using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.Json;
using APS7100TestTool.Models;
using MiniExcelLibs;

namespace APS7100TestTool.Services
{
    public class ConfigService
    {
        /// <summary>
        /// Config 文件夹路径
        /// </summary>
        public static readonly string ConfigFolder = Path.Combine(
            AppDomain.CurrentDomain.BaseDirectory, "Config");
        
        private static readonly string AppSettingsPath = Path.Combine(
            ConfigFolder, "appsettings.json");
        
        /// <summary>
        /// 默认的 Modbus 配置文件路径
        /// </summary>
        public static readonly string DefaultModbusConfigPath = Path.Combine(
            ConfigFolder, "ModbusConfig.xlsx");
        
        /// <summary>
        /// 静态构造函数，确保 Config 文件夹存在
        /// </summary>
        static ConfigService()
        {
            if (!Directory.Exists(ConfigFolder))
            {
                Directory.CreateDirectory(ConfigFolder);
            }
        }

        #region Modbus Config

        public List<ModbusRegisterMapping> LoadModbusConfig(string filePath)
        {
            try
            {
                var rows = MiniExcel.Query<ModbusRegisterMapping>(filePath).ToList();
                return rows;
            }
            catch (Exception ex)
            {
                throw new Exception($"加载配置文件失败: {ex.Message}", ex);
            }
        }

        /// <summary>
        /// 保存 Modbus 配置到文件
        /// </summary>
        public void SaveModbusConfig(string filePath, List<ModbusRegisterMapping> mappings)
        {
            try
            {
                // 如果文件已存在，先删除（MiniExcel 不支持覆盖）
                if (File.Exists(filePath))
                {
                    File.Delete(filePath);
                }
                MiniExcel.SaveAs(filePath, mappings);
            }
            catch (Exception ex)
            {
                throw new Exception($"保存配置文件失败: {ex.Message}", ex);
            }
        }

        public void CreateTemplate(string filePath)
        {
            // 模板示例：区分 APS7100 和 PSW250 的命令格式
            var data = new[]
            {
                // ========== APS7100 示例 ==========
                new ModbusRegisterMapping 
                { 
                    Address = 1, 
                    RegisterType = "Holding", 
                    OperationType = "Write", 
                    DataType = "Float", 
                    DeviceTarget = "APS7100",
                    ScpiCommand = "SOUR:VOLT {0}", 
                    ScaleFactor = 1.0, 
                    Description = "[APS] 设置电压 (V)" 
                },
                new ModbusRegisterMapping 
                { 
                    Address = 10, 
                    RegisterType = "Holding", 
                    OperationType = "Read", 
                    DataType = "Float", 
                    DeviceTarget = "APS7100",
                    // ⚠ APS7100 必须使用 MEAS:SCAL:VOLT?
                    ScpiCommand = "MEAS:SCAL:VOLT?", 
                    ScaleFactor = 1.0, 
                    Description = "[APS] 测量电压 (V)" 
                },
                new ModbusRegisterMapping 
                { 
                    Address = 20, 
                    RegisterType = "Holding", 
                    OperationType = "Write", 
                    DataType = "Int16", 
                    DeviceTarget = "APS7100",
                    TriggerValue = 1,
                    // ⚠ APS7100 必须使用 OUTP:STAT
                    ScpiCommand = "OUTP:STAT ON", 
                    ScaleFactor = 1.0, 
                    Description = "[APS] 开启输出" 
                },
                // ========== PSW250 示例 ==========
                new ModbusRegisterMapping 
                { 
                    Address = 100, 
                    RegisterType = "Holding", 
                    OperationType = "Write", 
                    DataType = "Float", 
                    DeviceTarget = "PSW250",
                    ScpiCommand = "SOUR:VOLT {0}", 
                    ScaleFactor = 1.0, 
                    Description = "[PSW] 设置电压 (V)" 
                },
                new ModbusRegisterMapping 
                { 
                    Address = 110, 
                    RegisterType = "Holding", 
                    OperationType = "Read", 
                    DataType = "Float", 
                    DeviceTarget = "PSW250",
                    // PSW250 支持简写命令
                    ScpiCommand = "MEAS:VOLT?", 
                    ScaleFactor = 1.0, 
                    Description = "[PSW] 测量电压 (V)" 
                },
            };
            MiniExcel.SaveAs(filePath, data);
        }

        #endregion

        #region App Settings

        /// <summary>
        /// 加载应用程序设置
        /// </summary>
        public AppSettings LoadAppSettings()
        {
            try
            {
                if (File.Exists(AppSettingsPath))
                {
                    string json = File.ReadAllText(AppSettingsPath);
                    var settings = JsonSerializer.Deserialize<AppSettings>(json);
                    return settings ?? new AppSettings();
                }
            }
            catch
            {
                // 如果加载失败，返回默认设置
            }
            return new AppSettings();
        }

        /// <summary>
        /// 保存应用程序设置
        /// </summary>
        public void SaveAppSettings(AppSettings settings)
        {
            try
            {
                settings.LastUpdated = DateTime.Now;
                var options = new JsonSerializerOptions 
                { 
                    WriteIndented = true 
                };
                string json = JsonSerializer.Serialize(settings, options);
                File.WriteAllText(AppSettingsPath, json);
            }
            catch (Exception ex)
            {
                throw new Exception($"保存设置失败: {ex.Message}", ex);
            }
        }

        #endregion
    }
}