/**
 * 
 */
package org.gcube.accounting.datamodel;

import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.UUID;

import org.gcube.accounting.datamodel.decorators.AggregatedField;
import org.gcube.accounting.datamodel.decorators.ComputedField;
import org.gcube.accounting.datamodel.decorators.FieldAction;
import org.gcube.accounting.datamodel.decorators.FieldDecorator;
import org.gcube.accounting.datamodel.decorators.RequiredField;
import org.gcube.accounting.datamodel.deprecationmanagement.annotations.DeprecatedWarning;
import org.gcube.accounting.datamodel.validations.annotations.NotEmpty;
import org.gcube.accounting.datamodel.validations.annotations.NotEmptyIfNotNull;
import org.gcube.accounting.datamodel.validations.annotations.ValidLong;
import org.gcube.accounting.datamodel.validations.annotations.ValidOperationResult;
import org.gcube.accounting.datamodel.validations.validators.NotEmptyIfNotNullValidator;
import org.gcube.accounting.exception.InvalidValueException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
 *
 */
public abstract class RawUsageRecord implements UsageRecord, Serializable {

	private static Logger logger = LoggerFactory.getLogger(RawUsageRecord.class);
	
	@RequiredField @NotEmpty
	public static final String ID = "id";
	@RequiredField @NotEmpty
	public static final String CREATOR_ID = "creatorId";
	@RequiredField @NotEmpty
	public static final String CONSUMER_ID = "consumerId";
	@RequiredField @ValidLong
	public static final String CREATION_TIME = "creationTime";
	@AggregatedField @ValidLong
	protected static final String START_TIME = "startTime";
	@AggregatedField @ValidLong
	protected static final String END_TIME = "endTime";
	
	@DeprecatedWarning
	protected static final String RESOURCE_TYPE = "resourceType";
	@RequiredField @NotEmpty
	protected static final String USAGE_RECORD_TYPE = "UsageRecordType";
	
	@RequiredField @NotEmpty
	public static final String RESOURCE_SCOPE = "resourceScope";
	@DeprecatedWarning @NotEmpty
	protected static final String RESOURCE_OWNER = "resourceOwner";
	
	@AggregatedField @NotEmptyIfNotNull
	protected static final String AGGREGATED = "aggregated";
	
	@AggregatedField @NotEmptyIfNotNull
	protected static final String AGGREGATED_USAGE_RECORD_ID = "aggregatedUsageRecordId";
	@NotEmptyIfNotNull @MoveToAggregatedUsageRecordId
	protected static final String AGGREGATED_ID = "aggregatedId";
	
	@Target(ElementType.FIELD)
	@Retention(RetentionPolicy.RUNTIME)
	@FieldDecorator(managed=MoveToAggregatedUsageRecordIdAction.class) 
	protected @interface MoveToAggregatedUsageRecordId { }
	protected class MoveToAggregatedUsageRecordIdAction implements FieldAction {
		@Override
		public Serializable validate(String key, Serializable value, UsageRecord usageRecord) throws InvalidValueException  {
			NotEmptyIfNotNullValidator neinnv = new NotEmptyIfNotNullValidator();
			value = neinnv.validate(key, value, usageRecord);
			usageRecord.setAggregatedUsageRecordId((String) value);
			return value;
		}
	}
	
	
	
	@RequiredField @ValidOperationResult
	public static final String OPERATION_RESULT = "operationResult";
	
	/**
	 * Generated Serial Version UID
	 */
	private static final long serialVersionUID = -2060728578456796388L;
	
	/** resource-specific properties */
	protected Map<String, Serializable> resourceProperties;
	
	protected Map<String, List<FieldAction>> validation;
	protected Set<String> requiredFields;
	protected Set<String> aggregatedFields;
	protected Set<String> computedFields;
	
	protected void initializeValidation() {
		logger.debug("Initializing Field Validators");
		List<Field> fields = Arrays.asList(this.getClass().getDeclaredFields());
		for(Field field : fields){
			String keyString;
			try {
				keyString = (String) field.get(null);
			} catch (Exception e) {
				continue;
			}
			List<FieldAction> fieldValidators = new ArrayList<FieldAction>();
			validation.put(keyString, fieldValidators);
			for (Annotation annotation : field.getAnnotations()){
				if (annotation.annotationType().isAnnotationPresent(FieldDecorator.class)){
					Class<? extends FieldAction> managedClass = ((FieldDecorator)annotation.annotationType().getAnnotation(FieldDecorator.class)).managed();
					FieldAction validator;
					try {
						validator = managedClass.newInstance();
					} catch (InstantiationException | IllegalAccessException e) {
						continue;
					}
					fieldValidators.add(validator);
				}
				if(annotation.annotationType().isAssignableFrom(RequiredField.class)){
					requiredFields.add(keyString);
				}
				if(annotation.annotationType().isAssignableFrom(AggregatedField.class)){
					aggregatedFields.add(keyString);
				}
				if(annotation.annotationType().isAssignableFrom(ComputedField.class)){
					computedFields.add(keyString);
				}
			}
		}
	}
	
	/**
	 * Initialize variable
	 */
	private void init() {
		this.validation = new HashMap<String, List<FieldAction>>();
		this.requiredFields = new HashSet<String>();
		initializeValidation();
	}
	
	public RawUsageRecord(){
		init();
		this.resourceProperties = new HashMap<String, Serializable>();
		this.resourceProperties.put(ID, UUID.randomUUID().toString());
		this.resourceProperties.put(USAGE_RECORD_TYPE, this.getClass().getSimpleName());
		Calendar calendar = Calendar.getInstance();
		this.resourceProperties.put(CREATION_TIME, calendar.getTimeInMillis());
	}

	public RawUsageRecord(Map<String, Serializable> properties) throws InvalidValueException {
		init();
		setResourceProperties(properties);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public String getId() {
		return (String) this.resourceProperties.get(ID);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setId(String id) throws InvalidValueException {
		setResourceProperty(ID, id);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public String getCreatorId() {
		return (String) this.resourceProperties.get(CREATOR_ID);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setCreatorId(String creatorId) throws InvalidValueException {
		setResourceProperty(CREATOR_ID, creatorId);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public String getConsumerId() {
		return (String) this.resourceProperties.get(CONSUMER_ID);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setConsumerId(String consumerId) throws InvalidValueException {
		setResourceProperty(CONSUMER_ID, consumerId);
	}
	
	protected Calendar timestampStringToCalendar(long millis){
		Calendar calendar = Calendar.getInstance();
		calendar.setTimeInMillis(millis);
		return calendar;
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public Calendar getCreationTime() {
		long millis = (Long) this.resourceProperties.get(CREATION_TIME);
		return timestampStringToCalendar(millis);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setCreationTime(Calendar creationTime) throws InvalidValueException {
		setResourceProperty(CREATION_TIME, creationTime.getTimeInMillis());
	}
	
	@Override
	@Deprecated
	public Date getCreateTime() {
		long millis = (Long) this.resourceProperties.get(CREATION_TIME);
		return timestampStringToCalendar(millis).getTime();
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public void setCreateTime(Date createTime) throws InvalidValueException {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(createTime);
		setCreationTime(calendar);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public Calendar getStartTime() {
		long millis = (Long) this.resourceProperties.get(START_TIME);
		return timestampStringToCalendar(millis);
	}
		
	/**
	 * Set the left end of the time interval covered by this {#UsageRecord}
	 * @param startTime Start Time
	 * @throws InvalidValueException
	 */
	protected void setStartTime(Calendar startTime) throws InvalidValueException {
		setResourceProperty(START_TIME, startTime.getTimeInMillis());
	}
	
	/* *
	 * {@inheritDoc}
	 * /
	@Override
	@Deprecated
	public void setStartTime(Date startTime) throws InvalidValueException {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(startTime);
		setStartTime(calendar);
	}
	*/
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public Calendar getEndTime() {
		long millis = (Long) this.resourceProperties.get(END_TIME);
		return timestampStringToCalendar(millis);
	}

	/**
	 * Set the right end of the time interval covered by this {#UsageRecord}
	 * @param endTime End Time
	 * @throws InvalidValueException
	 */
	protected void setEndTime(Calendar endTime) throws InvalidValueException {
		setResourceProperty(END_TIME, endTime.getTimeInMillis());
	}
	
	/* *
	 * {@inheritDoc}
	 * /
	@Override
	@Deprecated
	public void setEndTime(Date endTime) throws InvalidValueException {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(endTime);
		setEndTime(calendar);
	}
	*/
	
	protected String getUsageRecordType() {
		//return (String) this.resourceSpecificProperties.get(RESOURCE_TYPE);
		return this.getClass().getSimpleName();
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public String getResourceType(){
		return (String) this.resourceProperties.get(RESOURCE_TYPE);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Deprecated
	public void setResourceType(String resourceType){
		try {
			setResourceProperty(RESOURCE_TYPE, resourceType);
		}catch(InvalidValueException e){
			logger.error("Unable to Set {}", RESOURCE_TYPE);
		}
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public String getResourceScope() {
		return (String) this.resourceProperties.get(RESOURCE_SCOPE);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setResourceScope(String scope) throws InvalidValueException {
		setResourceProperty(RESOURCE_SCOPE, scope);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public String getResourceOwner() {
		return (String) this.resourceProperties.get(RESOURCE_OWNER);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public void setResourceOwner(String owner) throws InvalidValueException {
		setResourceProperty(RESOURCE_OWNER, owner);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public String getAggregatedId() {
		return (String) this.resourceProperties.get(AGGREGATED_ID);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override@
	Deprecated
	public void setAggregatedId(String aggregatedId)  throws InvalidValueException {
		setResourceProperty(AGGREGATED_ID, aggregatedId);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public String getAggregatedUsageRecordId() {
		return (String) this.resourceProperties.get(AGGREGATED_USAGE_RECORD_ID);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setAggregatedUsageRecordId(String aggregatedId)  throws InvalidValueException {
		setResourceProperty(AGGREGATED_USAGE_RECORD_ID, aggregatedId);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public Map<String, Serializable> getResourceSpecificProperties() {
		return getResourceProperties();
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public void setResourceSpecificProperties(Map<String, Serializable> properties) throws InvalidValueException {
		setResourceProperties(properties);
	}

	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public Map<String, Serializable> getResourceProperties() {
		return this.resourceProperties;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setResourceProperties(Map<String, Serializable> properties) throws InvalidValueException {
		validateProperties(properties);
		this.resourceProperties = new HashMap<String, Serializable>(properties);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public Serializable getResourceSpecificProperty(String key) {
		return getResourceProperty(key);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public void setResourceSpecificProperty(String key, Serializable value) throws InvalidValueException {
		setResourceProperty(key, value);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public Serializable getResourceProperty(String key) {
		return this.resourceProperties.get(key);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setResourceProperty(String key, Serializable value) throws InvalidValueException {
		Serializable checkedValue = validateField(key, value);
		if(checkedValue == null){
			this.resourceProperties.remove(key);
		}else{
			this.resourceProperties.put(key, checkedValue);
		}
	}
	
	protected Serializable validateField(String key, Serializable serializable) throws InvalidValueException {
		if(key == null){
			throw new InvalidValueException("The key of property to set cannot be null");
		}
		Serializable checkedValue = serializable;
		List<FieldAction> fieldValidators = validation.get(key);
		if(fieldValidators!=null){
			for(FieldAction fieldValidator : fieldValidators){
				checkedValue = fieldValidator.validate(key, checkedValue, this);
				/*
				 * Check here if the key is for a ComputedField or for an 
				 * AggregatedField
				 */
			}
		}
		return checkedValue;
	}
	
	protected void validateProperties(Map<String, Serializable> properties) throws InvalidValueException{
		for(String key : properties.keySet()){
			Serializable serializable = properties.get(key);
			validateField(key, serializable);
		}
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void validate() throws InvalidValueException {
		validateProperties(this.resourceProperties);
		Set<String> notPresentProperties = new HashSet<String>();
		for(String key : this.requiredFields){
			if(!this.resourceProperties.containsKey(key)){
				notPresentProperties.add(key);
			}
		}
		if(!notPresentProperties.isEmpty()){
			String pluralManagement = notPresentProperties.size() == 1 ? "y" : "ies";
			throw new InvalidValueException(String.format("The Usage Record does not contain the following required propert%s %s", pluralManagement, notPresentProperties.toString()));
		}
	}
	
	@Override
	public String toString(){
		return resourceProperties.toString();
	}


	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public String getFullyQualifiedConsumerId() {
		return getConsumerId();
	}


	/**
	 * {@inheritDoc}
	 */
	@Override
	@Deprecated
	public void setFullyQualifiedConsumerId(String fqcid) { }

	/**
	 * {@inheritDoc}
	 */
	@Override
	public OperationResult getOperationResult(){
		return OperationResult.valueOf((String) this.resourceProperties.get(OPERATION_RESULT));
	}
	
	/**
	 * {@inheritDoc}
	 * @throws InvalidValueException 
	 */
	@Override
	public void setOperationResult(OperationResult operationResult) throws InvalidValueException {
		setResourceProperty(OPERATION_RESULT, operationResult);
	}
	
	
	/**
	 * Compare this UsageRecord instance with the one provided as argument
	 * @param usageRecord the Usage Record to compare
	 * @return 0 is and only if the UsageRecord provided as parameter
	 * contains all and ONLY the parameters contained in this instance.
	 * If the number of parameters differs, the methods return the difference 
	 * between the number of parameter in this instance and the ones in the
	 * UsageRecord provided as parameter.
	 * If the size is the same but the UsageRecord provided as parameter does
	 * not contains all parameters in this instance, -1 is returned. 
	 */
	@Override
	public int compareTo(UsageRecord usageRecord) {
		Set<Entry<String, Serializable>> thisSet = this.resourceProperties.entrySet();
		Set<Entry<String, Serializable>> usageRecordSet = usageRecord.getResourceProperties().entrySet();
		if(thisSet.size() != usageRecordSet.size()){
			return thisSet.size() - usageRecordSet.size();
		}
		if(usageRecordSet.containsAll(thisSet)){
			return 0;
		}
		return 1;
	}

	
	@SuppressWarnings("unchecked")
	protected static Class<? extends UsageRecord> getClass(String usageRecordName, boolean aggregated) throws ClassNotFoundException {
		Class<? extends UsageRecord> clz = null;
		
		Class<? extends UsageRecord> utilityClass = org.gcube.accounting.datamodel.implementations.JobUsageRecord.class;
		if(aggregated){
			utilityClass = org.gcube.accounting.datamodel.implementations.aggregated.JobUsageRecord.class;
		}
		
		String classCanonicalName = utilityClass.getCanonicalName();
		classCanonicalName.replace(utilityClass.getSimpleName(), usageRecordName);
		
		try {
			clz = (Class<? extends UsageRecord>) Class.forName(classCanonicalName);
		} catch (ClassNotFoundException e) {
			logger.error("Unable to retrieve class {}", classCanonicalName);
			throw e;
		}
		
		return clz;
	}

	/**
	 * This method use the resourceType value contained in the Map to instance
	 * the right UsageRecord class and return it. If the type implementation
	 * does not exist or the validation of one or more field validation fails
	 * an exception is thrown
	 * @param usageRecordMap
	 * @return the instance of the UsageRecord class.
	 * @throws Exception if fails
	 */
	public static UsageRecord getUsageRecord(Map<String, Serializable> usageRecordMap) throws Exception {
		String className = (String) usageRecordMap.get(USAGE_RECORD_TYPE);
		boolean aggregated = false; 
		try {		
			aggregated = (Boolean) usageRecordMap.get(AGGREGATED);
		}catch(Exception e){}
		
		Class<? extends UsageRecord> clz = getClass(className, aggregated);
		logger.debug("Trying to instantiate {}", clz.getClass().getSimpleName());
		
		@SuppressWarnings("rawtypes")
		Class[] usageRecordArgTypes = { Map.class };
		Constructor<? extends UsageRecord> usageRecordConstructor = clz.getDeclaredConstructor(usageRecordArgTypes);
		Object[] usageRecordArguments = {usageRecordMap};
		
		UsageRecord usageRecord = usageRecordConstructor.newInstance(usageRecordArguments);
		
		logger.debug("Created Usage Record : {}", usageRecord);
		
		return usageRecord;
	}

}