using System;
using System.Collections.Generic;
using System.Linq;
using NuGet;
using Orchard.Environment.Extensions;


namespace Orchard.Packaging.Services {
    /// <summary>
    /// This repository implementation informs about what packages are already installed.
    /// </summary>
    public class ExtensionReferenceRepository : PackageRepositoryBase {
        private readonly IExtensionManager _extensionManager;
        
        public ExtensionReferenceRepository(IProjectSystem project, IPackageRepository sourceRepository, IExtensionManager extensionManager) {
            if (project == null) {
                throw new ArgumentNullException("project");
            }
            if (sourceRepository == null) {
                throw new ArgumentNullException("sourceRepository");
            }
            if (extensionManager == null) {
                throw new ArgumentNullException("extensionManager");
            }
            Project = project;
            SourceRepository = sourceRepository;
            _extensionManager = extensionManager;
        }

        private IProjectSystem Project {
            get;
            set;
        }

        private IPackageRepository SourceRepository {
            get;
            set;
        }

        public override IQueryable<IPackage> GetPackages() {
            IEnumerable<IPackage> packages;

            packages = from extension in _extensionManager.AvailableExtensions()
                       let id = "Orchard." + extension.ExtensionType + "." + extension.Id
                       let version = Version.Parse(extension.Version)
                       let package = SourceRepository.FindPackage(id, version)
                       where package != null
                       select package;

            return packages.AsQueryable();
        }

        public override void AddPackage(IPackage package) {
        }

        public override void RemovePackage(IPackage package) {
        }
    }
}