using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using PartSource.Automation.Models.Jobs;
using PartSource.Automation.Services;
using PartSource.Data.Contexts;
using PartSource.Data.Models;
using Ratermania.Automation.Interfaces;
using Ratermania.Shopify;
using Ratermania.Shopify.Resources;
using Ratermania.Shopify.Resources.Enums;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Mail;
using System.Threading.Tasks;

namespace PartSource.Automation.Jobs
{
	public class UpdatePricing : IAutomationJob
	{
		private readonly ILogger<UpdatePricing> _logger;
		private readonly PartSourceContext _partSourceContext;
		private readonly ShopifyClient _shopifyClient;
		private readonly EmailService _emailService;

		public UpdatePricing(ILogger<UpdatePricing> logger, PartSourceContext partSourceContext, ShopifyClient shopifyClient, EmailService emailService)
		{
			_logger = logger;
			_partSourceContext = partSourceContext;
			_shopifyClient = shopifyClient;
			_emailService = emailService;
		}

		public async Task Run()
		{
			List<UpdatePricingResult> pricingReport = new List<UpdatePricingResult>();
			IEnumerable<Product> products = null;
			IEnumerable<PartPrice> prices = null;

			try
			{
				products = await _shopifyClient.Products.Get(new Dictionary<string, object> { { "limit", 250 } });
				prices = await _partSourceContext.PartPrices.AsNoTracking().ToListAsync();
			}

			catch (Exception ex)
			{
				_logger.LogError(ex, "Failed to get the initial set of products from Shopify.");

				throw;
			}

			while (products != null && products.Any())
			{
				foreach (Product product in products)
				{
					List<UpdatePricingResult> productPricingUpdate = new List<UpdatePricingResult>();

					if (product.Variants.Length > 0)
					{
						bool hasUpdate = false;

						for (int i = 0; i < product.Variants.Length; i++)
						{
							Variant variant = product.Variants[i];
							PartPrice partPrice = prices.Where(p => p.SKU == variant.Sku).FirstOrDefault();

							if (partPrice == null || !partPrice.Your_Price.HasValue || !partPrice.Compare_Price.HasValue)
							{
								continue;
							}

							if (product.Variants[i].Price.ToString("G29") != partPrice.Your_Price.Value.ToString("G29") || product.Variants[i].CompareAtPrice.ToString("G29") != partPrice.Compare_Price.Value.ToString("G29"))
							{
								productPricingUpdate.Add(new UpdatePricingResult
								{
									Sku = variant.Sku,
									OldPrice = product.Variants[i].Price,
									NewPrice = partPrice.Your_Price.Value,
									OldCompareAt = product.Variants[i].CompareAtPrice,
									NewCompareAt = partPrice.Compare_Price.Value
								});

								product.Variants[i].Price = partPrice.Your_Price.Value;
								product.Variants[i].CompareAtPrice = partPrice.Compare_Price.Value;

								product.PublishedAt = partPrice.Active.Trim().ToUpperInvariant() == "Y" ? DateTime.Now : null;
								product.PublishedScope = PublishedScope.Global;

								//Metafield metafield = new Metafield
								//{
								//	Namespace = "Pricing",
								//	Key = "CorePrice",
								//	Value = partPrice.Core_Price.HasValue ? partPrice.Core_Price.Value.ToString() : "0.00",
								//	ValueType = "string",
								//	OwnerResource = "product",
								//	OwnerId = product.Id
								//};

								hasUpdate = true;
							}
						}

						if (hasUpdate)
						{
							try
							{
								//await _shopifyClient.Metafields.Add(metafield);
								await _shopifyClient.Products.Update(product);
								
								pricingReport.AddRange(productPricingUpdate);
							}

							catch (Exception ex)
							{
								_logger.LogWarning(ex, $"Failed to update pricing for product ID {product.Id}");
							}
						}
					}
				}

				try
				{
					products = await _shopifyClient.Products.GetNext();

					_logger.LogInformation($"Total updated: {pricingReport.Count}");
				}

				catch (Exception ex)
				{
					_logger.LogWarning(ex, "Failed to get the next set of products.  Retrying");
					products = await _shopifyClient.Products.GetPrevious();
				}
			}

			Attachment attachment = GetPricingReportAttachment(pricingReport);

			_emailService.Send("Pricing Update Completed", $"The pricing update has completed. Total updated: {pricingReport.Count}", attachment);
		}

		private Attachment GetPricingReportAttachment(IList<UpdatePricingResult> pricingReport)
		{
			string directory = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "Pricing Reports");
			string filename = Path.Combine(directory, $"Pricing Update {DateTime.Now.ToString("yyyy-MM-dd")}.csv"); 

			if (!Directory.Exists(directory))
			{
				Directory.CreateDirectory(directory);
			}

			if (File.Exists(filename))
			{
				File.Delete(filename);
			}

			using FileStream fileStream = File.OpenWrite(filename);
			using StreamWriter streamWriter = new StreamWriter(fileStream, System.Text.Encoding.UTF8);

			streamWriter.WriteLine("SKU, Old Price, New Price, Old Compare At, New Compare At");

			foreach (UpdatePricingResult pricingResult in pricingReport)
			{
				streamWriter.WriteLine($"{pricingResult.Sku},{pricingResult.OldPrice},{pricingResult.NewPrice},{pricingResult.OldCompareAt},{pricingResult.NewCompareAt}");
			}

			streamWriter.Close();
			fileStream.Close();

			return new Attachment(filename);
		}
	}
}