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

// Filename : CMoveMap.cs
// Creator  : ported from C++ (AutoPFImp/AutoMoveImp/MoveMap.*)
// Date     : 2026/01/09

namespace AutoMove
{
    /// <summary>
    /// Pathfinding map container (loads .cfg and its referenced .prmap/.pdhmap/.mlu).
    /// 寻路地图容器（加载 .cfg 及其引用的 .prmap/.pdhmap/.mlu）。
    /// </summary>
    public class CMoveMap
    {
        // C++: PFMAP_CFG_FILE_MAGIC (('c'<<24)|('f'<<16)|('g'<<8)|('f')) => bytes 'f''g''f''c' in LE.
        private const uint PFMAP_CFG_FILE_MAGIC = 0x63666766;
        private const uint PFMAP_CFG_FILE_VERSION = 1;

        // map origin (world pos of bottom-left corner) // 地图原点（左下角的世界坐标）
        private Vector3 m_vOrigin;
        private readonly List<CLayerMap> m_aLayers = new List<CLayerMap>(2);
        private int m_iMapWidth;
        private int m_iMapLength;
        private float m_fPixelSize = 1.0f;

        public int GetLayerCount() => m_aLayers.Count;
        public CLayerMap GetLayer(int index) => (index >= 0 && index < m_aLayers.Count) ? m_aLayers[index] : null;
        public int GetMapWidth() => m_iMapWidth;
        public int GetMapLength() => m_iMapLength;
        public float GetPixelSize() => m_fPixelSize;

        public void SetOrigin(Vector3 vOrigin)
        {
            // C++ only uses x/z.
            // C++ 只使用 x/z。
            m_vOrigin.x = vOrigin.x;
            m_vOrigin.z = vOrigin.z;
        }

        public void CalcOrigin()
        {
            // C++: use first layer rmap size and pixel size, then set origin to map center.
            // C++：用第一层 rmap 的尺寸与像素大小，然后设置 origin 为地图中心。
            if (m_aLayers.Count == 0) return;
            var rmap = m_aLayers[0].GetRMap();
            if (rmap == null) return;
            rmap.GetImageSize(out m_iMapWidth, out m_iMapLength);
            m_fPixelSize = rmap.GetPixelSize();

            m_vOrigin = Vector3.zero;
            m_vOrigin.x = -m_iMapWidth * m_fPixelSize * 0.5f;
            m_vOrigin.z = -m_iMapLength * m_fPixelSize * 0.5f;
        }

        public Vector2 TransMap2Wld(int x, int y)
        {
            return TransMap2Wld((float)x, (float)y);
        }

        public Vector2 TransMap2Wld(float mapX, float mapY)
        {
            float wx = m_vOrigin.x + (mapX + 0.5f) * m_fPixelSize;
            float wz = m_vOrigin.z + (mapY + 0.5f) * m_fPixelSize;
            return new Vector2(wx, wz);
        }

        public Vector2Int TransWld2Map(float wx, float wz)
        {
            int x = Mathf.FloorToInt((wx - m_vOrigin.x) / m_fPixelSize);
            int y = Mathf.FloorToInt((wz - m_vOrigin.z) / m_fPixelSize);
            return new Vector2Int(x, y);
        }

        public float GetDH(int iLayer, int x, int y)
        {
            var layer = GetLayer(iLayer);
            if (layer == null) return 0.0f;
            return layer.GetDH(x, y);
        }

        /// <summary>
        /// Load a movemap from cfg bytes. The resolver must return bytes for referenced files.
        /// 从 cfg 字节加载 movemap。resolver 必须返回引用文件的字节。
        /// </summary>
        public bool Load(byte[] cfgBytes, Func<string, byte[]> resolver, string debugBasePath)
        {
            try
            {
                m_aLayers.Clear();

                if (cfgBytes == null || cfgBytes.Length < 16) return false;
                int offset = 0;

                // Some PW client assets have a leading "MOXB" wrapper.
                // 一些完美客户端资源有 "MOXB" 前缀封装。
                if (cfgBytes.Length >= 8 &&
                    cfgBytes[0] == (byte)'M' && cfgBytes[1] == (byte)'O' &&
                    cfgBytes[2] == (byte)'X' && cfgBytes[3] == (byte)'B')
                {
                    offset += 4;
                }

                uint magic = BitConverter.ToUInt32(cfgBytes, offset); offset += 4;
                if (magic != PFMAP_CFG_FILE_MAGIC)
                {
                    Debug.LogWarning($"[CMoveMap] Invalid cfg magic for {debugBasePath} magic=0x{magic:X8}");
                    return false;
                }

                uint ver = BitConverter.ToUInt32(cfgBytes, offset); offset += 4;
                if (ver != PFMAP_CFG_FILE_VERSION)
                {
                    Debug.LogWarning($"[CMoveMap] Invalid cfg version for {debugBasePath} ver={ver}");
                    return false;
                }

                int count = BitConverter.ToInt32(cfgBytes, offset); offset += 4;
                if (count <= 0) return false;

                for (int i = 0; i < count; i++)
                {
                    int len = BitConverter.ToInt32(cfgBytes, offset); offset += 4;
                    string baseName = System.Text.Encoding.ASCII.GetString(cfgBytes, offset, len);
                    offset += len;

                    var layer = new CLayerMap();
                    m_aLayers.Add(layer);

                    uint flagR = BitConverter.ToUInt32(cfgBytes, offset); offset += 4;
                    if (flagR == 1)
                    {
                        byte[] prmap = resolver(baseName + ".prmap");
                        if (prmap == null || !layer.LoadRMap(prmap)) return false;
                    }

                    uint flagDH = BitConverter.ToUInt32(cfgBytes, offset); offset += 4;
                    if (flagDH == 1)
                    {
                        byte[] pdhmap = resolver(baseName + ".pdhmap");
                        if (pdhmap == null || !layer.LoadDHMap(pdhmap)) return false;
                    }

                    uint flagIsl = BitConverter.ToUInt32(cfgBytes, offset); offset += 4;
                    if (flagIsl == 1)
                    {
                        // island list not ported yet (rarely needed for basic route).
                        // island 列表暂未移植（基础寻路通常不依赖）。
                        _ = resolver(baseName + ".isl");
                    }
                }

                // mlu name (we load bytes to validate presence, but we don't port MultiCluGraph yet).
                // mlu 名称（我们读取以验证存在，但暂不移植 MultiCluGraph）。
                int mluLen = BitConverter.ToInt32(cfgBytes, offset); offset += 4;
                string mluBase = System.Text.Encoding.ASCII.GetString(cfgBytes, offset, mluLen);
                offset += mluLen;
                _ = resolver(mluBase + ".mlu");

                // compute dimensions & default origin
                // 计算尺寸与默认 origin
                CalcOrigin();
                return true;
            }
            catch (Exception ex)
            {
                Debug.LogWarning($"[CMoveMap] Load failed for {debugBasePath}: {ex.Message}");
                return false;
            }
        }
    }
}