using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;
using System.Text.Json;
using System.Text.Json.Serialization;
using System.Xml.Linq;
using System.Linq;
using System.Text;

namespace Nop.Plugin.Misc.FruitBankPlugin.Services
{
	/// <summary>
	/// Service for interacting with InnVoice Invoice API
	/// API Documentation: https://help.innvoice.hu/hc/hu/articles/360003142839
	/// </summary>
	public class InnVoiceApiService
	{
		private readonly HttpClient _httpClient;
		private readonly string _companyName;
		private readonly string _username;
		private readonly string _password;
		private readonly string _baseUrl;

		public InnVoiceApiService(string companyName, string username, string password, string baseUrl = "https://api.innvoice.hu")
		{
			_companyName = companyName ?? throw new ArgumentNullException(nameof(companyName));
			_username = username ?? throw new ArgumentNullException(nameof(username));
			_password = password ?? throw new ArgumentNullException(nameof(password));
			_baseUrl = baseUrl.TrimEnd('/');

			_httpClient = new HttpClient();
			SetupAuthentication();
		}

		private void SetupAuthentication()
		{
			var authToken = Convert.ToBase64String(
				System.Text.Encoding.ASCII.GetBytes($"{_username}:{_password}")
			);
			_httpClient.DefaultRequestHeaders.Authorization =
				new System.Net.Http.Headers.AuthenticationHeaderValue("Basic", authToken);
		}

		/// <summary>
		/// Get all invoices
		/// Rate limit: 20 times per hour without ID parameter
		/// </summary>
		public async Task<List<Invoice>> GetAllInvoicesAsync()
		{
			var url = $"{_baseUrl}/{_companyName}/invoice";
			return await GetInvoicesFromUrlAsync(url);
		}

		/// <summary>
		/// Get invoice by internal table ID
		/// </summary>
		public async Task<Invoice> GetInvoiceByIdAsync(int tableId)
		{
			var url = $"{_baseUrl}/{_companyName}/invoice/id/{tableId}";
			var invoices = await GetInvoicesFromUrlAsync(url);
			return invoices.Count > 0 ? invoices[0] : null;
		}

		/// <summary>
		/// Get invoice by invoice number
		/// </summary>
		public async Task<List<Invoice>> GetInvoiceByNumberAsync(string invoiceNumber)
		{
			var url = $"{_baseUrl}/{_companyName}/invoice/invoicenumber/{Uri.EscapeDataString(invoiceNumber)}";
			return await GetInvoicesFromUrlAsync(url);
		}

		/// <summary>
		/// Get invoices by creation date
		/// Format: YYYYMMDD
		/// </summary>
		public async Task<List<Invoice>> GetInvoicesByCreationDateAsync(DateTime date)
		{
			var dateStr = date.ToString("yyyyMMdd");
			var url = $"{_baseUrl}/{_companyName}/invoice/created/{dateStr}";
			return await GetInvoicesFromUrlAsync(url);
		}

		/// <summary>
		/// Get invoices by fulfillment date
		/// Format: YYYYMMDD
		/// </summary>
		public async Task<List<Invoice>> GetInvoicesByFulfillmentDateAsync(DateTime date)
		{
			var dateStr = date.ToString("yyyyMMdd");
			var url = $"{_baseUrl}/{_companyName}/invoice/fulfillment/{dateStr}";
			return await GetInvoicesFromUrlAsync(url);
		}

		/// <summary>
		/// Get invoices by due date
		/// Format: YYYYMMDD
		/// </summary>
		public async Task<List<Invoice>> GetInvoicesByDueDateAsync(DateTime date)
		{
			var dateStr = date.ToString("yyyyMMdd");
			var url = $"{_baseUrl}/{_companyName}/invoice/duedate/{dateStr}";
			return await GetInvoicesFromUrlAsync(url);
		}

		/// <summary>
		/// Get invoices by payment date
		/// Format: YYYYMMDD
		/// </summary>
		public async Task<List<Invoice>> GetInvoicesByPaymentDateAsync(DateTime date)
		{
			var dateStr = date.ToString("yyyyMMdd");
			var url = $"{_baseUrl}/{_companyName}/invoice/paymentdate/{dateStr}";
			return await GetInvoicesFromUrlAsync(url);
		}

		/// <summary>
		/// Get invoices by customer tax number
		/// </summary>
		public async Task<List<Invoice>> GetInvoicesByCustomerTaxNumberAsync(string taxNumber)
		{
			var url = $"{_baseUrl}/{_companyName}/invoice/taxnumber/{Uri.EscapeDataString(taxNumber)}";
			return await GetInvoicesFromUrlAsync(url);
		}

		/// <summary>
		/// Get invoices modified since a specific timestamp
		/// Format: YYYYMMDDHHmmss (year, month, day, hour, minute, second)
		/// Recommended for tracking changes every 10 minutes
		/// Rate limit: Full queries or queries older than current month limited to 10 times per 30 days
		/// Recommended: Only use current month dates
		/// </summary>
		public async Task<List<Invoice>> GetInvoicesByUpdateTimeAsync(DateTime updateTime)
		{
			var timeStr = updateTime.ToString("yyyyMMddHHmmss");
			var url = $"{_baseUrl}/{_companyName}/invoice/updatedtime/{timeStr}";
			return await GetInvoicesFromUrlAsync(url);
		}

		private async Task<List<Invoice>> GetInvoicesFromUrlAsync(string url)
		{
			try
			{
				var response = await _httpClient.GetAsync(url);
				response.EnsureSuccessStatusCode();

				var content = await response.Content.ReadAsStringAsync();
				var invoices = JsonSerializer.Deserialize<List<Invoice>>(content, new JsonSerializerOptions
				{
					PropertyNameCaseInsensitive = true
				});

				return invoices ?? new List<Invoice>();
			}
			catch (HttpRequestException ex)
			{
				throw new InnVoiceApiException($"Error calling InnVoice API: {ex.Message}", ex);
			}
			catch (JsonException ex)
			{
				throw new InnVoiceApiException($"Error parsing API response: {ex.Message}", ex);
			}
		}
	}

	// Models
	public class Invoice
	{
		[JsonPropertyName("TABLE_ID")]
		public int TableId { get; set; }

		[JsonPropertyName("InvoiceNumber")]
		public string InvoiceNumber { get; set; }

		[JsonPropertyName("Created")]
		public string Created { get; set; }

		[JsonPropertyName("Fulfillment")]
		public string Fulfillment { get; set; }

		[JsonPropertyName("DueDate")]
		public string DueDate { get; set; }

		[JsonPropertyName("PaymentDate")]
		public string PaymentDate { get; set; }

		[JsonPropertyName("CustomerName")]
		public string CustomerName { get; set; }

		[JsonPropertyName("CustomerTaxNumber")]
		public string CustomerTaxNumber { get; set; }

		[JsonPropertyName("CustomerAddress")]
		public string CustomerAddress { get; set; }

		[JsonPropertyName("TotalNet")]
		public decimal TotalNet { get; set; }

		[JsonPropertyName("TotalGross")]
		public decimal TotalGross { get; set; }

		[JsonPropertyName("Currency")]
		public string Currency { get; set; }

		[JsonPropertyName("Status")]
		public string Status { get; set; }

		[JsonPropertyName("InvoiceType")]
		public string InvoiceType { get; set; }

		[JsonPropertyName("PaymentMethod")]
		public string PaymentMethod { get; set; }

		// Add more properties as needed based on actual API response
	}

	public class InnVoiceApiException : Exception
	{
		public InnVoiceApiException(string message) : base(message) { }
		public InnVoiceApiException(string message, Exception innerException) : base(message, innerException) { }
	}

	// Invoice Creation Models
	public class InvoiceCreateRequest
	{
		public int VevoID { get; set; } = 0;
		public string VevoNev { get; set; }
		public string VevoIrsz { get; set; }
		public string VevoOrszag { get; set; }
		public string VevoTelep { get; set; }
		public string VevoUtcaHsz { get; set; }
		public string VevoEPNev { get; set; }
		public string VevoEPKod { get; set; }
		public string SzallNev { get; set; }
		public string SzallIrsz { get; set; }
		public string SzallTelep { get; set; }
		public string SzallUtcaHsz { get; set; }
		public string SzallOrszag { get; set; }
		public int SzamlatombID { get; set; }
		public DateTime SzamlaKelte { get; set; }
		public DateTime TeljesitesKelte { get; set; }
		public DateTime Hatarido { get; set; }
		public string Devizanem { get; set; }
		public string FizetesiMod { get; set; }
		public string Megjegyzes { get; set; }
		public string Nyelv1 { get; set; }
		public string Nyelv2 { get; set; }
		public decimal? Arfolyam { get; set; }
		public string ArfolyamDeviza { get; set; }
		public bool Fizetve { get; set; }
		public bool Eszamla { get; set; }
		public string VevoAdoszam { get; set; }
		public string VevoCsAdoszam { get; set; }
		public string Telefon { get; set; }
		public string Email { get; set; }
		public string MegrendelesSzamStr { get; set; }
		public string MegrendelesIdopontStr { get; set; }
		public bool Felretett { get; set; }
		public bool Proforma { get; set; }
		public bool AutomatikusAr { get; set; }
		public bool Eloleg { get; set; }
		public bool Sendmail { get; set; }
		public string MailSubject { get; set; }
		public string MailBody { get; set; }
		public string Eredetiszamla { get; set; }

		public List<InvoiceItem> Items { get; set; } = new List<InvoiceItem>();

		public void AddItem(InvoiceItem item)
		{
			Items.Add(item);
		}

		public string ToXml()
		{
			var invoices = new XElement("invoices");
			var invoice = new XElement("invoice");

			if (VevoID > 0)
				invoice.Add(new XElement("VevoID", new XCData(VevoID.ToString())));

			invoice.Add(new XElement("VevoNev", new XCData(VevoNev ?? "")));
			invoice.Add(new XElement("VevoIrsz", new XCData(VevoIrsz ?? "")));
			invoice.Add(new XElement("VevoTelep", new XCData(VevoTelep ?? "")));
			invoice.Add(new XElement("VevoOrszag", new XCData(VevoOrszag ?? "")));
			invoice.Add(new XElement("VevoUtcaHsz", new XCData(VevoUtcaHsz ?? "")));

			if (!string.IsNullOrEmpty(VevoEPNev))
				invoice.Add(new XElement("VevoEPNev", new XCData(VevoEPNev)));
			if (!string.IsNullOrEmpty(VevoEPKod))
				invoice.Add(new XElement("VevoEPKod", new XCData(VevoEPKod)));
			if (!string.IsNullOrEmpty(SzallNev))
				invoice.Add(new XElement("SzallNev", new XCData(SzallNev)));
			if (!string.IsNullOrEmpty(SzallIrsz))
				invoice.Add(new XElement("SzallIrsz", new XCData(SzallIrsz)));
			if (!string.IsNullOrEmpty(SzallTelep))
				invoice.Add(new XElement("SzallTelep", new XCData(SzallTelep)));
			if (!string.IsNullOrEmpty(SzallUtcaHsz))
				invoice.Add(new XElement("SzallUtcaHsz", new XCData(SzallUtcaHsz)));
			if (!string.IsNullOrEmpty(SzallOrszag))
				invoice.Add(new XElement("SzallOrszag", new XCData(SzallOrszag)));

			invoice.Add(new XElement("SzamlatombID", new XCData(SzamlatombID.ToString())));
			invoice.Add(new XElement("SzamlaKelte", new XCData(SzamlaKelte.ToString("yyyy.MM.dd."))));
			invoice.Add(new XElement("TeljesitesKelte", new XCData(TeljesitesKelte.ToString("yyyy.MM.dd."))));
			invoice.Add(new XElement("Hatarido", new XCData(Hatarido.ToString("yyyy.MM.dd."))));
			invoice.Add(new XElement("Devizanem", new XCData(Devizanem ?? "")));
			invoice.Add(new XElement("FizetesiMod", new XCData(FizetesiMod ?? "")));

			if (!string.IsNullOrEmpty(Megjegyzes))
				invoice.Add(new XElement("Megjegyzes", new XCData(Megjegyzes)));
			if (!string.IsNullOrEmpty(Nyelv1))
				invoice.Add(new XElement("Nyelv1", new XCData(Nyelv1)));
			if (!string.IsNullOrEmpty(Nyelv2))
				invoice.Add(new XElement("Nyelv2", new XCData(Nyelv2)));
			if (Arfolyam.HasValue)
				invoice.Add(new XElement("Arfolyam", new XCData(Arfolyam.Value.ToString())));
			if (!string.IsNullOrEmpty(ArfolyamDeviza))
				invoice.Add(new XElement("ArfolyamDeviza", new XCData(ArfolyamDeviza)));

			invoice.Add(new XElement("Fizetve", Fizetve ? "1" : "0"));
			invoice.Add(new XElement("Eszamla", Eszamla ? "1" : "0"));

			if (!string.IsNullOrEmpty(VevoAdoszam))
				invoice.Add(new XElement("VevoAdoszam", new XCData(VevoAdoszam)));
			if (!string.IsNullOrEmpty(VevoCsAdoszam))
				invoice.Add(new XElement("VevoCsAdoszam", new XCData(VevoCsAdoszam)));
			if (!string.IsNullOrEmpty(Telefon))
				invoice.Add(new XElement("Telefon", new XCData(Telefon)));
			if (!string.IsNullOrEmpty(Email))
				invoice.Add(new XElement("Email", new XCData(Email)));
			if (!string.IsNullOrEmpty(MegrendelesSzamStr))
				invoice.Add(new XElement("MegrendelesSzamStr", new XCData(MegrendelesSzamStr)));
			if (!string.IsNullOrEmpty(MegrendelesIdopontStr))
				invoice.Add(new XElement("MegrendelesIdopontStr", new XCData(MegrendelesIdopontStr)));

			invoice.Add(new XElement("Felretett", Felretett ? "1" : "0"));
			invoice.Add(new XElement("Proforma", Proforma ? "1" : "0"));

			if (AutomatikusAr)
				invoice.Add(new XElement("AutomatikusAr", "1"));
			if (Eloleg)
				invoice.Add(new XElement("Eloleg", "1"));
			if (Sendmail)
			{
				invoice.Add(new XElement("Sendmail", "1"));
				if (!string.IsNullOrEmpty(MailSubject))
					invoice.Add(new XElement("MailSubject", new XCData(MailSubject)));
				if (!string.IsNullOrEmpty(MailBody))
					invoice.Add(new XElement("MailBody", new XCData(MailBody)));
			}
			if (!string.IsNullOrEmpty(Eredetiszamla))
				invoice.Add(new XElement("Eredetiszamla", new XCData(Eredetiszamla)));

			// Add items
			foreach (var item in Items)
			{
				var tetel = new XElement("tetel");
				tetel.Add(new XElement("TetelNev", new XCData(item.TetelNev ?? "")));
				tetel.Add(new XElement("AfaSzoveg", item.AfaSzoveg ?? ""));
				tetel.Add(new XElement("Brutto", item.Brutto ? "1" : "0"));
				tetel.Add(new XElement("EgysegAr", item.EgysegAr.ToString()));
				tetel.Add(new XElement("Mennyiseg", item.Mennyiseg.ToString()));
				tetel.Add(new XElement("MennyisegEgyseg", new XCData(item.MennyisegEgyseg ?? "")));

				if (item.KedvezmenyOsszeg.HasValue)
					tetel.Add(new XElement("KedvezmenyOsszeg", item.KedvezmenyOsszeg.Value.ToString()));
				if (item.TermekID.HasValue)
					tetel.Add(new XElement("TermekID", item.TermekID.Value.ToString()));
				if (!string.IsNullOrEmpty(item.Megjegyzes))
					tetel.Add(new XElement("Megjegyzes", new XCData(item.Megjegyzes)));
				if (!string.IsNullOrEmpty(item.CikkSzam))
					tetel.Add(new XElement("CikkSzam", new XCData(item.CikkSzam)));
				if (!string.IsNullOrEmpty(item.VTSZSZJ))
					tetel.Add(new XElement("VTSZSZJ", new XCData(item.VTSZSZJ)));
				if (item.ElolegSzamlaTABLE_ID.HasValue)
					tetel.Add(new XElement("ElolegSzamlaTABLE_ID", item.ElolegSzamlaTABLE_ID.Value.ToString()));
				if (!string.IsNullOrEmpty(item.ElolegSzamlaSorszam))
					tetel.Add(new XElement("ElolegSzamlaSorszam", new XCData(item.ElolegSzamlaSorszam)));

				invoice.Add(tetel);
			}

			invoices.Add(invoice);
			return new XDeclaration("1.0", "UTF-8", null).ToString() + "\n" + invoices.ToString();
		}
	}

	public class InvoiceItem
	{
		public string TetelNev { get; set; }
		public string AfaSzoveg { get; set; }
		public bool Brutto { get; set; }
		public decimal EgysegAr { get; set; }
		public decimal Mennyiseg { get; set; }
		public string MennyisegEgyseg { get; set; }
		public decimal? KedvezmenyOsszeg { get; set; }
		public int? TermekID { get; set; }
		public string Megjegyzes { get; set; }
		public string CikkSzam { get; set; }
		public string VTSZSZJ { get; set; }
		public int? ElolegSzamlaTABLE_ID { get; set; }
		public string ElolegSzamlaSorszam { get; set; }
	}

	public class InvoiceCreateResponse
	{
		public string ErrorCode { get; set; }
		public string Message { get; set; }
		public int? TableId { get; set; }
		public int? VevoID { get; set; }
		public string TechId { get; set; }
		public string Sorszam { get; set; }
		public string PrintUrl { get; set; }

		public bool IsSuccess => ErrorCode == "200";

		public static InvoiceCreateResponse FromXml(string xml)
		{
			var doc = XDocument.Parse(xml);
			var invoice = doc.Descendants("invoice").FirstOrDefault();

			if (invoice == null)
			{
				throw new InnVoiceApiException("Invalid XML response format");
			}

			return new InvoiceCreateResponse
			{
				ErrorCode = invoice.Element("error")?.Value,
				Message = invoice.Element("message")?.Value?.Trim(),
				TableId = int.TryParse(invoice.Element("TABLE_ID")?.Value?.Trim(), out var tid) ? tid : (int?)null,
				VevoID = int.TryParse(invoice.Element("VevoID")?.Value?.Trim(), out var vid) ? vid : (int?)null,
				TechId = invoice.Element("techid")?.Value?.Trim(),
				Sorszam = invoice.Element("Sorszam")?.Value?.Trim(),
				PrintUrl = invoice.Element("PrintUrl")?.Value?.Trim()
			};
		}
    }

        /// <summary>
        /// Create a new invoice
        /// </summary>
        public async Task<InvoiceCreateResponse> CreateInvoiceAsync(InvoiceCreateRequest request)
		{
			var url = $"{_baseUrl}/{_companyName}/invoice";

			var xml = request.ToXml();
			var content = new FormUrlEncodedContent(new[]
			{
				new KeyValuePair<string, string>("data", xml)
			});

			try
			{
				var response = await _httpClient.PostAsync(url, content);
				response.EnsureSuccessStatusCode();

				var responseContent = await response.Content.ReadAsStringAsync();
				return InvoiceCreateResponse.FromXml(responseContent);
			}
			catch (HttpRequestException ex)
			{
				throw new InnVoiceApiException($"Error creating invoice: {ex.Message}", ex);
			}
		}

		/// <summary>
		/// Update an existing invoice
		/// </summary>
		public async Task<InvoiceCreateResponse> UpdateInvoiceAsync(int tableId, InvoiceCreateRequest request)
		{
			// Set the VevoID if updating customer information
			var url = $"{_baseUrl}/{_companyName}/invoice";

			var xml = request.ToXml();
			var content = new FormUrlEncodedContent(new[]
			{
				new KeyValuePair<string, string>("data", xml),
				new KeyValuePair<string, string>("id", tableId.ToString())
			});

			try
			{
				var response = await _httpClient.PostAsync(url, content);
				response.EnsureSuccessStatusCode();

				var responseContent = await response.Content.ReadAsStringAsync();
				return InvoiceCreateResponse.FromXml(responseContent);
			}
			catch (HttpRequestException ex)
			{
				throw new InnVoiceApiException($"Error updating invoice: {ex.Message}", ex);
			}
		}