using System;
using System.Collections.Generic;

using JetBrains.ProjectModel;
using JetBrains.ReSharper.Psi;
using JetBrains.ReSharper.Psi.Caches;
using JetBrains.ReSharper.Psi.Tree;
using JetBrains.ReSharper.UnitTestExplorer;
using JetBrains.Shell;
using JetBrains.Util;

namespace MbUnit.ReSharperRunner.Elements
{
    public abstract class MbUnitTestElementBase : UnitTestElement, IEquatable<MbUnitTestElementBase>
    {
        private readonly ProjectModelElementEnvoy currentProject;
        private readonly string currentTypeName;

        public MbUnitTestElementBase(IUnitTestProvider provider, UnitTestElement parent, IProjectModelElement project,
                                     string typeName)
            : base(provider, parent)
        {
            if ((project == null) && !Shell.Instance.IsTestShell)
            {
                throw new ArgumentNullException("project");
            }
            if (typeName == null)
            {
                throw new ArgumentNullException("typeName");
            }
            if (project != null)
            {
                currentProject = new ProjectModelElementEnvoy(project);
            }
            currentTypeName = typeName;
        }

        #region IEquatable<MbUnitElementBase> Members

        public bool Equals(MbUnitTestElementBase mbUnitTestElementBase)
        {
            if (mbUnitTestElementBase == null)
            {
                return false;
            }
            if (!base.Equals(mbUnitTestElementBase))
            {
                return false;
            }
            return
                Equals(currentProject, mbUnitTestElementBase.currentProject) &&
                Equals(currentTypeName, mbUnitTestElementBase.currentTypeName);
        }

        #endregion

        public override IProject GetProject()
        {
            return (currentProject.GetValidProjectElement() as IProject);
        }

        public override string GetTypeClrName()
        {
            return currentTypeName;
        }

        public override UnitTestNamespace GetNamespace()
        {
            return new UnitTestNamespace(new CLRTypeName(currentTypeName).NamespaceName);
        }

        public override IList<IProjectItem> GetProjectItems()
        {
            ITypeElement declaredType = GetDeclaredType();
            if (declaredType == null)
            {
                return EmptyArray<IProjectItem>.Instance;
            }
            return declaredType.GetProjectFiles();
        }

        protected ITypeElement GetDeclaredType()
        {
            ITypeElement typeElement;
            IProject project = GetProject();
            if (project == null)
            {
                return null;
            }
            PsiManager manager = PsiManager.GetInstance(project.GetSolution());
            using (ReadLockCookie.Create())
            {
                typeElement =
                    manager.GetDeclarationsCache(DeclarationsCacheScope.ProjectScope(project, true), true).
                        GetTypeElementByCLRName(currentTypeName);
            }
            return typeElement;
        }

        public override UnitTestElementDisposition GetDisposition()
        {
            IDeclaredElement element = GetDeclaredElement();
            if ((element == null) || !element.IsValid())
            {
                return UnitTestElementDisposition.ourInvalidDisposition;
            }
            List<UnitTestElementLocation> locations = new List<UnitTestElementLocation>();
            foreach (IDeclaration declaration in element.GetDeclarations())
            {
                IFile file = declaration.GetContainingFile();
                if (file != null)
                {
                    locations.Add(
                        new UnitTestElementLocation(file.ProjectItem, declaration.GetNameRange(),
                                                    declaration.GetDocumentRange().TextRange));
                }
            }
            return new UnitTestElementDisposition(locations, this);
        }

        public override bool Equals(object obj)
        {
            if (ReferenceEquals(this, obj))
            {
                return true;
            }
            return Equals(obj as MbUnitTestElementBase);
        }

        public override int GetHashCode()
        {
            int result = base.GetHashCode();
            result = 29 * result + (currentProject != null ? currentProject.GetHashCode() : 0);
            result = 29 * result + (currentTypeName != null ? currentTypeName.GetHashCode() : 0);
            return result;
        }
    }
}