using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.EntityFrameworkCore;
using WZExport.Data;
using WZExport.Models;
using static WZExport.Utilitys.ExcelHelper;

namespace WZExport.Pages.Lms
{
    public class ExportModel : PageModel
    {
        private readonly WZContext _context;

        public ExportModel(WZContext context)
        {
            _context = context;
        }

        private IList<Lm> _lms;

        public IActionResult OnGet()
        {           
            return Page();
        }

        public async Task<IActionResult> OnPostAsync()
        {
            _lms = await _context.Lm.ToListAsync();
            string webRootFolder = $"/temp/{nameof(Lm)}/{DateTime.Now:yyyyMMdd}";
            string fileName = $"栏目导出-{DateTime.Now:yyyyMMddHHmmss}";
            string zipFilePath = $"/temp/{nameof(Lm)}/{fileName}.zip";
            if (Directory.Exists(webRootFolder) is false)
            {
                Directory.CreateDirectory(webRootFolder);               
                var treeData = CoverTreeData();
                string sexLeveFolder = $"{webRootFolder}/层级6级及以内的栏目";
                Directory.CreateDirectory(sexLeveFolder);
                var sexLevelData = treeData.Where(lm => lm.Siteid <= 6).ToList();
                const int onceNumber = 1000;
                var onceData = new List<Lm>();
                int index = 0;
                foreach (var data in sexLevelData)
                {
                    index++;
                    if (data.Siteid == 1 && index>= onceNumber)
                    {
                        ExportLmUniversal(onceData, $"{fileName}-{index-1}", sexLeveFolder);
                        onceData.Clear();
                        index = 0;
                    }
                    onceData.Add(data);
                }
                ExportLmUniversal(onceData, $"{fileName}-{sexLevelData.Count}", sexLeveFolder);

                string otherFolder = $"{webRootFolder}/层级大于6级的栏目";
                Directory.CreateDirectory(otherFolder);
                var otherData = treeData.Where(lm => lm.Siteid > 6)
                                        .Select(lm=> { lm.Siteid = lm.Siteid - 6;return lm; })
                                        .ToList();
                var otherGpData = otherData.GroupBy(lm => lm.Parentid);               
                foreach (var data in otherGpData)
                {
                    string parentName = _lms.FirstOrDefault(lm=>lm.Channelid==data.Key).Chnldesc;
                    fileName = $"{parentName}-超出六级栏目";
                    ExportLmUniversal(data, fileName, otherFolder);
                }
            }                        
            ZipFile.CreateFromDirectory(webRootFolder, zipFilePath);

            return File(System.IO.File.OpenRead(zipFilePath), "application/x-zip-compressed", fileName+ ".zip");
        }

        private IList<Lm> CoverTreeData()
        {
            var treeLms = new List<Lm>();
            var parentLms = _lms.Where(lm =>lm.Parentid==0).OrderByDescending(lm =>lm.Chnlorder);
            foreach (var parentLm in parentLms)
            {
                FindSon(parentLm,1);
            }
            return treeLms;

            void FindSon(Lm parentLm,int index)
            {
                parentLm.Siteid = index;
                treeLms.Add(parentLm);
                var sonLms = _lms.Where(lm => lm.Parentid == parentLm.Channelid).OrderByDescending(lm => lm.Chnlorder).ToList();
                if (sonLms.Count > 0)
                {
                    foreach (var sonLm in sonLms)
                    {
                        FindSon(sonLm, index+1);
                    }
                }
            }
        }
    }
}