using System;
using System.Collections.Generic;
using System.Reflection;
using System.Threading;
using AspClassic.Scripting.Utils;

namespace AspClassic.Scripting.Runtime;

public sealed class ScriptDomainManager
{
	private readonly DynamicRuntimeHostingProvider _hostingProvider;

	private readonly SharedIO _sharedIO;

	private List<Assembly> _loadedAssemblies = new List<Assembly>();

	private int _lastContextId;

	private Scope _globals;

	private readonly DlrConfiguration _configuration;

	public PlatformAdaptationLayer Platform
	{
		get
		{
			PlatformAdaptationLayer platformAdaptationLayer = _hostingProvider.PlatformAdaptationLayer;
			if (platformAdaptationLayer == null)
			{
				throw new InvalidImplementationException();
			}
			return platformAdaptationLayer;
		}
	}

	public SharedIO SharedIO => _sharedIO;

	public DynamicRuntimeHostingProvider Host => _hostingProvider;

	public DlrConfiguration Configuration => _configuration;

	public Scope Globals
	{
		get
		{
			return _globals;
		}
		set
		{
			_globals = value;
		}
	}

	public event EventHandler<AssemblyLoadedEventArgs> AssemblyLoaded;

	public ScriptDomainManager(DynamicRuntimeHostingProvider hostingProvider, DlrConfiguration configuration)
	{
		ContractUtils.RequiresNotNull(hostingProvider, "hostingProvider");
		ContractUtils.RequiresNotNull(configuration, "configuration");
		configuration.Freeze();
		_hostingProvider = hostingProvider;
		_configuration = configuration;
		_sharedIO = new SharedIO();
		_globals = new Scope();
	}

	internal ContextId GenerateContextId()
	{
		return new ContextId(Interlocked.Increment(ref _lastContextId));
	}

	public LanguageContext GetLanguage(Type providerType)
	{
		ContractUtils.RequiresNotNull(providerType, "providerType");
		return GetLanguageByTypeName(providerType.AssemblyQualifiedName);
	}

	public LanguageContext GetLanguageByTypeName(string providerAssemblyQualifiedTypeName)
	{
		ContractUtils.RequiresNotNull(providerAssemblyQualifiedTypeName, "providerAssemblyQualifiedTypeName");
		AssemblyQualifiedTypeName providerName = AssemblyQualifiedTypeName.ParseArgument(providerAssemblyQualifiedTypeName, "providerAssemblyQualifiedTypeName");
		if (!_configuration.TryLoadLanguage(this, providerName, out var language))
		{
			throw Error.UnknownLanguageProviderType();
		}
		return language;
	}

	public bool TryGetLanguage(string languageName, out LanguageContext language)
	{
		ContractUtils.RequiresNotNull(languageName, "languageName");
		return _configuration.TryLoadLanguage(this, languageName, isExtension: false, out language);
	}

	public LanguageContext GetLanguageByName(string languageName)
	{
		if (!TryGetLanguage(languageName, out var language))
		{
			throw new ArgumentException($"Unknown language name: '{languageName}'");
		}
		return language;
	}

	public bool TryGetLanguageByFileExtension(string fileExtension, out LanguageContext language)
	{
		ContractUtils.RequiresNotEmpty(fileExtension, "fileExtension");
		return _configuration.TryLoadLanguage(this, DlrConfiguration.NormalizeExtension(fileExtension), isExtension: true, out language);
	}

	public LanguageContext GetLanguageByExtension(string fileExtension)
	{
		if (!TryGetLanguageByFileExtension(fileExtension, out var language))
		{
			throw new ArgumentException($"Unknown file extension: '{fileExtension}'");
		}
		return language;
	}

	public bool LoadAssembly(Assembly assembly)
	{
		ContractUtils.RequiresNotNull(assembly, "assembly");
		lock (_loadedAssemblies)
		{
			if (_loadedAssemblies.Contains(assembly))
			{
				return false;
			}
			_loadedAssemblies.Add(assembly);
		}
		this.AssemblyLoaded?.Invoke(this, new AssemblyLoadedEventArgs(assembly));
		return true;
	}

	public IList<Assembly> GetLoadedAssemblyList()
	{
		lock (_loadedAssemblies)
		{
			return _loadedAssemblies.ToArray();
		}
	}
}