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

public enum BuildingCategory
{
    Living,
    Working,
    Decorative,
    Infrastructure
}

[System.Serializable]
public class BuildingTemplate
{
    public string name;
    public BuildingCategory category;
    public GameObject prefab;
    public ResourceCost[] costs;
    public string description;
    public Vector2Int size = new Vector2Int(1, 1); // Grid size
    public bool requiresConstruction = false; // Whether building needs construction time
    public float constructionTime = 5f; // Time in seconds to build
}

[System.Serializable]
public class ResourceCost
{
    public ResourceType resourceType;
    public int amount;
}

public class BuildingSystem : MonoBehaviour
{
    [Header("Building Templates")]
    public List<BuildingTemplate> buildingTemplates = new List<BuildingTemplate>();

    [Header("Building Settings")]
    public LayerMask buildableLayer = 1; // Ground layer
    public Material previewMaterial;

    private BuildingTemplate selectedBuildingTemplate;
    private GameObject previewObject;
    private Camera playerCamera;
    private bool isBuildModeActive = false;

    // Events
    public static System.Action<BuildingTemplate> OnBuildingSelected;
    public static System.Action OnBuildModeEntered;
    public static System.Action OnBuildModeExited;
    public static System.Action<GameObject> OnBuildingPlaced;

    void Start()
    {
        playerCamera = Camera.main;
        InitializeBuildingTemplates();
    }

    void InitializeBuildingTemplates()
    {
        // Clear existing templates
        buildingTemplates.Clear();

        // Add House template
        buildingTemplates.Add(new BuildingTemplate
        {
            name = "House",
            category = BuildingCategory.Living,
            costs = new ResourceCost[]
            {
                new ResourceCost { resourceType = ResourceType.Wood, amount = 20 },
                new ResourceCost { resourceType = ResourceType.Stone, amount = 10 }
            },
            description = "Provides housing for villagers. Increases happiness and allows population growth.",
            size = new Vector2Int(2, 2)
        });

        // Add Builder's Workshop template
        buildingTemplates.Add(new BuildingTemplate
        {
            name = "Builder's Workshop",
            category = BuildingCategory.Working,
            costs = new ResourceCost[]
            {
                new ResourceCost { resourceType = ResourceType.Wood, amount = 30 },
                new ResourceCost { resourceType = ResourceType.Stone, amount = 15 }
            },
            description = "Allows villagers to work as builders. Required for construction projects.",
            size = new Vector2Int(2, 1)
        });

        // Add Farmhouse template
        buildingTemplates.Add(new BuildingTemplate
        {
            name = "Farmhouse",
            category = BuildingCategory.Working,
            costs = new ResourceCost[]
            {
                new ResourceCost { resourceType = ResourceType.Wood, amount = 40 },
                new ResourceCost { resourceType = ResourceType.Stone, amount = 20 }
            },
            description = "Houses farmers and allows construction of fields. Produces food from nearby fields.",
            size = new Vector2Int(2, 2),
            requiresConstruction = true, // Enable construction system
            constructionTime = 10f // Takes 10 seconds to build
        });

        Debug.Log($"Initialized {buildingTemplates.Count} building templates");
    }

    void Update()
    {
        if (isBuildModeActive)
        {
            HandleBuildMode();
        }
    }

    public void EnterBuildMode(BuildingTemplate template)
    {
        selectedBuildingTemplate = template;
        isBuildModeActive = true;

        CreatePreviewObject();
        OnBuildModeEntered?.Invoke();

        Debug.Log($"Entered build mode for: {template.name}");
    }

    public void ExitBuildMode()
    {
        isBuildModeActive = false;
        selectedBuildingTemplate = null;

        if (previewObject != null)
        {
            DestroyImmediate(previewObject);
        }

        OnBuildModeExited?.Invoke();
        Debug.Log("Exited build mode");
    }

    public List<BuildingTemplate> GetBuildingTemplates()
    {
        return buildingTemplates;
    }

    void CreatePreviewObject()
    {
        if (selectedBuildingTemplate?.prefab != null)
        {
            previewObject = Instantiate(selectedBuildingTemplate.prefab);

            // Make it a preview (transparent, non-interactive)
            MakePreviewObject(previewObject);
        }
        else
        {
            // Create a simple cube preview if no prefab
            previewObject = GameObject.CreatePrimitive(PrimitiveType.Cube);
            previewObject.name = $"{selectedBuildingTemplate.name}_Preview";

            // Scale based on building size
            previewObject.transform.localScale = new Vector3(
                selectedBuildingTemplate.size.x,
                1f,
                selectedBuildingTemplate.size.y
            );

            MakePreviewObject(previewObject);
        }
    }

    void MakePreviewObject(GameObject obj)
    {
        // Make transparent
        Renderer[] renderers = obj.GetComponentsInChildren<Renderer>();
        foreach (var renderer in renderers)
        {
            if (previewMaterial != null)
            {
                renderer.material = previewMaterial;
            }
            else
            {
                // Create basic transparent material
                Material transparentMat = new Material(Shader.Find("Standard"));
                transparentMat.SetFloat("_Mode", 3); // Transparent
                transparentMat.color = new Color(0, 1, 0, 0.5f);
                renderer.material = transparentMat;
            }
        }

        // Remove colliders to prevent interference
        Collider[] colliders = obj.GetComponentsInChildren<Collider>();
        foreach (var collider in colliders)
        {
            collider.enabled = false;
        }
    }

    void HandleBuildMode()
    {
        if (previewObject == null) return;

        // Update preview position based on mouse
        if (Mouse.current == null) return;

        Vector2 mousePosition = Mouse.current.position.ReadValue();
        Ray ray = playerCamera.ScreenPointToRay(mousePosition);

        if (Physics.Raycast(ray, out RaycastHit hit, Mathf.Infinity, buildableLayer))
        {
            Vector3 buildPosition = hit.point;

            // Snap to grid (optional)
            buildPosition.x = Mathf.Round(buildPosition.x);
            buildPosition.z = Mathf.Round(buildPosition.z);
            buildPosition.y = hit.point.y;

            previewObject.transform.position = buildPosition;

            // Check if position is valid
            bool canBuild = CanBuildAtPosition(buildPosition);

            // Change preview color based on validity
            ChangePreviewColor(canBuild);

            // Handle click to place building
            if (Mouse.current.leftButton.wasPressedThisFrame && canBuild)
            {
                PlaceBuilding(buildPosition);
            }
        }

        // Cancel build mode
        if (Keyboard.current.escapeKey.wasPressedThisFrame || Mouse.current.rightButton.wasPressedThisFrame)
        {
            ExitBuildMode();
        }
    }

    bool CanBuildAtPosition(Vector3 position)
    {
        // Check if we have enough resources
        if (!HasEnoughResources(selectedBuildingTemplate))
        {
            return false;
        }

        // Check for overlapping objects using a box that matches building size
        Vector3 boxSize = new Vector3(selectedBuildingTemplate.size.x, 2f, selectedBuildingTemplate.size.y);
        Collider[] overlapping = Physics.OverlapBox(position, boxSize * 0.5f, Quaternion.identity);

        foreach (var col in overlapping)
        {
            // Skip the preview object itself
            if (col.gameObject == previewObject)
                continue;

            // Skip ground/terrain objects
            string objName = col.gameObject.name.ToLower();
            if (objName.Contains("ground") || objName.Contains("terrain") || objName.Contains("plane"))
                continue;

            // Check for buildings
            if (col.GetComponent<Building>() != null)
            {
                Debug.Log($"Building blocked by existing building: {col.gameObject.name}");
                return false;
            }

            // Check for resource objects and other blocking objects by tag
            string tag = col.gameObject.tag;
            if (tag == "Tree" || tag == "Stone" || tag == "Farm" || tag == "TownHall" || tag == "Villager")
            {
                Debug.Log($"Building blocked by {tag}: {col.gameObject.name}");
                return false;
            }

            // Check for any other objects with colliders (except ground layer)
            if (col.gameObject.layer != 0) // Layer 0 is Default, usually ground
            {
                Debug.Log($"Building blocked by object: {col.gameObject.name} (layer: {col.gameObject.layer})");
                return false;
            }
        }

        return true;
    }

    bool HasEnoughResources(BuildingTemplate template)
    {
        if (GameManager.Instance?.resourceManager == null) return false;

        foreach (var cost in template.costs)
        {
            if (!GameManager.Instance.resourceManager.HasResource(cost.resourceType, cost.amount))
            {
                return false;
            }
        }

        return true;
    }

    void ChangePreviewColor(bool canBuild)
    {
        Color previewColor = canBuild ? Color.green : Color.red;
        previewColor.a = 0.5f;

        Renderer[] renderers = previewObject.GetComponentsInChildren<Renderer>();
        foreach (var renderer in renderers)
        {
            renderer.material.color = previewColor;
        }
    }

    void PlaceBuilding(Vector3 position)
    {
        // Consume resources
        foreach (var cost in selectedBuildingTemplate.costs)
        {
            GameManager.Instance.resourceManager.RemoveResource(cost.resourceType, cost.amount);
        }

        GameObject newBuilding;

        // Check if this building requires construction
        if (selectedBuildingTemplate.requiresConstruction)
        {
            // Create construction site
            newBuilding = CreateConstructionSite(selectedBuildingTemplate, position);
            Debug.Log($"Started construction of {selectedBuildingTemplate.name} at {position}");
        }
        else
        {
            // Create the building immediately (for simple buildings like houses)
            if (selectedBuildingTemplate.prefab != null)
            {
                newBuilding = Instantiate(selectedBuildingTemplate.prefab, position, Quaternion.identity);
            }
            else
            {
                newBuilding = CreateBasicBuilding(selectedBuildingTemplate, position);
            }

            // Add building component if it doesn't exist
            Building buildingComponent = newBuilding.GetComponent<Building>();
            if (buildingComponent == null)
            {
                buildingComponent = newBuilding.AddComponent<Building>();
            }

            buildingComponent.buildingName = selectedBuildingTemplate.name;
            buildingComponent.category = selectedBuildingTemplate.category;

            // Add specific building components
            if (selectedBuildingTemplate.name == "House")
            {
                if (newBuilding.GetComponent<House>() == null)
                    newBuilding.AddComponent<House>();
            }
            else if (selectedBuildingTemplate.name == "Farm")
            {
                if (newBuilding.GetComponent<Farm>() == null)
                    newBuilding.AddComponent<Farm>();
            }
            else if (selectedBuildingTemplate.name == "Farmhouse")
            {
                if (newBuilding.GetComponent<SimpleFarmhouse>() == null)
                    newBuilding.AddComponent<SimpleFarmhouse>();
            }

            Debug.Log($"Instantly placed {selectedBuildingTemplate.name} at {position}");
        }

        OnBuildingPlaced?.Invoke(newBuilding);

        // Exit build mode after placing
        ExitBuildMode();
    }

    GameObject CreateConstructionSite(BuildingTemplate template, Vector3 position)
    {
        // Create a temporary construction site object
        GameObject constructionSite = GameObject.CreatePrimitive(PrimitiveType.Cube);
        constructionSite.name = $"{template.name}_ConstructionSite";
        constructionSite.transform.position = position;
        constructionSite.transform.localScale = new Vector3(template.size.x, 0.5f, template.size.y);

        // Add construction site component
        ConstructionSite constructionComponent = constructionSite.AddComponent<ConstructionSite>();
        constructionComponent.buildingName = template.name;
        constructionComponent.buildingTemplate = template;
        constructionComponent.constructionTime = template.constructionTime;

        // Make it look like a construction site
        Renderer renderer = constructionSite.GetComponent<Renderer>();
        renderer.material.color = new Color(0.7f, 0.7f, 0.7f, 0.5f); // Semi-transparent gray

        return constructionSite;
    }
    GameObject CreateBasicBuilding(BuildingTemplate template, Vector3 position)
    {
        GameObject building = new GameObject(template.name);
        building.transform.position = position;

        // Create visual representation
        GameObject visual = GameObject.CreatePrimitive(PrimitiveType.Cube);
        visual.transform.SetParent(building.transform);
        visual.transform.localPosition = Vector3.zero;
        visual.transform.localScale = new Vector3(template.size.x, 1f, template.size.y);

        // Color based on category
        Renderer renderer = visual.GetComponent<Renderer>();
        renderer.material.color = GetCategoryColor(template.category);

        // Add collider for selection
        if (building.GetComponent<Collider>() == null)
        {
            BoxCollider collider = building.AddComponent<BoxCollider>();
            collider.size = new Vector3(template.size.x, 2f, template.size.y);
            collider.center = new Vector3(0, 1f, 0);
        }

        return building;
    }

    Color GetCategoryColor(BuildingCategory category)
    {
        return category switch
        {
            BuildingCategory.Living => new Color(0.8f, 0.6f, 0.4f), // Brown
            BuildingCategory.Working => new Color(0.6f, 0.6f, 0.8f), // Blue
            BuildingCategory.Decorative => new Color(0.8f, 0.4f, 0.8f), // Purple
            BuildingCategory.Infrastructure => new Color(0.6f, 0.8f, 0.6f), // Green
            _ => Color.gray
        };
    }

    public List<BuildingTemplate> GetBuildingsByCategory(BuildingCategory category)
    {
        List<BuildingTemplate> buildings = new List<BuildingTemplate>();

        foreach (var template in buildingTemplates)
        {
            if (template.category == category)
            {
                buildings.Add(template);
            }
        }

        return buildings;
    }

    public string GetResourceCostString(BuildingTemplate template)
    {
        if (template.costs == null || template.costs.Length == 0)
            return "Free";

        List<string> costStrings = new List<string>();
        foreach (var cost in template.costs)
        {
            costStrings.Add($"{cost.amount} {cost.resourceType}");
        }

        return string.Join(", ", costStrings);
    }

    // Debug visualization
    void OnDrawGizmos()
    {
        if (isBuildModeActive && selectedBuildingTemplate != null && previewObject != null)
        {
            // Draw building bounds
            Gizmos.color = Color.yellow;
            Vector3 boxSize = new Vector3(selectedBuildingTemplate.size.x, 2f, selectedBuildingTemplate.size.y);
            Gizmos.DrawWireCube(previewObject.transform.position, boxSize);
        }
    }
}