/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
#include "FileWatcherUnitTests.h"
#include "native/FileWatcher/FileWatcher.h"
#include "native/utilities/PlatformConfiguration.h"
#include "native/AssetManager/assetProcessorManager.h"
#include "native/assetprocessor.h"
#include <AzCore/Debug/Trace.h>
#include <QTemporaryDir>
#include <QCoreApplication>
#include <QDebug>
#include <QThread>
#include <QFile>
#include <QSet>
#include <QDir>
#include <QString>

using namespace AssetProcessor;

void FileWatcherUnitTestRunner::StartTest()
{
    // QTemporaryDir returns a path that may have symbolic links in it. for macOS
    // this fails because the file events use paths with no symbolic links. Use
    // QDir's canonicalPath to remove the symbolic links.
    QTemporaryDir tempDir;
    QDir dir(tempDir.path());
    QString tempPath = dir.canonicalPath();

    FileWatcher fileWatcher;

    FolderWatchCallbackEx folderWatch(tempPath, "", true);

    fileWatcher.AddFolderWatch(&folderWatch);
    fileWatcher.StartWatching();

    { // test a single file create/write
        bool foundFile = false;
        auto connection = QObject::connect(&folderWatch, &FolderWatchCallbackEx::fileAdded, this, [&](QString filename)
        {
            AZ_TracePrintf(AssetProcessor::DebugChannel, "Single file test Found asset: %s.\n", filename.toUtf8().data());
            foundFile = true;
        });

        // give the file watcher thread a moment to get started
        QThread::sleep(1);

        QFile testTif(tempPath + "/test.tif");
        bool open = testTif.open(QFile::WriteOnly);

        UNIT_TEST_EXPECT_TRUE(open);

        testTif.write("0");
        testTif.close();


        // Wait for file change to be found, timeout, and be delivered
        unsigned int tries = 0;
        while (!foundFile && tries++ < 100)
        {
            QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
            QThread::msleep(10);
        }

        UNIT_TEST_EXPECT_TRUE(foundFile);
        QObject::disconnect(connection);
    }

    { // test a whole bunch of files created/written
      // send enough files such that main thread is likely to be blocked:
        const unsigned long maxFiles = 10000;
        QSet<QString> outstandingFiles;

        auto connection = QObject::connect(&folderWatch, &FolderWatchCallbackEx::fileAdded, this, [&](QString filename)
        {
            outstandingFiles.remove(filename);
        });
        AZ_TracePrintf(AssetProcessor::DebugChannel, "Performing multi-file test...\n");

        // give the file watcher thread a moment to get started
        QThread::sleep(1);

        for (unsigned long fileIndex = 0; fileIndex < maxFiles; ++fileIndex)
        {
            if (fileIndex % 1000 == 0)
            {
                AZ_TracePrintf(AssetProcessor::DebugChannel, "Performing multi-file test... creating file  %d / %d\n", fileIndex, maxFiles);
            }
            QString filename = QString(tempPath + "/test%1.tif").arg(fileIndex);
            filename = QDir::toNativeSeparators(filename);
            outstandingFiles.insert(filename);
            QFile testTif(filename);
            bool open = testTif.open(QFile::WriteOnly);

            UNIT_TEST_EXPECT_TRUE(open);

            testTif.write("0");
            testTif.close();
        }

        // Wait for file change to be found, timeout, and be delivered
        unsigned int tries = 0;
        while (outstandingFiles.count() > 0 && tries++ < 50) // 5 secs is more than enough for all remaining deliveries.
        {
            QCoreApplication::processEvents(QEventLoop::AllEvents);
            QThread::msleep(100);
            AZ_TracePrintf(AssetProcessor::DebugChannel, "Waiting for remaining notifications: %d \n", outstandingFiles.count());
        }

        if (outstandingFiles.count() > 0)
        {
            AZ_TracePrintf(AssetProcessor::DebugChannel, "Timed out waiting for file changes: %d / %d  missed\n", outstandingFiles.count(), maxFiles);
            for (const QString& pending : outstandingFiles)
            {
                AZ_TracePrintf(AssetProcessor::DebugChannel, "Missed file: %s", pending.toUtf8().data());
            }
            Q_EMIT UnitTestFailed("Missed files waiting for file changes");
            return;
        }

        QObject::disconnect(connection);
    }

    AZ_TracePrintf(AssetProcessor::DebugChannel, "Deletion test ... \n");

    { // test deletion
        bool foundFile = false;
        auto connection = QObject::connect(&folderWatch, &FolderWatchCallbackEx::fileRemoved, this, [&](QString filename)
        {
            AZ_TracePrintf(AssetProcessor::DebugChannel, "Deleted asset: %s...\n", filename.toUtf8().data());
            foundFile = true;
        });

        // give the file watcher thread a moment to get started
        QThread::sleep(1);

        QString filename(tempPath + "/test.tif");
        bool removed = QFile::remove(filename);

        UNIT_TEST_EXPECT_TRUE(removed);

        // Wait for file change to be found, timeout, and be delivered
        unsigned int tries = 0;
        while (!foundFile && tries++ < 100)
        {
            QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
            QThread::msleep(10);
            AZ_TracePrintf(AssetProcessor::DebugChannel, "Deletion test ... waiting for deletion notification \n");
        }

        UNIT_TEST_EXPECT_TRUE(foundFile);

        QObject::disconnect(connection);
    }

    AZ_TracePrintf(AssetProcessor::DebugChannel, "rename/move test ...\n");

    {
        bool fileAddCalled = false;
        QString fileAddName;
        auto connectionAdd = QObject::connect(&folderWatch, &FolderWatchCallbackEx::fileAdded, this, [&](QString filename)
        {
            fileAddCalled = true;
            fileAddName = filename;
        });

        bool fileRemoveCalled = false;
        QString fileRemoveName;
        auto connectionRemove = QObject::connect(&folderWatch, &FolderWatchCallbackEx::fileRemoved, this, [&](QString filename)
        {
            fileRemoveCalled = true;
            fileRemoveName = filename;
        });

        QStringList fileModifiedNames;
        bool fileModifiedCalled = false;
        auto connectionModified = QObject::connect(&folderWatch, &FolderWatchCallbackEx::fileModified, this, [&](QString filename)
        {
            fileModifiedCalled = true;
            fileModifiedNames.append(filename);
        });

        // give the file watcher thread a moment to get started
        QThread::sleep(1);

        QDir tempDirPath(tempPath);
        tempDirPath.mkpath("dir1");
        tempDirPath.mkpath("dir2");
        tempDirPath.mkpath("dir3");

        QString originalName = tempDirPath.absoluteFilePath("dir1/test.tif");
        QString newName1 = tempDirPath.absoluteFilePath("dir1/test2.tif"); // change name only
        QString newName2 = tempDirPath.absoluteFilePath("dir2/test2.tif"); // change dir only
        QString newName3 = tempDirPath.absoluteFilePath("dir3/test3.tif"); // change name and dir.


        UNIT_TEST_EXPECT_TRUE(UnitTestUtils::CreateDummyFile(originalName));

        int tries = 0;
        while (!(fileAddCalled && fileRemoveCalled && fileModifiedCalled) && tries++ < 100)
        {
            QThread::msleep(10);
            QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
        }


        UNIT_TEST_EXPECT_TRUE(fileAddCalled);
        UNIT_TEST_EXPECT_FALSE(fileRemoveCalled);
        fileAddCalled = false;
        fileRemoveCalled = false;
        fileModifiedCalled = false;

        // okay, now rename it:
        UNIT_TEST_EXPECT_TRUE(QFile::rename(originalName, newName1));

        tries = 0;
        while (!(fileAddCalled && fileRemoveCalled && fileModifiedCalled) && tries++ < 100)
        {
            QThread::msleep(10);
            QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
        }

        // make sure both callbacks fired and that
        // the original was "removed" and the new was "added"
        UNIT_TEST_EXPECT_TRUE(fileAddCalled);
        UNIT_TEST_EXPECT_TRUE(fileRemoveCalled);

        UNIT_TEST_EXPECT_TRUE(fileModifiedCalled); // modified should be called on the folder that the file lives in

        UNIT_TEST_EXPECT_TRUE(QDir::toNativeSeparators(fileRemoveName).toLower() == QDir::toNativeSeparators(originalName).toLower());
        UNIT_TEST_EXPECT_TRUE(QDir::toNativeSeparators(fileAddName).toLower() == QDir::toNativeSeparators(newName1).toLower());

        fileAddCalled = false;
        fileRemoveCalled = false;
        fileModifiedCalled = false;

        // okay, now rename it to the second folder.
        UNIT_TEST_EXPECT_TRUE(QFile::rename(newName1, newName2));

        tries = 0;
        while (!(fileAddCalled && fileRemoveCalled && fileModifiedCalled) && tries++ < 100)
        {
            QThread::msleep(10);
            QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
        }

        // make sure both callbacks fired and that
        // the new1 was "removed" and the new2 was "added"
        UNIT_TEST_EXPECT_TRUE(fileAddCalled);
        UNIT_TEST_EXPECT_TRUE(fileRemoveCalled);
        UNIT_TEST_EXPECT_TRUE(fileModifiedCalled); // modified should be called on the folder that the file lives in
        UNIT_TEST_EXPECT_TRUE(QDir::toNativeSeparators(fileRemoveName).toLower() == QDir::toNativeSeparators(newName1).toLower());
        UNIT_TEST_EXPECT_TRUE(QDir::toNativeSeparators(fileAddName).toLower() == QDir::toNativeSeparators(newName2).toLower());

        // okay, now rename it to the 3rd folder.
        UNIT_TEST_EXPECT_TRUE(QFile::rename(newName2, newName3));

        fileAddCalled = false;
        fileRemoveCalled = false;
        fileModifiedCalled = false;

        tries = 0;
        while (!(fileAddCalled && fileRemoveCalled && fileModifiedCalled) && tries++ < 100)
        {
            QThread::msleep(10);
            QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
        }
        // make sure both callbacks fired and that
        // the new1 was "removed" and the new2 was "added"
        UNIT_TEST_EXPECT_TRUE(fileAddCalled);
        UNIT_TEST_EXPECT_TRUE(fileRemoveCalled);
        UNIT_TEST_EXPECT_TRUE(fileModifiedCalled); // modified should be called on the folder that the file lives in
        UNIT_TEST_EXPECT_TRUE(QDir::toNativeSeparators(fileRemoveName).toLower() == QDir::toNativeSeparators(newName2).toLower());
        UNIT_TEST_EXPECT_TRUE(QDir::toNativeSeparators(fileAddName).toLower() == QDir::toNativeSeparators(newName3).toLower());

        // final test... make sure that renaming a DIRECTORY works too
        QDir renamer;
        fileAddCalled = false;
        fileRemoveCalled = false;
        fileModifiedCalled = false;

        UNIT_TEST_EXPECT_TRUE(renamer.rename(tempDirPath.absoluteFilePath("dir3"), tempDirPath.absoluteFilePath("dir4")));

        tries = 0;
        while (!(fileAddCalled && fileRemoveCalled && fileModifiedCalled) && tries++ < 100)
        {
            QThread::msleep(10);
            QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
        }

        UNIT_TEST_EXPECT_TRUE(fileAddCalled);
        UNIT_TEST_EXPECT_TRUE(fileRemoveCalled);

        // note that when you rename a directory ONLY, its os-specific as to whether you get a modify callback.  Windows does not
        // but we don't specify or require or deny it in our API.

        UNIT_TEST_EXPECT_TRUE(QDir::toNativeSeparators(fileRemoveName).toLower() == QDir::toNativeSeparators(tempDirPath.absoluteFilePath("dir3")).toLower());
        UNIT_TEST_EXPECT_TRUE(QDir::toNativeSeparators(fileAddName).toLower() == QDir::toNativeSeparators(tempDirPath.absoluteFilePath("dir4")).toLower());


        QObject::disconnect(connectionRemove);
        QObject::disconnect(connectionAdd);
        QObject::disconnect(connectionModified);
    }


    Q_EMIT UnitTestPassed();
}

REGISTER_UNIT_TEST(FileWatcherUnitTestRunner)