using System.Collections.Generic;
using JetBrains.Annotations;
using UnityEngine.Scripting;
using UnityEngine;
using System;
using System.IO;
using System.Linq;

namespace Fruitomation.Game
{
    public class BuildingManager : MonoBehaviour
    {
        [SerializeField] private BuildingRegistry Registry;
        
        private class BuildingInfo
        {
            public BuildingInfo(Building b, RectTransform rt)
            {
                Building = b;
                Rect = rt;
            }

            public Building Building { get; }
            public RectTransform Rect { get; }
        }

        [Serializable] private class SerializedBuilding
        {
            [SerializeField, Preserve, UsedImplicitly] public Vector2Int GridPosition;
            [SerializeField, Preserve, UsedImplicitly] public Vector2Int Position;
            [SerializeField, Preserve, UsedImplicitly] public string PrefabName;
            [SerializeField, Preserve, UsedImplicitly] public bool IsFlipped;

            public SerializedBuilding(Vector2Int gridPosition, Vector2Int pos, string name, bool flipped)
            {
                GridPosition = gridPosition;
                IsFlipped = flipped;
                PrefabName = name;
                Position = pos;
            }
        }

        [Serializable] private class SerializedBuildings
        {
            [SerializeField, Preserve, UsedImplicitly] private SerializedBuilding[] Buildings;
            public SerializedBuilding[] Get() => Buildings;

            public SerializedBuildings(List<SerializedBuilding> buildings) =>
                Buildings = buildings.ToArray();
        }
        
        private static string Filepath => Path.Combine(Application.persistentDataPath, "buildings.json");

        private bool[,] InhabitedCells { get; } = new bool[96, 49];
        private List<Building> Buildings { get; } = new();

        private void Start()
        {
            if (!File.Exists(Filepath))
            {
                return;
            }

            string json = File.ReadAllText(Filepath);
            SerializedBuilding[] buildings = JsonUtility.FromJson<SerializedBuildings>(json).Get();

            foreach (SerializedBuilding building in buildings)
            {
                GameObject prefab = Registry.GetBuildingOf(building.PrefabName);
                GameObject go = Instantiate(prefab, transform);

                BuildingInfo info = new
                (
                    go.GetComponent<Building>(),
                    go.GetComponent<RectTransform>()
                );
                
                info.Rect.transform.localScale = new Vector3(building.IsFlipped ? -1f : 1f, 1f, 1f);
                info.Rect.sizeDelta = info.Building.SizeOnGrid * 40;
                info.Rect.anchoredPosition = building.Position;
                go.name = $"{building.PrefabName}";
                
                info.Building.Init(this, building.GridPosition, building.Position, building.IsFlipped);
                Buildings.Add(info.Building);
                
                for (int x = building.GridPosition.x; x < building.GridPosition.x + info.Building.SizeOnGrid.x; x++)
                for (int y = building.GridPosition.y; y < building.GridPosition.y + info.Building.SizeOnGrid.y; y++)
                {
                    InhabitedCells[x, y] = true;
                }
            }
        }

        private void OnDestroy()
        {
            Debug.Log($"Buildings: [{Buildings.Count}]");

            List<SerializedBuilding> serialized = Buildings.Select(building => new SerializedBuilding
                (
                    building.GridPosition,
                    building.Position,
                    building.name,
                    building.IsFlipped
                )
            ).ToList();

            string json = JsonUtility.ToJson(new SerializedBuildings(serialized), true);
            File.WriteAllText(Filepath, json);
        }

        public void RemoveBuilding(Building building) => Buildings.Remove(building);

        public bool AddBuildingAt(Vector2Int position, BuildingRegistry.BuildingInfo building, bool isFlipped)
        {
            //
            GameObject go = Instantiate(building.Prefab, transform);
            BuildingInfo info = new
            (
                go.GetComponent<Building>(),
                go.GetComponent<RectTransform>()
            );
            go.name = $"{building.Name}";

            Vector2Int p0 = position * 40;
            Vector2Int p1 = p0 + new Vector2Int(20, 100);

            Vector2Int g0 = position + new Vector2Int(48, 24);

            Vector2Int off0 = info.Building.SizeOnGrid - Vector2Int.one;
            Vector2Int off1 = off0 * 20;
            Vector2Int p2 = p1 + off1;

            info.Rect.sizeDelta = info.Building.SizeOnGrid * 40;
            info.Rect.anchoredPosition = p2;
            
            info.Rect.transform.localScale = new Vector3(isFlipped ? -1f : 1f, 1f, 1f);

            //
            for (int x = g0.x; x < g0.x + info.Building.SizeOnGrid.x; x++)
            for (int y = g0.y; y < g0.y + info.Building.SizeOnGrid.y; y++)
            {
                if (InhabitedCells[x, y])
                {
                    DestroyImmediate(go);
                    return false;
                }
            }

            //
            for (int x = g0.x; x < g0.x + info.Building.SizeOnGrid.x; x++)
            for (int y = g0.y; y < g0.y + info.Building.SizeOnGrid.y; y++)
            {
                InhabitedCells[x, y] = true;
            }

            info.Building.Init(this, g0, p2, isFlipped);
            Buildings.Add(info.Building);
            
            return true;
        }
    }
}