Assets/Scripts/BuildSystem/ConstructionManager.cs

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ConstructionManager : MonoBehaviour
{
    public static ConstructionManager Instance { get; set; }

    public GameObject itemToBeConstructed;
    public bool inConstructionMode = false;
    public GameObject constructionHoldingSpot;

    public bool isValidPlacement;

    public bool selectingAGhost;
    public GameObject selectedGhost;

    // Materials we store as refereces for the ghosts
    public Material ghostSelectedMat;
    public Material ghostSemiTransparentMat;
    public Material ghostFullTransparentMat;

    public GameObject itemToBeDestroyed;

    // We keep a reference to all ghosts currently in our world,
    // so the manager can monitor them for various operations
    public List<GameObject> allGhostsInExistence = new List<GameObject>();

    private void Awake()
    {
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
        }
        else
        {
            Instance = this;
        }
    }

    public void ActivateConstructionPlacement(string itemToConstruct)
    {
        GameObject item = Instantiate(Resources.Load<GameObject>(itemToConstruct));

        //change the name of the gameobject so it will not be (clone)
        item.name = itemToConstruct;

        item.transform.SetParent(constructionHoldingSpot.transform, false);
        itemToBeConstructed = item;
        itemToBeConstructed.gameObject.tag = "activeConstructable";

        // Disabling the non-trigger collider so our mouse can cast a ray
        itemToBeConstructed.GetComponent<Constructable>().solidCollider.enabled = false;

        // Activating Construction mode
        inConstructionMode = true;
    }

    private void GetAllGhosts(GameObject itemToBeConstructed)
    {
        List<GameObject> ghostlist = itemToBeConstructed.gameObject.GetComponent<Constructable>().ghostList;

        foreach (GameObject ghost in ghostlist)
        {
            Debug.Log(ghost);
            allGhostsInExistence.Add(ghost);
        }
    }

    private void PerformGhostDeletionScan()
    {

        foreach (GameObject ghost in allGhostsInExistence)
        {
            if (ghost != null)
            {
                if (ghost.GetComponent<GhostItem>().hasSamePosition == false) // if we did not already add a flag
                {
                    foreach (GameObject ghostX in allGhostsInExistence)
                    {
                        // First we check that it is not the same object
                        if (ghost.gameObject != ghostX.gameObject)
                        {
                            // If its not the same object but they have the same position
                            if (XPositionToAccurateFloat(ghost) == XPositionToAccurateFloat(ghostX) && ZPositionToAccurateFloat(ghost) == ZPositionToAccurateFloat(ghostX))
                            {
                                if (ghost != null && ghostX != null)
                                {
                                    // setting the flag
                                    ghostX.GetComponent<GhostItem>().hasSamePosition = true;
                                    break;
                                }

                            }

                        }

                    }

                }
            }
        }

        foreach (GameObject ghost in allGhostsInExistence)
        {
            if (ghost != null)
            {
                if (ghost.GetComponent<GhostItem>().hasSamePosition)
                {
                    DestroyImmediate(ghost);
                }
            }

        }
    }

    private float XPositionToAccurateFloat(GameObject ghost)
    {
        if (ghost != null)
        {
            // Turning the position to a 2 decimal rounded float
            Vector3 targetPosition = ghost.gameObject.transform.position;
            float pos = targetPosition.x;
            float xFloat = Mathf.Round(pos * 100f) / 100f;
            return xFloat;
        }
        return 0;
    }

    private float ZPositionToAccurateFloat(GameObject ghost)
    {

        if (ghost != null)
        {
            // Turning the position to a 2 decimal rounded float
            Vector3 targetPosition = ghost.gameObject.transform.position;
            float pos = targetPosition.z;
            float zFloat = Mathf.Round(pos * 100f) / 100f;
            return zFloat;

        }
        return 0;
    }

    private void Update()
    {

        if (itemToBeConstructed != null && inConstructionMode)
        {
            if (CheckValidConstructionPosition())
            {
                isValidPlacement = true;
                itemToBeConstructed.GetComponent<Constructable>().SetValidColor();
            }
            else
            {
                isValidPlacement = false;
                itemToBeConstructed.GetComponent<Constructable>().SetInvalidColor();
            }


            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            RaycastHit hit;
            if (Physics.Raycast(ray, out hit))
            {
                var selectionTransform = hit.transform;
                if (selectionTransform.gameObject.CompareTag("ghost"))
                {
                    itemToBeConstructed.SetActive(false);
                    selectingAGhost = true;
                    selectedGhost = selectionTransform.gameObject;
                }
                else
                {
                    itemToBeConstructed.SetActive(true);
                    selectingAGhost = false;
                }

            }
        }

        // Left Mouse Click to Place item
        if (Input.GetMouseButtonDown(0) && inConstructionMode)
        {
            if (isValidPlacement && selectedGhost == false) // We don't want the freestyle to be triggered when we select a ghost.
            {
                PlaceItemFreeStyle();
            }

            if (selectingAGhost)
            {
                PlaceItemInGhostPosition(selectedGhost);
            }
        }
        // Right Mouse Click to Cancel                      //TODO - don't destroy the ui item until you actually placed it.
        if (Input.GetMouseButtonDown(0) && isValidPlacement)
        {     // Left Mouse Button



        }
    }

    private void PlaceItemInGhostPosition(GameObject copyOfGhost)
    {

        Vector3 ghostPosition = copyOfGhost.transform.position;
        Quaternion ghostRotation = copyOfGhost.transform.rotation;

        selectedGhost.gameObject.SetActive(false);

        // Setting the item to be active again (after we disabled it in the ray cast)
        itemToBeConstructed.gameObject.SetActive(true);
        // Setting the parent to be the root of our scene
        itemToBeConstructed.transform.SetParent(transform.parent.transform.parent, true);

        itemToBeConstructed.transform.position = ghostPosition;
        itemToBeConstructed.transform.rotation = ghostRotation;

        // Making the Ghost Children to no longer be children of this item
        itemToBeConstructed.GetComponent<Constructable>().ExtractGhostMembers();
        // Setting the default color/material
        itemToBeConstructed.GetComponent<Constructable>().SetDefaultColor();
        itemToBeConstructed.tag = "placedFoundation";

        // Enabling back the solider collider that we disabled earlier
        itemToBeConstructed.GetComponent<Constructable>().solidCollider.enabled = true;

        //Adding all the ghosts of this item into the manager's ghost bank
        GetAllGhosts(itemToBeConstructed);
        PerformGhostDeletionScan();

        itemToBeConstructed = null;

        inConstructionMode = false;
    }


    private void PlaceItemFreeStyle()
    {
        // Setting the parent to be the root of our scene
        itemToBeConstructed.transform.SetParent(transform.parent.transform.parent, true);

        // Making the Ghost Children to no longer be children of this item
        itemToBeConstructed.GetComponent<Constructable>().ExtractGhostMembers();
        // Setting the default color/material
        itemToBeConstructed.GetComponent<Constructable>().SetDefaultColor();
        itemToBeConstructed.tag = "placedFoundation";
        itemToBeConstructed.GetComponent<Constructable>().enabled = false;
        // Enabling back the solider collider that we disabled earlier
        itemToBeConstructed.GetComponent<Constructable>().solidCollider.enabled = true;

        //Adding all the ghosts of this item into the manager's ghost bank
        GetAllGhosts(itemToBeConstructed);
        PerformGhostDeletionScan();

        itemToBeConstructed = null;

        inConstructionMode = false;
    }

    private bool CheckValidConstructionPosition()
    {
        if (itemToBeConstructed != null)
        {
            return itemToBeConstructed.GetComponent<Constructable>().isValidToBeBuilt;
        }

        return false;
    }

    void DestroyItem(GameObject item)
    {
        DestroyImmediate(item);
        InventorySystem.Instance.ReCalculateList();
        CraftingSystem.Instance.RefreshNeededItems();
    }
}