/*

 * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.codemodel.internal;

/**

 * JClass for generating expressions containing operators

 */

abstract public class JOp {

    private JOp() {

    }

    /**

     * Determine whether the top level of an expression involves an

     * operator.

     */

    static boolean hasTopOp(JExpression e) {

        return (e instanceof UnaryOp) || (e instanceof BinaryOp);

    }

    /* -- Unary operators -- */

    static private class UnaryOp extends JExpressionImpl {

        protected String op;

        protected JExpression e;

        protected boolean opFirst = true;

        UnaryOp(String op, JExpression e) {

            this.op = op;

            this.e = e;

        }

        UnaryOp(JExpression e, String op) {

            this.op = op;

            this.e = e;

            opFirst = false;

        }

        public void generate(JFormatter f) {

            if (opFirst)

                f.p('(').p(op).g(e).p(')');

            else

                f.p('(').g(e).p(op).p(')');

        }

    }

    public static JExpression minus(JExpression e) {

        return new UnaryOp("-", e);

    }

    /**

     * Logical not <tt>'!x'</tt>.

     */

    public static JExpression not(JExpression e) {

        if (e == JExpr.TRUE) return JExpr.FALSE;

        if (e == JExpr.FALSE) return JExpr.TRUE;

        return new UnaryOp("!", e);

    }

    public static JExpression complement(JExpression e) {

        return new UnaryOp("~", e);

    }

    static private class TightUnaryOp extends UnaryOp {

        TightUnaryOp(JExpression e, String op) {

            super(e, op);

        }

        public void generate(JFormatter f) {

            if (opFirst)

                f.p(op).g(e);

            else

                f.g(e).p(op);

        }

    }

    public static JExpression incr(JExpression e) {

        return new TightUnaryOp(e, "++");

    }

    public static JExpression decr(JExpression e) {

        return new TightUnaryOp(e, "--");

    }

    /* -- Binary operators -- */

    static private class BinaryOp extends JExpressionImpl {

        String op;

        JExpression left;

        JGenerable right;

        BinaryOp(String op, JExpression left, JGenerable right) {

            this.left = left;

            this.op = op;

            this.right = right;

        }

        public void generate(JFormatter f) {

            f.p('(').g(left).p(op).g(right).p(')');

        }

    }

    public static JExpression plus(JExpression left, JExpression right) {

        return new BinaryOp("+", left, right);

    }

    public static JExpression minus(JExpression left, JExpression right) {

        return new BinaryOp("-", left, right);

    }

    public static JExpression mul(JExpression left, JExpression right) {

        return new BinaryOp("*", left, right);

    }

    public static JExpression div(JExpression left, JExpression right) {

        return new BinaryOp("/", left, right);

    }

    public static JExpression mod(JExpression left, JExpression right) {

        return new BinaryOp("%", left, right);

    }

    public static JExpression shl(JExpression left, JExpression right) {

        return new BinaryOp("<<", left, right);

    }

    public static JExpression shr(JExpression left, JExpression right) {

        return new BinaryOp(">>", left, right);

    }

    public static JExpression shrz(JExpression left, JExpression right) {

        return new BinaryOp(">>>", left, right);

    }

    public static JExpression band(JExpression left, JExpression right) {

        return new BinaryOp("&", left, right);

    }

    public static JExpression bor(JExpression left, JExpression right) {

        return new BinaryOp("|", left, right);

    }

    public static JExpression cand(JExpression left, JExpression right) {

        if (left == JExpr.TRUE) return right;

        if (right == JExpr.TRUE) return left;

        if (left == JExpr.FALSE) return left;    // JExpr.FALSE

        if (right == JExpr.FALSE) return right;   // JExpr.FALSE

        return new BinaryOp("&&", left, right);

    }

    public static JExpression cor(JExpression left, JExpression right) {

        if (left == JExpr.TRUE) return left;    // JExpr.TRUE

        if (right == JExpr.TRUE) return right;   // JExpr.FALSE

        if (left == JExpr.FALSE) return right;

        if (right == JExpr.FALSE) return left;

        return new BinaryOp("||", left, right);

    }

    public static JExpression xor(JExpression left, JExpression right) {

        return new BinaryOp("^", left, right);

    }

    public static JExpression lt(JExpression left, JExpression right) {

        return new BinaryOp("<", left, right);

    }

    public static JExpression lte(JExpression left, JExpression right) {

        return new BinaryOp("<=", left, right);

    }

    public static JExpression gt(JExpression left, JExpression right) {

        return new BinaryOp(">", left, right);

    }

    public static JExpression gte(JExpression left, JExpression right) {

        return new BinaryOp(">=", left, right);

    }

    public static JExpression eq(JExpression left, JExpression right) {

        return new BinaryOp("==", left, right);

    }

    public static JExpression ne(JExpression left, JExpression right) {

        return new BinaryOp("!=", left, right);

    }

    public static JExpression _instanceof(JExpression left, JType right) {

        return new BinaryOp("instanceof", left, right);

    }

    /* -- Ternary operators -- */

    static private class TernaryOp extends JExpressionImpl {

        String op1;

        String op2;

        JExpression e1;

        JExpression e2;

        JExpression e3;

        TernaryOp(String op1, String op2,

                  JExpression e1, JExpression e2, JExpression e3) {

            this.e1 = e1;

            this.op1 = op1;

            this.e2 = e2;

            this.op2 = op2;

            this.e3 = e3;

        }

        public void generate(JFormatter f) {

            f.p('(').g(e1).p(op1).g(e2).p(op2).g(e3).p(')');

        }

    }

    public static JExpression cond(JExpression cond,

                                   JExpression ifTrue, JExpression ifFalse) {

        return new TernaryOp("?", ":", cond, ifTrue, ifFalse);

    }

}