/*

 * Copyright (c) 2018, 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 lib.jdb;

import jdk.test.lib.Utils;

import jdk.test.lib.process.OutputAnalyzer;

import jdk.test.lib.process.ProcessTools;

import java.io.IOException;

import java.nio.file.Files;

import java.nio.file.Paths;

import java.util.Arrays;

import java.util.LinkedList;

import java.util.List;

import java.util.concurrent.TimeUnit;

import java.util.concurrent.TimeoutException;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import java.util.stream.Collectors;

public abstract class JdbTest {

    public static class LaunchOptions {

        public final String debuggeeClass;

        public final List<String> debuggeeOptions = new LinkedList<>();

        public String sourceFilename;

        public LaunchOptions(String debuggeeClass) {

            this.debuggeeClass = debuggeeClass;

        }

        public LaunchOptions addDebuggeeOption(String option) {

            debuggeeOptions.add(option);

            return this;

        }

        public LaunchOptions addDebuggeeOptions(String[] options) {

            debuggeeOptions.addAll(Arrays.asList(options));

            return this;

        }

        public LaunchOptions setSourceFilename(String name) {

            sourceFilename = name;

            return this;

        }

    }

    public JdbTest(LaunchOptions launchOptions) {

        this.launchOptions = launchOptions;

    }

    public JdbTest(String debuggeeClass) {

        this(new LaunchOptions(debuggeeClass));

    }

    // sourceFilename is used by setBreakpoints and redefineClass

    public JdbTest(String debuggeeClass, String sourceFilename) {

        this(new LaunchOptions(debuggeeClass).setSourceFilename(sourceFilename));

    }

    protected Jdb jdb;

    protected Process debuggee;

    private final List<String> debuggeeOutput = new LinkedList<>();

    private final LaunchOptions launchOptions;

    // returns the whole jdb output as a string

    public String getJdbOutput() {

        return jdb == null ? "" : jdb.getJdbOutput();

    }

    // returns the whole debuggee output as a string

    public String getDebuggeeOutput() {

        return debuggeeOutput.stream().collect(Collectors.joining(lineSeparator));

    }

    public void run() {

        try {

            setup();

            runCases();

        } catch (Throwable e) {

            jdb.log("=======================================");

            jdb.log("Exception thrown during test execution: " + e.getMessage());

            jdb.log("=======================================");

            throw e;

        } finally {

            shutdown();

        }

    }

    protected void setup() {

        /* run debuggee as:

            java -agentlib:jdwp=transport=dt_socket,address=0,server=n,suspend=y <debuggeeClass>

        it reports something like : Listening for transport dt_socket at address: 60810

        after that connect jdb by:

            jdb -connect com.sun.jdi.SocketAttach:port=60810

        */

        // launch debuggee

        List<String> debuggeeArgs = new LinkedList<>();

        // specify address=0 to automatically select free port

        debuggeeArgs.add("-agentlib:jdwp=transport=dt_socket,address=0,server=y,suspend=y");

        debuggeeArgs.addAll(launchOptions.debuggeeOptions);

        debuggeeArgs.add(launchOptions.debuggeeClass);

        ProcessBuilder pbDebuggee = ProcessTools.createJavaProcessBuilder(true, debuggeeArgs.toArray(new String[0]));

        // debuggeeListen[0] - transport, debuggeeListen[1] - address

        String[] debuggeeListen = new String[2];

        Pattern listenRegexp = Pattern.compile("Listening for transport \\b(.+)\\b at address: \\b(\\d+)\\b");

        try {

            debuggee = ProcessTools.startProcess("debuggee", pbDebuggee,

                    s -> debuggeeOutput.add(s),  // output consumer

                    s -> {  // warm-up predicate

                        Matcher m = listenRegexp.matcher(s);

                        if (!m.matches()) {

                            return false;

                        }

                        debuggeeListen[0] = m.group(1);

                        debuggeeListen[1] = m.group(2);

                        return true;

                    },

                    30, TimeUnit.SECONDS);

        } catch (IOException | InterruptedException | TimeoutException ex) {

            throw new RuntimeException("failed to launch debuggee", ex);

        }

        // launch jdb

        try {

            jdb = new Jdb("-connect", "com.sun.jdi.SocketAttach:port=" + debuggeeListen[1]);

        } catch (Throwable ex) {

            // terminate debuggee if something went wrong

            debuggee.destroy();

            throw ex;

        }

        // wait while jdb is initialized

        jdb.waitForPrompt(1, false);

    }

    protected abstract void runCases();

    protected void shutdown() {

        if (jdb != null) {

            jdb.shutdown();

        }

        // shutdown debuggee

        if (debuggee != null && debuggee.isAlive()) {

            try {

                debuggee.waitFor(Utils.adjustTimeout(10), TimeUnit.SECONDS);

            } catch (InterruptedException e) {

                // ignore

            } finally {

                if (debuggee.isAlive()) {

                    debuggee.destroy();

                }

            }

        }

    }

    protected static final String lineSeparator = System.getProperty("line.separator");

    // Parses the specified source file for "@{id} breakpoint" tags and returns

    // list of the line numbers containing the tag.

    // Example:

    //   System.out.println("BP is here");  // @1 breakpoint

    public static List<Integer> parseBreakpoints(String filePath, int id) {

        final String pattern = "@" + id + " breakpoint";

        int lineNum = 1;

        List<Integer> result = new LinkedList<>();

        try {

            for (String line: Files.readAllLines(Paths.get(filePath))) {

                if (line.contains(pattern)) {

                    result.add(lineNum);

                }

                lineNum++;

            }

        } catch (IOException ex) {

            throw new RuntimeException("failed to parse " + filePath, ex);

        }

        return result;

    }

    // sets breakpoints to the lines parsed by {@code parseBreakpoints}

    // returns number of the breakpoints set.

    public static int setBreakpoints(Jdb jdb, String debuggeeClass, String sourcePath, int id) {

        List<Integer> bps = parseBreakpoints(sourcePath, id);

        for (int bp : bps) {

            String reply = jdb.command(JdbCommand.stopAt(debuggeeClass, bp)).stream()

                    .collect(Collectors.joining("\n"));

            if (reply.contains("Unable to set")) {

                throw new RuntimeException("jdb failed to set breakpoint at " + debuggeeClass + ":" + bp);

            }

        }

        return bps.size();

    }

    // sets breakpoints to the lines parsed by {@code parseBreakpoints}

    // from the file from test source directory.

    // returns number of the breakpoints set.

    protected int setBreakpointsFromTestSource(String debuggeeFileName, int id) {

        return setBreakpoints(jdb, launchOptions.debuggeeClass,

                              getTestSourcePath(debuggeeFileName), id);

    }

    // sets breakpoints in the class {@code launchOptions.debuggeeClass}

    // to the lines parsed by {@code parseBreakpoints}

    // from the file from test source directory specified by {@code launchOptions.sourceFilename}.

    // returns number of the breakpoints set.

    protected int setBreakpoints(int id) {

        verifySourceFilename();

        return setBreakpointsFromTestSource(launchOptions.sourceFilename, id);

    }

    // transforms class with the specified id (see {@code ClassTransformer})

    // and executes "redefine" jdb command for {@code launchOptions.debuggeeClass}.

    // returns reply for the command.

    protected List<String> redefineClass(int id, String... compilerOptions) {

        verifySourceFilename();

        String transformedClassFile = ClassTransformer.fromTestSource(launchOptions.sourceFilename)

                .transform(id, launchOptions.debuggeeClass, compilerOptions);

        return jdb.command(JdbCommand.redefine(launchOptions.debuggeeClass, transformedClassFile));

    }

    // gets full test source path for the given test filename

        return Paths.get(System.getProperty("test.src")).resolve(fileName).toString();

    }

    // verifies that sourceFilename is specified in ctor

    private void verifySourceFilename() {

        if (launchOptions.sourceFilename == null) {

            throw new RuntimeException("launchOptions.sourceFilename must be specified.");

        }

    }

    protected OutputAnalyzer execCommand(JdbCommand cmd) {

        List<String> reply = jdb.command(cmd);

        return new OutputAnalyzer(reply.stream().collect(Collectors.joining(lineSeparator)));

    }

    // helpers for "eval" jdb command.

    // executes "eval <expr>" and verifies output contains the specified text

    protected void evalShouldContain(String expr, String expectedString) {

        execCommand(JdbCommand.eval(expr))

                .shouldContain(expectedString);

    }

    // executes "eval <expr>" and verifies output does not contain the specified text

    protected void evalShouldNotContain(String expr, String unexpectedString) {

        execCommand(JdbCommand.eval(expr))

                .shouldNotContain(unexpectedString);

    }

}