using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using System.Linq;
using System.Linq.Expressions;
using JetBrains.TeamCity.NuGet.ExtendedCommands.Data;
using NuGet;

namespace JetBrains.TeamCity.NuGet.ExtendedCommands
{
  public abstract class ListCommandBase : CommandBase
  {
    [Import]
    public IPackageRepositoryFactory RepositoryFactoryTC { get; set; }

    /// <exception cref="InvalidFeedUrlException">may be thrown on error</exception>    
    protected void GetAllPackages(INuGetSource feed,
                                  PackageFetchOption fetchOption,
                                  IEnumerable<string> ids,
                                  Action<IPackage> processor)
    {
      System.Console.Out.WriteLine("Checking packages on source: {0}", feed);

      ValidateSourceUrl(feed);


      var repo = RepositoryFactoryTC.CreateRepository(feed.Source);

      var param = Expression.Parameter(typeof(IPackage));
      Expression filter = QueryBuilder.GenerateQuery(fetchOption, ids, param);

      var filtered = repo.GetPackages().Where(Expression.Lambda<Func<IPackage, bool>>(filter, param));
      foreach (var package in filtered)
      {
        processor(package);
      }
    }

    private static void ValidateSourceUrl(INuGetSource feed)
    {
      string source = feed.Source;
      Uri uri;
      try
      {
        uri = new Uri(source);
      }
      catch (Exception e)
      {
        throw new InvalidFeedUrlException(source, e.Message);
      }

      if (uri.IsFile && !Directory.Exists(uri.LocalPath))
      {
        throw new InvalidFeedUrlException(source, "Local path does not exist: " + uri.LocalPath);
      }
    }
  }
}