using System.Linq;
using UnityEngine.Localization.Settings;
using Yarn.Unity;
using AibisDream.Framework;
using UnityEngine;

namespace AibisDream
{
    public class LocalisedLineProvider : LineProviderBehaviour
    {
        private const string LocalizationPrefix = "l10n.";
        
        private LocalizationTable _localizationTable;

        public override string LocaleCode => LocalizationSettings.SelectedLocale.Identifier.Code;

        // 本地化表存在即可用
        public override bool LinesAvailable => _localizationTable != null;

        // We're good to go!
        public override LocalizedLine GetLocalizedLine(Yarn.Line line)
        {
            var text = line.ID;
            if (_localizationTable != null)
            {
                text = _localizationTable[line.ID]?.LocalizedValue ??
                       $"Error: Missing localisation for line {line.ID} in string table {_localizationTable.LocaleIdentifier}";
            }

            LocalizeSubstitutions(line);

            // Construct the localized line
            LocalizedLine localizedLine = new LocalizedLine
            {
                TextID = line.ID,
                RawText = text,
                Substitutions = line.Substitutions,
                Metadata = YarnProject.lineMetadata.GetMetadata(line.ID)
            };

            // Attempt to fetch metadata tags for this line from the string
            // table
            if (_localizationTable == null) return localizedLine;
            
            var metadata = _localizationTable[line.ID]?.SharedEntry.Metadata
                .GetMetadata<Yarn.Unity.UnityLocalization.LineMetadata>();

            if (metadata != null && localizedLine.Metadata != null)
            {
                localizedLine.Metadata = localizedLine.Metadata.Concat(metadata.tags).ToArray();
            }
            else if (localizedLine.Metadata == null && metadata != null)
            {
                localizedLine.Metadata = metadata.tags;
            }

            return localizedLine;
        }

        private void LocalizeSubstitutions(Yarn.Line line)
        {
            for (var i = 0; i < line.Substitutions.Length; i++)
            {
                if (line.Substitutions[i].StartsWith(LocalizationPrefix))
                {
                    var localizationKey = line.Substitutions[i].Substring(LocalizationPrefix.Length);
                    // 获取本地化值
                    if (_localizationTable.TryGetValue(localizationKey, out var value))
                    {
                        line.Substitutions[i] = value.LocalizedValue;
                    }
                    else
                    {
                        // 如果找不到，则使用原始值
                        Debug.LogWarning($"Variable Key '{localizationKey}' not found in localization table.");
                        line.Substitutions[i] = localizationKey;
                    }
                }
            }
        }

        /// <summary>
        /// 初始化StringTable
        /// </summary>
        /// <param name="tableName">本地化表名称</param>
        /// <returns>协程</returns>
        public void InitStringTable(string tableName)
        {
            Debug.Log(tableName + "Init");
            // 释放
            _localizationTable?.Dispose();
            // 加载
            _localizationTable = new LocalizationTable(tableName);
        }

        public string GetStringTableName()
        {
            return _localizationTable.TableName;
        }
    }
}