package com.gpc.server.servlet;

import java.io.Writer;
import java.math.BigDecimal;
import java.rmi.RemoteException;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;

import com.gpc.common.ApplicationContext;
import com.gpc.common.PointOfSaleException;
import com.gpc.common.Profile;
import com.gpc.common.exception.ApplicationException;
import com.gpc.common.util.FwoUtil;
import com.gpc.common.util.PartNumberFormatCertifier;
import com.gpc.server.dataaccess.customer.Customer;
import com.gpc.server.inventory.dataaccess.Inventory;
import com.gpc.server.price.dataaccess.PriceLoader;
import com.gpc.valueobjects.customer.CustomerVO;
import com.gpc.valueobjects.inventory.InventoryVO;
import com.gpc.valueobjects.price.PricesInVO;
import com.gpc.valueobjects.price.PricesOutVO;
import com.gpc.valueobjects.profile.StoreProfileVO;

/**
 * This class is used to retrieve the price attributes including tax from 'GetPrice' functionality.
 *
 * @author $Author:
 *
 * @version $Revision: $, $Date: $
 */
public class GetPriceServlet extends HttpServlet {

    /** The Constant serialVersionUID. */
    private static final long serialVersionUID = 14236536576577L;

    /** The logger. */
    private static Logger logger = Logger.getLogger(GetPriceServlet.class);

    /** The Constant CUSTOMER_NUMBER. */
    private static final String CUSTOMER_NUMBER = "CUSTOMER_NUMBER";

    /** The Constant PART_NUMBER. */
    private static final String PART_NUMBER = "PART_NUMBER";

    /** The Constant LINE_ABBREV. */
    private static final String LINE_ABBREV = "LINE_ABBREV";

    /** The Constant LOC. */
    private static final String LOC = "LOC";

    /** The Constant CONTENT_TYPE. */
    private static final String CONTENT_TYPE = "text/plain";

    /** The Constant PIPE. */
    private static final String PIPE = "|";

    /** The Constant COMMA. */
    private static final String COMMA = ", ";

    /** The Constant EMPTY_STRING. */
    private static final String EMPTY_STRING = "";

    /** The Constant NEW_LINE. */
    private static final String NEW_LINE = "\n";

    /** The Constant ZERO. */
    private static final BigDecimal ZERO = new BigDecimal("0.0000");

    /*
     * (non-Javadoc)
     * 
     * @see javax.servlet.GenericServlet#init(javax.servlet.ServletConfig)
     */
    public void init(javax.servlet.ServletConfig config) throws javax.servlet.ServletException {
        super.init(config);
    }

    /*
     * (non-Javadoc)
     * 
     * @see javax.servlet.http.HttpServlet#service(javax.servlet.http.HttpServletRequest,
     * javax.servlet.http.HttpServletResponse)
     */
    public void service(HttpServletRequest request, HttpServletResponse response)
            throws javax.servlet.ServletException, java.io.IOException {

        Writer writer = response.getWriter();
        response.setContentType(CONTENT_TYPE);

        final String customerNumber = request.getParameter(CUSTOMER_NUMBER);
        String partNumber = request.getParameter(PART_NUMBER);
        if(partNumber != null) {
            partNumber = FwoUtil.stripChars(partNumber, new char[] {
                PartNumberFormatCertifier.DASH, PartNumberFormatCertifier.FORWARD_SLASH,
                PartNumberFormatCertifier.PERIOD, PartNumberFormatCertifier.SPACE });
        }
        final String lineAbbrev = request.getParameter(LINE_ABBREV);
        final String location = request.getParameter(LOC);

        final String errorMessage = validateInputParameters(partNumber, lineAbbrev, customerNumber,
                location);
        if (errorMessage != null && errorMessage.trim().length() > 0) {
            writer.write(errorMessage);
        } else {
            writer.write(getPriceDetails(partNumber, lineAbbrev, new Integer(customerNumber),
                    new Integer(location)));
        }

        response.setHeader("Cache-Control", "no-cache");
        response.addHeader("Cache-Control", "no-store");
        response.setHeader("Cache-Control", "max-age=0");
        response.setHeader("Pragma", "no-cache");
        // Avoids caching at proxy / gateway servers
        response.setDateHeader("Expires", 0);

        writer.write(NEW_LINE);
        writer.close();
        return;
    }

    /**
     * Method is used to fetch the price attributes and display price attributes including all
     * applicable taxes from 'GetPrice' functionality.
     * 
     * @param partNumber is the part number.
     * 
     * @param lineAbbrev is the line abbreviation
     * 
     * @param customerNumber is the customer number.
     * 
     * @param location is the location values
     * 
     * @return a string containing the price attributes retrieved from 'GetPrice' functionality.
     */
    private String getPriceDetails(final String partNumber, final String lineAbbrev,
            final Integer customerNumber, Integer location) {

        // Get Store Profile Details
        final StoreProfileVO storeProfileVO = ApplicationContext.getInstance()
                .getProfile(Profile.SERVER, location.intValue()).getStoreProfile();
        if (storeProfileVO == null) {
            return "ERROR - Store information not found";
        }

        // Get Customer Details
        final CustomerVO customerVO = getCustomerDetails(customerNumber, storeProfileVO, location);
        if (customerVO == null) {
            return "ERROR - Customer information not found";
        }

        // Get Inventory Details
        final InventoryVO inventoryVO = getInventoryDetails(partNumber, lineAbbrev, customerVO,
                storeProfileVO, location);
        if (inventoryVO == null) {
            return "ERROR - Part not found ";
        }

        // Load price from 'GetPrice' functionality
        final PricesOutVO priceOutputVO = getPriceDetails(partNumber, lineAbbrev, customerVO,
                location);
        if (priceOutputVO == null) {
            return "ERROR - Price information not found";
        }
        return buildGetPriceServletResponse(priceOutputVO, storeProfileVO);
    }

    /**
     * Method is used to validate Get Price servlet input parameters
     * 
     * @param partNumber is the part number
     * 
     * @param lineAbbrev is the line abbreviation
     * 
     * @param customerNumber is the customer number
     * 
     * @param locationValue is the location value.
     * 
     * @return a message containing validation results
     */
    private String validateInputParameters(final String partNumber, final String lineAbbrev,
            final String customerNumber, final String locationValue) {

        final StringBuffer missingInputParams = new StringBuffer();
        String errorMessage = null;
        boolean invalidParameter = false;

        if (isEmpty(customerNumber)) {
            missingInputParams.append("Customer Number");
            invalidParameter = true;
        }

        if (isEmpty(partNumber)) {
            missingInputParams.append(invalidParameter ? COMMA : EMPTY_STRING)
                    .append("Part Number");
            invalidParameter = true;
        }

        if (isEmpty(lineAbbrev)) {
            missingInputParams.append(invalidParameter ? COMMA : EMPTY_STRING)
                    .append("Line Abbreviation");
            invalidParameter = true;
        }

        if (isEmpty(locationValue)) {
            missingInputParams.append(invalidParameter ? COMMA : EMPTY_STRING).append("Location");
            invalidParameter = true;
        }
        if (invalidParameter) {
            errorMessage = "ERROR - Input parameter missing : " + missingInputParams.toString();
        }
        if (errorMessage == null) {
            if (!isNumeric(locationValue) || !isNumeric(customerNumber)) {
                errorMessage = "ERROR - Customer Number or Location value should be numeric ";
            }
        }
        return errorMessage;
    }  

    /**
     * Method is used to fetch the customer details.
     * 
     * @param customerNumber is the customer number
     * 
     * @param {@link StoreProfileVO} value object containing store profile information.
     * 
     * @param location is the location value.
     * 
     * @return {@link CustomerVO} value object containing customer information.
     */
    private CustomerVO getCustomerDetails(final Integer customerNumber,
            final StoreProfileVO storeProfileVO, Integer location) {
        CustomerVO customerVO = null;
        try {
            customerVO = new Customer().getCustomerDetailInfo(location, customerNumber,
                    storeProfileVO.getRefLanguageCd());
        } catch (PointOfSaleException exception) {
            logger.error(exception.getMessage(), exception);
        } catch (ApplicationException applicationException) {
            logger.error(applicationException.getMessage(), applicationException);
        }
        return customerVO;
    }

    /**
     * Method is used to fetch the inventory details based on part number and line abbreviation
     * 
     * @param partNumber is the part number.
     * 
     * @param lineAbbrev is the line abbreviation.
     * 
     * @param {@link CustomerVO} value object containing customer information.
     * 
     * @param {@link StoreProfileVO} value object containing store profile information.
     * 
     * @param location is the location value.
     * 
     * @return {@link InventoryVO} value object containing inventory information.
     */
    private InventoryVO getInventoryDetails(final String partNumber, final String lineAbbrev,
            final CustomerVO customerVO, final StoreProfileVO storeProfileVO, Integer location) {
        InventoryVO inventoryVO = null;
        Inventory inventory = new Inventory();
        try {
            inventoryVO = inventory.getPartDetailInfo(customerVO, location, partNumber, lineAbbrev,
                    storeProfileVO.getRefLanguageCd(), true);
        } catch (RemoteException remoteException) {
            logger.error(remoteException.getMessage(), remoteException);
        } catch (PointOfSaleException exception) {
            logger.error(exception.getMessage(), exception);
        }
        return inventoryVO;
    }

    /**
     * Method is used to fetch the price attributes from 'GetPrice' functionality.
     * 
     * @param partNumber is the part number
     * 
     * @param lineAbbrev is the line abbreviation
     * 
     * @param {@link CustomerVO} value object containing customer information
     * 
     * @param location is the location value.
     * 
     * @return {@link PricesOutVO} value object containing 'GetPrice' functionality output values.
     */
    private PricesOutVO getPriceDetails(final String partNumber, final String lineAbbrev,
            final CustomerVO customerVO, final Integer location) {
        final String methodSpec = "GetPriceServlet.getPriceDetails - ";
        PricesOutVO pricesOutVO = null;
        final PricesInVO pricesInputVO = new PricesInVO();
        pricesInputVO.setLocation(location);
        pricesInputVO.setCustomerId(customerVO.getID());
        pricesInputVO.setCustomerTypeCD(customerVO.getCustomerTypeCD());
        pricesInputVO.setPartNumber(partNumber);
        pricesInputVO.setLineAbbreviation(lineAbbrev);
        pricesInputVO.setFieldsPassedIn("N");

        final PriceLoader priceLoader = new PriceLoader();
        try {
            pricesOutVO = priceLoader.getPrices(pricesInputVO);
        } catch (PointOfSaleException pointOfSaleException) {
            logger.error(methodSpec + " Error occured while loading getPrice details "
                    + pointOfSaleException);
        }
        return pricesOutVO;
    }

    /**
     * Method is used to build the GetPriceServlet response based on the price attributes retrieved
     * from 'GetPrice' functionality.
     * 
     * @param {@link PricesOutVO} value object containing 'GetPrice' details.
     * 
     * @param {@link StoreProfileVO} value object containing store profile information
     * 
     * @return a value containing all the 'Get Price' attributes separated by pipe delimiter.
     */
    private String buildGetPriceServletResponse(final PricesOutVO priceOutputVO,
            final StoreProfileVO storeProfileVO) {
        final String methodSpec = "GetPriceServlet.buildGetPriceServletResponse -";
        boolean displayPriceWithTax = storeProfileVO.getIncludeTaxInPrice().booleanValue();
        final StringBuffer response = new StringBuffer();
        if (displayPriceWithTax) {
            response.append(formatPriceValue(priceOutputVO.getDisplayListPrice()));
            response.append(PIPE);
            response.append(formatPriceValue(priceOutputVO.getDisplayUnitPrice()));
            response.append(PIPE);
            response.append(priceOutputVO.getPriceDecision());
            response.append(PIPE);
            response.append(priceOutputVO.getCalcString());
            response.append(PIPE);
            response.append(priceOutputVO.getMarkup());
            response.append(PIPE);
            response.append(formatPriceValue(priceOutputVO.getDisplayUnitCost()));
            response.append(PIPE);
            response.append(priceOutputVO.getUnitRebate());
            response.append(PIPE);
            response.append(formatPriceValue(priceOutputVO.getDisplayCoreCost()));
            response.append(PIPE);
            response.append(formatPriceValue(priceOutputVO.getDisplayCorePrice()));
            response.append(PIPE);
            response.append(formatPriceValue(priceOutputVO.getDisplayUsualPrice()));
            response.append(PIPE);
            response.append(formatPriceValue(priceOutputVO.getDisplayCustomPrice()));
            response.append(PIPE);
            response.append(formatPriceValue(priceOutputVO.getDisplaySpecialPrice()));
        } else {
            response.append(priceOutputVO.getCalculatedList());
            response.append(PIPE);
            response.append(priceOutputVO.getUnitPrice());
            response.append(PIPE);
            response.append(priceOutputVO.getPriceDecision());
            response.append(PIPE);
            response.append(priceOutputVO.getCalcString());
            response.append(PIPE);
            response.append(priceOutputVO.getMarkup());
            response.append(PIPE);
            response.append(priceOutputVO.getUnitCost());
            response.append(PIPE);
            response.append(priceOutputVO.getUnitRebate());
            response.append(PIPE);
            response.append(priceOutputVO.getCoreCost());
            response.append(PIPE);
            response.append(priceOutputVO.getCorePrice());
            response.append(PIPE);
            response.append(priceOutputVO.getUsualPrice());
            response.append(PIPE);
            response.append(priceOutputVO.getCustomPrice());
            response.append(PIPE);
            response.append(priceOutputVO.getSpecialPrice());
        }
        if( response.length() > 0) {
            response.append(PIPE);//Adding Unit Saved to response.
            response.append(priceOutputVO.getUnitSaved());    
        }
        logger.debug(methodSpec + response.toString());
        return response.toString();
    }

    /**
     * Method is used to format the price value to 4 decimal places.
     *
     * @param price is the input price value
     * 
     * @return price value formatted to four decimal places
     */
    private BigDecimal formatPriceValue(BigDecimal price) {
        return price != null ? price.setScale(4) : ZERO;
    }
    
    /**
     * Method is used to check whether the given input param is empty or not.
     * 
     * @param inputParam is the input param value.
     * 
     * @return a boolean value to indicate whether the given input param is empty or not.
     */
    private boolean isEmpty(final String inputParam) {
        return inputParam == null || inputParam.trim().length() <= 0;
    }

    /**
     * Method is used to check whether the given input param is numeric or not.
     * 
     * @param inputParam is the input param value.
     * 
     * @return a boolean value to indicate whether the given input param is numeric or not.
     */
    private boolean isNumeric(final String inputParam) {
        boolean isNumeric = true;
        try {
            Integer.parseInt(inputParam);
        } catch (NumberFormatException numberFormatException) {
            isNumeric = false;
        }
        return isNumeric;
    }

    /*
     * (non-Javadoc)
     * 
     * @see javax.servlet.GenericServlet#getServletConfig()
     */
    public javax.servlet.ServletConfig getServletConfig() {
        return super.getServletConfig();
    }

    /*
     * (non-Javadoc)
     * 
     * @see javax.servlet.GenericServlet#getServletInfo()
     */
    public String getServletInfo() {
        return super.getServletInfo();
    }

    /*
     * (non-Javadoc)
     * 
     * @see javax.servlet.GenericServlet#destroy()
     */
    public void destroy() {
        super.destroy();
    }

}