/*

 * Copyright (c) 1997, 2012, 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;

import java.util.ArrayList;

import java.util.List;

import java.util.Collections;

/**

 * A block of Java code, which may contain statements and local declarations.

 *

 * <p>

 * {@link JBlock} contains a large number of factory methods that creates new

 * statements/declarations. Those newly created statements/declarations are

 * inserted into the {@link #pos() "current position"}. The position advances

 * one every time you add a new instruction.

 */

public final class JBlock implements JGenerable, JStatement {

    /**

     * Declarations and statements contained in this block.

     * Either {@link JStatement} or {@link JDeclaration}.

     */

    private final List<Object> content = new ArrayList<Object>();

    /**

     * Whether or not this block must be braced and indented

     */

    private boolean bracesRequired = true;

    private boolean indentRequired = true;

    /**

     * Current position.

     */

    private int pos;

    public JBlock() {

        this(true,true);

    }

    public JBlock(boolean bracesRequired, boolean indentRequired) {

        this.bracesRequired = bracesRequired;

        this.indentRequired = indentRequired;

    }

    /**

     * Returns a read-only view of {@link JStatement}s and {@link JDeclaration}

     * in this block.

     */

    public List<Object> getContents() {

        return Collections.unmodifiableList(content);

    }

    private <T> T insert( T statementOrDeclaration ) {

        content.add(pos,statementOrDeclaration);

        pos++;

        return statementOrDeclaration;

    }

    /**

     * Gets the current position to which new statements will be inserted.

     *

     * For example if the value is 0, newly created instructions will be

     * inserted at the very beginning of the block.

     *

     * @see #pos(int)

     */

    public int pos() {

        return pos;

    }

    /**

     * Sets the current position.

     *

     * @return

     *      the old value of the current position.

     * @throws IllegalArgumentException

     *      if the new position value is illegal.

     *

     * @see #pos()

     */

    public int pos(int newPos) {

        int r = pos;

        if(newPos>content.size() || newPos<0)

            throw new IllegalArgumentException();

        pos = newPos;

        return r;

    }

    /**

     * Returns true if this block is empty and does not contain

     * any statement.

     */

    public boolean isEmpty() {

        return content.isEmpty();

    }

    /**

     * Adds a local variable declaration to this block

     *

     * @param type

     *        JType of the variable

     *

     * @param name

     *        Name of the variable

     *

     * @return Newly generated JVar

     */

    public JVar decl(JType type, String name) {

        return decl(JMod.NONE, type, name, null);

    }

    /**

     * Adds a local variable declaration to this block

     *

     * @param type

     *        JType of the variable

     *

     * @param name

     *        Name of the variable

     *

     * @param init

     *        Initialization expression for this variable.  May be null.

     *

     * @return Newly generated JVar

     */

    public JVar decl(JType type, String name, JExpression init) {

        return decl(JMod.NONE, type, name, init);

    }

    /**

     * Adds a local variable declaration to this block

     *

     * @param mods

     *        Modifiers for the variable

     *

     * @param type

     *        JType of the variable

     *

     * @param name

     *        Name of the variable

     *

     * @param init

     *        Initialization expression for this variable.  May be null.

     *

     * @return Newly generated JVar

     */

    public JVar decl(int mods, JType type, String name, JExpression init) {

        JVar v = new JVar(JMods.forVar(mods), type, name, init);

        insert(v);

        bracesRequired = true;

        indentRequired = true;

        return v;

    }

    /**

     * Creates an assignment statement and adds it to this block.

     *

     * @param lhs

     *        Assignable variable or field for left hand side of expression

     *

     * @param exp

     *        Right hand side expression

     */

    public JBlock assign(JAssignmentTarget lhs, JExpression exp) {

        insert(new JAssignment(lhs, exp));

        return this;

    }

    public JBlock assignPlus(JAssignmentTarget lhs, JExpression exp) {

        insert(new JAssignment(lhs, exp, "+"));

        return this;

    }

    /**

     * Creates an invocation statement and adds it to this block.

     *

     * @param expr

     *        JExpression evaluating to the class or object upon which

     *        the named method will be invoked

     *

     * @param method

     *        Name of method to invoke

     *

     * @return Newly generated JInvocation

     */

    public JInvocation invoke(JExpression expr, String method) {

        JInvocation i = new JInvocation(expr, method);

        insert(i);

        return i;

    }

    /**

     * Creates an invocation statement and adds it to this block.

     *

     * @param expr

     *        JExpression evaluating to the class or object upon which

     *        the method will be invoked

     *

     * @param method

     *        JMethod to invoke

     *

     * @return Newly generated JInvocation

     */

    public JInvocation invoke(JExpression expr, JMethod method) {

        return insert(new JInvocation(expr, method));

    }

    /**

     * Creates a static invocation statement.

     */

    public JInvocation staticInvoke(JClass type, String method) {

        return insert(new JInvocation(type, method));

    }

    /**

     * Creates an invocation statement and adds it to this block.

     *

     * @param method

     *        Name of method to invoke

     *

     * @return Newly generated JInvocation

     */

    public JInvocation invoke(String method) {

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

    }

    /**

     * Creates an invocation statement and adds it to this block.

     *

     * @param method

     *        JMethod to invoke

     *

     * @return Newly generated JInvocation

     */

    public JInvocation invoke(JMethod method) {

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

    }

    /**

     * Adds a statement to this block

     *

     * @param s

     *        JStatement to be added

     *

     * @return This block

     */

    public JBlock add(JStatement s) { // ## Needed?

        insert(s);

        return this;

    }

    /**

     * Create an If statement and add it to this block

     *

     * @param expr

     *        JExpression to be tested to determine branching

     *

     * @return Newly generated conditional statement

     */

    public JConditional _if(JExpression expr) {

        return insert(new JConditional(expr));

    }

    /**

     * Create a For statement and add it to this block

     *

     * @return Newly generated For statement

     */

    public JForLoop _for() {

        return insert(new JForLoop());

    }

    /**

     * Create a While statement and add it to this block

     *

     * @return Newly generated While statement

     */

    public JWhileLoop _while(JExpression test) {

        return insert(new JWhileLoop(test));

    }

    /**

     * Create a switch/case statement and add it to this block

     */

    public JSwitch _switch(JExpression test) {

        return insert(new JSwitch(test));

    }

    /**

     * Create a Do statement and add it to this block

     *

     * @return Newly generated Do statement

     */

    public JDoLoop _do(JExpression test) {

        return insert(new JDoLoop(test));

    }

    /**

     * Create a Try statement and add it to this block

     *

     * @return Newly generated Try statement

     */

    public JTryBlock _try() {

        return insert(new JTryBlock());

    }

    /**

     * Create a return statement and add it to this block

     */

    public void _return() {

        insert(new JReturn(null));

    }

    /**

     * Create a return statement and add it to this block

     */

    public void _return(JExpression exp) {

        insert(new JReturn(exp));

    }

    /**

     * Create a throw statement and add it to this block

     */

    public void _throw(JExpression exp) {

        insert(new JThrow(exp));

    }

    /**

     * Create a break statement and add it to this block

     */

    public void _break() {

        _break(null);

    }

    public void _break(JLabel label) {

        insert(new JBreak(label));

    }

    /**

     * Create a label, which can be referenced from

     * <code>continue</code> and <code>break</code> statements.

     */

    public JLabel label(String name) {

        JLabel l = new JLabel(name);

        insert(l);

        return l;

    }

    /**

     * Create a continue statement and add it to this block

     */

    public void _continue(JLabel label) {

        insert(new JContinue(label));

    }

    public void _continue() {

        _continue(null);

    }

    /**

     * Create a sub-block and add it to this block

     */

    public JBlock block() {

        JBlock b = new JBlock();

        b.bracesRequired = false;

        b.indentRequired = false;

        return insert(b);

    }

    /**

     * Creates a "literal" statement directly.

     *

     * <p>

     * Specified string is printed as-is.

     * This is useful as a short-cut.

     *

     * <p>

     * For example, you can invoke this method as:

     * <code>directStatement("a=b+c;")</code>.

     */

    public JStatement directStatement(final String source) {

        JStatement s = new JStatement() {

            public void state(JFormatter f) {

                f.p(source).nl();

            }

        };

        add(s);

        return s;

    }

    public void generate(JFormatter f) {

        if (bracesRequired)

            f.p('{').nl();

        if (indentRequired)

            f.i();

        generateBody(f);

        if (indentRequired)

            f.o();

        if (bracesRequired)

            f.p('}');

    }

    void generateBody(JFormatter f) {

        for (Object o : content) {

            if (o instanceof JDeclaration)

                f.d((JDeclaration) o);

            else

                f.s((JStatement) o);

        }

    }

    /**

     * Creates an enhanced For statement based on j2se 1.5 JLS

     * and add it to this block

     *

     * @return Newly generated enhanced For statement per j2se 1.5

     * specification

    */

    public JForEach forEach(JType varType, String name, JExpression collection) {

        return insert(new JForEach( varType, name, collection));

    }

    public void state(JFormatter f) {

        f.g(this);

        if (bracesRequired)

            f.nl();

    }

}