using Kean.Infrastructure.Database;
using Kean.Infrastructure.Database.Repository.Default;
using Kean.Infrastructure.Database.Repository.Default.Entities;
using System;
using System.Threading.Tasks;

namespace Kean.Infrastructure.Repository
{
    /// <summary>
    /// 菜单仓库
    /// </summary>
    public class MenuRepository :
        Domain.Order.Repositories.IMenuRepository
    {
        private const int CUSTOM_MIN = 9901; // 自定义菜单最小 ID
        private const int CUSTOM_MAX = 9999; // 自定义菜单最大 ID

        private readonly IDefaultDb _database; // 默认数据库

        /// <summary>
        /// 构造函数
        /// </summary>
        public MenuRepository(
            IDefaultDb database)
        {
            _database = database;
        }

        /*
         * 实现 Kean.Domain.Order.Repositories.IMenuRepository.Create 方法
         */
        public async Task<int> Create(string header, string url, int parent)
        {
            var last = await _database.From<T_SYS_MENU>()
                .Where(m => m.MENU_ID >= CUSTOM_MIN && m.MENU_ID <= CUSTOM_MAX)
                .OrderBy(m => m.MENU_ID, Order.Descending)
                .Single();
            var timestamp = DateTime.Now;
            var menu = new T_SYS_MENU
            {
                MENU_HEADER = header,
                MENU_URL = url,
                MENU_PARENT_ID = parent,
                MENU_FLAG = true,
                CREATE_TIME = timestamp,
                UPDATE_TIME = timestamp
            };
            if (last == null)
            {
                menu.MENU_ID = CUSTOM_MIN;
            }
            else
            {
                if ((menu.MENU_ID = last.MENU_ID + 1) > CUSTOM_MAX)
                {
                    throw new OverflowException("菜单长度超出范围");
                }
            }
            await _database.From<T_SYS_MENU>().Add(menu);
            return menu.MENU_ID;
        }

        /*
         * 实现 Kean.Domain.Order.Repositories.IMenuRepository.Modify 方法
         */
        public async Task Modify(int id, string header, string url, int parent)
        {
            await _database.From<T_SYS_MENU>()
                .Where(m => m.MENU_ID == id)
                .Update(new
                {
                    MENU_HEADER = header,
                    MENU_URL = url,
                    MENU_PARENT_ID = parent,
                    UPDATE_TIME = DateTime.Now
                });
        }

        /*
         * 实现 Kean.Domain.Order.Repositories.IMenuRepository.Delete 方法
         */
        public async Task Delete(int id)
        {
            await _database.From<T_SYS_MENU>()
                .Where(m => m.MENU_ID == id)
                .Delete();
        }

        /*
         * 实现 Kean.Domain.Order.Repositories.IMenuRepository.Sort 方法
         */
        public async Task Sort(int id, int order)
        {
            var timestamp = DateTime.Now;
            var index = -1;
            var flag = false;
            var parent = _database.From<T_SYS_MENU>().Where(m => m.MENU_ID == id).Query(m => m.MENU_PARENT_ID);
            foreach (var item in await _database.From<T_SYS_MENU>()
                .Where(m => parent.Contains(m.MENU_PARENT_ID))
                .OrderBy(m => m.MENU_ORDER, Order.Ascending)
                .OrderBy(m => m.MENU_ID, Order.Ascending)
                .Select())
            {
                if (++index >= order)
                {
                    int value;
                    if (!flag)
                    {
                        if (item.MENU_ID != id)
                        {
                            value = index - order + 2;
                        }
                        else
                        {
                            value = 1;
                            flag = true;
                        }
                    }
                    else
                    {
                        value = index - order + 1;
                    }
                    await _database.From<T_SYS_MENU>()
                        .Where(m => m.MENU_ID == item.MENU_ID)
                        .Update(new
                        {
                            MENU_ORDER = value,
                            UPDATE_TIME = timestamp
                        });
                }
            }
        }
    }
}