/*

 * Copyright (c) 2010, 2013, 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 jdk.nashorn.internal.ir.debug;

import java.util.List;

import jdk.nashorn.internal.ir.BinaryNode;

import jdk.nashorn.internal.ir.Block;

import jdk.nashorn.internal.ir.BlockStatement;

import jdk.nashorn.internal.ir.BreakNode;

import jdk.nashorn.internal.ir.CaseNode;

import jdk.nashorn.internal.ir.CatchNode;

import jdk.nashorn.internal.ir.ContinueNode;

import jdk.nashorn.internal.ir.ExpressionStatement;

import jdk.nashorn.internal.ir.ForNode;

import jdk.nashorn.internal.ir.FunctionNode;

import jdk.nashorn.internal.ir.IdentNode;

import jdk.nashorn.internal.ir.IfNode;

import jdk.nashorn.internal.ir.JoinPredecessor;

import jdk.nashorn.internal.ir.JoinPredecessorExpression;

import jdk.nashorn.internal.ir.LabelNode;

import jdk.nashorn.internal.ir.LexicalContext;

import jdk.nashorn.internal.ir.LocalVariableConversion;

import jdk.nashorn.internal.ir.Node;

import jdk.nashorn.internal.ir.SplitNode;

import jdk.nashorn.internal.ir.Statement;

import jdk.nashorn.internal.ir.SwitchNode;

import jdk.nashorn.internal.ir.ThrowNode;

import jdk.nashorn.internal.ir.TryNode;

import jdk.nashorn.internal.ir.UnaryNode;

import jdk.nashorn.internal.ir.VarNode;

import jdk.nashorn.internal.ir.WhileNode;

import jdk.nashorn.internal.ir.WithNode;

import jdk.nashorn.internal.ir.visitor.NodeVisitor;

/**

 * Print out the AST as human readable source code.

 * This works both on lowered and unlowered ASTs

 *

 * see the flags --print-parse and --print-lower-parse

 */

public final class PrintVisitor extends NodeVisitor<LexicalContext> {

    /** Tab width */

    private static final int TABWIDTH = 4;

    /** Composing buffer. */

    private final StringBuilder sb;

    /** Indentation factor. */

    private int indent;

    /** Line separator. */

    private final String EOLN;

    /** Print line numbers */

    private final boolean printLineNumbers;

    /** Print inferred and optimistic types */

    private final boolean printTypes;

    private int lastLineNumber = -1;

    /**

     * Constructor.

     */

    public PrintVisitor() {

        this(true, true);

    }

    /**

     * Constructor

     *

     * @param printLineNumbers  should line number nodes be included in the output?

     * @param printTypes        should we print optimistic and inferred types?

     */

    public PrintVisitor(final boolean printLineNumbers, final boolean printTypes) {

        super(new LexicalContext());

        this.EOLN             = System.lineSeparator();

        this.sb               = new StringBuilder();

        this.printLineNumbers = printLineNumbers;

        this.printTypes       = printTypes;

    }

    /**

     * Constructor

     *

     * @param root  a node from which to start printing code

     */

    public PrintVisitor(final Node root) {

        this(root, true, true);

    }

    /**

     * Constructor

     *

     * @param root              a node from which to start printing code

     * @param printLineNumbers  should line numbers nodes be included in the output?

     * @param printTypes        should we print optimistic and inferred types?

     */

    public PrintVisitor(final Node root, final boolean printLineNumbers, final boolean printTypes) {

        this(printLineNumbers, printTypes);

        visit(root);

    }

    private void visit(final Node root) {

        root.accept(this);

    }

    @Override

    public String toString() {

        return sb.append(EOLN).toString();

    }

    /**

     * Insert spaces before a statement.

     */

    private void indent() {

        for (int i = indent; i > 0; i--) {

            sb.append(' ');

        }

    }

    /*

     * Visits.

     */

    @Override

    public boolean enterDefault(final Node node) {

        node.toString(sb, printTypes);

        return false;

    }

    @Override

    public boolean enterContinueNode(final ContinueNode node) {

        node.toString(sb, printTypes);

        printLocalVariableConversion(node);

        return false;

    }

    @Override

    public boolean enterBreakNode(final BreakNode node) {

        node.toString(sb, printTypes);

        printLocalVariableConversion(node);

        return false;

    }

    @Override

    public boolean enterThrowNode(final ThrowNode node) {

        node.toString(sb, printTypes);

        printLocalVariableConversion(node);

        return false;

    }

    @Override

    public boolean enterBlock(final Block block) {

        sb.append(' ');

        sb.append('{');

        indent += TABWIDTH;

        final List<Statement> statements = block.getStatements();

        for (final Statement statement : statements) {

            if (printLineNumbers) {

                final int lineNumber = statement.getLineNumber();

                sb.append('\n');

                if (lineNumber != lastLineNumber) {

                    indent();

                    sb.append("[|").append(lineNumber).append("|];").append('\n');

                }

                lastLineNumber = lineNumber;

            }

            indent();

            statement.accept(this);

            int  lastIndex = sb.length() - 1;

            char lastChar  = sb.charAt(lastIndex);

            while (Character.isWhitespace(lastChar) && lastIndex >= 0) {

                lastChar = sb.charAt(--lastIndex);

            }

            if (lastChar != '}' && lastChar != ';') {

                sb.append(';');

            }

            if (statement.hasGoto()) {

                sb.append(" [GOTO]");

            }

            if (statement.isTerminal()) {

                sb.append(" [TERMINAL]");

            }

        }

        indent -= TABWIDTH;

        sb.append(EOLN);

        indent();

        sb.append('}');

        printLocalVariableConversion(block);

        return false;

    }

    @Override

    public boolean enterBlockStatement(final BlockStatement statement) {

        statement.getBlock().accept(this);

        return false;

    }

    @Override

    public boolean enterBinaryNode(final BinaryNode binaryNode) {

        binaryNode.lhs().accept(this);

        sb.append(' ');

        sb.append(binaryNode.tokenType());

        sb.append(' ');

        binaryNode.rhs().accept(this);

        return false;

    }

    @Override

    public boolean enterJoinPredecessorExpression(final JoinPredecessorExpression expr) {

        expr.getExpression().accept(this);

        printLocalVariableConversion(expr);

        return false;

    }

    @Override

    public boolean enterIdentNode(final IdentNode identNode) {

        identNode.toString(sb, printTypes);

        printLocalVariableConversion(identNode);

        return true;

    }

    private void printLocalVariableConversion(final JoinPredecessor joinPredecessor) {

        LocalVariableConversion.toString(joinPredecessor.getLocalVariableConversion(), sb);

    }

    @Override

    public boolean enterUnaryNode(final UnaryNode unaryNode) {

        unaryNode.toString(sb, new Runnable() {

            @Override

            public void run() {

                unaryNode.getExpression().accept(PrintVisitor.this);

            }

        }, printTypes);

        return false;

    }

    @Override

    public boolean enterExpressionStatement(final ExpressionStatement expressionStatement) {

        expressionStatement.getExpression().accept(this);

        return false;

    }

    @Override

    public boolean enterForNode(final ForNode forNode) {

        forNode.toString(sb, printTypes);

        forNode.getBody().accept(this);

        return false;

    }

    @Override

    public boolean enterFunctionNode(final FunctionNode functionNode) {

        functionNode.toString(sb, printTypes);

        enterBlock(functionNode.getBody());

        return false;

    }

    @Override

    public boolean enterIfNode(final IfNode ifNode) {

        ifNode.toString(sb, printTypes);

        ifNode.getPass().accept(this);

        final Block fail = ifNode.getFail();

        if (fail != null) {

            sb.append(" else ");

            fail.accept(this);

        }

        if(ifNode.getLocalVariableConversion() != null) {

            assert fail == null;

            sb.append(" else ");

            printLocalVariableConversion(ifNode);

            sb.append(";");

        }

        return false;

    }

    @Override

    public boolean enterLabelNode(final LabelNode labeledNode) {

        indent -= TABWIDTH;

        indent();

        indent += TABWIDTH;

        labeledNode.toString(sb, printTypes);

        labeledNode.getBody().accept(this);

        printLocalVariableConversion(labeledNode);

        return false;

    }

    @Override

    public boolean enterSplitNode(final SplitNode splitNode) {

        splitNode.toString(sb, printTypes);

        sb.append(EOLN);

        indent += TABWIDTH;

        indent();

        return true;

    }

    @Override

    public Node leaveSplitNode(final SplitNode splitNode) {

        sb.append("</split>");

        sb.append(EOLN);

        indent -= TABWIDTH;

        indent();

        return splitNode;

    }

    @Override

    public boolean enterSwitchNode(final SwitchNode switchNode) {

        switchNode.toString(sb, printTypes);

        sb.append(" {");

        final List<CaseNode> cases = switchNode.getCases();

        for (final CaseNode caseNode : cases) {

            sb.append(EOLN);

            indent();

            caseNode.toString(sb, printTypes);

            printLocalVariableConversion(caseNode);

            indent += TABWIDTH;

            caseNode.getBody().accept(this);

            indent -= TABWIDTH;

            sb.append(EOLN);

        }

        if(switchNode.getLocalVariableConversion() != null) {

            sb.append(EOLN);

            indent();

            sb.append("default: ");

            printLocalVariableConversion(switchNode);

            sb.append("{}");

        }

        sb.append(EOLN);

        indent();

        sb.append("}");

        return false;

    }

    @Override

    public boolean enterTryNode(final TryNode tryNode) {

        tryNode.toString(sb, printTypes);

        printLocalVariableConversion(tryNode);

        tryNode.getBody().accept(this);

        final List<Block> catchBlocks = tryNode.getCatchBlocks();

        for (final Block catchBlock : catchBlocks) {

            final CatchNode catchNode = (CatchNode)catchBlock.getStatements().get(0);

            catchNode.toString(sb, printTypes);

            catchNode.getBody().accept(this);

        }

        final Block finallyBody = tryNode.getFinallyBody();

        if (finallyBody != null) {

            sb.append(" finally ");

            finallyBody.accept(this);

        }

        return false;

    }

    @Override

    public boolean enterVarNode(final VarNode varNode) {

        sb.append("var ");

        varNode.getName().toString(sb, printTypes);

        printLocalVariableConversion(varNode.getName());

        final Node init = varNode.getInit();

        if (init != null) {

            sb.append(" = ");

            init.accept(this);

        }

        return false;

    }

    @Override

    public boolean enterWhileNode(final WhileNode whileNode) {

        printLocalVariableConversion(whileNode);

        if (whileNode.isDoWhile()) {

            sb.append("do");

            whileNode.getBody().accept(this);

            sb.append(' ');

            whileNode.toString(sb, printTypes);

        } else {

            whileNode.toString(sb, printTypes);

            whileNode.getBody().accept(this);

        }

        return false;

    }

    @Override

    public boolean enterWithNode(final WithNode withNode) {

        withNode.toString(sb, printTypes);

        withNode.getBody().accept(this);

        return false;

    }

}