// ****************************************************************

// Copyright 2010, Charlie Poole

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org

// ****************************************************************

using System;

using NUnit.Core;



namespace NUnit.Util

{

    public class RuntimeFrameworkSelector : IRuntimeFrameworkSelector

    {

        static Logger log = InternalTrace.GetLogger(typeof(RuntimeFrameworkSelector));



        /// <summary>

        /// Selects a target runtime framework for a TestPackage based on

        /// the settings in the package and the assemblies themselves.

        /// The package RuntimeFramework setting may be updated as a 

        /// result and the selected runtime is returned.

        /// </summary>

        /// <param name="package">A TestPackage</param>

        /// <returns>The selected RuntimeFramework</returns>

        public RuntimeFramework SelectRuntimeFramework(TestPackage package)

        {

            RuntimeFramework currentFramework = RuntimeFramework.CurrentFramework;

            RuntimeFramework requestedFramework = package.Settings["RuntimeFramework"] as RuntimeFramework;



            log.Debug("Current framework is {0}", currentFramework);

            if (requestedFramework == null)

                log.Debug("No specific framework requested");

            else

                log.Debug("Requested framework is {0}", requestedFramework);



            RuntimeType targetRuntime = requestedFramework == null

                ? RuntimeType.Any 

                : requestedFramework.Runtime;

            Version targetVersion = requestedFramework == null

                ? RuntimeFramework.DefaultVersion

                : requestedFramework.FrameworkVersion;



            if (targetRuntime == RuntimeType.Any)

                targetRuntime = currentFramework.Runtime;



            if (targetVersion == RuntimeFramework.DefaultVersion)

            {

                foreach (string assembly in package.Assemblies)

                {

                    using (AssemblyReader reader = new AssemblyReader(assembly))

                    {

                        Version v = new Version(reader.ImageRuntimeVersion.Substring(1));

                        log.Debug("Assembly {0} uses version {1}", assembly, v);

                        if (v > targetVersion) targetVersion = v;

                    }

                }



                RuntimeFramework checkFramework = new RuntimeFramework(targetRuntime, targetVersion);

                if (!checkFramework.IsAvailable || NUnitConfiguration.GetTestAgentExePath(targetVersion) == null)

                {

                    log.Debug("Preferred version {0} is not installed or this NUnit installation does not support it", targetVersion);

                    if (targetVersion < currentFramework.FrameworkVersion)

                        targetVersion = currentFramework.FrameworkVersion;

                }

            }



            RuntimeFramework targetFramework = new RuntimeFramework(targetRuntime, targetVersion);

            package.Settings["RuntimeFramework"] = targetFramework;



            log.Debug("Test will use {0} framework", targetFramework);



            return targetFramework;

        }

    }

}