package pyUML.pythonTree;

import java.io.File;
import java.util.List;
import java.util.Vector;

import org.eclipse.core.runtime.IPath;
import org.python.pydev.parser.jython.SimpleNode;
import org.python.pydev.parser.jython.ast.ClassDef;
import org.python.pydev.parser.jython.ast.Module;
import org.python.pydev.parser.jython.ast.stmtType;
import org.python.pydev.refactoring.ast.visitors.VisitorFactory;

import pyUML.backend.EclipseHelperMethods;
import pyUML.backend.ParseHelpers;
import pyUML.exceptions.PyUMLCancelledException;
import pyUML.exceptions.PyUMLParseException;



/**
 * This class represents a Python file in the Python
 * Package structure.
 * It must have a parent package and contains a
 * pydev Abstract Syntax Tree (AST)
 *
 */
public class PythonTreeFile extends PythonTreeNode{
	private IPath filePath;
	private PythonTreePackage parent;
	private SimpleNode ast;
	private List<PythonTreeClass> classesInFile;
	private String fileContent;
	private String[] splittedFileContent = null;
	
	
	public PythonTreeFile(IPath filePath, PythonTreePackage parent) throws PyUMLParseException, PyUMLCancelledException{
		super(parent);
		this.filePath = filePath;
		this.parent = parent;
		this.name = filePath.lastSegment();
		
		this.classesInFile = new Vector<PythonTreeClass>();
		this.initAst();
		this.initClassesWithAST();
	}
	
	/**
	 * Parses the given Python file and saves the ast
	 */
	private void initAst() throws PyUMLParseException{
		// init AST so that it will never be null
		this.ast=new SimpleNode();
		// try to get content of python file
		this.fileContent = ParseHelpers.fileToString(
			new File(filePath.toOSString()), this.getProject());
		if (this.fileContent==null) {
			return;
		}
		
		// get AST of file
		try{
			this.ast = VisitorFactory.getRootNodeFromString(this.fileContent);
		} catch (Throwable t) {
			String message = t.getClass().getName()+ " while parsing file " 
				+ this.filePath.toOSString() +"\n\n" +t.getMessage();
			throw new PyUMLParseException(message);
		}
	}
	
	/**
	 * extracts all the top level clases (no inner classes)
	 * out of the AST
	 */
	private void initClassesWithAST() throws PyUMLParseException, PyUMLCancelledException{
		if (this.ast instanceof Module) {
			Module pyModule = (Module) this.ast;
			stmtType[] statements = pyModule.body;
			for (int i = 0; i < statements.length; i++) {
				if (statements[i] instanceof ClassDef) {
					// get end line of class -> look for following statement
					int followingLine = 0;
					if (i +1 < statements.length) {
						stmtType followingStmt = statements[i+1];
						followingLine = followingStmt.beginLine;
					}
					ClassDef pyClass = (ClassDef) statements[i];
					PythonTreeClass cl = new PythonTreeClass(this.parent, this, pyClass, followingLine-1);
					this.classesInFile.add(cl);
				}
			}
		}
	}
	
	public void updateFileInEclipse() {
		EclipseHelperMethods.updateFile(this.getFilePath().toOSString(), this.getProject());
	}
	
	/**
	 * re-inits a file -> re-parses the content
	 * and adds new classes, if needed.
	 * @throws PyUMLParseException
	 */
	public void reInitFile() throws PyUMLParseException, PyUMLCancelledException {
		for (PythonTreeClass cl : this.getClassesInFile()) {
			this.getRoot().getClassDict().remove(cl.getPackageStructure()+cl.getName());
			this.getRoot().getClassNameDict().remove(cl.getPackageStructure()+cl.getName());
			this.getParent().getChildClasses().remove(cl);		
		}
		
		this.splittedFileContent=null;
		this.classesInFile = new Vector<PythonTreeClass>();
		this.initAst();
		this.initClassesWithAST();
		this.getParent().getChildClasses().addAll(this.getClassesInFile());
		this.getRoot().getChildClasses().addAll(this.getParent().getChildClasses());

	}
	
	/**
	 * Splits the file content by "\n", which results in an array of lines.
	 * The result is cached for performance reasons.
	 * @return an Array containing the lines of the file content
	 */
	public String[] getSplittedFileContent() {
		if (splittedFileContent == null)
			splittedFileContent = fileContent.split("\n");
		return splittedFileContent;
	}
	
	public IPath getFilePath() {
		return filePath;
	}
	public SimpleNode getAst() {
		return ast;
	}
	public PythonTreePackage getParent() {
		return parent;
	}

	public List<PythonTreeClass> getClassesInFile() {
		return classesInFile;
	}
	
	/** 
	 * @return the content of the whole file as a String
	 */
	public String getFileContent() {
		return fileContent;
	}

	/**
	 * Set this objects "file content" string. This does *not*
	 * update any real file!
	 * @param fileContent the file content as a String
	 */
	public void setFileContent(String fileContent) {
		this.fileContent = fileContent;
		this.splittedFileContent=null;
	}

	public void setFilePath(IPath filePath) {
		this.filePath = filePath;
	}
}