using Mapster;
using SqlSugar;
using YY.Admin.Core;
using YY.Admin.Core.Session;
using YY.Admin.Services.Service.Role;
using YY.Admin.Services.Service.User;

namespace YY.Admin.Services.Service.Menu
{
    public class SysMenuService : ISysMenuService, ISingletonDependency
    {
        private readonly ISqlSugarClient _dbContext;
        private readonly SysUserRoleService _sysUserRoleService; 
        private readonly SysRoleMenuService _sysRoleMenuService; 
        public SysMenuService(
            ISqlSugarClient context,
                 SysRoleMenuService sysRoleMenuService,
            SysUserRoleService sysUserRoleService) {
            _dbContext=context;
            _sysUserRoleService=sysUserRoleService;
            _sysRoleMenuService=sysRoleMenuService;
        }
        /// <summary>
        /// 获取登录菜单树
        /// </summary>
        /// <returns></returns>
        public async Task<List<MenuOutput>> GetLoginMenuTree()
        {
            var currentUser = AppSession.CurrentUser;
            if (currentUser == null)
            {
                return new List<MenuOutput>();
            }

            var tenantId = currentUser.TenantId ?? 0;
            var (query, _) = GetSugarQueryableAndTenantId(tenantId);
            if (currentUser.IsSuperAdmin || currentUser.IsSysAdmin)
            {
                var menuList = await query.Where(u => u.Type != MenuTypeEnum.Btn && u.Status == StatusEnum.Enable)
                    .OrderBy(u => new { u.OrderNo, u.Id })
                    .ToTreeAsync(u => u.Children, u => u.Pid, 0);
                return menuList.Adapt<List<MenuOutput>>();
            }
            var menuIdList = await GetMenuIdList();
            if (menuIdList == null || menuIdList.Count == 0)
            {
                // Jeecg自动建档用户可能暂未分配本地角色，这里回退显示基础菜单
                var fallbackMenus = await GetFallbackMenuTreeAsync();
                return fallbackMenus.Adapt<List<MenuOutput>>();
            }

            var menuTree = await query.Where(u => u.Type != MenuTypeEnum.Btn && u.Status == StatusEnum.Enable)
                .OrderBy(u => new { u.OrderNo, u.Id }).ToTreeAsync(u => u.Children, u => u.Pid, 0, menuIdList.Select(d => (object)d).ToArray());

            // 角色或租户菜单未配置时，避免左侧功能列表全空白
            if (menuTree == null || menuTree.Count == 0)
            {
                menuTree = await GetFallbackMenuTreeAsync();
            }

            return menuTree.Adapt<List<MenuOutput>>();
        }
        /// <summary>
        /// 获取当前用户菜单Id集合
        /// </summary>
        /// <returns></returns>
        public async Task<List<long>> GetMenuIdList()
        {
            var currentUser = AppSession.CurrentUser;
            if (currentUser == null)
            {
                return new List<long>();
            }

            var roleIdList = await _sysUserRoleService.GetUserRoleIdList(currentUser.Id);
            return await _sysRoleMenuService.GetRoleMenuIdList(roleIdList);
        }
        /// <summary>
        /// 根据租户id获取构建菜单联表查询实例
        /// </summary>
        /// <param name="tenantId"></param>
        /// <returns></returns>
        public (ISugarQueryable<SysMenu, SysTenantMenu> query, long tenantId) GetSugarQueryableAndTenantId(long tenantId)
        {
            if (!AppSession.CurrentUser!.IsSuperAdmin) tenantId = AppSession.CurrentUser.TenantId!.Value;

            // 超管用户菜单范围：种子菜单 + 租户id菜单
            ISugarQueryable<SysMenu, SysTenantMenu> query;
            if (AppSession.CurrentUser.IsSuperAdmin)
            {
                if (tenantId <= 0)
                {
                    query = _dbContext.Queryable<SysMenu>().InnerJoinIF<SysTenantMenu>(false, (u, t) => true);
                }
                else
                {
                    // 指定租户的菜单
                    var menuIds = _dbContext.Queryable<SysTenantMenu>().Where(u => u.TenantId == tenantId).ToList(u => u.MenuId) ?? new();

                    // 种子菜单
                    //menuIds.AddRange(new SysMenuSeedData().HasData().Select(u => u.Id).ToList());

                    menuIds = menuIds.Distinct().ToList();
                    query = _dbContext.Queryable<SysMenu>().InnerJoinIF<SysTenantMenu>(false, (u, t) => true).Where(u => menuIds.Contains(u.Id));
                }
            }
            else if (AppSession.CurrentUser.IsSysAdmin)
            {
                // 系统管理员直接读取全量启用菜单，不依赖租户菜单关联表
                query = _dbContext.Queryable<SysMenu>().InnerJoinIF<SysTenantMenu>(false, (u, t) => true);
            }
            else
            {
                query = _dbContext.Queryable<SysMenu>().InnerJoinIF<SysTenantMenu>(tenantId > 0, (u, t) => t.TenantId == tenantId && u.Id == t.MenuId);
            }

            return (query, tenantId);
        }

        /// <summary>
        /// 菜单兜底：当角色/租户未完成绑定时返回可用基础菜单，避免界面空白
        /// </summary>
        private async Task<List<SysMenu>> GetFallbackMenuTreeAsync()
        {
            return await _dbContext.Queryable<SysMenu>()
                .Where(u => u.Type != MenuTypeEnum.Btn && u.Status == StatusEnum.Enable)
                .OrderBy(u => new { u.OrderNo, u.Id })
                .ToTreeAsync(u => u.Children, u => u.Pid, 0);
        }

        /// <inheritdoc />
        public async Task<List<SysMenu>> GetAllMenusForManageAsync()
        {
            return await _dbContext.Queryable<SysMenu>()
                .OrderBy(m => m.OrderNo)
                .OrderBy(m => m.Id)
                .ToListAsync();
        }

        /// <inheritdoc />
        public async Task<(bool ok, string message, long id)> CreateMenuAsync(SysMenu input)
        {
            if (string.IsNullOrWhiteSpace(input.Title))
                return (false, "菜单名称不能为空", 0);

            var all = await GetAllMenusForManageAsync();
            if (input.Pid != 0 && all.All(m => m.Id != input.Pid))
                return (false, "父级菜单不存在", 0);

            var id = SnowflakeId.Next();
            input.Id = id;
            input.CreateTime = DateTime.Now;
            input.UpdateTime = null;
            input.Children = new List<SysMenu>();

            var n = await _dbContext.Insertable(input).ExecuteCommandAsync();
            if (n <= 0)
                return (false, "保存失败", 0);

            if (input.IsDefaultDesktopHome)
                await ClearDefaultDesktopHomeExceptAsync(input.Id);

            await TryLinkCurrentTenantMenuAsync(id);
            return (true, "保存成功", id);
        }

        /// <inheritdoc />
        public async Task<(bool ok, string message)> UpdateMenuAsync(SysMenu input)
        {
            if (input.Id <= 0)
                return (false, "无效的菜单 Id");
            if (string.IsNullOrWhiteSpace(input.Title))
                return (false, "菜单名称不能为空");

            var all = await GetAllMenusForManageAsync();
            var existing = all.FirstOrDefault(m => m.Id == input.Id);
            if (existing == null)
                return (false, "菜单不存在");

            if (input.Pid != 0 && all.All(m => m.Id != input.Pid))
                return (false, "父级菜单不存在");

            if (NewParentIsInsideMenuSubtree(input.Id, input.Pid, all))
                return (false, "不能将父级设为当前菜单或其子菜单");

            if (input.IsDefaultDesktopHome)
                await ClearDefaultDesktopHomeExceptAsync(input.Id);

            existing.Pid = input.Pid;
            existing.Type = input.Type;
            existing.Name = input.Name;
            existing.Path = input.Path;
            existing.Component = input.Component;
            existing.Redirect = input.Redirect;
            existing.Permission = input.Permission;
            existing.Title = input.Title.Trim();
            existing.Icon = input.Icon;
            existing.IsIframe = input.IsIframe;
            existing.OutLink = input.OutLink;
            existing.IsHide = input.IsHide;
            existing.IsKeepAlive = input.IsKeepAlive;
            existing.IsAffix = input.IsAffix;
            existing.IsDefaultDesktopHome = input.IsDefaultDesktopHome;
            existing.OrderNo = input.OrderNo;
            existing.Status = input.Status;
            existing.Remark = input.Remark;
            existing.UpdateTime = DateTime.Now;

            var n = await _dbContext.Updateable(existing).ExecuteCommandAsync();
            if (n <= 0)
                return (false, "更新失败");
            await TryLinkCurrentTenantMenuAsync(input.Id);
            return (true, "保存成功");
        }

        /// <inheritdoc />
        public async Task<(bool ok, string message)> DeleteMenuAsync(long id)
        {
            if (id <= 0)
                return (false, "无效的菜单 Id");

            var childCount = await _dbContext.Queryable<SysMenu>().Where(m => m.Pid == id).CountAsync();
            if (childCount > 0)
                return (false, "存在子菜单，请先删除子节点");

            await _dbContext.Deleteable<SysRoleMenu>().Where(r => r.MenuId == id).ExecuteCommandAsync();
            await _dbContext.Deleteable<SysTenantMenu>().Where(t => t.MenuId == id).ExecuteCommandAsync();
            var n = await _dbContext.Deleteable<SysMenu>().Where(m => m.Id == id).ExecuteCommandAsync();
            return n > 0 ? (true, "已删除") : (false, "删除失败");
        }

        /// <summary>
        /// 保证全表仅一条菜单为桌面默认首页（当前保留项除外全部置 false）
        /// </summary>
        private async Task ClearDefaultDesktopHomeExceptAsync(long keepMenuId)
        {
            await _dbContext.Updateable<SysMenu>()
                .SetColumns(m => new SysMenu { IsDefaultDesktopHome = false })
                .Where(m => m.Id != keepMenuId && m.IsDefaultDesktopHome)
                .ExecuteCommandAsync();
        }

        private async Task TryLinkCurrentTenantMenuAsync(long menuId)
        {
            var tenantId = AppSession.CurrentUser?.TenantId;
            if (tenantId == null || tenantId <= 0)
                return;

            var exists = await _dbContext.Queryable<SysTenantMenu>()
                .AnyAsync(t => t.TenantId == tenantId && t.MenuId == menuId);
            if (exists)
                return;

            await _dbContext.Insertable(new SysTenantMenu
            {
                Id = SnowflakeId.Next(),
                TenantId = tenantId.Value,
                MenuId = menuId
            }).ExecuteCommandAsync();
        }

        /// <summary>
        /// 判断 newPid 是否位于以 menuId 为根的子树内（含自身），用于防止环状父级
        /// </summary>
        private static bool NewParentIsInsideMenuSubtree(long menuId, long newPid, List<SysMenu> all)
        {
            if (newPid == 0)
                return false;
            if (newPid == menuId)
                return true;

            var cur = all.FirstOrDefault(x => x.Id == newPid);
            for (var i = 0; i < 5000 && cur != null; i++)
            {
                if (cur.Pid == menuId)
                    return true;
                if (cur.Pid == 0)
                    return false;
                cur = all.FirstOrDefault(x => x.Id == cur.Pid);
            }

            return false;
        }
    }
}