package org.matheclipse.core.eval;

import java.io.Writer;

import org.matheclipse.core.builtin.function.JavaForm;
import org.matheclipse.core.convert.AST2Expr;
import org.matheclipse.core.form.mathml.MathMLContentFormFactory;
import org.matheclipse.core.interfaces.IExpr;
import org.matheclipse.parser.client.Parser;
import org.matheclipse.parser.client.ast.ASTNode;

/**
 * Convert an expression into content MathML output
 * 
 * 
 */
public class MathMLContentUtilities {
	protected EvalEngine fEvalEngine;

	protected MathMLContentFormFactory fMathMLFactory;

	Parser fParser;

	public MathMLContentUtilities(final EvalEngine evalEngine, final boolean relaxedSyntax) {
		fEvalEngine = evalEngine;
		// set the thread local instance
		startRequest();

		fMathMLFactory = new MathMLContentFormFactory();

		fParser = new Parser(relaxedSyntax);
	}

	/**
	 * Converts the inputExpression string into a MathML expression and writes the result to the given Writer
	 * 
	 * @param inputExpression
	 * @param out
	 */
	synchronized public void toMathML(final String inputExpression, final Writer out) {
		IExpr parsedExpression = null;
		ASTNode node;
		if (inputExpression != null) {
			try {
				node = fParser.parse(inputExpression);
				parsedExpression = AST2Expr.CONST.convert(node);
			} catch (final Throwable e) {
				return;
				// parsedExpression == null ==> fError occured
			}
		}
		toMathML(parsedExpression, out);
	}

	/**
	 * Converts the objectExpression into a MathML expression and writes the result to the given Writer
	 * 
	 * @param objectExpression
	 * @param out
	 */
	synchronized public void toMathML(final IExpr objectExpression, final Writer out) {
		final StringBuffer buf = new StringBuffer();

		if (objectExpression != null) {
			fMathMLFactory.convert(buf, objectExpression, 0);
			try {

				out.write("\n");
				out.write("\n");
				out.write(buf.toString());
				out.write("\n");

			} catch (final Throwable e) {
				// parsedExpression == null ==> fError occured
			}
		}
	}

	synchronized public void toJava(final String inputExpression, final Writer out, boolean strictJava) {
		IExpr parsedExpression = null;
		ASTNode node;
		if (inputExpression != null) {
			try {
				node = fParser.parse(inputExpression);
				parsedExpression = AST2Expr.CONST.convert(node);
				out.write(JavaForm.javaForm(parsedExpression, strictJava));
				// out.write(parsedExpression.internalFormString(strictJava, 0));
			} catch (final Throwable e) {
				return;
				// parsedExpression == null ==> fError occured
			}
		}
	}

	/**
	 * Assign the associated EvalEngine to the current thread. Every subsequent action evaluation in this thread affects the
	 * EvalEngine in this class.
	 */
	public void startRequest() {
		EvalEngine.set(fEvalEngine);
	}

	/**
	 * Stop the current evaluation thread.
	 */
	public void stopRequest() {
		fEvalEngine.stopRequest();
	}
}