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

namespace DMS.Application.Services.Database;

/// <summary>
/// 菜单应用服务，负责处理菜单相关的业务逻辑。
/// 实现 <see cref="IMenuAppService"/> 接口。
/// </summary>
public class MenuAppService : IMenuAppService
{
    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 MenuAppService(IRepositoryManager repoManager, IMapper mapper)
    {
        _repoManager = repoManager;
        _mapper = mapper;
    }

    /// <summary>
    /// 异步根据ID获取菜单。
    /// </summary>
    /// <param name="id">菜单ID。</param>
    /// <returns>菜单对象。</returns>
    public async Task<MenuBean> GetMenuByIdAsync(int id)
    {
        var menu = await _repoManager.Menus.GetByIdAsync(id);
        return _mapper.Map<MenuBean>(menu);
    }

    /// <summary>
    /// 异步获取所有菜单列表。
    /// </summary>
    /// <returns>菜单列表。</returns>
    public async Task<List<MenuBean>> GetAllMenusAsync()
    {
        var menus = await _repoManager.Menus.GetAllAsync();
        return _mapper.Map<List<MenuBean>>(menus);
    }

    /// <summary>
    /// 异步创建一个新菜单（事务性操作）。
    /// </summary>
    /// <param name="menu">要创建的菜单。</param>
    /// <returns>新创建菜单的ID。</returns>
    /// <exception cref="ApplicationException">如果创建菜单时发生错误。</exception>
    public async Task<int> CreateMenuAsync(MenuBean menu)
    {
        try
        {
            await _repoManager.BeginTranAsync();
            await _repoManager.Menus.AddAsync(menu);
            await _repoManager.CommitAsync();
            return menu.Id;
        }
        catch (Exception ex)
        {
            await _repoManager.RollbackAsync();
            throw new ApplicationException("创建菜单时发生错误，操作已回滚。", ex);
        }
    }

    /// <summary>
    /// 异步更新一个已存在的菜单（事务性操作）。
    /// </summary>
    /// <param name="menu">要更新的菜单。</param>
    /// <returns>受影响的行数。</returns>
    /// <exception cref="ApplicationException">如果找不到菜单或更新菜单时发生错误。</exception>
    public async Task<int> UpdateMenuAsync(MenuBean menu)
    {
        try
        {
            await _repoManager.BeginTranAsync();
            var dbmenu = await _repoManager.Menus.GetByIdAsync(menu.Id);
            if (dbmenu == null)
            {
                throw new ApplicationException($"Menu with ID {menu.Id} not found.");
            }
            _mapper.Map(menu, dbmenu);
            int res = await _repoManager.Menus.UpdateAsync(dbmenu);
            await _repoManager.CommitAsync();
            return res;
        }
        catch (Exception ex)
        {
            await _repoManager.RollbackAsync();
            throw new ApplicationException("更新菜单时发生错误，操作已回滚。", ex);
        }
    }

    /// <summary>
    /// 异步删除一个菜单（事务性操作）。
    /// </summary>
    /// <param name="id">要删除菜单的ID。</param>
    /// <returns>如果删除成功则为 true，否则为 false。</returns>
    /// <exception cref="InvalidOperationException">如果删除菜单失败。</exception>
    /// <exception cref="ApplicationException">如果删除菜单时发生其他错误。</exception>
    public async Task<bool> DeleteMenuAsync(int id)
    {
        try
        {
            await _repoManager.BeginTranAsync();
            var menu = await _repoManager.Menus.GetByIdAsync(id);
            if (menu == null)
            {
                throw new InvalidOperationException($"删除菜单失败：菜单ID:{id}，请检查菜单Id是否存在");
            }
            var delRes = await _repoManager.Menus.DeleteAsync(menu);
            if (delRes == 0)
            {
                throw new InvalidOperationException($"删除菜单失败：菜单ID:{id}，请检查菜单Id是否存在");
            }
            await _repoManager.CommitAsync();
            return true;
        }
        catch (Exception ex)
        {
            await _repoManager.RollbackAsync();
            throw new ApplicationException("删除菜单时发生错误，操作已回滚。", ex);
        }
    }
}