package application.parsing;

import java.io.BufferedWriter;
import java.io.File;
import java.io.IOException;
import java.io.Writer;
import java.text.ParseException;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.HashMap;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import application.enums.BiologicalSex;
import application.enums.BloodType;
import application.enums.EntryType;
import application.enums.SkinType;
import application.helpers.Utils;
import application.helpers.wrappers.AttributeDataInfoTuple;
import application.helpers.wrappers.GeneralSaveInfo;
import application.helpers.wrappers.MeSaveInfo;
import application.helpers.wrappers.Occupation;
import application.helpers.wrappers.WrappedException;
import application.helpers.wrappers.WriteSelection;
import application.res.Text;

public class WriteHandler extends DefaultHandler
{
	/**
	 * Contains the StringBuilders for the nested attributes which need to be added
	 * to the complete Row. Key is the tag name of the nested attribute
	 */
	private HashMap<String, AttributeDataInfoTuple> nestedAttributes;
	/** The text to be written as one row into the files **/
	private StringBuilder completeRow;
	/** the selection of the user **/
	private WriteSelection selection;
	/** all files which will be written. Key is the readable name **/
	private HashMap<String, FileWrapper> allFiles;
	/**
	 * In case of records and workouts there will be sub elements. The name will be
	 * saved here.
	 **/
	private String subElementName = null;
	/**
	 * All error messages will be appended here as {@link DefaultHandler} does not
	 * permit other exceptions in the startElement and endElement methods
	 **/
	private StringBuilder errorMessages;

	/**
	 * Initializes the variables and creates all files needed for the selected data
	 * 
	 * @param selection The selection of the user
	 * @param job       The job given by the user
	 */
	public WriteHandler(WriteSelection selection, Occupation job)
	{
		this.selection = selection;
		this.errorMessages = new StringBuilder();
		resetSubAttributes();
		// figure out what is selected
		// create files for the selected
		allFiles = new HashMap<>();
		try
		{
			boolean me = false;
			for (EntryType meElem : EntryType.ALL_ME_ONES)
			{
				if (this.selection.entrySelected(meElem))
				{
					me = true;
				}
			}
			if (!job.equals(Text.NOT_SET))
			{ // job given
				me = true;
			}
			if (me)
			{
				FileWrapper fw = new FileWrapper("me_info.txt", "MainInfo");
				allFiles.put(fw.getReadableFilename(), fw);
				if (!job.getLevelOne().equals(Text.NOT_SET))
				{
					writeToMeFile(new MeSaveInfo(EntryType.JOB, Text.OCCUPATION_LEVEL_ONE, job.getLevelOne()));
					if (!job.getLevelTwo().equals(Text.NOT_SET))
					{
						writeToMeFile(new MeSaveInfo(EntryType.JOB, Text.OCCUPATION_LEVEL_TWO, job.getLevelTwo()));
						if (!job.getLevelThree().equals(Text.NOT_SET))
						{
							writeToMeFile(new MeSaveInfo(EntryType.JOB, Text.OCCUPATION_LEVEL_THREE, job.getLevelThree()));
							if (!job.getLevelFour().equals(Text.NOT_SET))
							{
								writeToMeFile(new MeSaveInfo(EntryType.JOB, Text.OCCUPATION_LEVEL_FOUR, job.getLevelFour()));
							}
						}
					}
				}
			}
			if (this.selection.entrySelected(EntryType.ACTIVITY_SUMMARY))
			{
				FileWrapper fw = new FileWrapper("activity_summary.csv", EntryType.ACTIVITY_SUMMARY.getValue(), null,
						Utils.ACTIV_SUMM_ATTR);
				allFiles.put(fw.getReadableFilename(), fw);
			}
			if (this.selection.entrySelected(EntryType.WORKOUT))
			{
				for (String selectedType : selection.getWorkouts())
				{
					FileWrapper fw = new FileWrapper("workout_" + selectedType + ".csv", EntryType.WORKOUT.getValue(),
							Utils.shortenHKStrings(selectedType), Utils.workoutAttributes);
					allFiles.put(fw.getReadableFilename(), fw);
				}
			}
			if (this.selection.entrySelected(EntryType.RECORD))
			{
				for (String selectedType : selection.getRecords())
				{
					FileWrapper fw = new FileWrapper("record_" + selectedType + ".csv", EntryType.RECORD.getValue(),
							Utils.shortenHKStrings(selectedType), Utils.recordAttributes);
					allFiles.put(fw.getReadableFilename(), fw);
				}
			}
		}
		catch (WrappedException e)
		{
			errorMessages.append(e.getReason());
			errorMessages.append("\n");
		}
		catch (Exception e)
		{
			errorMessages.append(Text.E_CREATE_TEMP_FILES);
			errorMessages.append("\n");
		}
	}

	@Override
	public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException
	{
		try
		{
			// ME Entries not of the me tag
			if (selection.entrySelected(EntryType.REGION_CODE) && qName.equalsIgnoreCase(Text.TAG_NAME_HEALTH_DATA))
			{
				writeToMeFile(new MeSaveInfo(EntryType.REGION_CODE, attributes.getValue(Text.TAG_ATTR_REGION_CODE)));
			}
			else if (selection.entrySelected(EntryType.EXPORT_DATE)
					&& qName.equalsIgnoreCase(EntryType.EXPORT_DATE.getValue()))
			{
				writeToMeFile(new MeSaveInfo(EntryType.EXPORT_DATE, attributes.getValue(Text.TAG_ATTR_EXPORT_DATE)));
			}
			// ME Tag
			else if (qName.equalsIgnoreCase(Text.TAG_NAME_ME_INFO))
			{
				for (EntryType me : EntryType.ALL_ORIGINAL_ME_ONES)
				{
					if (selection.entrySelected(me))
					{
						String dateOfBirthString = attributes.getValue(Text.TAG_ATTR_DATE_OF_BIRTH);
						// first the simple ones
						if (me != EntryType.DATE_OF_BIRTH)
						{
							String value = "";
							if (me == EntryType.BIOLOGICAL_SEX)
							{
								value = BiologicalSex.getValue(attributes.getValue(Text.TAG_ATTR_BIOLOGICAL_SEX))
										.getReadableValue();
							}
							else if (me == EntryType.BLOOD_TYPE)
							{
								value = BloodType.getValue(attributes.getValue(Text.TAG_ATTR_BLOOD_TYPE))
										.getReadableValue();
							}
							else if (me == EntryType.SKIN_TYPE)
							{
								value = SkinType.getValue(attributes.getValue(Text.TAG_ATTR_SKIN_TYPE))
										.getReadableValue();
							}
							writeToMeFile(new MeSaveInfo(me, value));
						}
						else if (dateOfBirthString != null && !dateOfBirthString.equals(""))
						{// now the date of birth with individually selected parts
							try
							{
								Calendar dateOfBirth = new GregorianCalendar();
								dateOfBirth.setTime(Utils.formatDateOfBirth.parse(dateOfBirthString));

								if (selection.birthPartSelected(Text.YEAR))
								{
									writeToMeFile(new MeSaveInfo(EntryType.DATE_OF_BIRTH, Text.YEAR,
											dateOfBirth.get(Calendar.YEAR) + ""));
								}
								if (selection.birthPartSelected(Text.MONTH))
								{
									writeToMeFile(new MeSaveInfo(EntryType.DATE_OF_BIRTH, Text.MONTH,
											"" + (dateOfBirth.get(Calendar.MONTH) + 1)));
								}
								if (selection.birthPartSelected(Text.DAY))
								{
									writeToMeFile(new MeSaveInfo(EntryType.DATE_OF_BIRTH, Text.DAY,
											dateOfBirth.get(Calendar.DAY_OF_MONTH) + ""));
								}
							}
							catch (ParseException e)
							{
								// bad luck. Do nothing if parsing error
							}
						}
					}
				}
			}
			// activity summaries: only one file and no special cases
			else if (selection.entrySelected(EntryType.ACTIVITY_SUMMARY)
					&& qName.equalsIgnoreCase(EntryType.ACTIVITY_SUMMARY.getValue()))
			{
				writeToFile(new GeneralSaveInfo(getValuesToAttributes(Utils.ACTIV_SUMM_ATTR, attributes),
						EntryType.ACTIVITY_SUMMARY));
			}
			// The following ones might need completion in the endElement-method
			else if (qName.equalsIgnoreCase(EntryType.WORKOUT.getValue()) && selection.workoutSelected(attributes))
			{
				subElementName = Utils.shortenHKStrings(attributes.getValue(Text.TAG_ATTR_WORKOUT_TYPE));
				completeRow.append(getNonNestedAttributeValues(
						getValuesToAttributes(Utils.workoutAttributes, attributes), Utils.workoutAttributes, true));
			}
			else if (qName.equalsIgnoreCase(EntryType.RECORD.getValue()) && selection.recordSelected(attributes))
			{
				subElementName = Utils.shortenHKStrings(attributes.getValue(Text.TAG_ATTR_RECORD_TYPE));
				completeRow.append(getNonNestedAttributeValues(
						getValuesToAttributes(Utils.recordAttributes, attributes), Utils.recordAttributes, true));
			}
			// These are now nested elements with nested attributes
			else if (subElementName != null && isNestedAttribute(qName))
			{
				for (String tagName : nestedAttributes.keySet())
				{
					if (qName.equals(tagName))
					{ // all entries in attributes
						AttributeDataInfoTuple tuple = nestedAttributes.get(tagName);
						if (tagName.equals(Text.TAG_NAME_HR_LIST))
						{ // this one is completely nested
							tuple.getBuilder().append("[");
						}
						else
						{
							tuple.getBuilder()
									.append(getNonNestedAttributeValues(
											getValuesToAttributes(tuple.getSubAttributes(), attributes),
											tuple.getSubAttributes(), false));
							if (!tagName.equals(Text.TAG_NAME_WORKOUT_ROUTE))
							{ // workout route is nested again and isn't complete yet
								tuple.getBuilder().append(",");

							}
						}
					}

				}
			}
		}
		catch (WrappedException e)
		{
			errorMessages.append(e.getReason());
			errorMessages.append("\n");
		}
	}

	/**
	 * Writes all attributes of an element up to the first nested attribute
	 * 
	 * @param values attribute values to be written
	 * @param names  attribute names to check for nesting
	 * @param top    indicates whether this is already a nested attribute
	 *               ({@code False}) or whether we are at top level ({@code True}
	 * @return The complete string for the element if there are no nested values,
	 *         otherwise the incomplete beginning which needs to be finished with
	 *         {@code addAllNestedAttributes}
	 */
	private String getNonNestedAttributeValues(String[] values, String[] names, boolean top)
	{
		StringBuilder res = new StringBuilder();
		// Start element with a bracket
		res.append("[");
		for (int i = 0; i < names.length; i++)
		{
			if (isNestedAttribute(names[i]))
			{ // stop if attribute is nested, then we need to finish at another point
				// here is no bracket at the end!
				return res.toString();
			}
			res.append(values[i]);
			if (top)
			{
				res.append(";");
			}
			else
			{
				res.append(",");
			}
		}
		// replace last char (, or ;) with bracket
		res = res.replace(res.length() - 1, res.length(), "]");
		return res.toString();
	}

	/**
	 * Determines for an attribute name whether it is a nested attribute
	 * 
	 * @param attr the name to check
	 * @return {@code True} if it is a nested attribute, {@code False} otherwise.
	 */
	private boolean isNestedAttribute(String attr)
	{
		for (String nestedAttribute : nestedAttributes.keySet())
		{
			if (attr.equals(nestedAttribute))
			{
				return true;
			}
		}
		return false;
	}

	@Override
	public void endElement(String uri, String localName, String qName) throws SAXException
	{
		if (subElementName != null)
		{ // we have a selected value which is nested / has nested attributes
			if (isNestedAttribute(qName))
			{ // nested case: either hr_list or workout_route

				if (qName.equals(Text.TAG_NAME_HR_LIST))
				{ // all entries in IBperMinutes
					appendSubEntry(Text.TAG_NAME_HR_LIST, Text.TAG_NAME_IB_PER_MINUTES);
					nestedAttributes.put(Text.TAG_NAME_IB_PER_MINUTES,
							new AttributeDataInfoTuple(Utils.IB_PER_MINUTES_ATTR));
					nestedAttributes.get(Text.TAG_NAME_HR_LIST).getBuilder().append("],");
				}
				if (qName.equals(Text.TAG_NAME_WORKOUT_ROUTE))
				{ // last entry not in attributes! (MetaDataEntry)
					appendSubEntry(Text.TAG_NAME_WORKOUT_ROUTE, Text.TAG_NAME_META_DATA_ENTRY);
					nestedAttributes.put(Text.TAG_NAME_META_DATA_ENTRY,
							new AttributeDataInfoTuple(Utils.META_DATA_ATTR));
					nestedAttributes.get(Text.TAG_NAME_WORKOUT_ROUTE).getBuilder().append("],");
				}
			}
			else
			{ // this can only be a record or workout
				// non nested ones were written in the start method, so only add the nested ones
				// now
				if (qName.equalsIgnoreCase(EntryType.WORKOUT.getValue()))
				{
					addAllNestedAttributes(completeRow, Utils.workoutAttributes);
				}
				else
				{
					addAllNestedAttributes(completeRow, Utils.recordAttributes);
				}

				completeRow = removeOuterBrackets(completeRow);
				FileWrapper fw = allFiles.get(FileWrapper.createReadableFileName(qName, subElementName));
				if (fw != null)
				{
					try
					{
						fw.getBufferedWriter().append(completeRow);
						fw.getBufferedWriter().newLine();
					}
					catch (IOException e)
					{
						errorMessages.append(Text.E_WRITE_TO_TEMP_FILES);
						errorMessages.append("\n");
					}
				}
				resetSubAttributes();
			}
		}
	}

	/**
	 * Used for removing the outer Brackets in a StringBuilder, but in truth just
	 * removes the first and last char of it.... So be careful, it doesn't check for
	 * brackets!
	 * 
	 * @param sb The StringBuilder to be shortened
	 * @return The shortened StringBuilder
	 */
	private StringBuilder removeOuterBrackets(StringBuilder sb)
	{
		sb = sb.replace(0, 1, "");
		return sb.replace(sb.length() - 1, sb.length(), "");
	}

	/**
	 * Nested Attributes (which are ALLWAYS at the end of attribute lists) are here
	 * appended at the end of the current row
	 * 
	 * @param toAppend   Contains the current row which should be appended
	 * @param attributes The whole attribute list of the current row. But only the
	 *                   nested ones will be appended thus the non nested ones need
	 *                   to already be in the StringBuilder
	 */
	private void addAllNestedAttributes(StringBuilder toAppend, String[] attributes)
	{
		for (int i = 0; i < attributes.length; i++)
		{
			for (String tagName : nestedAttributes.keySet())
			{
				if (attributes[i].equals(tagName))
				{
					appendSubEntry(toAppend, tagName);
					toAppend.append(";");
				}
			}
		}
		toAppend = toAppend.replace(toAppend.length() - 1, toAppend.length(), "]");
	}

	/**
	 * Appends the text of a sub entry to its containing row. All sub entries (even
	 * if they are empty) will be surrounded by brackets [].
	 * 
	 * @param toAppendTo The containing row which should be appended
	 * @param nestedInfo The name of the attribute containing the sub entry
	 *                   information
	 */
	private void appendSubEntry(StringBuilder toAppendTo, String nestedInfo)
	{
		toAppendTo.append("[");
		StringBuilder toAppendWith = nestedAttributes.get(nestedInfo).getBuilder();
		if (toAppendWith.length() > 0) // there is an element here, so there is also a ',' too much
		{
			toAppendTo.append(toAppendWith.substring(0, toAppendWith.length() - 1));
		}
		toAppendTo.append("]");
	}

	/**
	 * Appends the text of a sub entry to its containing row. All sub entries (even
	 * if they are empty) will be surrounded by brackets [].
	 * 
	 * @param topLevelInfo The name of the attribute which should be appended with a
	 *                     sub attribute
	 * @param nestedInfo   The name of the attribute containing the sub entry
	 *                     information
	 */
	private void appendSubEntry(String topLevelInfo, String nestedInfo)
	{
		appendSubEntry(nestedAttributes.get(topLevelInfo).getBuilder(), nestedInfo);
	}

	/**
	 * /** Writes one line of information to a file (but not the ME File)
	 * 
	 * @param info The information about what to write.
	 * @throws WrappedException if the file could not be written
	 */
	private void writeToFile(GeneralSaveInfo info) throws WrappedException
	{
		FileWrapper fw = allFiles.get(info.getReadableFilename());
		if (fw != null)
		{
			BufferedWriter bout = fw.getBufferedWriter();
			try
			{
				writeNormalRow(bout, info.getValues(), true);
				bout.newLine();
			}
			catch (IOException e)
			{
				throw new WrappedException(e, Text.E_WRITE_TO_TEMP_FILES);
			}
		}
	}

	/**
	 * Writes one line of information to the me file
	 * 
	 * @param info The information about what to write.
	 * @throws WrappedException if the file could not be written
	 */
	private void writeToMeFile(MeSaveInfo info) throws WrappedException
	{
		FileWrapper fw = allFiles.get(FileWrapper.createReadableFileName(Text.ME_FILE_DESC));
		if (fw != null)
		{
			BufferedWriter bout = fw.getBufferedWriter();
			try
			{
				bout.write(String.format(Text.F_ME_SAVE, info.getSaveKey(), info.getSaveValue()));
				bout.newLine();
			}
			catch (IOException e)
			{
				throw new WrappedException(e, Text.E_WRITE_TO_TEMP_FILES);
			}
		}
	}

	/**
	 * Initializes the HashMap containing the nested attributes info, as well as the
	 * completeRow and sets the subElementname to {@code null}
	 */
	private void resetSubAttributes()
	{
		nestedAttributes = new HashMap<>();
		nestedAttributes.put(Text.TAG_NAME_META_DATA_ENTRY, new AttributeDataInfoTuple(Utils.META_DATA_ATTR));
		nestedAttributes.put(Text.TAG_NAME_WORKOUT_EVENT, new AttributeDataInfoTuple(Utils.WORKOUT_EVENT_ATTR));
		nestedAttributes.put(Text.TAG_NAME_WORKOUT_ROUTE, new AttributeDataInfoTuple(Utils.WORKOUT_ROUTE_ATTR));
		nestedAttributes.put(Text.TAG_NAME_HR_LIST, new AttributeDataInfoTuple(Utils.HR_LIST_ATTR));
		nestedAttributes.put(Text.TAG_NAME_IB_PER_MINUTES, new AttributeDataInfoTuple(Utils.IB_PER_MINUTES_ATTR));

		completeRow = new StringBuilder();
		subElementName = null;
	}

	/**
	 * Gets the values for the given attributes and returns them in an array where
	 * the values are saved at the index corresponding to their keys.
	 * 
	 * @param attributeName Keys / names of the attributes.
	 * @param values        The object containing the values
	 * @return The described array
	 */
	private String[] getValuesToAttributes(String[] attributeName, Attributes values)
	{
		String[] res = new String[attributeName.length];
		for (int i = 0; i < res.length; i++)
		{
			String v = values.getValue(attributeName[i]);
			if(attributeName[i].equals("device")&&v!=null)
			{
				//Entry left out due to privacy
				String device="<HKDevice:";
				String actualDeviceSubstring=v.substring(v.indexOf(device),v.indexOf(">")+1);
				v=v.replace(actualDeviceSubstring, "device_anonymized");
			}
			if (v == null)
			{
				res[i] = "";
			}
			else if (v.contains(",") || v.contains(";"))
			{
				res[i] = "\"" + v + "\"";
			}
			else
			{
				res[i] = v;
			}
		}
		return res;
	}

	/**
	 * Writes a non nested row into a file
	 * 
	 * @param bout   The writer of the file
	 * @param values the values in correct order needed to fit with the header row
	 *               which should be written
	 * @param top    shows whether this is a "nested row" / nested attribute entry
	 * @throws IOException if there was an error writing
	 */
	private void writeNormalRow(Writer bout, String[] values, boolean top) throws IOException
	{
		for (int i = 0; i < values.length; i++) // for every attribute value
		{
			bout.write(values[i]);
			if (i < values.length - 1)
			{
				if (top)
				{
					bout.write(";");
				}
				else
				{
					bout.write(",");
				}
			}
		}
	}

	/**
	 * Returns all files written in temp directory with the readable name as key and
	 * the {@link File} as value. It also closes the writers and thus can only be
	 * used after the end of writing.
	 * 
	 * @return The described value.
	 */
	public HashMap<String, File> getAllFiles()
	{
		HashMap<String, File> res = new HashMap<>();
		for (String key : allFiles.keySet())
		{
			FileWrapper fw = allFiles.get(key);
			try
			{
				fw.getBufferedWriter().close();
			}
			catch (IOException e)
			{
				// Stream couldn't be closed. Bad luck.
			}
			res.put(key, fw.getFile());
		}
		return res;
	}

	/**
	 * Returns all accumulated error messages.
	 * 
	 * @return The described value or {@code null} if there is no error message.
	 */
	public String getErrorMessages()
	{
		if (errorMessages.length()==0)
		{
			return null;
		}
		return errorMessages.toString();
	}

}