/**
 *                                                                            
 *  Copyright (c) 2011, 2018 - Loetz GmbH&Co.KG (69115 Heidelberg, Germany) 
 *                                                                            
 *  All rights reserved. This program and the accompanying materials           
 *  are made available under the terms of the Eclipse Public License 2.0        
 *  which accompanies this distribution, and is available at                  
 *  https://www.eclipse.org/legal/epl-2.0/                                 
 *                                 
 *  SPDX-License-Identifier: EPL-2.0                                 
 *                                                                            
 *  Contributors:                                                      
 * 	   Christophe Loetz (Loetz GmbH&Co.KG) - initial implementation
 * 
 * generated by Xtext 2.11.0
 * 
 */

package org.eclipse.osbp.xtext.signal.validation

import java.nio.file.FileSystems
import java.nio.file.PathMatcher
import java.text.ParseException
import java.util.HashSet
import java.util.regex.PatternSyntaxException
import javax.inject.Inject
import org.eclipse.emf.common.util.EList
import org.eclipse.osbp.xtext.datainterchange.validation.DataDSLValidator
import org.eclipse.osbp.xtext.signal.CronScheduler
import org.eclipse.osbp.xtext.signal.DailyScheduler
import org.eclipse.osbp.xtext.signal.HourlyScheduler
import org.eclipse.osbp.xtext.signal.MonthlyScheduler
import org.eclipse.osbp.xtext.signal.SignalDSLPackage
import org.eclipse.osbp.xtext.signal.SignalDatainterchange
import org.eclipse.osbp.xtext.signal.SignalDefinition
import org.eclipse.osbp.xtext.signal.SignalPackage
import org.eclipse.osbp.xtext.signal.SignalScheduler
import org.eclipse.osbp.xtext.signal.SignalWatcher
import org.eclipse.osbp.xtext.signal.WatcherWithFileMask
import org.eclipse.osbp.xtext.signal.WatcherWithFileName
import org.eclipse.osbp.xtext.signal.WeeklyScheduler
import org.eclipse.osbp.xtext.signal.common.SignalConstants
import org.eclipse.osbp.xtext.signal.jvmmodel.SignalDSLJvmModelInferrer
import org.eclipse.xtext.validation.Check
import org.quartz.CronExpression

/**
 * This class contains custom validation rules. 
 * 
 * See https://www.eclipse.org/Xtext/documentation/303_runtime_concepts.html#validation
 */
class SignalDSLValidator extends AbstractSignalDSLValidator {
	
	@Inject extension DataDSLValidator dv
	@Inject extension SignalDSLJvmModelInferrer jvm

	@Check
	def checkDuplicateWatcherNames(SignalPackage pkg) {
		var signals = new HashSet<String>()
		for (signal : pkg.signals) {
			if (!signals.contains(signal.name)) {
				signals.add(signal.name)
			} else {
				error("Watcher's and scheduler's ID have to be unique and [" + signal.name +
					"] is already in use. Please change it.", signal, SignalDSLPackage.Literals.SIGNAL_DEFINITION__NAME)
			}
		}
	}

	@Check
	def void checkSignalSchedulerValidity(SignalScheduler signal) {
		if (signal.getSchedulertype !== null && signal.getSchedulertype instanceof CronScheduler) {
			checkCronExpressionValidity(signal.getSchedulertype as CronScheduler)
		} else if (signal.getSchedulertype !== null && signal.getSchedulertype instanceof HourlyScheduler) {
			checkHourlySchedulerValidity(signal.getSchedulertype as HourlyScheduler)
		} else if (signal.getSchedulertype !== null && signal.getSchedulertype instanceof DailyScheduler) {
			checkDailySchedulerValidity(signal.getSchedulertype as DailyScheduler)
		} else if (signal.getSchedulertype !== null && signal.getSchedulertype instanceof WeeklyScheduler) {
			checkWeeklySchedulerValidity(signal.getSchedulertype as WeeklyScheduler)
		} else if (signal.getSchedulertype !== null && signal.getSchedulertype instanceof MonthlyScheduler) {
			checkMonthlySchedulerValidity(signal.getSchedulertype as MonthlyScheduler)
		}
	}

	def void checkCronExpressionValidity(CronScheduler scheduler) {
		var expression = scheduler.expression // format: s m h dm m dw
		try {
			if (!CronExpression.isValidExpression(expression)) {
				CronExpression.validateExpression(expression)
			}
		} catch (ParseException exception) {
			error("The cron expression you have entered is invalid.\n\n" + exception + SignalConstants.CRONEXP_NOTICE,
				scheduler, SignalDSLPackage.Literals.CRON_SCHEDULER__EXPRESSION)
		}
	}

	def void checkHourlySchedulerValidity(HourlyScheduler scheduler) {
		if (!(scheduler.minute >= 0 && scheduler.minute <= 59)) {
			error("The minute entry has to be between 0 and 59.", scheduler,
				SignalDSLPackage.Literals.HOURLY_SCHEDULER__MINUTE)
		}
	}

	def void checkDailySchedulerValidity(DailyScheduler scheduler) {
		if (!(scheduler.hour >= 0 && scheduler.hour <= 23)) {
			error("The hour entry has to be between 0 and 23.", scheduler,
				SignalDSLPackage.Literals.DAILY_SCHEDULER__HOUR)
		}
		if (!(scheduler.minute >= 0 && scheduler.minute <= 59)) {
			error("The minute entry has to be between 0 and 59.", scheduler,
				SignalDSLPackage.Literals.DAILY_SCHEDULER__MINUTE)
		}
	}

	def void checkWeeklySchedulerValidity(WeeklyScheduler scheduler) {
		if (!(scheduler.hour >= 0 && scheduler.hour <= 23)) {
			error("The hour entry has to be between 0 and 23.", scheduler,
				SignalDSLPackage.Literals.WEEKLY_SCHEDULER__HOUR)
		}
		if (!(scheduler.minute >= 0 && scheduler.minute <= 59)) {
			error("The minute entry has to be between 0 and 59.", scheduler,
				SignalDSLPackage.Literals.WEEKLY_SCHEDULER__MINUTE)
		}

	}

	def void checkMonthlySchedulerValidity(MonthlyScheduler scheduler) {
		if (!(scheduler.dayofmonth >= 1 && scheduler.dayofmonth <= 31)) {
			error("The hour entry has to be between 1 and 31.", scheduler,
				SignalDSLPackage.Literals.MONTHLY_SCHEDULER__DAYOFMONTH)
		}
		if (!(scheduler.hour >= 0 && scheduler.hour <= 23)) {
			error("The hour entry has to be between 0 and 23.", scheduler,
				SignalDSLPackage.Literals.MONTHLY_SCHEDULER__HOUR)
		}
		if (!(scheduler.minute >= 0 && scheduler.minute <= 59)) {
			error("The minute entry has to be between 0 and 59.", scheduler,
				SignalDSLPackage.Literals.MONTHLY_SCHEDULER__MINUTE)
		}
	}

	@Check
	def void checkFilePolicy(SignalDefinition signal) {
		if(signal instanceof SignalWatcher){
			var watcher = signal.definition
			if(watcher instanceof WatcherWithFileMask){
				if (watcher.filemask !== null && !watcher.filemask.isEmpty && watcher.executiontype !== null) {
					if (watcher.interchange === null) {
						error("You must define the task, on which the file mask must be applied on.",
							watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__INTERCHANGE)
					}
				}
			}
			else if(watcher instanceof WatcherWithFileName){
				if (watcher.filename !== null && !watcher.filename.isEmpty && watcher.executiontype !== null) {
					if (watcher.interchanges.basedInterchangeDefined == 0) {
						error("The task on which the file name must be applied on, have to be marked with the keyword 'applyon'.",
							watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_NAME__INTERCHANGES)
					} else if (watcher.interchanges.basedInterchangeDefined > 1) {
						error("Only one task may be marked with the keyword 'applyon'.", watcher,
							SignalDSLPackage.Literals.WATCHER_WITH_FILE_NAME__INTERCHANGES)
					}
				}
			}
		}
		else if(signal instanceof SignalScheduler){
			if (signal.interchanges.basedInterchangeDefined >= 1) {
				error("No task may be marked here with the keyword 'applyon'.", signal,
				SignalDSLPackage.Literals.SIGNAL_SCHEDULER__INTERCHANGES)
			}
		}
	}

	def int basedInterchangeDefined(EList<SignalDatainterchange> interchanges) {
		var count = 0
		for (unit : interchanges) {
			if (unit.baseinterchange) {
				count++
			}
		}
		return count
	}

	@Check
	def void checkDuplicateFileMaskOrFileName(SignalPackage pck) {
		var filemasks = new HashSet<String>()
		for (signal : pck.signals) {
			if(signal instanceof SignalWatcher){
				var watcher = signal.definition
				if(watcher instanceof WatcherWithFileMask){
					if (!filemasks.contains(watcher.filemask)) {
						filemasks.add(watcher.filemask)
					} else {
						error("This file mask is already in use in another watcher. Please change it.", watcher,
							SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)
					}
				}
				else if(watcher instanceof WatcherWithFileName){
					if (!filemasks.contains(watcher.filename)) {
						filemasks.add(watcher.filename)
					} else {
						error("This file name is already in use in another watcher. Please change it.", watcher,
							SignalDSLPackage.Literals.WATCHER_WITH_FILE_NAME__FILENAME)
					}
				}
			}
		}
	}

	@Check
	def void checkFileMaskAndFileNameValidity(SignalDefinition signal) {
		checkFileNameValidityCheck(signal);
		
		if(signal instanceof SignalWatcher){
			var watcher = signal.definition
			if(watcher instanceof WatcherWithFileMask){
				if (watcher !== null && watcher.filemask !== null && !watcher.filemask.isEmpty) {
					try {
						FileSystems.^default.getPathMatcher("glob:" + watcher.filemask)
					} catch (PatternSyntaxException exception) {
						error("The pattern of this file mask is invalid, please change it. Error: " + exception.message,
							watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)
					} catch (UnsupportedOperationException exception) {
						error("The pattern of this file mask is not recognized, please change it. Error: " + exception.message,
							watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)
					} catch (IllegalArgumentException exception) {
						error("The pattern of this file mask is invalid, please change it. Error: " + exception.message,
							watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)
					}
				}
			}
		}
	}
	
	def void checkFileNameValidityCheck(SignalDefinition signal){
		if(signal instanceof SignalWatcher){
			var watcher = signal.definition
			if(watcher instanceof WatcherWithFileMask){
				if (watcher !== null && watcher.filemask !== null && !watcher.filemask.isEmpty 
					&& watcher.interchange !== null && watcher.interchange.dataRef !== null) {
					var baseinterchange = watcher.interchange.dataRef
					
					if (baseinterchange !== null && baseinterchange.fileEndpoint !== null){
						var allowed_extension = getValidExtensionToInterchange(baseinterchange.fileEndpoint)
						
						if (allowed_extension !== null) {
							if(allowed_extension.equals(CSV_EXTENSION) && !isExtensionAllowedForInterchange(watcher.filemask, allowed_extension)){
								error("The file mask ["+watcher.filemask+"] you have entered is not valid. Only file masks ending with the extension "+allowed_extension+" are allowed for this watcher!",
								watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)						
									
							}
							else if (allowed_extension.equals(EDI_EXTENSION) && !isExtensionAllowedForInterchange(watcher.filemask, allowed_extension)){
								error("The file mask ["+watcher.filemask+"] you have entered is not valid. Only file masks ending with the extension "+allowed_extension+" are allowed for this watcher!",
								watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)	
							}
							else if (allowed_extension.equals(XML_EXTENSION) && !isExtensionAllowedForInterchange(watcher.filemask, allowed_extension)){
								error("The file mask ["+watcher.filemask+"] you have entered is not valid. Only file masks ending with the extension "+allowed_extension+" are allowed for this watcher!",
								watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)			
							}
						}
						if (!isExtensionValid(watcher.filemask)) {
							error("The file mask extension you have entered is not currently supported. Only file masks ending with either one of following extension are allowed: '.csv' '.edi' or '.xml' .",
								watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)	
						}
					}
				}
			}
			else if(watcher instanceof WatcherWithFileName){
				if (watcher !== null && watcher.filename !== null && !watcher.filename.isEmpty && watcher.interchanges !== null
					&& !watcher.interchanges.empty && signal.getBaseInterchange !== null) {
					
					var baseinterchange = signal.getBaseInterchange.dataRef
					
					if (baseinterchange !== null && baseinterchange.fileEndpoint !== null){
						var allowed_extension = getValidExtensionToInterchange(baseinterchange.fileEndpoint)
						
						if (allowed_extension !== null) {
							if(allowed_extension.equals(CSV_EXTENSION) && !isExtensionAllowedForInterchange(watcher.filename, allowed_extension)){
								error("The file name ["+watcher.filename+"] you have entered is not valid. Only file names ending with the extension "+allowed_extension+" are allowed for this watcher!",
								watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_NAME__FILENAME)						
									
							}
							else if (allowed_extension.equals(EDI_EXTENSION) && !isExtensionAllowedForInterchange(watcher.filename, allowed_extension)){
								error("The file name ["+watcher.filename+"] you have entered is not valid. Only file names ending with the extension "+allowed_extension+" are allowed for this watcher!",
								watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_NAME__FILENAME)	
							}
							else if (allowed_extension.equals(XML_EXTENSION) && !isExtensionAllowedForInterchange(watcher.filename, allowed_extension)){
								error("The file name ["+watcher.filename+"] you have entered is not valid. Only file names ending with the extension "+allowed_extension+" are allowed for this watcher!",
								watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_NAME__FILENAME)				
							}
						}
						else{
							error("The file name extension you have entered is not currently supported. Only file names ending with either one of following extension are allowed: '.csv' '.edi' or '.xml' .",
								watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_NAME__FILENAME)	
						}
					}
				}
			}
		}
	}
	
//		// TODO need to be tested and completed
//	@Check
//	def void arePatternMatching(SignalPackage pck) {
//		for (signal : pck.signals) {
//			if (signal instanceof SignalWatcher) {
//				var watcher = signal.definition
//				if (watcher instanceof WatcherWithFileMask) {
//					if (watcher.filemask.isFileMaskValid !== null) {
//						var temp = escapeCharacters(watcher.filemask)
//						for (signal2 : pck.signals) {
//							
//							if (signal2 instanceof SignalWatcher) {
//								var watcher2 = signal2.definition
//							
//								if (watcher2 instanceof WatcherWithFileMask) {
//									if (watcher2 !== watcher && watcher2.filemask.isFileMaskValid !== null) {
//										try{
//											// check if they are the same
//											if (watcher.filemask.equals(watcher2.filemask)) {
//												error("This file mask is already in use, please change it.", watcher,
//													SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)
//											} else if (watcher2.filemask.isFileMaskValid.matches(Paths.get(temp))) {
//												warning(
//													"This file mask is matched by the one [" + signal2.filemask +
//														"] defined in the watcher named [" + signal2.name +
//														"]. This may cause unintended effects, if the monitored directories are the same. We recommend you to change it, and define a unique file mask for this watcher instead.",
//														watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)
//											}
//										}
//										catch(InvalidPathException e){
//											warning("One of those two file masks is not valid! File mask #1 [" + watcher.filemask +"] from watcher [" + watcher.name +"] and file mask #2 [" + watcher2.filemask +"] from watcher [" + watcher2.name 
//												+"] This may cause unintended effects. We recommend you to review both file masks, and define a unique file mask for this watcher instead.",
//												watcher, SignalDSLPackage.Literals.WATCHER_WITH_FILE_MASK__FILEMASK)
//										}
//										
//									}
//								}
//							}
//						}
//					}
//				}
//			}			
//		}
//	}

	def PathMatcher isFileMaskValid(String filemask) {
		if (filemask !== null && !filemask.isEmpty) {
			try {
				return FileSystems.^default.getPathMatcher("glob:" + filemask)
			} catch (Exception exception) {
				return null
			}
		}
		return null
	}

	def String escapeCharacters(String pattern) {
		if (pattern !== null && !pattern.isEmpty) {
			var result = pattern
			if (result.indexOf('*') !== -1) {
				result = result.replaceAll("\\*", "")
			}
			if (result.contains("\\")) {
				result = result.replaceAll("\\", "")
			}
			if (result.contains("?")) {
				result = result.replaceAll("\\?", "")
			}
			return result
		}
		return null
	}

}