using System.Collections.Generic;
using System.Linq;
using EscapeRoomEngine.Engine.Runtime.Modules;
using EscapeRoomEngine.Engine.Runtime.Utilities;
using NaughtyAttributes;
using UnityEngine;
using Logger = EscapeRoomEngine.Engine.Runtime.Utilities.Logger;
using LogType = EscapeRoomEngine.Engine.Runtime.Utilities.LogType;

namespace EscapeRoomEngine.Engine.Runtime
{
    public class Engine : MonoBehaviour
    {
        public static Engine DefaultEngine
        {
            get
            {
                if (_foundEngine == null)
                {
                    _foundEngine = FindObjectOfType<Engine>();
                }
                return _foundEngine;
            }
        }
        private static Engine _foundEngine;

        public delegate void UpdateUIHandler();
        public event UpdateUIHandler UpdateUIEvent;

        [Required] public EngineTheme theme;

        public int NumberOfRooms => _rooms.Count;
        public IOption<Room> CurrentRoom => NumberOfRooms > 0 ? Some<Room>.Of(_rooms[^1]) : None<Room>.New();

        private readonly List<Room> _rooms = new();
        private GameObject _playSpaceOrigin, _environment;

        private void Start()
        {
            _playSpaceOrigin = new GameObject("Play Space Origin");
            _playSpaceOrigin.transform.SetParent(transform);
            _playSpaceOrigin.transform.localPosition = new Vector3(-theme.playSpace.x / 2f, 0, -theme.playSpace.y / 2f);

            if (theme.environment)
            {
                _environment = Instantiate(theme.environment, _playSpaceOrigin.transform, false);
            }

            GenerateRoom();
        }

        public void GenerateRoom()
        {
            Logger.Log("Generating room...", LogType.RoomGeneration);
            
            // get the last entrance from the newest room or create a spawn passage with no entrance door for where the player will start
            var entrance = NumberOfRooms > 0 ? _rooms.Last().exit : new Passage(new DoorModule(null, theme.spawnDoor), true);
            
            var room = new Room(entrance);
            _rooms.Add(room);
            
            GenerateSpace(room, entrance); // TODO: rooms with more than one space
            
            room.InstantiateRoom(_playSpaceOrigin.transform, (_rooms.Count - 1).ToString());

            UpdateUI();
        }

        private void GenerateSpace(Room room, Passage entrance)
        {
            Logger.Log("Generating space...", LogType.RoomGeneration);
            
            // create space
            var space = new Space(room, entrance);
            
            // add exit
            var exitDoor = new DoorModule(space, theme.exitDoorTypes.RandomElement());
            if (!space.AddModuleWithRequirements(exitDoor))
                throw new EngineException("Could not satisfy requirements for exit door.");
            var exit = new Passage(exitDoor);

            // add puzzles
            var puzzleCount = Utilities.Utilities.RandomInclusive(theme.puzzleCount.x, theme.puzzleCount.y);
            for (var i = 0; i < puzzleCount; i++)
            {
                space.AddModuleWithRequirements(Module.CreateModuleByType(space, theme.puzzleTypes.RandomElement()));
            }
            
            room.AddSpace(space, exit);
        }

        public void HidePreviousRoom()
        {
            if (NumberOfRooms > 1)
            {
                _rooms[NumberOfRooms - 2].roomObject.SetActive(false);
            }
        }

        private void UpdateUI() => UpdateUIEvent?.Invoke();
    }
}