using Microsoft.Extensions.DependencyInjection;
using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using Microsoft.Extensions.Logging;

namespace SmartCode.App
{
 public class PluginManager : IPluginManager
 {
 private readonly SmartCodeOptions _smartCodeOptions;
 private readonly IServiceProvider _serviceProvider;
 private readonly ILogger<PluginManager> _logger;

 public PluginManager(
 SmartCodeOptions smartCodeOptions
 , IServiceProvider serviceProvider
 , ILogger<PluginManager> logger)
 {
 _smartCodeOptions = smartCodeOptions;
 _serviceProvider = serviceProvider;
 _logger = logger;
 }

 public TPlugin Resolve<TPlugin>(string name = "") where TPlugin : IPlugin
 {
 var plugins = ResolvePlugins<TPlugin>();
 IPlugin plugin = default;
 if (plugins.Count() == 0)
 {
 var errMsg = $"Can not find any Plugin:{typeof(TPlugin).Name}";
 _logger.LogError(errMsg);
 throw new SmartCodeException(errMsg);
 }
 if (String.IsNullOrEmpty(name))
 {
 plugin = plugins.FirstOrDefault();
 }
 else
 {
 plugin = plugins.FirstOrDefault(m => String.Equals(m.Name, name, StringComparison.CurrentCultureIgnoreCase));
 if (plugin == null)
 {
 plugin = plugins.First();
 var errMsg = $"Can not find Plugin:{typeof(TPlugin).Name},Name:{name},Use Default Plugin:{plugin.GetType().FullName}";
 _logger.LogWarning(errMsg);
 }
 }
 _logger.LogDebug($"GetPlugin Name:{name},PluginType:{typeof(TPlugin).FullName},ImplType:{plugin.GetType().FullName}!");
 return (TPlugin)plugin;
 }

 private IEnumerable<TPlugin> ResolvePlugins<TPlugin>() where TPlugin : IPlugin
 {
 var plugins = _serviceProvider.GetServices<TPlugin>();
 foreach (var plugin in plugins)
 {
 if (!plugin.Initialized)
 {
 var pluginType = plugin.GetType();
 var names = pluginType.AssemblyQualifiedName.Split(',');
 var typeName = names[0].Trim();
 var assName = names[1].Trim();
 var pluginConfig = _smartCodeOptions
 .Plugins
 .FirstOrDefault(m => m.ImplAssemblyName == assName && m.ImplTypeName == typeName);
 plugin.Initialize(pluginConfig.Parameters);
 }
 }
 return plugins;
 }
 }
}