using System;
using System.Collections.Generic;
using System.Net;
using System.Reflection;
using AllocsFixes.NetConnections.Servers.Web.API;

namespace AllocsFixes.NetConnections.Servers.Web.Handlers {
	public class ApiHandler : AbsHandler {
		private readonly Dictionary<string, AbsWebAPI> apis = new CaseInsensitiveStringDictionary<AbsWebAPI> ();

		public ApiHandler () : base (null) {

		}

		public override void SetBasePathAndParent (Web _parent, string _relativePath) {
			base.SetBasePathAndParent (_parent, _relativePath);

			Type[] apiWithParentCtorTypes = { typeof (Web) };
			Object[] apiWithParentCtorArgs = { _parent };

			Type[] apiEmptyCtorTypes = { };
			Object[] apiEmptyCtorArgs = { };
			
			foreach (Type t in Assembly.GetExecutingAssembly ().GetTypes ()) {
				if (!t.IsAbstract && t.IsSubclassOf (typeof (AbsWebAPI))) {
					ConstructorInfo ctor = t.GetConstructor (apiWithParentCtorTypes);
					if (ctor != null) {
						AbsWebAPI apiInstance = (AbsWebAPI) ctor.Invoke (apiWithParentCtorArgs);
						addApi (apiInstance);
						continue;
					}
					
					ctor = t.GetConstructor (apiEmptyCtorTypes);
					if (ctor != null) {
						AbsWebAPI apiInstance = (AbsWebAPI) ctor.Invoke (apiEmptyCtorArgs);
						addApi (apiInstance);
					}
				}
			}

			// Permissions that don't map to a real API
			addApi (new Null ("viewallclaims"));
			addApi (new Null ("viewallplayers"));
		}

		private void addApi (AbsWebAPI _api) {
			apis.Add (_api.Name, _api);
			WebPermissions.Instance.AddKnownModule ("webapi." + _api.Name, _api.DefaultPermissionLevel ());
		}

#if ENABLE_PROFILER
		private static readonly UnityEngine.Profiling.CustomSampler apiHandlerSampler = UnityEngine.Profiling.CustomSampler.Create ("API_Handler");
#endif

		public override void HandleRequest (RequestContext _context) {

			string apiName;
			string subPath = null;

			int pathSeparatorIndex = _context.RequestPath.IndexOf ('/', urlBasePath.Length);
			if (pathSeparatorIndex >= 0) {
				apiName = _context.RequestPath.Substring (urlBasePath.Length, pathSeparatorIndex - urlBasePath.Length);
				subPath = _context.RequestPath.Substring (pathSeparatorIndex + 1);
			} else {
				apiName = _context.RequestPath.Substring (urlBasePath.Length);
			}
			
			if (!apis.TryGetValue (apiName, out AbsWebAPI api)) {
				Log.Out ($"Error in {nameof(ApiHandler)}.HandleRequest(): No handler found for API \"{apiName}\"");
				_context.Response.StatusCode = (int) HttpStatusCode.NotFound;
				return;
			}

			if (!AuthorizeForApi (apiName, _context.PermissionLevel)) {
				_context.Response.StatusCode = (int) HttpStatusCode.Forbidden;
				if (_context.Connection != null) {
					//Log.Out ($"{nameof(ApiHandler)}: user '{user.SteamID}' not allowed to execute '{apiName}'");
				}

				return;
			}

			_context.RequestPath = subPath;

			try {
#if ENABLE_PROFILER
				apiHandlerSampler.Begin ();
#endif
				api.HandleRequest (_context);
#if ENABLE_PROFILER
				apiHandlerSampler.End ();
#endif
			} catch (Exception e) {
				Log.Error ($"Error in {nameof(ApiHandler)}.HandleRequest(): Handler {api.Name} threw an exception:");
				Log.Exception (e);
				_context.Response.StatusCode = (int) HttpStatusCode.InternalServerError;
			}
		}

		private bool AuthorizeForApi (string _apiName, int _permissionLevel) {
			return WebPermissions.Instance.ModuleAllowedWithLevel ("webapi." + _apiName, _permissionLevel);
		}
	}
}