/*
 * Copyright (c) 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 jdk.jpackage.test;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.spi.ToolProvider;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public final class Executor extends CommandArguments<Executor> {

    public Executor() {
        saveOutputType = SaveOutputType.NONE;
    }

    public Executor setExecutable(String v) {
        executable = v;
        if (executable != null) {
            toolProvider = null;
        }
        return this;
    }

    public Executor setToolProvider(ToolProvider v) {
        toolProvider = v;
        if (toolProvider != null) {
            executable = null;
        }
        return this;
    }

    public Executor setDirectory(Path v) {
        directory = v;
        return this;
    }

    public Executor setExecutable(JavaTool v) {
        return setExecutable(v.getPath().getAbsolutePath());
    }

    public Executor saveOutput() {
        saveOutputType = SaveOutputType.FULL;
        return this;
    }

    public Executor saveFirstLineOfOutput() {
        saveOutputType = SaveOutputType.FIRST_LINE;
        return this;
    }

    public Executor dumpOtput() {
        saveOutputType = SaveOutputType.DUMP;
        return this;
    }

    public class Result {

        Result(int exitCode) {
            this.exitCode = exitCode;
        }

        public String getFirstLineOfOutput() {
            return output.get(0);
        }

        public List<String> getOutput() {
            return output;
        }

        public String getPrintableCommandLine() {
            return Executor.this.getPrintableCommandLine();
        }

        public Result assertExitCodeIs(int expectedExitCode) {
            Test.assertEquals(expectedExitCode, exitCode, String.format(
                    "Check command %s exited with %d code",
                    getPrintableCommandLine(), expectedExitCode));
            return this;
        }

        public Result assertExitCodeIsZero() {
            return assertExitCodeIs(0);
        }

        final int exitCode;
        private List<String> output;
    }

    public Result execute() {
        if (toolProvider != null) {
            return runToolProvider();
        }

        try {
            if (executable != null) {
                return runExecutable();
            }
        } catch (RuntimeException e) {
            throw e;
        } catch (IOException | InterruptedException e) {
            throw new RuntimeException(e);
        }

        throw new IllegalStateException("No command to execute");
    }

    public String executeAndGetFirstLineOfOutput() {
        return saveFirstLineOfOutput().execute().assertExitCodeIsZero().getFirstLineOfOutput();
    }

    public List<String> executeAndGetOutput() {
        return saveOutput().execute().assertExitCodeIsZero().getOutput();
    }

    private Result runExecutable() throws IOException, InterruptedException {
        List<String> command = new ArrayList<>();
        command.add(executable);
        command.addAll(args);
        Path outputFile = null;
        ProcessBuilder builder = new ProcessBuilder(command);
        StringBuilder sb = new StringBuilder(getPrintableCommandLine());
        if (saveOutputType != SaveOutputType.NONE) {
            builder.redirectErrorStream(true);

            if (saveOutputType == SaveOutputType.DUMP) {
                builder.inheritIO();
                sb.append("; redirect output to stdout");
            } else {
                outputFile = Test.createTempFile(".out");
                builder.redirectOutput(outputFile.toFile());
                sb.append(String.format("; redirect output to [%s]", outputFile));
            }
        }
        if (directory != null) {
            builder.directory(directory.toFile());
            sb.append(String.format("; in directory [%s]", directory));
        }

        try {
            Test.trace("Execute " + sb.toString() + "...");
            Process process = builder.start();
            Result reply = new Result(process.waitFor());
            Test.trace("Done. Exit code: " + reply.exitCode);
            if (saveOutputType == SaveOutputType.FIRST_LINE) {
                // If the command produced no ouput, save null in 'result.output' list.
                reply.output = Arrays.asList(
                        Files.readAllLines(outputFile).stream().findFirst().orElse(
                                null));
            } else if (saveOutputType == SaveOutputType.FULL) {
                reply.output = Collections.unmodifiableList(Files.readAllLines(
                        outputFile));
            }
            return reply;
        } finally {
            if (outputFile != null) {
                Files.deleteIfExists(outputFile);
            }
        }
    }

    private Result runToolProvider() {
        StringWriter writer = new StringWriter();
        PrintWriter pw = new PrintWriter(writer);

        Test.trace("Execute " + getPrintableCommandLine() + "...");
        Result reply = new Result(toolProvider.run(pw, pw, args.toArray(
                String[]::new)));
        Test.trace("Done. Exit code: " + reply.exitCode);

        List lines = List.of(writer.toString().split("\\R", -1));

        if (saveOutputType == SaveOutputType.FIRST_LINE) {
            reply.output = Stream.of(lines).findFirst().get();
        } else if (saveOutputType == SaveOutputType.FULL) {
            reply.output = Collections.unmodifiableList(lines);
        }
        return reply;
    }

    public String getPrintableCommandLine() {
        final String exec;
        String format = "[%s](%d)";
        if (toolProvider == null && executable == null) {
            exec = "<null>";
        } else if (toolProvider != null) {
            format = "tool provider " + format;
            exec = toolProvider.name();
        } else {
            exec = executable;
        }

        return String.format(format, printCommandLine(exec, args),
                args.size() + 1);
    }

    private static String printCommandLine(String executable, List<String> args) {
        // Want command line printed in a way it can be easily copy/pasted
        // to be executed manally
        Pattern regex = Pattern.compile("\\s");
        return Stream.concat(Stream.of(executable), args.stream()).map(
                v -> (v.isEmpty() || regex.matcher(v).find()) ? "\"" + v + "\"" : v).collect(
                        Collectors.joining(" "));
    }

    private ToolProvider toolProvider;
    private String executable;
    private SaveOutputType saveOutputType;
    private Path directory;

    private static enum SaveOutputType {
        NONE, FULL, FIRST_LINE, DUMP
    };
}