using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Runtime.CompilerServices;
using JD.Collections.Extensions;
using JD.Kernel.StaticHelpers;
using JD.LogService;
using JD.TeaBoxAddinSystem.Addins.Management;

namespace JD.TeaBoxAddinSystem.Bootstrap
{
    /// <summary>
    /// Static class that holds many properties of the current application.
    /// </summary>
    /// <remarks>
    /// Note that these properties are only valid after an <see cref="ApplicationStartup"/> has been started.
    /// </remarks>
    public static class Runtime
    {
        private static bool _commandLineMode = true; // True by default so that it's true in unit tests.
        private static ApplicationConfiguration _configuration;
        
        [MethodImpl(MethodImplOptions.NoInlining)] // Ensures that Assembly.GetCallingAssembly() works as expected
        static Runtime()
        {
            EntryAssembly = Assembly.GetCallingAssembly();

            var entryAssembly = Assembly.GetEntryAssembly();
            ApplicationName = entryAssembly != null ? entryAssembly.GetName().Name : "Unknown application";
        }

        /// <summary>
        /// Whether the runtime has been initialized.
        /// </summary>
        public static bool Initialized { get; private set; }

        /// <summary>
        /// Entry Assembly of the application..
        /// </summary>
        public static Assembly EntryAssembly { get; }

        /// <summary>
        /// Unique identifier used to identify the application.
        /// </summary>
        public static string UniqueIdentifier
        {
            get { return EntryAssembly.FullName; }
        }
        
        // Useful for shared data (playlists, scripts)
        // Takes deployed apps (BuildBox) into account
        public static string DeploymentPath
        {
            get
            {
                string deploymentPath = null;

                // First check if the working directory contains a Scripts folder and use that if it does
                // Useful for forcing a specific scripts folder when launching from VS
                string currentDirectory = Environment.CurrentDirectory;

                // HACK: Would be nice if we didn't have to hardcode the folder name
                foreach (string folderName in new[] {"Script", "Scripts"})
                {
                    string scriptDirectory = Path.Combine(currentDirectory, folderName);
                    if (Directory.Exists(scriptDirectory) &&
                        !Directory.GetFiles(scriptDirectory, "*.cs", SearchOption.AllDirectories).IsEmpty())
                    {
                        deploymentPath = currentDirectory;
                        break;
                    }
                }

                if (deploymentPath == null)
                {
                    deploymentPath = ApplicationRootPath;
                }

                return FileUtility.CleanPath(deploymentPath);
            }
        }

        /// <summary>
        /// Arguments that were used to start the application.
        /// </summary>
        public static Arguments Arguments { get; private set; }

        /// <summary>
        /// Application Root Path.
        /// </summary>
        public static string ApplicationRootPath { get; private set; } = Environment.CurrentDirectory;

        /// <summary>
        /// Whether the application was started in command-line mode.
        /// </summary>
        public static bool CommandLineMode
        {
            get { return _commandLineMode; }
            set
            {
                if (_commandLineMode != value)
                {
                    _commandLineMode = value;
                    MessageService.MessageService.IsCommandLine = _commandLineMode;
                }
            }
        }
        
        public static ApplicationType ApplicationType
        {
            get { return CommandLineMode ? ApplicationType.Default : ApplicationType.Gui; }
        }

        /// <summary>
        /// The mode into which this application was started.
        /// </summary>
        public static RuntimeMode RuntimeMode { get; private set; } = RuntimeMode.Normal;

        /// <summary>
        /// Whether the app is running in embedded mode.
        /// </summary>
        public static bool IsEmbedded
        {
            get
            {
                switch (RuntimeMode)
                {
                    case RuntimeMode.Normal:
                        return false;

                    case RuntimeMode.EmbeddedInProcess:
                    case RuntimeMode.SystemTests:
                        return true;

                    default:
                        throw new NotImplementedException();
                }
            }
        }

        /// <summary>
        /// Application Name.
        /// </summary>
        public static string ApplicationName { get; private set; }

        public const int SuccessErrorCode = 0;
        public const int FailureErrorCode = 1;

        /// <summary>
        /// Gets or sets the exit code of the application.
        /// </summary>
        public static int ExitCode { get; set; } = SuccessErrorCode;

        /// <summary>
        /// The directory used to store user-specific preferences.
        /// </summary>
        /// <remarks>
        /// By default, this is ApplicationData/ApplicationName in the MyDocuments folder of the current user.
        /// </remarks>
        public static string ConfigDirectory
        {
            get { return _configuration == null ? null : _configuration.ConfigDirectory; }
        }

        /// <summary>
        /// The directory used to store global resources.
        /// </summary>
        /// <remarks>
        /// By default, this is ApplicationRootPath/Data.
        /// </remarks>
        public static string DataDirectory
        {
            get { return _configuration == null ? null : _configuration.DataDirectory; }
        }

        /// <summary>
        /// Paths in the Addin Tree where CommandLineHandlers are.
        /// </summary>
        public static IEnumerable<string> CommandLineHandlerPaths
        {
            get { return _configuration == null ? new string[0] : _configuration.CommandLineHandlerPaths; }
        }

        /// <summary>
        /// Addin Repository of this application.
        /// </summary>
        public static AddinRepository AddinRepository { get; private set; }

        /// <summary>
        /// Whether this application should start its own instance.
        /// </summary>
        public static bool ShouldStartOwnInstance
        {
            get
            {
                return (CommandLineMode || Arguments.Parameters.Count == 0 || !ApplicationInstanceManager.IsInstanceRunning(UniqueIdentifier));
            }
        }

        internal static void Initialize(ApplicationStartup startup, ILogger logger)
        {
            Initialized = true;

            ApplicationRootPath = !string.IsNullOrEmpty(startup.Configuration.ApplicationRootPath)
                ? startup.Configuration.ApplicationRootPath
                : Path.GetDirectoryName(EntryAssembly.Location);

            RuntimeMode = startup.RuntimeMode;
            Arguments = startup.Arguments;
            ApplicationName = startup.ApplicationName;
            AddinRepository = new AddinRepository(ApplicationRootPath);
            _configuration = startup.Configuration;

            var defaultPropertiesFileName = $"{Path.GetFileNameWithoutExtension(AppDomain.CurrentDomain.FriendlyName)}Properties.xml";
            var defaultPropertiesFilePath = Path.Combine(_configuration.ConfigDirectory, defaultPropertiesFileName);
            PropertyService.PropertyService.DefaultFilePath = defaultPropertiesFilePath;
        }
    }
}