package pyUML.pythonTree;

import java.util.List;
import java.util.Vector;

import org.eclipse.uml2.uml.Comment;
import org.eclipse.uml2.uml.NamedElement;
import org.eclipse.uml2.uml.Property;
import org.eclipse.uml2.uml.VisibilityKind;
import org.python.pydev.parser.jython.ast.Assign;
import org.python.pydev.parser.jython.ast.Attribute;
import org.python.pydev.parser.jython.ast.Call;
import org.python.pydev.parser.jython.ast.Name;
import org.python.pydev.parser.jython.ast.NameTok;
import org.python.pydev.parser.jython.ast.exprType;

import pyUML.backend.GlobalConstants;
import pyUML.backend.ParseHelpers;


/**
 * This PythonTree member represents a python attribute.
 * It can represent static attributes (defined outside any method)
 * or object attributes (defined with "self." inside __init__()  
 */
public class PythonTreeAttribute extends PythonTreeNode {
	private Assign astNode;
	private boolean valid;
	private boolean staticAtt;
	private String value;
	private String fullValue;
	private int line;
	private int col;
	private int nextLine;

	/**
	 * @param parent the parent in the PythonTree
	 * @param astNode the corresponding Python AST node
	 * @param staticAtt true, if this is an attribute outside a
	 *        function definition
	 * @param nextLine the line of the next Python statement. This
	 * 		  is needed to extract multi-line-attributes
	 */
	public PythonTreeAttribute(PythonTreeNode parent, Assign astNode, boolean staticAtt, int nextLine) {
		super(parent);
		this.astNode = astNode;
		this.staticAtt = staticAtt;
		this.nextLine = nextLine;
		this.valid = this.initAttribute();
		
	}
	
	/**
	 * @return false, if this is no valid attribute
	 */
	private boolean initAttribute(){
		exprType left  = this.astNode.targets[0];
		exprType right = this.astNode.value;
		
		// analyze the left side of the assign and see
		// if this might be a valid attribute
		try {
			if (staticAtt) { //static: attr without "self"
				this.name = ((Name)left).id;
				this.line = ((Name)left).beginLine;
				this.col = ((Name)left).beginColumn;
			}
			else{ // object attr: begins with "self."
				Attribute leftAtt = (Attribute)left;
				if (! ((Name)leftAtt.value).id.equals("self"))
					return false;
				this.name =((NameTok)(leftAtt).attr).id;
				this.line = ((NameTok)(leftAtt).attr).beginLine;
				this.col = ((NameTok)(leftAtt).attr).beginColumn;
				
			}
		}
		catch (ClassCastException e) {
			// if anything is not like expected, this is not a
			// 		att=value
			// or 	self.att=value
			// attribute -> this is not considered a valid attribute!
			return false;
		}
		
		// now, look at the right side
		if (right instanceof Call)
			return false;
		this.value = ParseHelpers.getStringOfExpr(right, this.getParent().getInFile(), true, true, this.nextLine);
		
		// if the value was abbreviated, save full value, also.
		if (this.value.endsWith("(...)")) {
			this.fullValue = ParseHelpers.getStringOfExpr(right, this.getParent().getInFile(), true, false, this.nextLine);
		}		
		
		// if everything went right, this is considered a valid attribute!
		return true;
	}
	
	/**
	 * A PythonTreeAttribute is created always when an Assign
	 * is found in the class body or the constructor.
	 * Sometimes an assign does not declare an attribute; then,
	 * this object should not be added to the PythonTreeClass 
	 * attributes and be left for the garbage collector.
	 *  
	 * @return if this astNode really represents a python
	 * static/object attribute and shall be saved
	 */
	public boolean isValid() {
		return this.valid;
	}
	
	public boolean isStatic() {
		return staticAtt;
	}

	/**
	 * @return this attribute's (default) value
	 */
	public String getValue() {
		return value;
	}
	
	public boolean synchronizeModel(NamedElement modelElement) {
		Property modelProperty = (Property) modelElement;

		// set this attribute private in model, if its name starts with "__"
		// use protected, if class starts with "_" (this is only python convention)		
		if (this.getName().startsWith("__")) {
			modelProperty.setVisibility(VisibilityKind.PRIVATE_LITERAL);
		} else if (this.getName().startsWith("_")) {
			modelProperty.setVisibility(VisibilityKind.PROTECTED_LITERAL);
		}
		
		String defVal = this.getValue();
		if (! "None".equals(defVal)) 
			modelProperty.setDefault(this.getValue());
		// if default value was abbreviated ->
		// save full default value as comment,
		// beginning with a PyUML Marker
		if (this.fullValue != null) {
			Comment fullValueComment = null; 
			 for (Comment comment : modelProperty.getOwnedComments()) {
				 if (comment.getBody().startsWith(GlobalConstants.getFullDefault())) {
					 fullValueComment=comment;
					 break;
				 }
			 }
			if (fullValueComment == null)
				fullValueComment = modelProperty.createOwnedComment();
			
			fullValueComment.setBody(GlobalConstants.getFullDefault()
					+ this.fullValue);
		} else {
			// there is no "full" value -> delete all comments
			// that save a full value
			List<Comment> commentList = new Vector<Comment>();
			commentList.addAll(modelProperty.getOwnedComments());
			for (Comment comment : commentList) {
				if (comment.getBody().startsWith(GlobalConstants.getFullDefault())) {
					comment.destroy();
				}
			}
		}
		modelProperty.setIsStatic(this.isStatic());
		return true;
	}

	public int getLine() {
		return line;
	}

	public int getCol() {
		return col;
	}
	
	public PythonTreeClass getParent() {
		return (PythonTreeClass) super.getParent();
	}

	/** 
	 * @return the un-abbreviated attribute (default) value 
	 * for this attribute
	 */
	public String getFullValue() {
		return fullValue;
	}

	public int getNextLine() {
		return nextLine;
	}
}