using AutoMapper;
using DMS.Application.DTOs;
using DMS.Application.Interfaces;
using DMS.Application.Interfaces.Database;
using DMS.Core.Interfaces;
using DMS.Core.Models;

namespace DMS.Application.Services.Database;

/// <summary>
/// 变量应用服务，负责处理变量相关的业务逻辑。
/// 实现 <see cref="IVariableAppService"/> 接口。
/// </summary>
public class VariableAppService : IVariableAppService
{
    private readonly IRepositoryManager _repoManager;
    private readonly IMapper _mapper;

    /// <summary>
    /// 构造函数，通过依赖注入获取仓储管理器和AutoMapper实例。
    /// </summary>
    /// <param name="repoManager">仓储管理器实例。</param>
    /// <param name="mapper">AutoMapper 实例。</param>
    public VariableAppService(IRepositoryManager repoManager, IMapper mapper)
    {
        _repoManager = repoManager;
        _mapper = mapper;
    }

    /// <summary>
    /// 异步根据ID获取变量数据传输对象。
    /// </summary>
    /// <param name="id">变量ID。</param>
    /// <returns>变量数据传输对象。</returns>
    public async Task<Variable> GetVariableByIdAsync(int id)
    {
        var variable = await _repoManager.Variables.GetByIdAsync(id);
        return variable;
    }



    /// <summary>
    /// 异步获取所有变量数据传输对象列表。
    /// </summary>
    /// <returns>变量数据传输对象列表。</returns>
    public async Task<List<Variable>> GetAllVariablesAsync()
    {
        var variables = await _repoManager.Variables.GetAllAsync();
        return _mapper.Map<List<Variable>>(variables);
    }

    /// <summary>
    /// 异步创建一个新变量（事务性操作）。
    /// </summary>
    /// <param name="variable">要创建的变量数据传输对象。</param>
    public async Task<Variable> AddAsync(Variable variable)
    {
        try
        {
            await _repoManager.BeginTranAsync();
            var addedVariable = await _repoManager.Variables.AddAsync(variable); await _repoManager.CommitAsync();
            return _mapper.Map<Variable>(addedVariable);
        }
        catch (Exception ex)
        {
            await _repoManager.RollbackAsync();
            throw new ApplicationException($"创建变量时发生错误，操作已回滚,错误信息:{ex.Message}", ex);
        }
    }

    /// <summary>
    /// 异步更新一个已存在的变量（事务性操作）。
    /// </summary>
    /// <param name="variable">要更新的变量数据传输对象。</param>
    public async Task<int> UpdateAsync(Variable variable)
    {
        try
        {
            await _repoManager.BeginTranAsync();
            var existingVariable = await _repoManager.Variables.GetByIdAsync(variable.Id);
            if (existingVariable == null)
            {
                throw new ApplicationException($"Variable with ID {variable.Id} not found.");
            }
            _mapper.Map(variable, existingVariable);
            int res = await _repoManager.Variables.UpdateAsync(variable);
            await _repoManager.CommitAsync();
            return res;
        }
        catch (Exception ex)
        {
            await _repoManager.RollbackAsync();
            throw new ApplicationException($"更新变量时发生错误，操作已回滚,错误信息:{ex.Message}", ex);
        }
    }

    /// <summary>
    /// 异步批量更新变量（事务性操作）。
    /// </summary>
    /// <param name="variables">要更新的变量数据传输对象列表。</param>
    /// <returns>受影响的行数。</returns>
    /// <exception cref="ApplicationException">如果更新变量时发生错误。</exception>
    public async Task<int> UpdateAsync(List<Variable> variables)
    {
        try
        {
            await _repoManager.BeginTranAsync();
            int totalAffected = 0;

            foreach (var variable in variables)
            {
                var existingVariable = await _repoManager.Variables.GetByIdAsync(variable.Id);
                if (existingVariable == null)
                {
                    throw new ApplicationException($"Variable with ID {variable.Id} not found.");
                }
                _mapper.Map(variable, existingVariable);
                int res = await _repoManager.Variables.UpdateAsync(existingVariable);
                totalAffected += res;
            }

            await _repoManager.CommitAsync();
            return totalAffected;
        }
        catch (Exception ex)
        {
            await _repoManager.RollbackAsync();
            throw new ApplicationException($"批量更新变量时发生错误，操作已回滚,错误信息:{ex.Message}", ex);
        }
    }

    /// <summary>
    /// 异步删除一个变量（事务性操作）。
    /// </summary>
    /// <param name="variable1"></param>
    /// <returns>如果删除成功则为 true，否则为 false。</returns>
    /// <exception cref="InvalidOperationException">如果删除变量失败。</exception>
    /// <exception cref="ApplicationException">如果删除变量时发生其他错误。</exception>
    public async Task<bool> DeleteAsync(Variable variable)
    {
        try
        {
            await _repoManager.BeginTranAsync();
            var delRes = await _repoManager.Variables.DeleteAsync(variable);
            if (delRes == 0)
            {
                throw new InvalidOperationException($"删除变量失败：变量ID:{variable.Id}，请检查变量Id是否存在");
            }
            await _repoManager.CommitAsync();
            return true;
        }
        catch (Exception ex)
        {
            await _repoManager.RollbackAsync();
            throw new ApplicationException($"删除变量时发生错误，操作已回滚,错误信息:{ex.Message}", ex);
        }
    }

    /// <summary>
    /// 异步批量删除变量（事务性操作）。
    /// </summary>
    /// <param name="variables"></param>
    /// <returns>如果删除成功则为 true，否则为 false。</returns>
    /// <exception cref="ArgumentException">如果ID列表为空或null。</exception>
    /// <exception cref="ApplicationException">如果删除变量时发生错误。</exception>
    public async Task<bool> DeleteAsync(List<Variable> variables)
    {

        try
        {
            await _repoManager.BeginTranAsync();

            // 批量删除变量
            var deletedCount = await _repoManager.Variables.DeleteAsync(variables);

            // 检查是否所有变量都被成功删除
            if (deletedCount != variables.Count)
            {
                throw new InvalidOperationException($"删除变量失败：请求删除 {variables.Count} 个变量，实际删除 {deletedCount} 个变量");
            }

            await _repoManager.CommitAsync();
            return true;
        }
        catch (Exception ex)
        {
            await _repoManager.RollbackAsync();
            throw new ApplicationException($"批量删除变量时发生错误，操作已回滚,错误信息:{ex.Message}", ex);
        }
    }

    public async Task<List<Variable>> AddAsync(List<Variable> variables)
    {
        return await _repoManager.Variables.AddAsync(variables);
    }
}