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

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(); }

    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)
    {
        TextAsset textAsset = Resources.Load<TextAsset>(resourceName);
        if (textAsset == null)
        {
            Debug.LogError($"[CECStringTab] Resource not found: {resourceName}");
            return false;
        }

        // Giải mã bytes -> string (ANSI: dùng Encoding.Default)
        string content = ByteToStringUtils.ByteArrayToCP936String(textAsset.bytes);
        using var sr = new StringReader(content);
        return ParseIntoDict(sr, isWide: false);
    }

    protected bool LoadWideStrings(string resourceName)
    {
        TextAsset textAsset = Resources.Load<TextAsset>(resourceName);
        if (textAsset == null)
        {
            Debug.LogError($"[CECStringTab] Resource not found: {resourceName}");
            return false;
        }

        // Unity TextAsset mặc định đã decode text UTF8 -> textAsset.text
        // nhưng để chắc chắn BOM/Unicode thì đọc từ bytes
        string content;
        content = ByteToStringUtils.ByteArrayToUnicodeString(textAsset.bytes);

        using var sr = new StringReader(content);
        return ParseIntoDict(sr, isWide: true);
    }

    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;
                        PutString(idx, text, 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))
        {
            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;
    }

    private void PutString(int id, string value, bool isWide)
    {
        if (isWide) m_WStrTab[id] = value;
        else m_AStrTab[id] = value;
    }
}