using System.Collections.Generic;
using SplashEdit.RuntimeCode;
using UnityEngine;
using UnityEngine.Serialization;

namespace SplashEdit.RuntimeCode
{
    /// <summary>
    /// Collision type for PS1 runtime
    /// </summary>
    public enum PSXCollisionType
    {
        None = 0,           // No collision
        Solid = 1,          // Solid collision - blocks movement
        Trigger = 2,        // Trigger - fires events but doesn't block
        Platform = 3        // Platform - solid from above, passable from below
    }
    
    /// <summary>
    /// Object behavior flags for PS1 runtime
    /// </summary>
    [System.Flags]
    public enum PSXObjectFlags
    {
        None = 0,
        Static = 1 << 0,            // Object never moves (can be optimized)
        Dynamic = 1 << 1,           // Object can move
        Visible = 1 << 2,           // Object is rendered
        CastsShadow = 1 << 3,       // Object casts shadows (future)
        ReceivesShadow = 1 << 4,    // Object receives shadows (future)
        Interactable = 1 << 5,      // Player can interact with this
        AlwaysRender = 1 << 6,      // Skip frustum culling for this object
    }

    [RequireComponent(typeof(Renderer))]
    public class PSXObjectExporter : MonoBehaviour, IPSXExportable
    {
        public LuaFile LuaFile => luaFile;

        [FormerlySerializedAs("IsActive")]
        [SerializeField] private bool isActive = true;
        public bool IsActive => isActive;

        public List<PSXTexture2D> Textures { get; set; } = new List<PSXTexture2D>();
        public PSXMesh Mesh { get; protected set; }
        
        [Header("Export Settings")]
        [FormerlySerializedAs("BitDepth")]
        [SerializeField] private PSXBPP bitDepth = PSXBPP.TEX_8BIT;
        [SerializeField] private LuaFile luaFile;
        
        [Header("Object Flags")]
        [SerializeField] private PSXObjectFlags objectFlags = PSXObjectFlags.Static | PSXObjectFlags.Visible;
        
        [Header("Collision Settings")]
        [SerializeField] private PSXCollisionType collisionType = PSXCollisionType.None;
        [SerializeField] private bool exportCollisionMesh = false;
        [SerializeField] private Mesh customCollisionMesh; // Optional simplified collision mesh
        [Tooltip("Layer mask for collision detection (1-8)")]
        [Range(1, 8)]
        [SerializeField] private int collisionLayer = 1;

        [Header("Navigation")]
        [Tooltip("Include this object's walkable surfaces in nav region generation")]
        [SerializeField] private bool generateNavigation = false;
        
        [Header("Gizmo Settings")]
        [FormerlySerializedAs("PreviewNormals")]
        [SerializeField] private bool previewNormals = false;
        [SerializeField] private float normalPreviewLength = 0.5f;
        [SerializeField] private bool showCollisionBounds = true;

        // Public accessors for editor and export
        public PSXBPP BitDepth => bitDepth;
        public PSXCollisionType CollisionType => collisionType;
        public bool ExportCollisionMesh => exportCollisionMesh;
        public Mesh CustomCollisionMesh => customCollisionMesh;
        public int CollisionLayer => collisionLayer;
        public PSXObjectFlags ObjectFlags => objectFlags;
        public bool GenerateNavigation => generateNavigation;
        
        // For assigning texture from editor
        public Texture2D texture;

        private readonly Dictionary<(int, PSXBPP), PSXTexture2D> cache = new();

        private void OnDrawGizmos()
        {
            if (previewNormals)
            {
                MeshFilter filter = GetComponent<MeshFilter>();

                if (filter != null)
                {
                    Mesh mesh = filter.sharedMesh;
                    Vector3[] vertices = mesh.vertices;
                    Vector3[] normals = mesh.normals;

                    Gizmos.color = Color.green;

                    for (int i = 0; i < vertices.Length; i++)
                    {
                        Vector3 worldVertex = transform.TransformPoint(vertices[i]);
                        Vector3 worldNormal = transform.TransformDirection(normals[i]);

                        Gizmos.DrawLine(worldVertex, worldVertex + worldNormal * normalPreviewLength);
                    }
                }
            }
        }
        
        private void OnDrawGizmosSelected()
        {
            // Draw collision bounds when object is selected
            if (showCollisionBounds && collisionType != PSXCollisionType.None)
            {
                MeshFilter filter = GetComponent<MeshFilter>();
                Mesh collisionMesh = customCollisionMesh != null ? customCollisionMesh : (filter?.sharedMesh);
                
                if (collisionMesh != null)
                {
                    Bounds bounds = collisionMesh.bounds;
                    
                    // Choose color based on collision type
                    switch (collisionType)
                    {
                        case PSXCollisionType.Solid:
                            Gizmos.color = new Color(1f, 0.3f, 0.3f, 0.5f); // Red
                            break;
                        case PSXCollisionType.Trigger:
                            Gizmos.color = new Color(0.3f, 1f, 0.3f, 0.5f); // Green
                            break;
                        case PSXCollisionType.Platform:
                            Gizmos.color = new Color(0.3f, 0.3f, 1f, 0.5f); // Blue
                            break;
                    }
                    
                    // Draw AABB
                    Matrix4x4 oldMatrix = Gizmos.matrix;
                    Gizmos.matrix = transform.localToWorldMatrix;
                    Gizmos.DrawWireCube(bounds.center, bounds.size);
                    
                    // Draw filled with lower alpha
                    Color fillColor = Gizmos.color;
                    fillColor.a = 0.1f;
                    Gizmos.color = fillColor;
                    Gizmos.DrawCube(bounds.center, bounds.size);
                    
                    Gizmos.matrix = oldMatrix;
                }
            }
        }

        public void CreatePSXTextures2D()
        {
            Renderer renderer = GetComponent<Renderer>();
            Textures.Clear();
            if (renderer != null)
            {
                // If an override texture is set, use it for all submeshes
                if (texture != null)
                {
                    PSXTexture2D tex;
                    if (cache.ContainsKey((texture.GetInstanceID(), bitDepth)))
                    {
                        tex = cache[(texture.GetInstanceID(), bitDepth)];
                    }
                    else
                    {
                        tex = PSXTexture2D.CreateFromTexture2D(texture, bitDepth);
                        tex.OriginalTexture = texture;
                        cache.Add((texture.GetInstanceID(), bitDepth), tex);
                    }
                    Textures.Add(tex);
                    return;
                }

                Material[] materials = renderer.sharedMaterials;

                foreach (Material mat in materials)
                {
                    if (mat != null && mat.mainTexture != null)
                    {
                        Texture mainTexture = mat.mainTexture;
                        Texture2D tex2D = null;

                        if (mainTexture is Texture2D existingTex2D)
                        {
                            tex2D = existingTex2D;
                        }
                        else
                        {
                            tex2D = ConvertToTexture2D(mainTexture);
                        }

                        if (tex2D != null)
                        {
                            PSXTexture2D tex;
                            if (cache.ContainsKey((tex2D.GetInstanceID(), bitDepth)))
                            {
                                tex = cache[(tex2D.GetInstanceID(), bitDepth)];
                            }
                            else
                            {
                                tex = PSXTexture2D.CreateFromTexture2D(tex2D, bitDepth);
                                tex.OriginalTexture = tex2D;
                                cache.Add((tex2D.GetInstanceID(), bitDepth), tex);
                            }
                            Textures.Add(tex);
                        }
                    }
                }
            }
        }

        private Texture2D ConvertToTexture2D(Texture texture)
        {
            Texture2D texture2D = new Texture2D(texture.width, texture.height, TextureFormat.RGBA32, false);

            RenderTexture currentActiveRT = RenderTexture.active;
            RenderTexture.active = texture as RenderTexture;

            texture2D.ReadPixels(new Rect(0, 0, texture.width, texture.height), 0, 0);
            texture2D.Apply();

            RenderTexture.active = currentActiveRT;

            return texture2D;
        }

        public PSXTexture2D GetTexture(int index)
        {
            if (index >= 0 && index < Textures.Count)
            {
                return Textures[index];
            }
            return null;
        }

        public void CreatePSXMesh(float GTEScaling)
        {
            Renderer renderer = GetComponent<Renderer>();
            if (renderer != null)
            {
                Mesh = PSXMesh.CreateFromUnityRenderer(renderer, GTEScaling, transform, Textures);
            }
        }
    }
}