using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using XP.Scan.Attributes;
using XP.Scan.Models;

namespace XP.Scan.Services
{
    /// <summary>
    /// 扫描配置 INI 序列化实现 | Scan config INI serialization implementation
    /// 通过反射 + 自定义特性自动生成/解析 INI 内容
    /// </summary>
    public class ScanConfigSerializer : IScanConfigSerializer
    {
        /// <summary>
        /// 将配置数据序列化为 INI 格式字符串
        /// </summary>
        public string Serialize(ScanConfigData config)
        {
            if (config == null) throw new ArgumentNullException(nameof(config));

            var sb = new StringBuilder();
            var sections = GetSectionObjects(config);

            foreach (var (sectionName, sectionObj) in sections)
            {
                sb.AppendLine($"[{sectionName}]");
                SerializeSection(sb, sectionObj);
                sb.AppendLine();
            }

            return sb.ToString().TrimEnd();
        }

        /// <summary>
        /// 将配置数据写入 INI 文件
        /// </summary>
        public void SaveToFile(ScanConfigData config, string filePath)
        {
            if (string.IsNullOrEmpty(filePath)) throw new ArgumentNullException(nameof(filePath));

            var directory = Path.GetDirectoryName(filePath);
            if (!string.IsNullOrEmpty(directory) && !Directory.Exists(directory))
            {
                Directory.CreateDirectory(directory);
            }

            var content = Serialize(config);
            File.WriteAllText(filePath, content, new UTF8Encoding(false));
        }

        /// <summary>
        /// 从 INI 文件读取配置数据
        /// </summary>
        public ScanConfigData LoadFromFile(string filePath)
        {
            if (!File.Exists(filePath))
                throw new FileNotFoundException($"INI file not found: {filePath}", filePath);

            var lines = File.ReadAllLines(filePath, Encoding.UTF8);
            var iniData = ParseIniLines(lines);

            var config = new ScanConfigData();
            DeserializeSection(iniData, config.ProjectInfo);
            DeserializeSection(iniData, config.XRay);
            DeserializeSection(iniData, config.Detector);
            DeserializeSection(iniData, config.MoveControl);
            DeserializeSection(iniData, config.ScanSettings);
            DeserializeSection(iniData, config.Correction);

            return config;
        }

        #region 序列化辅助方法

        /// <summary>
        /// 获取 ScanConfigData 中所有标注了 [IniSection] 的子对象
        /// </summary>
        private List<(string SectionName, object SectionObj)> GetSectionObjects(ScanConfigData config)
        {
            var result = new List<(string, object)>();

            foreach (var prop in typeof(ScanConfigData).GetProperties())
            {
                var obj = prop.GetValue(config);
                if (obj == null) continue;

                var sectionAttr = obj.GetType().GetCustomAttribute<IniSectionAttribute>();
                if (sectionAttr != null)
                {
                    result.Add((sectionAttr.SectionName, obj));
                }
            }

            return result;
        }

        /// <summary>
        /// 序列化单个 Section 的所有属性为 key=value 行
        /// </summary>
        private void SerializeSection(StringBuilder sb, object sectionObj)
        {
            foreach (var prop in sectionObj.GetType().GetProperties())
            {
                var keyAttr = prop.GetCustomAttribute<IniKeyAttribute>();
                var keyName = keyAttr?.KeyName ?? prop.Name;
                var value = prop.GetValue(sectionObj);
                var valueStr = FormatValue(value);

                sb.AppendLine($"{keyName}={valueStr}");
            }
        }

        /// <summary>
        /// 格式化属性值为 INI 字符串（使用 InvariantCulture）
        /// </summary>
        private string FormatValue(object? value)
        {
            if (value == null) return string.Empty;

            return value switch
            {
                double d => d.ToString(CultureInfo.InvariantCulture),
                float f => f.ToString(CultureInfo.InvariantCulture),
                _ => value.ToString() ?? string.Empty
            };
        }

        #endregion

        #region 反序列化辅助方法

        /// <summary>
        /// 解析 INI 文件行为 Section → Key/Value 字典
        /// </summary>
        private Dictionary<string, Dictionary<string, string>> ParseIniLines(string[] lines)
        {
            var result = new Dictionary<string, Dictionary<string, string>>(StringComparer.OrdinalIgnoreCase);
            string currentSection = string.Empty;

            foreach (var rawLine in lines)
            {
                var line = rawLine.Trim();

                // 跳过空行和注释
                if (string.IsNullOrEmpty(line) || line.StartsWith(";") || line.StartsWith("#"))
                    continue;

                // Section 头
                if (line.StartsWith("[") && line.EndsWith("]"))
                {
                    currentSection = line.Substring(1, line.Length - 2).Trim();
                    if (!result.ContainsKey(currentSection))
                    {
                        result[currentSection] = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
                    }
                    continue;
                }

                // Key=Value
                var eqIndex = line.IndexOf('=');
                if (eqIndex > 0 && !string.IsNullOrEmpty(currentSection))
                {
                    var key = line.Substring(0, eqIndex).Trim();
                    var val = line.Substring(eqIndex + 1).Trim();
                    result[currentSection][key] = val;
                }
            }

            return result;
        }

        /// <summary>
        /// 将 INI 数据反序列化到模型对象
        /// </summary>
        private void DeserializeSection(Dictionary<string, Dictionary<string, string>> iniData, object sectionObj)
        {
            var sectionAttr = sectionObj.GetType().GetCustomAttribute<IniSectionAttribute>();
            if (sectionAttr == null) return;

            if (!iniData.TryGetValue(sectionAttr.SectionName, out var sectionData))
                return;

            foreach (var prop in sectionObj.GetType().GetProperties())
            {
                var keyAttr = prop.GetCustomAttribute<IniKeyAttribute>();
                var keyName = keyAttr?.KeyName ?? prop.Name;

                if (!sectionData.TryGetValue(keyName, out var valueStr))
                    continue;

                try
                {
                    var convertedValue = ConvertValue(valueStr, prop.PropertyType);
                    if (convertedValue != null)
                    {
                        prop.SetValue(sectionObj, convertedValue);
                    }
                }
                catch
                {
                    // 转换失败时保留默认值
                }
            }
        }

        /// <summary>
        /// 将字符串值转换为目标类型
        /// </summary>
        private object? ConvertValue(string value, Type targetType)
        {
            if (targetType == typeof(string))
                return value;

            if (targetType == typeof(int))
                return int.TryParse(value, NumberStyles.Any, CultureInfo.InvariantCulture, out var i) ? i : null;

            if (targetType == typeof(double))
                return double.TryParse(value, NumberStyles.Any, CultureInfo.InvariantCulture, out var d) ? d : null;

            if (targetType == typeof(float))
                return float.TryParse(value, NumberStyles.Any, CultureInfo.InvariantCulture, out var f) ? f : null;

            if (targetType == typeof(bool))
                return bool.TryParse(value, out var b) ? b : null;

            return null;
        }

        #endregion
    }
}