using DiunaBIWebAPI.dataProcessors;
using Google.Apis.Sheets.v4;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System;
using System.Globalization;
using WebAPI.Controllers;
using WebAPI.Models;

namespace WebAPI.dataProcessors
{
    public class T3SingleSourceProcessor
    {
        private readonly AppDbContext db;
        private readonly SpreadsheetsResource.ValuesResource googleSheetValues;
        private readonly LayersController controller;

        public T3SingleSourceProcessor(
            AppDbContext _db,
            SpreadsheetsResource.ValuesResource _googleSheetValues,
            LayersController _controller)
        {
            db = _db;
            googleSheetValues = _googleSheetValues;
            controller = _controller;
        }

        public void process(Layer processWorker)
        {
            int year = int.Parse(processWorker?.Records?.SingleOrDefault(x => x.Code == "Year")?.Desc1!);
            int month = int.Parse(processWorker?.Records?.SingleOrDefault(x => x.Code == "Month")?.Desc1!);
            string? sourceLayer = processWorker?.Records?.SingleOrDefault(x => x.Code == "SourceLayer")?.Desc1;
            if (sourceLayer == null)
            {
                throw new Exception("SourceLayer record not found");
            }
            Layer? sourceImportWorker = db.Layers.SingleOrDefault(x => x.Name == sourceLayer);
            if (sourceImportWorker == null)
            {
                throw new Exception("SourceImportWorkerL layer not found");
            }
            string? source= processWorker?.Records?.SingleOrDefault(x => x.Code == "Source")?.Desc1;
            if (sourceLayer == null)
            {
                throw new Exception("Source record not found");
            }

            Layer? processedLayer = db.Layers
                                    .Where(x => x.ParentId == processWorker!.Id)
                                    .OrderByDescending(x => x.CreatedAt)
                                    .FirstOrDefault();

            bool isNew = false;
            if (processedLayer == null)
            {
                isNew = true;
                processedLayer = new Layer
                {
                    Id = Guid.NewGuid(),
                    Source = "",
                    Type = LayerType.processed,
                    ParentId = processWorker!.Id,
                    Number = db.Layers.Count() + 1,
                };
                processedLayer.Name = $"L{processedLayer.Number}-P-{year}/{month}-{source}-T3";
                processedLayer.CreatedById = Guid.Parse("F392209E-123E-4651-A5A4-0B1D6CF9FF9D");
                processedLayer.ModifiedById = Guid.Parse("F392209E-123E-4651-A5A4-0B1D6CF9FF9D");
                processedLayer.CreatedAt = DateTime.UtcNow;
                processedLayer.ModifiedAt = DateTime.UtcNow;
            }
            processedLayer.Sources = new List<ProcessSource>();
            processedLayer.ModifiedById = Guid.Parse("F392209E-123E-4651-A5A4-0B1D6CF9FF9D");
            processedLayer.ModifiedAt = DateTime.UtcNow;

            
            List<Record> newRecords = new List<Record>();

            List<Layer> dataSources = db.Layers
                .Include(x => x.Records)
                .Where(x => x.ParentId == sourceImportWorker.Id
                            && !x.IsDeleted)
                .OrderBy(x => x.CreatedAt)
                .ToList();
            if (dataSources.Count == 0)
            {
                throw new Exception($"DataSources are empty, {sourceImportWorker.Name}");
            }


            List<Record> allRecords = dataSources.SelectMany(x => x.Records!).ToList();

            foreach (Record baseRecord in dataSources.Last()?.Records!)
            {
                List<Record> codeRecords = allRecords.Where(x => x.Code == baseRecord.Code).ToList();

                Record processedRecord = new Record
                {
                    Id = Guid.NewGuid(),
                    Code = baseRecord.Code,
                    CreatedAt = DateTime.UtcNow,
                    ModifiedAt = DateTime.UtcNow
                };

                int lastDayInMonth = DateTime.DaysInMonth(year, month);
                double previousValue = 0;
                //day 1
                double firstVal = codeRecords
                    .Where(x => x.CreatedAt.Date <= new DateTime(year, month, 1))
                    .OrderByDescending(x => x.CreatedAt)
                    .FirstOrDefault()?.Value1 ?? 0;
                ProcessHelper.setValue(processedRecord, 1, firstVal);
                previousValue = firstVal;
                //days 2-29/30
                for (int i=2; i<lastDayInMonth; i++)
                {
                    double? dayVal = codeRecords
                        .Where(x => x.CreatedAt.Day == i && x.CreatedAt.Month == month)
                        .OrderByDescending(x => x.CreatedAt)
                        .FirstOrDefault()?.Value1;
                    if (dayVal == null)
                    {
                        //TODO: missing day value? Should I log it?
                        ProcessHelper.setValue(processedRecord, i, 0);
                    } else
                    {
                        double processedVal = (dayVal ?? 0) - previousValue;
                        ProcessHelper.setValue(processedRecord, i, processedVal);
                        previousValue = dayVal ?? 0;
                    }
                }
                //last day
                double? lastVal = codeRecords
                    .Where(x => x.CreatedAt.Date >= new DateTime(year, month, lastDayInMonth))
                    .OrderByDescending(x => x.CreatedAt)
                    .FirstOrDefault()?.Value1;

                if (lastVal == null)
                {
                    ProcessHelper.setValue(processedRecord, lastDayInMonth, 0);
                } else
                {
                    ProcessHelper.setValue(processedRecord, lastDayInMonth, (lastVal ?? 0) - previousValue);
                }

                // copy last value
                double? valueToCopy = codeRecords
                    .OrderByDescending(x => x.CreatedAt)
                    .FirstOrDefault()?.Value1;
                ProcessHelper.setValue(processedRecord, 32, valueToCopy);

                newRecords.Add(processedRecord);
            }
            
            if (isNew)
            {
                db.Layers.Add(processedLayer);
            } else
            {
                db.Layers.Update(processedLayer);
            }
            controller.SaveRecords(processedLayer.Id, newRecords, Guid.Parse("F392209E-123E-4651-A5A4-0B1D6CF9FF9D"));
            db.SaveChanges();
        }
        
    }
}