Name}-{dep.Version}.tvm";
            if(File.Exists(fileName))
            {
                return new TLangDependencyResponse(){Stream = File.OpenRead(fileName)};
            }
            return new TLangDependencyResponse(){Found = false};
        }

        public bool DependencyExists(TLangDependency dependency)
        {
            return items.Any(e=>
                e.Dependency.Equals(dependency)
            );
        }

        public IEnumerator<(TLangDependency Dependency, TVMFile File)> GetEnumerator()
        {
            return items.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return this.GetEnumerator();
        }
    }
}