/*

 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. 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.  Oracle designates this

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

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.codemodel.internal;

/**

 * Factory methods that generate various {@link JExpression}s.

 */

public abstract class JExpr {

    /**

     * This class is not instanciable.

     */

    private JExpr() { }

    public static JExpression assign(JAssignmentTarget lhs, JExpression rhs) {

        return new JAssignment(lhs, rhs);

    }

    public static JExpression assignPlus(JAssignmentTarget lhs, JExpression rhs) {

        return new JAssignment(lhs, rhs, "+");

    }

    public static JInvocation _new(JClass c) {

        return new JInvocation(c);

    }

    public static JInvocation _new(JType t) {

        return new JInvocation(t);

    }

    public static JInvocation invoke(String method) {

        return new JInvocation((JExpression)null, method);

    }

    public static JInvocation invoke(JMethod method) {

        return new JInvocation((JExpression)null,method);

    }

    public static JInvocation invoke(JExpression lhs, JMethod method) {

        return new JInvocation(lhs, method);

    }

    public static JInvocation invoke(JExpression lhs, String method) {

        return new JInvocation(lhs, method);

    }

    public static JFieldRef ref(String field) {

        return new JFieldRef((JExpression)null, field);

    }

    public static JFieldRef ref(JExpression lhs, JVar field) {

        return new JFieldRef(lhs,field);

    }

    public static JFieldRef ref(JExpression lhs, String field) {

        return new JFieldRef(lhs, field);

    }

    public static JFieldRef refthis(String field) {

         return new JFieldRef(null, field, true);

    }

    public static JExpression dotclass(final JClass cl) {

        return new JExpressionImpl() {

                public void generate(JFormatter f) {

                    JClass c;

                    if(cl instanceof JNarrowedClass)

                        c = ((JNarrowedClass)cl).basis;

                    else

                        c = cl;

                    f.g(c).p(".class");

                }

            };

    }

    public static JArrayCompRef component(JExpression lhs, JExpression index) {

        return new JArrayCompRef(lhs, index);

    }

    public static JCast cast(JType type, JExpression expr) {

        return new JCast(type, expr);

    }

    public static JArray newArray(JType type) {

        return newArray(type,null);

    }

    /**

     * Generates {@code new T[size]}.

     *

     * @param type

     *      The type of the array component. 'T' or {@code new T[size]}.

     */

    public static JArray newArray(JType type, JExpression size) {

        // you cannot create an array whose component type is a generic

        return new JArray(type.erasure(), size);

    }

    /**

     * Generates {@code new T[size]}.

     *

     * @param type

     *      The type of the array component. 'T' or {@code new T[size]}.

     */

    public static JArray newArray(JType type, int size) {

        return newArray(type,lit(size));

    }

    private static final JExpression __this = new JAtom("this");

    /**

     * Returns a reference to "this", an implicit reference

     * to the current object.

     */

    public static JExpression _this() { return __this; }

    private static final JExpression __super = new JAtom("super");

    /**

     * Returns a reference to "super", an implicit reference

     * to the super class.

     */

    public static JExpression _super() { return __super; }

    /* -- Literals -- */

    private static final JExpression __null = new JAtom("null");

    public static JExpression _null() {

        return __null;

    }

    /**

     * Boolean constant that represents <code>true</code>

     */

    public static final JExpression TRUE = new JAtom("true");

    /**

     * Boolean constant that represents <code>false</code>

     */

    public static final JExpression FALSE = new JAtom("false");

    public static JExpression lit(boolean b) {

        return b?TRUE:FALSE;

    }

    public static JExpression lit(int n) {

        return new JAtom(Integer.toString(n));

    }

    public static JExpression lit(long n) {

        return new JAtom(Long.toString(n) + "L");

    }

    public static JExpression lit(float f) {

        if (f == Float.NEGATIVE_INFINITY)

        {

                return new JAtom("java.lang.Float.NEGATIVE_INFINITY");

        }

        else if (f == Float.POSITIVE_INFINITY)

        {

                return new JAtom("java.lang.Float.POSITIVE_INFINITY");

        }

        else if (Float.isNaN(f))

        {

                return new JAtom("java.lang.Float.NaN");

        }

        else

        {

                return new JAtom(Float.toString(f) + "F");

        }

    }

    public static JExpression lit(double d) {

        if (d == Double.NEGATIVE_INFINITY)

        {

                return new JAtom("java.lang.Double.NEGATIVE_INFINITY");

        }

        else if (d == Double.POSITIVE_INFINITY)

        {

                return new JAtom("java.lang.Double.POSITIVE_INFINITY");

        }

        else if (Double.isNaN(d))

        {

                return new JAtom("java.lang.Double.NaN");

        }

        else

        {

                return new JAtom(Double.toString(d) + "D");

        }

    }

    static final String charEscape = "\b\t\n\f\r\"\'\\";

    static final String charMacro  = "btnfr\"'\\";

    /**

     * Escapes the given string, then surrounds it by the specified

     * quotation mark.

     */

    public static String quotify(char quote, String s) {

        int n = s.length();

        StringBuilder sb = new StringBuilder(n + 2);

        sb.append(quote);

        for (int i = 0; i < n; i++) {

            char c = s.charAt(i);

            int j = charEscape.indexOf(c);

            if(j>=0) {

                if((quote=='"' && c=='\'') || (quote=='\'' && c=='"')) {

                    sb.append(c);

                } else {

                    sb.append('\\');

                    sb.append(charMacro.charAt(j));

                }

            } else {

                // technically Unicode escape shouldn't be done here,

                // for it's a lexical level handling.

                //

                // However, various tools are so broken around this area,

                // so just to be on the safe side, it's better to do

                // the escaping here (regardless of the actual file encoding)

                //

                // see bug

                if( c<0x20 || 0x7E<c ) {

                    // not printable. use Unicode escape

                    sb.append("\\u");

                    String hex = Integer.toHexString(((int)c)&0xFFFF);

                    for( int k=hex.length(); k<4; k++ )

                        sb.append('0');

                    sb.append(hex);

                } else {

                    sb.append(c);

                }

            }

        }

        sb.append(quote);

        return sb.toString();

    }

    public static JExpression lit(char c) {

        return new JAtom(quotify('\'', "" + c));

    }

    public static JExpression lit(String s) {

        return new JStringLiteral(s);

    }

    /**

     * Creates an expression directly from a source code fragment.

     *

     * <p>

     * This method can be used as a short-cut to create a JExpression.

     * For example, instead of <code>_a.gt(_b)</code>, you can write

     * it as: {@code JExpr.direct("a>b")}.

     *

     * <p>

     * Be warned that there is a danger in using this method,

     * as it obfuscates the object model.

     */

    public static JExpression direct( final String source ) {

        return new JExpressionImpl(){

            public void generate( JFormatter f ) {

                    f.p('(').p(source).p(')');

            }

        };

    }

}