package com.alexanderlogistics;

import java.io.Serializable;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.ParseException;
import java.time.LocalDate;
import java.time.YearMonth;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.logging.Logger;
import java.util.stream.Collectors;

import org.imixs.marty.team.TeamService;
import org.imixs.workflow.ItemCollection;
import org.imixs.workflow.engine.DocumentService;
import org.imixs.workflow.exceptions.QueryException;
import org.imixs.workflow.faces.data.WorkflowController;
import org.imixs.workflow.office.forms.AnalyticController;
import org.imixs.workflow.office.forms.AnalyticEvent;

import jakarta.enterprise.context.ConversationScoped;
import jakarta.enterprise.event.Observes;
import jakarta.inject.Inject;
import jakarta.inject.Named;

/**
 * Der AGLAnalyticControllerDebitor berechnet verschiedene Analyse Daten von
 * Ausgangsrechnungen
 * 
 * @author rsoika
 *
 */
@Named
@ConversationScoped
public class AGLAnalyticControllerDebitor implements Serializable {

	private static final long serialVersionUID = 1L;
	private static Logger logger = Logger.getLogger(AnalyticController.class.getName());

	@Inject
	protected DocumentService documentService;

	@Inject
	protected AGLConfigController aglConfigController;

	@Inject
	protected WorkflowController workflowController;

	@Inject
	TeamService teamService;

	TreeMap<String, DebitorStatistikData> stats = null;

	List<ItemCollection> invoices = null;
	int countAll = 0;
	int countOpen = 0;
	int countDue = 0;
	int countDunning = 0;

	double totalAllCurrency1 = 0;
	double totalAllCurrency2 = 0;

	double totalOpenCurrency1 = 0;
	double totalOpenCurrency2 = 0;

	double totalDueCurrency1 = 0;
	double totalDueCurrency2 = 0;

	double totalDunningCurrency1 = 0;
	double totalDunningCurrency2 = 0;

	double averagePaymentDue = 0;
	double averagePaymentDays = 0;

	String chartData = "";

	public void onEvent(@Observes AnalyticEvent event) {
		if (!"workitem".equals(event.getWorkitem().getType())
				|| !event.getWorkitem().getModelVersion().startsWith("analyse-debitor")) {
			// no op
			return;
		}
		String dbtrNumber = event.getWorkitem().getItemValueString("dbtr.number");
		String dbtrNumberLast = event.getWorkitem().getItemValueString("dbtr.number.last");

		// Recompute only if last dbtr.number has changed or no values yet computed

		// load all invoices?
		if (invoices == null || (!dbtrNumber.isEmpty() && !dbtrNumber.equals(dbtrNumberLast))) {
			resetStats(event);
			event.getWorkitem().setItemValue("dbtr.number.last", dbtrNumber);
			logger.info("Analyse new debitor data for : " + dbtrNumber);
			loadRechnungen(event);
			chartData = buildChartData();
		}

		// use cache?
		if (event.getWorkitem().hasItem(event.getKey())) {
			// logger.info(" use cache for " + event.getKey());
			// no op
			return;
		}

		String link = "/pages/workitems/worklist.xhtml" + "?phrase=" + getDbtNr();
		logger.fine("process ref=" + workflowController.getWorkitem().getItemValueString("process.ref"));
		ItemCollection process = documentService
				.load(workflowController.getWorkitem().getItemValueString("process.ref"));
		if (process != null) {
			link = link + "&processref=" + process.getUniqueID()
					+ "&phrase=" + getDbtNr();
		}
		if ("analytic.invoices.count.all".equals(event.getKey())) {
			event.setValue("" + countAll);
			event.setLabel(formatTotals(totalAllCurrency1, totalAllCurrency2));
			event.setDescription("Total invoices");
			event.getWorkitem().setItemValue("invoices.total", event.getValue());
			event.setLink(link);
		}

		if ("analytic.invoices.count.open".equals(event.getKey())) {
			event.setValue("" + countOpen);
			event.setLabel(formatTotals(totalOpenCurrency1, totalOpenCurrency2));
			event.setDescription("Total invoices not yet in due");
			event.getWorkitem().setItemValue("invoices.total.open", event.getValue());
			event.setLink(link);
		}

		if ("analytic.invoices.count.due".equals(event.getKey())) {
			event.setValue("" + countDue);
			event.setLabel(formatTotals(totalDueCurrency1, totalDueCurrency2));
			event.setDescription("Total invoices in due");
			event.getWorkitem().setItemValue("invoices.total.due", event.getValue());
			event.setLink(link);
		}
		if ("analytic.invoices.count.dunning".equals(event.getKey())) {
			event.setValue("" + countDunning);
			event.setLabel(formatTotals(totalDunningCurrency1, totalDunningCurrency2));
			event.setDescription("Total invoices in dunning");
			event.getWorkitem().setItemValue("invoices.total.dunning", event.getValue());
			event.setLink(link);
		}

		if ("analytic.payment.avg.due".equals(event.getKey())) {
			event.setValue("" + averagePaymentDue);
			event.setLabel("days");
			event.setDescription("Average terms of credit in the last 12 months.");
			event.getWorkitem().setItemValue("payment.avg.due", event.getValue());
			event.setLink(link);
		}
		if ("analytic.payment.avg.days".equals(event.getKey())) {
			event.setValue("" + averagePaymentDays);
			event.setLabel("days");
			event.setDescription("Average duration for payment during the last 12 months.");
			event.getWorkitem().setItemValue("payment.avg.days", event.getValue());
			event.setLink(link);
		}

		if ("analytic.invoices.trend".equals(event.getKey())) {
			event.setValue(chartData);
			event.setLabel("Payment duration in days");
			event.setDescription("Payment practice by week");
		}
	}

	/**
	 * Formatiert zwei währungen untereinander
	 * 
	 * @param totalCurrency1
	 * @param totalCurrency2
	 * @return
	 */
	private String formatTotals(double totalCurrency1, double totalCurrency2) {

		List<String> currencies = aglConfigController.getWorkitem().getItemValueList("currency.out", String.class);
		if (currencies.size() < 2) {
			currencies.add(currencies.get(0));
		}
		String label = "<span class=\"pull-right\">" + formatCurrency(totalCurrency1) + " " + currencies.get(0)
				+ "</span>";
		label = label + "</br><span class=\"pull-right\">" +
				formatCurrency(totalCurrency2) + " " + currencies.get(1) + "</span>";

		return label;
	}

	private void loadRechnungen(AnalyticEvent event) {
		if (getDbtNr().isEmpty()) {
			invoices = new ArrayList();
			stats = null;
		} else {
			logger.info("	├──load invoices for " + getDbtNr() + "....");
			String query = "(type:workitem) AND dbtr.number:" + getDbtNr()
					+ " AND $modelversion:rechnungsausgang-*";
			try {
				logger.info("	├──refresh invoice stats for " + getDbtNr() + "....");
				invoices = documentService.find(query, 999, 0, "$created", false);
				calculateStats(event);
			} catch (QueryException e) {
				logger.warning("Failed to query invoices: " + query + " - Error: " + e.getMessage());
				invoices = new ArrayList();
			}
		}

	}

	/**
	 * Läd die statistik daten zu einem debitor aus den aktuellen Rechnungen
	 */
	private void calculateStats(AnalyticEvent event) {
		countAll = 0;
		countOpen = 0;
		countDue = 0;
		countDunning = 0;
		logger.info("	├──calculate stats for " + getDbtNr() + "....");
		// do we have data?
		if (invoices != null && invoices.size() > 0) {
			countAll = invoices.size();

			for (ItemCollection invoice : invoices) {

				// währung 1 oder 2?
				if (invoice.getItemValueDouble("invoice.rate") == 0) {
					totalAllCurrency1 = totalAllCurrency1 + invoice.getItemValueDouble("invoice.saldo");
				} else {
					totalAllCurrency2 = totalAllCurrency2 + invoice.getItemValueDouble("invoice.saldo");
				}

				int task = invoice.getTaskID();

				// Open
				if (task >= 5000 && task <= 5099) {
					countOpen++;
					// währung 1 oder 2?
					if (invoice.getItemValueDouble("invoice.rate") == 0) {
						totalOpenCurrency1 = totalOpenCurrency1 + invoice.getItemValueDouble("invoice.saldo");
					} else {
						totalOpenCurrency2 = totalOpenCurrency2 + invoice.getItemValueDouble("invoice.saldo");
					}
				}

				// Due
				if (task >= 5100 && task <= 5199) {
					countDue++;
					// währung 1 oder 2?
					if (invoice.getItemValueDouble("invoice.rate") == 0) {
						totalDueCurrency1 = totalDueCurrency1 + invoice.getItemValueDouble("invoice.saldo");
					} else {
						totalDueCurrency2 = totalDueCurrency2 + invoice.getItemValueDouble("invoice.saldo");
					}
				}

				// Dunning
				if (task >= 5200) {
					countDunning++;
					// währung 1 oder 2?
					if (invoice.getItemValueDouble("invoice.rate") == 0) {
						totalDunningCurrency1 = totalDunningCurrency1 + invoice.getItemValueDouble("invoice.saldo");
					} else {
						totalDunningCurrency2 = totalDunningCurrency2 + invoice.getItemValueDouble("invoice.saldo");
					}
				}
			}

			totalAllCurrency1 = InvoiceUtil.round(totalAllCurrency1);
			totalAllCurrency2 = InvoiceUtil.round(totalAllCurrency2);
			totalOpenCurrency1 = InvoiceUtil.round(totalOpenCurrency1);
			totalOpenCurrency2 = InvoiceUtil.round(totalOpenCurrency2);
			totalDueCurrency1 = InvoiceUtil.round(totalDueCurrency1);
			totalDueCurrency2 = InvoiceUtil.round(totalDueCurrency2);
			totalDunningCurrency1 = InvoiceUtil.round(totalDunningCurrency1);
			totalDunningCurrency2 = InvoiceUtil.round(totalDunningCurrency2);

		} else {
			// reset data because no invoices are available ...
			resetStats(event);

		}

	}

	/**
	 * Setzt alle Statistikwerte zurück
	 */
	private void resetStats(AnalyticEvent event) {
		logger.info("	├──reset stats for " + getDbtNr() + "....");
		stats = null;

		totalAllCurrency1 = 0;
		totalAllCurrency2 = 0;
		totalOpenCurrency1 = 0;
		totalOpenCurrency2 = 0;
		totalDueCurrency1 = 0;
		totalDueCurrency2 = 0;
		totalDunningCurrency1 = 0;
		totalDunningCurrency2 = 0;

		// chartData = null;
		chartData = "{}";

		averagePaymentDue = 0;
		averagePaymentDays = 0;

		event.getWorkitem().removeItem("analytic.invoices.count.all");
		event.getWorkitem().removeItem("analytic.invoices.count.open");
		event.getWorkitem().removeItem("analytic.invoices.count.due");
		event.getWorkitem().removeItem("analytic.invoices.count.dunning");

		event.getWorkitem().removeItem("analytic.payment.avg.due");
		event.getWorkitem().removeItem("analytic.payment.avg.days");
		event.getWorkitem().removeItem("analytic.invoices.trend");

	}

	private void getDurchschnittZahlungsziel() {
		if (stats == null) {
			averagePaymentDue = 0;
			return;
		}
		int count = 0;
		long gesamt = 0;
		for (Map.Entry<String, DebitorStatistikData> entry : stats.entrySet()) {
			DebitorStatistikData statData = entry.getValue();
			if (statData.count > 0) {
				gesamt = gesamt + statData.getAverageDueDays();
				count++;
			}
		}
		averagePaymentDue = Math.round((double) gesamt / count);
	}

	private void getDurchschnittZahlungsdauer() {
		if (stats == null) {
			averagePaymentDays = 0;
			return;
		}
		int count = 0;
		long gesamt = 0;
		for (Map.Entry<String, DebitorStatistikData> entry : stats.entrySet()) {
			DebitorStatistikData statData = entry.getValue();
			if (statData.count > 0) {
				gesamt = gesamt + statData.getAveragePaymentDays();
				count++;
			}
		}
		averagePaymentDays = Math.round((double) gesamt / count);
	}

	private String formatCurrency(Double value) {

		DecimalFormatSymbols symbols = new DecimalFormatSymbols(Locale.getDefault());
		symbols.setGroupingSeparator('.');
		symbols.setDecimalSeparator(',');
		DecimalFormat formatter = new DecimalFormat("#,##0.00", symbols);

		return formatter.format(value);
	}

	/**
	 * Hilfsmethode die das fuehrende K/D aus der Debitorennummer entfernt
	 * 
	 * @return
	 */
	private String getDbtNr() {
		String dbtNr = workflowController.getWorkitem().getItemValueString("dbtr.number");
		if (dbtNr.startsWith("D") || dbtNr.startsWith("K")) {
			dbtNr = dbtNr.substring(1);
		}
		return dbtNr;
	}

	/**
	 * Sucht alle Rechnugnen aus einem Zeitraum und sammelt Zahlungsziel und
	 * Zahlungszeitspanne gruppiert nach monaten
	 * 
	 */
	public Map<String, DebitorStatistikData> loadStats() {

		if (stats != null) {
			return stats;
		}

		logger.info("	├──load stats for " + getDbtNr() + "....");
		// recompute
		stats = new TreeMap<String, DebitorStatistikData>();
		if (getDbtNr().isEmpty()) {
			return stats;
		}

		// Letzen 12 Monate
		LocalDate endDate = LocalDate.now();
		LocalDate startDate = endDate.minusMonths(12);
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
		String startDateStr = startDate.format(formatter);
		String endDateStr = endDate.format(formatter);

		String query = "(type:workitemarchive) AND "
				+ " invoice.date:[" + startDateStr + " TO " + endDateStr + "] AND "
				+ "dbtr.number:" + getDbtNr()
				+ " AND $modelversion:rechnungsausgang-* AND ($taskid:[5900 TO 5999])";

		logger.fine("query = " + query);
		try {
			List<ItemCollection> invoices = documentService
					.findStubs(query, 9999, 0, "$created", false);

			for (ItemCollection invoice : invoices) {
				try {

					logger.fine("Rechnung: " + invoice.getUniqueID());
					Date invoiceDate = invoice.getItemValueDate("invoice.date");
					Date invoiceDueDate = invoice.getItemValueDate("invoice.duedate");
					Date paymentDate = findPaymentDateByWorkitem(invoice);
					if (paymentDate == null) {
						logger.fine("Es wurde kein Zahlungseingang gefunden");
						continue;
					}

					if (invoiceDate != null && paymentDate != null && invoiceDueDate != null) {
						// do we have a stats object?
						DebitorStatistikData statData = stats.get(getYearMonth(invoiceDate));
						if (statData == null) {
							// create a new one
							statData = new DebitorStatistikData(invoiceDate);
						}
						// jetzt irgendwas ausrechnen
						statData.compute(invoiceDate, invoiceDueDate, paymentDate);
						// .. und wieder speichern
						stats.put(statData.toString(), statData);

					} else {
						logger.warning("No payment Date found for invoice " + invoice.getUniqueID());
					}

				} catch (ParseException e) {
					logger.warning("Unable to parse payment Date for invoice " + invoice.getUniqueID());
				}
			}

		} catch (QueryException e) {
			logger.severe("Failed to get statistic: " + e.getMessage());
		}
		// Step 2: Sort the list based on the alphanumeric order of the keys
		completeMissingMonths();

		// berechne zahluntsziel durchscnitt
		getDurchschnittZahlungsziel();
		getDurchschnittZahlungsdauer();
		return stats;

	}

	/**
	 * Finds the payment.date for a invoice.
	 * 
	 * Wir suchen alle zugeordneten Zahlungseingägne und nehmen den letzten.
	 * 
	 * WICHTIG: Es muss ggf. der index neu aufgebaut werden, da payment.date nun ein
	 * index feld ist
	 * 
	 * @param invoice
	 * @return
	 * @throws ParseException
	 */
	public Date findPaymentDateByWorkitem(ItemCollection invoice) throws ParseException {

		// Wir selektieren alle Zahlungseingänge interessieren uns aber nur für den
		// letzten
		String sQuery = " (type:\"workitem\" OR type:\"workitemarchive\") " + //
				" AND ($modelversion:zahlungseingang-*) AND ($workitemref:\""
				+ invoice.getUniqueID() + "\" )";

		List<ItemCollection> workitems = null;

		try {
			workitems = documentService.findStubs(sQuery, 99, 0,
					"payment.date", true);
			if (workitems.size() > 0) {
				return workitems.get(0).getItemValueDate("payment.date");
			}
		} catch (QueryException e) {

			e.printStackTrace();
		}

		// no date found!
		return null;

	}

	/**
	 * Diese Methode baut die Datenstruktur für das Chart Diagram zusammen
	 * 
	 * 
	 * <pre>
		{
		 labels: ["January", "February", "March", "April", "May", "June", "July"],
		 datasets: [{
			label: 'Dataset 1',
			//backgroundColor: color(window.chartColors.red).alpha(0.5).rgbString(),
			//borderColor: window.chartColors.red,
			borderWidth: 1,
			data: [
				70, 70, 70, 70, 79, 50, 50
			]
		}, {
			label: 'Dataset 2',
			//backgroundColor: color(window.chartColors.blue).alpha(0.5).rgbString(),
			//borderColor: window.chartColors.blue,
			borderWidth: 1,
			data: [
				70, 70, 170, 7, 79, 50, 50
			]
		}]
	   }
	 * </pre>
	 * 
	 * @return
	 */
	public String buildChartData() {

		loadStats();
		logger.info("	├──build chart for " + getDbtNr() + "....");
		// build a list of all lables....
		List<String> statusLabels = new ArrayList<String>();

		Set<String> keys = stats.keySet();
		for (String _key : keys) {
			statusLabels.add(_key);
		}

		String result = "{\n \"type\": \"bar\",\n  \"data\": { ";

		// Lables
		result = result + "\"labels\" : [ ";
		result = result + statusLabels.stream().collect(Collectors.joining("\",\"", "\"", "\""));
		result = result + "],";
		result = result + "\"datasets\": [";

		// Datasets 1
		result = result + "{\"label\": \"Days for payment\",\"borderWidth\": 1,";
		result = result + " \"borderColor\": [\"#3B6B82\"],";
		result = result + " \"backgroundColor\" : [\"#CFE9F5\"],  \"fill\": true,\"tension\": 0.5,";

		result = result + "\"data\": [";
		for (Map.Entry<String, DebitorStatistikData> entry : stats.entrySet()) {
			result = result + entry.getValue().getAverageDueDays() + ",";
		}
		// cut last comma
		if (result.endsWith(",")) {
			result = result.substring(0, result.length() - 1);
		}
		result = result + "]";
		result = result + "}, ";

		// Datasets 2
		result = result + "{\"label\": \"Payment duration\",\"borderWidth\": 1,";
		result = result
				+ " \"borderColor\": [\"#E73B65\"],\"backgroundColor\" : [\"#70B088\" ], \"tension\": 0.5,\"fill\": true,";

		result = result
				+ " \"trendlineLinear\": { \"colorMin\": \"red\", \"colorMax\": \"green\", \"lineStyle\": \"dotted\", \"width\": 2 , \"projection\": true },";

		result = result + "\"data\": [";
		for (Map.Entry<String, DebitorStatistikData> entry : stats.entrySet()) {
			result = result + entry.getValue().getAveragePaymentDays() + ",";
		}
		// cut last comma
		if (result.endsWith(",")) {
			result = result.substring(0, result.length() - 1);
		}
		result = result + "]";
		result = result + "} ";

		// ende
		result = result + "] }";

		result = result + "}";

		return result;
	}

	/**
	 * Hilfsmethode ergänzt die fehlenden Monate
	 * 
	 * @param yearMonths
	 * @return
	 */
	private void completeMissingMonths() {
		if (stats == null || stats.size() < 3) {
			return;
		}

		// Convert the list of strings to a list of LocalDate objects
		List<LocalDate> dates = new ArrayList<>();
		Set<String> yearMonths = this.stats.keySet();
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMM");
		for (String yearMonth : yearMonths) {
			dates.add(YearMonth.parse(yearMonth, formatter).atDay(1));
		}

		// Find the lowest and highest dates
		LocalDate lowestDate = Collections.min(dates);
		LocalDate highestDate = Collections.max(dates);

		LocalDate current = lowestDate;
		current = current.plusMonths(1);
		while (!current.isAfter(highestDate)) {

			// existiert der monat?
			String formattedDate = current.format(formatter);
			DebitorStatistikData entry = stats.get(formattedDate);
			if (entry == null) {
				// add missing entry
				stats.put(formattedDate, new DebitorStatistikData(current.getYear(), current.getMonthValue()));
			}
			current = current.plusMonths(1);

		}

	}

	/**
	 * returns
	 * 
	 * 202304 from a given date
	 */
	public String getYearMonth(Date date) {

		// Create a Calendar instance and set the date
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);

		// Get the year from the Calendar object
		int year = calendar.get(Calendar.YEAR);
		// Get the month from the Calendar object
		int month = calendar.get(Calendar.MONTH);
		// Increment the month by 1 since Calendar months are zero-based
		month++;
		// Convert the month to a String with leading "0" if necessary
		return "" + year + (month < 10 ? "0" + month : "" + month);

	}

}