using System;
using System.Collections;
using System.Collections.Generic;
using System.Configuration.Install;
using System.ServiceProcess;

namespace PRSServer
{
    // Class to manage the installation of services
    public class PRSServiceInstaller
    {
        private static bool IsInstalled(string serviceName)
        {
            using (var controller =
                   new ServiceController(serviceName))
            {
                try
                {
                    var status = controller.Status;
                }
                catch
                {
                    return false;
                }

                return true;
            }
        }

        private static bool IsRunning(string serviceName)
        {
            using (var controller =
                   new ServiceController(serviceName))
            {
                if (!IsInstalled(serviceName)) return false;
                return controller.Status == ServiceControllerStatus.Running;
            }
        }

        private static AssemblyInstaller GetInstaller(string serviceName, string description, string displayName, string? username, string? password)
        {
            // The arguments passed here are received by PRSInstaller, which it uses to set service metadata.
            // /name=servicename is *REQUIRED* because otherwise Windows can't find the service in the executable.

            var installProperties = new List<string>
            {
                "/name=" + serviceName,
                "/description=" + description,
                "/displayName=" + displayName
            };
            if(!string.IsNullOrWhiteSpace(username))
            {
                installProperties.Add("/username=" + username);
                installProperties.Add("/password=" + (password ?? ""));
            }

            var installer = new AssemblyInstaller(
                typeof(App).Assembly, installProperties.ToArray());
            installer.UseNewContext = true;
            return installer;
        }

        private static AssemblyInstaller GetUninstaller(string serviceName)
        {
            // The argument passed here is received by PRSInstaller. /name=serviceName is used to find the serviceName
            // in the PRSServer.exe, which can then execute the uninstaller.
            var installer = new AssemblyInstaller(
                typeof(App).Assembly, new[] { "/name=" + serviceName });
            installer.UseNewContext = true;
            return installer;
        }

        public static void InstallService(string serviceName, string description, string displayName, string? username, string? password)
        {
            if (IsInstalled(serviceName)) return;
            using (var installer = GetInstaller(serviceName, description, displayName, username, password))
            {
                IDictionary state = new Hashtable();
                try
                {
                    installer.Install(state);
                    installer.Commit(state);
                }
                catch
                {
                    try
                    {
                        //installer.Rollback(state);
                    }
                    catch
                    {
                    }

                    throw;
                }
            }
        }

        public static void UninstallService(string serviceName)
        {
            if (!IsInstalled(serviceName)) return;
            using (var installer = GetUninstaller(serviceName))
            {
                IDictionary state = new Hashtable();
                installer.Uninstall(state);
            }
        }

        public static void ChangeService(string serviceName, string description, string displayName, string? username, string? password)
        {
            if (IsInstalled(serviceName)) UninstallService(serviceName);
            InstallService(serviceName, description, displayName, username, password);

            /*
            // Delegate the configuration of the service to sc.exe, and execute.
            // I haven't found a way to do it without using sc.exe. (Unless we decided to change the registry, which is surely a bad idea.)
    
            // Convert quotes and backslashes to escaped quotes and backslashes
            var newServiceName = serviceName.Replace("\"", "\\\"").Replace("\\", "\\\\");
            var newDisplayName = displayName.Replace("\"", "\\\"").Replace("\\", "\\\\");
            var newDescription = description.Replace("\"", "\\\"").Replace("\\", "\\\\");
    
            RunCommand("sc.exe", "description \"" + newServiceName + "\" \"" + newDescription + "\"");
            RunCommand("sc.exe", "config \"" + newServiceName + "\" displayname=\"" + newDisplayName + "\"");
            */
        }

        public static void StartService(string serviceName)
        {
            if (!IsInstalled(serviceName)) return;

            using (var controller =
                   new ServiceController(serviceName))
            {
                if (controller.Status != ServiceControllerStatus.Running)
                {
                    controller.Start();
                    controller.WaitForStatus(ServiceControllerStatus.Running,
                        TimeSpan.FromSeconds(10));
                }
            }
        }

        public static void StopService(string serviceName)
        {
            if (!IsInstalled(serviceName)) return;
            using (var controller =
                   new ServiceController(serviceName))
            {
                if (controller.Status != ServiceControllerStatus.Stopped)
                {
                    controller.Stop();
                    controller.WaitForStatus(ServiceControllerStatus.Stopped,
                        TimeSpan.FromSeconds(10));
                }
            }
        }
    }
}