using ModelRenderer.Scripts.Common;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using UnityEngine; // thêm để dùng Resources & TextAsset

namespace BrewMonster
{
    public class CECStringTab
    {
        private readonly Dictionary<int, string> m_AStrTab = new Dictionary<int, string>();
        private readonly Dictionary<int, string> m_WStrTab = new Dictionary<int, string>();

        private bool m_bInit = false;
        private bool m_bUnicode = false;

        public CECStringTab() { }
        ~CECStringTab() { Release(); }

        /// <summary>
        /// Initialize the table directly from a Unity TextAsset (e.g. loaded via Addressables).
        /// </summary>
        public bool InitFromTextAsset(TextAsset textAsset, bool bUnicode)
        {
            Release();
            m_bUnicode = bUnicode;

            try
            {
                if (textAsset == null)
                {
                    Debug.LogError("[CECStringTab] InitFromTextAsset failed: textAsset is null");
                    return false;
                }

                bool ok;
                if (bUnicode)
                {
                    // Unity TextAsset.text is already UTF-8 decoded.
                    using var sr = new StringReader(textAsset.text);
                    ok = ParseIntoDict(sr, isWide: true);
                }
                else
                {
                    // ANSI tables are in CP936 in original PW; keep using CP936 decoder.
                    string content = ByteToStringUtils.ByteArrayToCP936String(textAsset.bytes);
                    using var sr = new StringReader(content);
                    ok = ParseIntoDict(sr, isWide: false);
                }

                m_bInit = ok;
                return ok;
            }
            catch (Exception e)
            {
                Debug.LogError($"[CECStringTab] InitFromTextAsset failed: {e}");
                Release();
                return false;
            }
        }

        public bool Init(string szFile, bool bUnicode)
        {
            Release();
            m_bUnicode = bUnicode;

            try
            {
                bool ok = bUnicode ? LoadWideStrings(szFile) : LoadANSIStrings(szFile);
                m_bInit = ok;
                return ok;
            }
            catch (Exception e)
            {
                Debug.LogError($"[CECStringTab] Init failed: {e}");
                Release();
                return false;
            }
        }

        public void Release()
        {
            m_AStrTab.Clear();
            m_WStrTab.Clear();
            m_bInit = false;
            m_bUnicode = false;
        }

        public string GetANSIString(int n) => m_AStrTab.TryGetValue(n, out var s) ? s : null;
        public string GetWideString(int n) => m_WStrTab.TryGetValue(n, out var s) ? s : null;
        public string GetWideStringObject(int n) => GetWideString(n);
        public bool IsInitialized() => m_bInit;

        // ==== Đọc từ Resources thay vì đường dẫn ====

        protected bool LoadANSIStrings(string resourceName)
        {
            try
            {
                // If a real file path is provided (e.g. StreamingAssets), read directly from disk.
                // 如果提供的是实际文件路径（例如 StreamingAssets），则直接从磁盘读取。
                if (File.Exists(resourceName))
                {
                    // ANSI tables are in CP936 in original PW; keep using CP936 decoder.
                    // 原版完美世界的ANSI表是CP936编码，这里保持一致。
                    byte[] bytes = File.ReadAllBytes(resourceName);
                    string content = ByteToStringUtils.ByteArrayToCP936String(bytes);
                    using var srFile = new StringReader(content);
                    return ParseIntoDict(srFile, isWide: false);
                }

                // Fallback to Resources (old behaviour).
                // 回退到 Resources 加载（旧行为）。
                TextAsset textAsset = Resources.Load<TextAsset>(resourceName);
                if (textAsset == null)
                {
                    Debug.LogError($"[CECStringTab] Resource not found: {resourceName}");
                    return false;
                }

                string resContent = ByteToStringUtils.ByteArrayToCP936String(textAsset.bytes);
                using var srRes = new StringReader(resContent);
                return ParseIntoDict(srRes, isWide: false);
            }
            catch (Exception e)
            {
                Debug.LogError($"[CECStringTab] LoadANSIStrings failed for '{resourceName}': {e}");
                return false;
            }
        }

        protected bool LoadWideStrings(string resourceName)
        {
            try
            {
                // Support absolute / relative filesystem paths (e.g. StreamingAssets/configs/*.txt)
                // 支持文件系统路径（例如 StreamingAssets/configs/*.txt）
                if (File.Exists(resourceName))
                {
                    // String tables we ship in StreamingAssets are saved as UTF-8.
                    // 我们放在 StreamingAssets 里的字符串表保存为 UTF-8。
                    string content = File.ReadAllText(resourceName, Encoding.UTF8);
                    using var srFile = new StringReader(content);
                    return ParseIntoDict(srFile, isWide: true);
                }

                // Fallback to Resources-based loading (old behaviour)
                // 回退到基于 Resources 的加载（旧行为）
                TextAsset textAsset = Resources.Load<TextAsset>(resourceName);
                if (textAsset == null)
                {
                    Debug.LogError($"[CECStringTab] Resource not found: {resourceName}");
                    return false;
                }

                // Unity TextAsset.text is already UTF-8 decoded.
                string resContent = textAsset.text;
                using var srRes = new StringReader(resContent);
                return ParseIntoDict(srRes, isWide: true);
            }
            catch (Exception e)
            {
                Debug.LogError($"[CECStringTab] LoadWideStrings failed for '{resourceName}': {e}");
                return false;
            }
        }

        private static Encoding DetectEncoding(byte[] bom)
        {
            if (bom.Length >= 3 && bom[0] == 0xEF && bom[1] == 0xBB && bom[2] == 0xBF) return Encoding.UTF8;
            if (bom.Length >= 2 && bom[0] == 0xFF && bom[1] == 0xFE) return Encoding.Unicode;
            if (bom.Length >= 2 && bom[0] == 0xFE && bom[1] == 0xFF) return Encoding.BigEndianUnicode;
            return null;
        }

        private bool ParseIntoDict(StringReader sr, bool isWide)
        {
            bool bIndexMode = false;
            bool bBegan = false;
            int autoIndex = 0;

            var allLines = new List<string>();
            string line;
            while ((line = sr.ReadLine()) != null)
            {
                allLines.Add(line);
            }

            for (int i = 0; i < allLines.Count; i++)
            {
                var ln = allLines[i].Trim();
                if (ln.Length == 0) continue;

                if (ln.Equals("#_index", StringComparison.OrdinalIgnoreCase))
                {
                    bIndexMode = true;
                }
                else if (ln.Equals("#_begin", StringComparison.OrdinalIgnoreCase))
                {
                    bBegan = true;

                    for (int j = i + 1; j < allLines.Count; j++)
                    {
                        var payload = allLines[j].Trim();
                        if (payload.Length == 0) continue;
                        if (payload.StartsWith("#")) continue;
                        if (payload.StartsWith("//")) continue;

                        if (bIndexMode)
                        {
                            if (!TrySplitIndexAndText(payload, out int idx, out string text))
                                continue;
                            
                            // Check if the text is a multiline quoted string
                            string fullText = ReadMultilineQuotedString(text, allLines, ref j);
                            PutString(idx, fullText, isWide);
                        }
                        else
                        {
                            PutString(autoIndex++, payload, isWide);
                        }
                    }
                    break;
                }
            }

            return bBegan;
        }

        private static bool TrySplitIndexAndText(string line, out int index, out string text)
        {
            index = 0; text = null;

            int eq = line.IndexOf('=');
            if (eq >= 0)
            {
                var left = line.Substring(0, eq).Trim();
                var right = line.Substring(eq + 1);
                if (int.TryParse(left, out index))
                {
                    text = right;
                    return true;
                }
                return false;
            }

            int sp = FirstWhiteSpaceIndex(line);
            if (sp <= 0) return false;

            var left2 = line.Substring(0, sp).Trim();
            var right2 = line.Substring(sp).TrimStart();
            if (int.TryParse(left2, out index))
            {
                if (right2.Length > 0 && (right2[0] == '"' || right2[0] == '\''))
                {
                    text = right2;
                    return true;
                }
            }
            return false;
        }

        private static int FirstWhiteSpaceIndex(string s)
        {
            for (int i = 0; i < s.Length; i++)
                if (char.IsWhiteSpace(s[i])) return i;
            return -1;
        }

        /// <summary>
        /// Reads a multiline quoted string similar to C++ AWScriptFile.GetNextToken(false)
        /// If the string starts with " but doesn't end with ", continues reading subsequent lines
        /// </summary>
        private string ReadMultilineQuotedString(string firstLine, List<string> allLines, ref int currentIndex)
        {
            // If it doesn't start with a quote, return as-is
            if (string.IsNullOrEmpty(firstLine) || firstLine[0] != '"')
                return firstLine;

            // Check if the string is already complete (starts and ends with quotes on same line)
            if (firstLine.Length >= 2 && firstLine[firstLine.Length - 1] == '"')
            {
                // Check if it's not an escaped quote by looking at preceding character
                // Simple check: if there's more than one char and last is ", assume complete
                return firstLine;
            }

            // The string is incomplete - need to read more lines
            StringBuilder sb = new StringBuilder();
            sb.Append(firstLine);

            // Continue reading lines until we find the closing quote
            for (int k = currentIndex + 1; k < allLines.Count; k++)
            {
                string nextLine = allLines[k];
                
                // Append newline to preserve original formatting (matching C++ behavior)
                sb.Append("\n");
                sb.Append(nextLine);

                // Check if this line contains the closing quote
                // Look for " at the end of the trimmed line
                string trimmedNext = nextLine.TrimEnd();
                if (trimmedNext.Length > 0 && trimmedNext[trimmedNext.Length - 1] == '"')
                {
                    // Found the closing quote, update the index and return
                    currentIndex = k;
                    return sb.ToString();
                }
            }

            // If we reach here, the closing quote wasn't found - return what we have
            return sb.ToString();
        }

        private void PutString(int id, string value, bool isWide)
        {
            if (string.IsNullOrEmpty(value))
                return;

            // Many PW string tables wrap the payload in double quotes, e.g.:
            //  12345  "^ffcb4aSome text\rMore text"
            // Strip a single leading/trailing quote pair to avoid showing raw quotes in UI.
            // 许多字符串表会用双引号包裹内容，这里去掉首尾各一个引号以避免在UI中显示多余的引号。
            if (value.Length >= 2 && value[0] == '"' && value[value.Length - 1] == '"')
            {
                value = value.Substring(1, value.Length - 2);
            }
            if (isWide) m_WStrTab[id] = value;
            else m_AStrTab[id] = value;
        }
    }
}