/*
 * 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.lang.reflect.Array;
import java.lang.reflect.Method;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.*;
import java.util.function.Predicate;
import java.util.function.Supplier;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import jdk.jpackage.test.Functional.ThrowingConsumer;
import jdk.jpackage.test.Functional.ThrowingFunction;
import jdk.jpackage.test.Functional.ThrowingRunnable;

final class TestInstance implements ThrowingRunnable {

    static class TestDesc {
        private TestDesc() {
        }

        String testFullName() {
            StringBuilder sb = new StringBuilder();
            sb.append(clazz.getSimpleName());
            if (instanceArgs != null) {
                sb.append('(').append(instanceArgs).append(')');
            }
            if (functionName != null) {
                sb.append('.');
                sb.append(functionName);
                if (functionArgs != null) {
                    sb.append('(').append(functionArgs).append(')');
                }
            }
            return sb.toString();
        }

        static Builder createBuilder() {
            return new Builder();
        }

        static final class Builder implements Supplier<TestDesc> {
            private Builder() {
            }

            Builder method(Method v) {
                method = v;
                return this;
            }

            Builder ctorArgs(Object... v) {
                ctorArgs = ofNullable(v);
                return this;
            }

            Builder methodArgs(Object... v) {
                methodArgs = ofNullable(v);
                return this;
            }

            @Override
            public TestDesc get() {
                TestDesc desc = new TestDesc();
                if (method == null) {
                    desc.clazz = enclosingMainMethodClass();
                } else {
                    desc.clazz = method.getDeclaringClass();
                    desc.functionName = method.getName();
                    desc.functionArgs = formatArgs(methodArgs);
                    desc.instanceArgs = formatArgs(ctorArgs);
                }
                return desc;
            }

            private static String formatArgs(List<Object> values) {
                if (values == null) {
                    return null;
                }
                return values.stream().map(v -> {
                    if (v != null && v.getClass().isArray()) {
                        return String.format("%s(length=%d)",
                                Arrays.deepToString((Object[]) v),
                                Array.getLength(v));
                    }
                    return String.format("%s", v);
                }).collect(Collectors.joining(", "));
            }

            private static List<Object> ofNullable(Object... values) {
                List<Object> result = new ArrayList();
                for (var v: values) {
                    result.add(v);
                }
                return result;
            }

            private List<Object> ctorArgs;
            private List<Object> methodArgs;
            private Method method;
        }

        static TestDesc create(Method m, Object... args) {
            TestDesc desc = new TestDesc();
            desc.clazz = m.getDeclaringClass();
            desc.functionName = m.getName();
            if (args.length != 0) {
                desc.functionArgs = Stream.of(args).map(v -> {
                    if (v.getClass().isArray()) {
                        return String.format("%s(length=%d)",
                                Arrays.deepToString((Object[]) v),
                                Array.getLength(v));
                    }
                    return String.format("%s", v);
                }).collect(Collectors.joining(", "));
            }
            return desc;
        }

        private Class clazz;
        private String functionName;
        private String functionArgs;
        private String instanceArgs;
    }

    TestInstance(ThrowingRunnable testBody) {
        assertCount = 0;
        this.testConstructor = (unused) -> null;
        this.testBody = (unused) -> testBody.run();
        this.beforeActions = Collections.emptyList();
        this.afterActions = Collections.emptyList();
        this.testDesc = TestDesc.createBuilder().get();
        this.dryRun = false;
        this.workDir = createWorkDirName(testDesc);
    }

    TestInstance(MethodCall testBody, List<ThrowingConsumer> beforeActions,
            List<ThrowingConsumer> afterActions, boolean dryRun) {
        assertCount = 0;
        this.testConstructor = v -> ((MethodCall)v).newInstance();
        this.testBody = testBody;
        this.beforeActions = beforeActions;
        this.afterActions = afterActions;
        this.testDesc = testBody.createDescription();
        this.dryRun = dryRun;
        this.workDir = createWorkDirName(testDesc);
    }

    void notifyAssert() {
        assertCount++;
    }

    void notifySkipped(RuntimeException ex) {
        skippedTestException = ex;
    }

    boolean passed() {
        return status == Status.Passed;
    }

    boolean skipped() {
        return status == Status.Skipped;
    }

    boolean failed() {
        return status == Status.Failed;
    }

    String functionName() {
        return testDesc.functionName;
    }

    String baseName() {
        return testDesc.clazz.getSimpleName();
    }

    String fullName() {
        return testDesc.testFullName();
    }

    void rethrowIfSkipped() {
        if (skippedTestException != null) {
            throw skippedTestException;
        }
    }

    Path workDir() {
        return workDir;
    }

    @Override
    public void run() throws Throwable {
        final String fullName = fullName();
        TKit.log(String.format("[ RUN      ] %s", fullName));
        try {
            Object testInstance = testConstructor.apply(testBody);
            beforeActions.forEach(a -> ThrowingConsumer.toConsumer(a).accept(
                    testInstance));
            try {
                if (!dryRun) {
                    Files.createDirectories(workDir);
                    testBody.accept(testInstance);
                }
            } finally {
                afterActions.forEach(a -> TKit.ignoreExceptions(() -> a.accept(
                        testInstance)));
            }
            status = Status.Passed;
        } finally {
            if (skippedTestException != null) {
                status = Status.Skipped;
            } else if (status == null) {
                status = Status.Failed;
            }

            if (!KEEP_WORK_DIR.contains(status)) {
                TKit.deleteDirectoryRecursive(workDir);
            }

            TKit.log(String.format("%s %s; checks=%d", status, fullName,
                    assertCount));
        }
    }

    private static Class enclosingMainMethodClass() {
        StackTraceElement st[] = Thread.currentThread().getStackTrace();
        for (StackTraceElement ste : st) {
            if ("main".equals(ste.getMethodName())) {
                return Functional.ThrowingSupplier.toSupplier(() -> Class.forName(
                        ste.getClassName())).get();
            }
        }
        return null;
    }

    private static boolean isCalledByJavatest() {
        StackTraceElement st[] = Thread.currentThread().getStackTrace();
        for (StackTraceElement ste : st) {
            if (ste.getClassName().startsWith("com.sun.javatest.")) {
                return true;
            }
        }
        return false;
    }

    private static Path createWorkDirName(TestDesc testDesc) {
        Path result = Path.of(".");
        if (!isCalledByJavatest()) {
            result = result.resolve(testDesc.clazz.getSimpleName());
        }

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

        final String testFunctionName = testDesc.functionName;
        if (testFunctionName != null) {
            components.add(testFunctionName);
        }

        final boolean isPrametrized = Stream.of(testDesc.functionArgs,
                testDesc.instanceArgs).anyMatch(Objects::nonNull);
        if (isPrametrized) {
            components.add(String.format("%08x", testDesc.testFullName().hashCode()));
        }

        if (!components.isEmpty()) {
            result = result.resolve(String.join(".", components));
        }

        return result;
    }

    private enum Status {
        Passed("[       OK ]"),
        Failed("[  FAILED  ]"),
        Skipped("[  SKIPPED ]");

        Status(String msg) {
            this.msg = msg;
        }

        @Override
        public String toString() {
            return msg;
        }

        private final String msg;
    }

    private int assertCount;
    private Status status;
    private RuntimeException skippedTestException;
    private final TestDesc testDesc;
    private final ThrowingFunction testConstructor;
    private final ThrowingConsumer testBody;
    private final List<ThrowingConsumer> beforeActions;
    private final List<ThrowingConsumer> afterActions;
    private final boolean dryRun;
    private final Path workDir;

    private final static Set<Status> KEEP_WORK_DIR = Functional.identity(
            () -> {
                final String propertyName = "keep-work-dir";
                Set<String> keepWorkDir = TKit.tokenizeConfigProperty(
                        propertyName);
                if (keepWorkDir == null) {
                    return Set.of(Status.Failed);
                }

                Predicate<Set<String>> isOneOf = options -> {
                    return !Collections.disjoint(keepWorkDir, options);
                };

                Set<Status> result = new HashSet<>();
                if (isOneOf.test(Set.of("pass", "p"))) {
                    result.add(Status.Passed);
                }
                if (isOneOf.test(Set.of("fail", "f"))) {
                    result.add(Status.Failed);
                }

                return Collections.unmodifiableSet(result);
            }).get();

}