using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using POSV.Entity;
using POSV.Utils;

namespace POSV.Component
{
    public class TableMerge
    {
        public static List<Table> Merge(int rows , int cols , List<Table> dataSource , bool touchEnabled)
        {
            //启用触摸屏，不分页
            if (touchEnabled)
            {
                return dataSource;
            }

            //移除可能存在的分页标识
            dataSource.RemoveAll(x => Constant.PREV_PAGER.Equals(x.Name) || Constant.NEXT_PAGER.Equals(x.Name));

            int pageSize = rows * cols;

            int totalCount = dataSource.Count;

            //启用分页
            int pageCount = ((totalCount - 1) + (pageSize - 2) - 1) / (pageSize - 2);

            if(pageCount > 1)
            {
                int offset = 0;
                for (int page = 1; page <= pageCount; page++)
                {
                    if (page == 1)
                    {
                        offset = page * pageSize - 1;

                        var entity = new Table();
                        entity.Id = IdWorkerUtils.Instance.NextId();
                        entity.Name = Constant.NEXT_PAGER;
                        entity.Pager = (page + 1);

                        dataSource.Insert(offset , entity);
                    }
                    else if (page < pageCount)
                    {
                        offset = page * pageSize - 2;

                        var entity = new Table();
                        entity.Id = IdWorkerUtils.Instance.NextId();
                        entity.Name = Constant.PREV_PAGER;
                        entity.Pager = (page - 1);
                        dataSource.Insert(offset , entity);

                        offset++;

                        entity = new Table();
                        entity.Id = IdWorkerUtils.Instance.NextId();
                        entity.Name = Constant.NEXT_PAGER;
                        entity.Pager = (page + 1);

                        dataSource.Insert(offset , entity);
                    }
                    else
                    {
                        var entity = new Table();
                        entity.Id = IdWorkerUtils.Instance.NextId();
                        entity.Name = Constant.PREV_PAGER;
                        entity.Pager = (page - 1);

                        dataSource.Add(entity);
                    }
                }
            }

            return dataSource;
        }
    }
}