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

namespace Luneraria.View
{
    /// <summary>
    /// The shared material library (port of scripts/luneraria/view/lune_materials.gd). Models name
    /// their surfaces (LN_*, ENV_*); Dress swaps them for one shared material per name and team,
    /// so all buildings share a few materials (SRP batcher friendly). Team 0 Blau, 1 Rot, 2 neutral.
    /// </summary>
    public sealed class LuneMaterialSet : ScriptableObject
    {
        [Serializable]
        public sealed class Entry
        {
            public string Key;
            public Material Neutral;
            public Material Blau;
            public Material Rot;
        }

        public List<Entry> Entries = new List<Entry>();
        Dictionary<string, Entry> _index;

        public Material Get(string key, int team)
        {
            if (_index == null)
            {
                _index = new Dictionary<string, Entry>();
                foreach (Entry entry in Entries)
                    _index[entry.Key] = entry;
            }
            if (!_index.TryGetValue(key, out Entry found))
                return null;
            Material team_material = team == 0 ? found.Blau : team == 1 ? found.Rot : null;
            return team_material != null ? team_material : found.Neutral;
        }

        /// <summary>Material key of an imported slot material ("LN_Stone_Pale", "ENV_bark (Instance)" -> key).</summary>
        public static string KeyOf(Material material)
        {
            if (material == null)
                return "";
            string name = material.name;
            int cut = name.IndexOf(" (", StringComparison.Ordinal);
            return cut < 0 ? name : name.Substring(0, cut);
        }

        /// <summary>H1: material key of a skin ("AI_Sylvara" + "blutmond" -> "AI_Sylvara_Blutmond").</summary>
        public static string SkinKey(string key, string skin)
        {
            return key + "_" + char.ToUpperInvariant(skin[0]) + skin.Substring(1);
        }

        /// <summary>
        /// Swaps every known surface below root for the shared material of the team; with a skin
        /// (H1, heroes) its variant of a material is taken where one exists.
        /// </summary>
        public void Dress(GameObject root, int team, string skin = "")
        {
            foreach (Renderer renderer in root.GetComponentsInChildren<Renderer>(true))
            {
                Material[] materials = renderer.sharedMaterials;
                bool changed = false;
                for (int i = 0; i < materials.Length; i++)
                {
                    Material shared = !string.IsNullOrEmpty(skin) ? Get(SkinKey(KeyOf(materials[i]), skin), team) : null;
                    if (shared == null)
                        shared = Get(KeyOf(materials[i]), team);
                    if (shared != null && shared != materials[i])
                    {
                        materials[i] = shared;
                        changed = true;
                    }
                }
                if (changed)
                    renderer.sharedMaterials = materials;
            }
        }
    }
}