/*

 * Copyright (c) 2009, 2019, 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 org.graalvm.compiler.debug;

import java.io.PrintStream;

import java.lang.reflect.Field;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.Map;

import java.util.regex.Pattern;

import org.graalvm.compiler.serviceprovider.GraalServices;

/**

 * A collection of static methods for printing debug and informational output to a global

 * {@link LogStream}. The output can be (temporarily) suppressed per thread through use of a

 * {@linkplain Filter filter}.

 */

public class TTY {

    /**

     * Support for thread-local suppression of {@link TTY}.

     */

    public static class Filter implements AutoCloseable {

        private LogStream previous;

        private final Thread thread = Thread.currentThread();

        /**

         * Creates an object that will suppress {@link TTY} for the current thread if the given

         * filter does not match the given object. To revert the suppression state to how it was

         * before this call, the {@link #remove()} method must be called on the suppression object.

         *

         * @param filter the pattern for matching. If {@code null}, then the match is successful. If

         *            it starts with "~", then a regular expression

         *            {@linkplain Pattern#matches(String, CharSequence) match} is performed where

         *            the regular expression is specified by {@code filter} without the "~" prefix.

         *            Otherwise, a simple {@linkplain String#contains(CharSequence) substring} match

         *            is performed where {@code filter} is the substring used.

         * @param object an object whose {@linkplain Object#toString() string} value is matched

         *            against {@code filter}

         */

        public Filter(String filter, Object object) {

            boolean suppressed = false;

            if (filter != null) {

                String input = object.toString();

                if (filter.startsWith("~")) {

                    suppressed = !Pattern.matches(filter.substring(1), input);

                } else {

                    suppressed = !input.contains(filter);

                }

                if (suppressed) {

                    previous = out();

                    log.set(LogStream.SINK);

                }

            }

        }

        /**

         * Creates an object that will suppress {@link TTY} for the current thread. To revert the

         * suppression state to how it was before this call, the {@link #remove()} method must be

         * called on this filter object.

         */

        public Filter() {

            previous = out();

            log.set(LogStream.SINK);

        }

        /**

         * Creates an object that will overwrite {@link TTY} for the current thread with a custom

         * log stream. To revert the overwritten state to how it was before this call, the

         * {@link #remove()} method must be called on this filter object.

         */

        public Filter(LogStream newStream) {

            previous = out();

            log.set(newStream);

        }

        /**

         * Reverts the suppression state of {@link TTY} to how it was before this object was

         * constructed.

         */

        public void remove() {

            assert thread == Thread.currentThread();

            if (previous != null) {

                log.set(previous);

            }

        }

        @Override

        public void close() {

            remove();

        }

    }

    /**

     * The {@link PrintStream} to which all non-suppressed output from {@link TTY} is written.

     * Substituted by {@code com.oracle.svm.graal.Target_org_graalvm_compiler_debug_TTY}.

     */

    public static final PrintStream out;

    static {

        TTYStreamProvider p = GraalServices.loadSingle(TTYStreamProvider.class, false);

        out = p == null ? System.out : p.getStream();

    }

    private static final ThreadLocal<LogStream> log = new ThreadLocal<LogStream>() {

        @Override

        protected LogStream initialValue() {

            return new LogStream(out);

        }

    };

    public static boolean isSuppressed() {

        return log.get() == LogStream.SINK;

    }

    /**

     * Gets the thread-local log stream to which the static methods of this class send their output.

     * This will either be a global log stream or the global {@linkplain LogStream#SINK sink}

     * depending on whether any suppression {@linkplain Filter filters} are in effect for the

     * current thread.

     */

    public static LogStream out() {

        return log.get();

    }

    /**

     * @see LogStream#print(String)

     */

    public static void print(String s) {

        out().print(s);

    }

    /**

     * @see LogStream#print(int)

     */

    public static void print(int i) {

        out().print(i);

    }

    /**

     * @see LogStream#print(long)

     */

    public static void print(long i) {

        out().print(i);

    }

    /**

     * @see LogStream#print(char)

     */

    public static void print(char c) {

        out().print(c);

    }

    /**

     * @see LogStream#print(boolean)

     */

    public static void print(boolean b) {

        out().print(b);

    }

    /**

     * @see LogStream#print(double)

     */

    public static void print(double d) {

        out().print(d);

    }

    /**

     * @see LogStream#print(float)

     */

    public static void print(float f) {

        out().print(f);

    }

    /**

     * @see LogStream#println(String)

     */

    public static void println(String s) {

        out().println(s);

    }

    /**

     * @see LogStream#println()

     */

    public static void println() {

        out().println();

    }

    /**

     * @see LogStream#println(int)

     */

    public static void println(int i) {

        out().println(i);

    }

    /**

     * @see LogStream#println(long)

     */

    public static void println(long l) {

        out().println(l);

    }

    /**

     * @see LogStream#println(char)

     */

    public static void println(char c) {

        out().println(c);

    }

    /**

     * @see LogStream#println(boolean)

     */

    public static void println(boolean b) {

        out().println(b);

    }

    /**

     * @see LogStream#println(double)

     */

    public static void println(double d) {

        out().println(d);

    }

    /**

     * @see LogStream#println(float)

     */

    public static void println(float f) {

        out().println(f);

    }

    public static void printf(String format, Object... args) {

        out().printf(format, args);

    }

    public static void println(String format, Object... args) {

        out().printf(format + "%n", args);

    }

    public static void fillTo(int i) {

        out().fillTo(i, ' ');

    }

    public static void printFields(Class<?> javaClass) {

        final String className = javaClass.getSimpleName();

        TTY.println(className + " {");

        for (final Field field : javaClass.getFields()) {

            printField(field, false);

        }

        TTY.println("}");

    }

    public static void printField(final Field field, boolean tabbed) {

        final String fieldName = String.format("%35s", field.getName());

        try {

            String prefix = tabbed ? "" : "    " + fieldName + " = ";

            String postfix = tabbed ? "\t" : "\n";

            if (field.getType() == int.class) {

                TTY.print(prefix + field.getInt(null) + postfix);

            } else if (field.getType() == boolean.class) {

                TTY.print(prefix + field.getBoolean(null) + postfix);

            } else if (field.getType() == float.class) {

                TTY.print(prefix + field.getFloat(null) + postfix);

            } else if (field.getType() == String.class) {

                TTY.print(prefix + field.get(null) + postfix);

            } else if (field.getType() == Map.class) {

                Map<?, ?> m = (Map<?, ?>) field.get(null);

                TTY.print(prefix + printMap(m) + postfix);

            } else {

                TTY.print(prefix + field.get(null) + postfix);

            }

        } catch (IllegalAccessException e) {

            // do nothing.

        }

    }

    private static String printMap(Map<?, ?> m) {

        StringBuilder sb = new StringBuilder();

        List<String> keys = new ArrayList<>();

        for (Object key : m.keySet()) {

            keys.add((String) key);

        }

        Collections.sort(keys);

        for (String key : keys) {

            sb.append(key);

            sb.append("\t");

            sb.append(m.get(key));

            sb.append("\n");

        }

        return sb.toString();

    }

    public static void flush() {

        out().flush();

    }

}