software-versions-processor-lib/src/main/java/org/gcube/common/software/model/Variables.java

package org.gcube.common.software.model;

import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.gcube.com.fasterxml.jackson.annotation.JsonAnySetter;
import org.gcube.com.fasterxml.jackson.annotation.JsonIgnore;
import org.gcube.common.software.utils.Utils;

/**
 * @author Luca Frosini (ISTI - CNR)
 */
public class Variables {

	public static final String REGEX;
	public static final Pattern PATTERN;
	
	static {
		REGEX = "\\{\\{[a-zA-Z\\-\\_]+\\}\\}";
		PATTERN = Pattern.compile(REGEX);
	}
	
	protected Map<String, Object> properties;
	
	public Variables() {
		properties = new LinkedHashMap<>();
	}
	
	/**
	 * Search the variables used in the String provided as argument
	 * @param string the string to analyze to find variables
	 * @return the list of used variables 
	 */
	protected Set<String> findVariables(String value) {
		Set<String> variables = new HashSet<>();
		Matcher m = Variables.PATTERN.matcher(value);
	    if(m.find()) {
	        do {
	            String variable = m.group();
	            variable = variable.replaceAll("\\{", "");
	            variable = variable.replaceAll("\\}", "");
	            variables.add(variable);
	        } while(m.find(m.start()+1));
	    }
		return variables;
	}
	
	public String replaceAllVariables(String value) throws Exception {
		Set<String> missingVariables = new HashSet<>();
		Set<String> variableNames = findVariables(value);
		for(String variableName : variableNames) {
			if(properties.containsKey(variableName)) {
				try {
					String variableValue = properties.get(variableName).toString();
					value = Utils.replaceVariable(variableName, variableValue, value);
				}catch (Exception e) {
					missingVariables.add(variableName);
				}
				
			}else {
				missingVariables.add(variableName);
			}
		}
		if(missingVariables.size()>0) {
			throw new Exception("The following variables cannot be replaced because they don't exists " + missingVariables.toString());
		}
		return value;
	}
	
	
	protected Set<String> replaceAllVariables(String key, String value) throws Exception {
		Set<String> missingVariables = new HashSet<>();
		Set<String> variableNames = findVariables(value);
		for(String variableName : variableNames) {
			if(variableName.compareTo(key)==0) {
				throw new Exception("You can't define self as variable in the value");
			}
			if(properties.containsKey(variableName)) {
				String variableValue = properties.get(variableName).toString();
				value = Utils.replaceVariable(variableName, variableValue, value);
			}else {
				missingVariables.add(variableName);
			}
		}
		properties.replace(key, value);
		return missingVariables;
	}
	
	protected Set<String> parseAndReplace() throws Exception {
		Set<String> missingVariables = new HashSet<>();
		Set<String> keys = properties.keySet();
		for(String key : keys) {
			Object objectValue = properties.get(key);
			if(objectValue instanceof String) {
				String value = (String) objectValue;
				missingVariables.addAll(replaceAllVariables(key, value));
			}
			
			// TODO check variables in nested obj
		}
		return missingVariables;
	}
	
	public Set<String> parse() throws Exception {
		Set<String> missingVariables = parseAndReplace();
		while(missingVariables.size()>0) {
			Set<String> newMissingVariables = parseAndReplace();
			if(newMissingVariables.containsAll(missingVariables)) {
				return missingVariables;
			}else {
				missingVariables = newMissingVariables;
			}
		}
		return missingVariables;
	}

	@JsonIgnore
	public Map<String, Object> getProperties() {
		return properties;
	}

	@JsonIgnore
	public void setProperties(Map<String, Object> properties) {
		this.properties = properties;
	}
	
	@JsonAnySetter
    public void addProperty(String key, Object value) {
		this.properties.put(key, value);
    }
	
//	/**
//	 * Add to this object the missing properties
//	 * and replace the properties already present 
//	 * with the values contained in the provided 
//	 * object as argument 
//	 * @param variables the properties to merge with this object
//	 * @throws Exception 
//	 */
//	@JsonIgnore
//	public void merge(Variables variables) throws Exception {
//		Map<String, Object> properties = variables.getProperties(); 
//		Set<String> keys = properties.keySet();
//		for(String key : keys) {
//			Object value = properties.get(key); 
//			this.properties.put(key, value);
//		}
//		parse();
//	}
	
}