package com.alexanderlogistics.metrics;

import java.util.List;
import java.util.logging.Logger;

import org.imixs.workflow.ItemCollection;
import org.imixs.workflow.engine.DocumentService;
import org.imixs.workflow.exceptions.PluginException;
import org.imixs.workflow.exceptions.QueryException;

import com.alexanderlogistics.InvoiceUtil;

import jakarta.ejb.Stateless;
import jakarta.ejb.TransactionAttribute;
import jakarta.ejb.TransactionAttributeType;
import jakarta.inject.Inject;
import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;
import jakarta.ws.rs.Produces;
import jakarta.ws.rs.core.MediaType;
import jakarta.ws.rs.core.Response;

@Path("metrics/dbtr")
@Stateless
public class MetricDebitorRestService {

    private static Logger logger = Logger.getLogger(MetricDebitorRestService.class.getName());

    @Inject
    DocumentService documentService;

    @Inject
    MetricDebitorService metricDebitorService;

    @Inject
    MetricDataService metricDataService;

    @GET
    @Path("/ping")
    @Produces({ MediaType.TEXT_PLAIN })
    public String ping() {
        logger.info("GET ping");
        return "ping: " + System.currentTimeMillis();
    }

    /**
     * This method initializes the metrics for all debitors with open invoices.
     * 
     * The method first deletes all existing metrics and than creates or updates the
     * metric entires for each debitor.
     * 
     * @return
     */
    @GET
    @Path("/rebuild")
    @Produces({ MediaType.TEXT_PLAIN })
    public Response rebuildMetrics() {

        StringBuffer messageBuffer = new StringBuffer();
        long l = System.currentTimeMillis();
        log("├── rebuild dbtr metrics...", messageBuffer);

        try {
            log("│   ├── delete all metrics", messageBuffer);
            // first clear the metric cache
            metricDebitorService.reset();
            log("│   ├── reset metric cache", messageBuffer);

            computeMetrics(messageBuffer);

            String message = "├── rebuild dbtr metrics completed in "
                    + (System.currentTimeMillis() - l)
                    + "ms";
            log(message, messageBuffer);
            return Response.ok().entity(messageBuffer.toString()).build();

        } catch (Exception e) {
            e.printStackTrace();
            log("Failed to initialize metrics: " + e.getMessage(), messageBuffer);
            return Response.serverError()
                    .entity(messageBuffer.toString() + e.getMessage())
                    .build();
        }
    }

    /**
     * Diese Methode berechnet alle Metriken auf basis der existierenden Rechnungen
     * neu
     * 
     * @throws QueryException
     * @throws InterruptedException
     * @throws PluginException
     * 
     */
    public void computeMetrics(StringBuffer messageBuffer)
            throws QueryException, InterruptedException, PluginException {
        long l = System.currentTimeMillis();
        int batchSize = 500;
        int totalInvoices = 0;
        log("│   │   ├── recalculate metrics...", messageBuffer);

        String query = "$modelversion:rechnungsausgang-* AND type:workitem";
        // Gesamtanzahl ermitteln
        int totalCount = documentService.count(query);
        log("│   │   ├── found " + totalCount + " open invoices", messageBuffer);

        // Berechne Anzahl der benötigten Pages
        int totalPages = (int) Math.ceil((double) totalCount / batchSize);

        // Verarbeite Page für Page
        for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
            totalInvoices = totalInvoices + computeInvoiceMetrics(query, batchSize, pageIndex);
            // List<ItemCollection> invoices = documentService.find(query, batchSize,
            // pageIndex);

            // for (ItemCollection invoice : invoices) {
            // try {
            // ItemCollection metricData = metricDebitorService.getMetricByInvoice(invoice);
            // // Jetzt Rechnung addieren
            // metricDebitorService.addInvoice(metricData, invoice);
            // logger.fine("│   │   │   ├── update metric " + InvoiceUtil.getBPId(invoice));
            // metricDebitorService.updateMetric(metricData, true);
            // totalInvoices++;
            // } catch (PluginException e) {
            // // invalid invoice - e.g. no dbtr. number
            // }
            // }

            // Fortschritt loggen
            log("│   │   ├── Processed page " + (pageIndex + 1) + " of " + totalPages +
                    " (" + totalInvoices + " of " + totalCount + " invoices)", messageBuffer);
            // Optional: Kurze Pause nach jedem 5. Batch
            Thread.sleep(100);

        }
        long duration = System.currentTimeMillis() - l;
        double invoicesPerSecond = totalInvoices / (duration / 1000.0);
        log("│   │   ├── Successfully processed " + totalInvoices + " invoices in " +
                duration + "ms (" + String.format("%.1f", invoicesPerSecond) + " invoices/sec)", messageBuffer);
        log("│   │   ├── Updated " + metricDebitorService.getMetricCount() + " metrics.", messageBuffer);

    }

    /**
     * Helper method runs in new transaction
     * 
     * @param query
     * @param batchSize
     * @param pageIndex
     * @throws PluginException
     * @throws QueryException
     */
    @TransactionAttribute(value = TransactionAttributeType.REQUIRES_NEW)
    public int computeInvoiceMetrics(String query, int batchSize, int pageIndex)
            throws PluginException, QueryException {

        int updates = 0;
        List<ItemCollection> invoices = documentService.find(query, batchSize, pageIndex);

        for (ItemCollection invoice : invoices) {
            try {
                ItemCollection metricData = metricDebitorService.getMetricByInvoice(invoice);
                // Jetzt Rechnung addieren
                metricDebitorService.addInvoice(metricData, invoice);
                logger.fine("│   │   │   ├── update metric " + InvoiceUtil.getBPId(invoice));
                metricDebitorService.updateMetric(metricData, true);
                updates++;
            } catch (PluginException e) {
                // invalid invoice - e.g. no dbtr. number
            }
        }
        return updates;
    }

    private void log(String message, StringBuffer messageLog) {
        logger.info(message);
        messageLog.append(message + "\n");

    }
}