/*
 * Copyright (c) 2009, 2011, 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.
 *
 * 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.oracle.max.graal.compiler.debug;

import static com.oracle.max.graal.compiler.debug.InstructionPrinter.InstructionLineColumn.*;

import com.oracle.max.graal.compiler.ir.*;

/**
 * A {@link ValueVisitor} for {@linkplain #printInstruction(Value) printing}
 * an {@link Instruction} as an expression or statement.
 *
 * @author Doug Simon
 */
public class InstructionPrinter {


    /**
     * The columns printed in a tabulated instruction
     * {@linkplain InstructionPrinter#printInstructionListing(Value) listing}.
     */
    public enum InstructionLineColumn {
        /**
         * The instruction's bytecode index.
         */
        BCI(2, "bci"),

        /**
         * The instruction's use count.
         */
        USE(7, "use"),

        /**
         * The instruction as a {@linkplain com.oracle.max.graal.compiler.util.Util#valueString(com.oracle.max.graal.compiler.ir.Value) value}.
         */
        VALUE(12, "tid"),

        /**
         * The instruction formatted as an expression or statement.
         */
        INSTRUCTION(19, "instr"),

        END(60, "");

        final int position;
        final String label;

        private InstructionLineColumn(int position, String label) {
            this.position = position;
            this.label = label;
        }

        /**
         * Prints this column's label to a given stream after padding the stream with '_' characters
         * until its {@linkplain LogStream#position() position} is equal to this column's position.
         * @param out the print stream
         */
        public void printLabel(LogStream out) {
            out.fillTo(position + out.indentationLevel(), '_');
            out.print(label);
        }

        /**
         * Prints space characters to a given stream until its {@linkplain LogStream#position() position}
         * is equal to this column's position.
         * @param out the print stream
         */
        public void advance(LogStream out) {
            out.fillTo(position + out.indentationLevel(), ' ');
        }
    }

    private final LogStream out;

    public InstructionPrinter(LogStream out) {
        this.out = out;
    }

    public LogStream out() {
        return out;
    }

    /**
     * Prints a given instruction as an expression or statement.
     *
     * @param instruction the instruction to print
     */
    public void printInstruction(Value instruction) {
        instruction.print(out);
    }


    /**
     * Prints a header for the tabulated data printed by {@link #printInstructionListing(Value)}.
     */
    public void printInstructionListingHeader() {
        BCI.printLabel(out);
        USE.printLabel(out);
        VALUE.printLabel(out);
        INSTRUCTION.printLabel(out);
        END.printLabel(out);
        out.println();
    }

    /**
     * Prints an instruction listing on one line. The instruction listing is composed of the
     * columns specified by {@link InstructionLineColumn}.
     *
     * @param instruction the instruction to print
     */
    public void printInstructionListing(Value instruction) {
        int indentation = out.indentationLevel();
        out.fillTo(BCI.position + indentation, ' ').
             print(0).
             fillTo(USE.position + indentation, ' ').
             print("0").
             fillTo(VALUE.position + indentation, ' ').
             print(instruction).
             fillTo(INSTRUCTION.position + indentation, ' ');
        printInstruction(instruction);
        String flags = instruction.flagsToString();
        if (!flags.isEmpty()) {
            out.print("  [flags: " + flags + "]");
        }
        if (instruction instanceof StateSplit) {
            out.print("  [state: " + ((StateSplit) instruction).stateAfter() + "]");
        }
        out.println();
    }
}