using System.Collections.Generic;
using System.Linq;
using GammaJul.ForTea.Core.Psi.Resolve.Assemblies;
using GammaJul.ForTea.Core.Psi.Resolve.Assemblies.Impl;
using GammaJul.ForTea.Core.Psi.Resolve.Macros.Impl;
using JetBrains.Annotations;
using JetBrains.Application.Parts;
using JetBrains.Lifetimes;
using JetBrains.ProjectModel;
using JetBrains.ProjectModel.Model2.Assemblies.Interfaces;
using JetBrains.Util;

namespace JetBrains.ForTea.RiderPlugin.Psi.Resolve.Assemblies.Impl
{
  /// <summary>
  /// This resolver is capable of resolving everything its parent can,
  /// and it is additionally capable of resolving EnvDTE.
  /// </summary>
  [SolutionComponent(Instantiation.DemandAnyThreadSafe)]
  public sealed class T4DteAwareAssemblyReferenceResolver : T4AssemblyReferenceResolver
  {
    public T4DteAwareAssemblyReferenceResolver(
      [NotNull] IModuleReferenceResolveManager resolveManager,
      [NotNull] IT4LightWeightAssemblyReferenceResolver preprocessor
    ) : base(
      resolveManager,
      preprocessor
    )
    {
    }

    public override VirtualFileSystemPath Resolve(T4ResolvedPath pathWithMacros) =>
      base.Resolve(pathWithMacros) ?? ResolveAsDte(pathWithMacros.ResolvedPath);

    [CanBeNull]
    private static VirtualFileSystemPath ResolveAsDte([NotNull] string assemblyName) =>
      NameToEnvDteAssemblyMap.TryGetValue(assemblyName);

    private static IDictionary<string, VirtualFileSystemPath> NameToEnvDteAssemblyMap { get; } =
      FindEnvDteAssemblies();

    private static Dictionary<string, VirtualFileSystemPath> FindEnvDteAssemblies()
    {
      var lifetimeDirectory =
        typeof(Lifetime).Assembly.GetPath().ToVirtualFileSystemPath()
          .Parent;
      var envDteAssembliesInLifetimeDirectory = FindEnvDteAssemblies(lifetimeDirectory);
      if (!envDteAssembliesInLifetimeDirectory.IsEmpty()) return envDteAssembliesInLifetimeDirectory;
      var envDteAssembliesInLifetimeDirectoryParent = FindEnvDteAssemblies(lifetimeDirectory.Parent);
      return envDteAssembliesInLifetimeDirectoryParent;
    }

    private static Dictionary<string, VirtualFileSystemPath> FindEnvDteAssemblies(
      VirtualFileSystemPath directory
    ) => directory
      .GetChildren("*EnvDTE*.dll")
      .Select(child => child.GetAbsolutePath())
      .ToDictionary(assembly => assembly.NameWithoutExtension);
  }
}