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 * OpenSpace                                                                             *
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 * Copyright (c) 2014-2020                                                               *
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#include <modules/gaia/tasks/readfitstask.h>

#include <modules/gaia/tasks/readfilejob.h>
#include <openspace/documentation/documentation.h>
#include <openspace/documentation/verifier.h>

#include <ghoul/misc/dictionary.h>
#include <ghoul/filesystem/filesystem.h>
#include <ghoul/filesystem/directory.h>
#include <ghoul/logging/logmanager.h>
#include <ghoul/fmt.h>

#include <fstream>
#include <set>

namespace {
    constexpr const char* KeyInFileOrFolderPath = "InFileOrFolderPath";
    constexpr const char* KeyOutFileOrFolderPath = "OutFileOrFolderPath";
    constexpr const char* KeySingleFileProcess = "SingleFileProcess";
    constexpr const char* KeyThreadsToUse = "ThreadsToUse";
    constexpr const char* KeyFirstRow = "FirstRow";
    constexpr const char* KeyLastRow = "LastRow";
    constexpr const char* KeyFilterColumnNames = "FilterColumnNames";

    constexpr const char* _loggerCat = "ReadFitsTask";
} // namespace

namespace openspace {

ReadFitsTask::ReadFitsTask(const ghoul::Dictionary& dictionary) {
    openspace::documentation::testSpecificationAndThrow(
        documentation(),
        dictionary,
        "ReadFitsTask"
    );

    _inFileOrFolderPath = absPath(dictionary.value<std::string>(KeyInFileOrFolderPath));
    _outFileOrFolderPath = absPath(dictionary.value<std::string>(KeyOutFileOrFolderPath));

    if (dictionary.hasKey(KeySingleFileProcess)) {
        _singleFileProcess = dictionary.value<bool>(KeySingleFileProcess);
    }

    if (dictionary.hasKey(KeyThreadsToUse)) {
        _threadsToUse = static_cast<size_t>(dictionary.value<double>(KeyThreadsToUse));
        if (_threadsToUse < 1) {
            LINFO(fmt::format(
                "User defined ThreadsToUse was: {}. Will be set to 1", _threadsToUse
            ));
            _threadsToUse = 1;
        }
    }

    if (dictionary.hasKey(KeyFirstRow)) {
        _firstRow = static_cast<int>(dictionary.value<double>(KeyFirstRow));
    }

    if (dictionary.hasKey(KeyLastRow)) {
        _lastRow = static_cast<int>(dictionary.value<double>(KeyLastRow));
    }


    if (dictionary.hasKey(KeyFilterColumnNames)) {
        ghoul::Dictionary d = dictionary.value<ghoul::Dictionary>(KeyFilterColumnNames);

        // Ugly fix for ASCII sorting when there are more columns read than 10.
        std::set<int> intKeys;
        for (const std::string& key : d.keys()) {
            intKeys.insert(std::stoi(key));
        }

        for (int key : intKeys) {
            _filterColumnNames.push_back(d.value<std::string>(std::to_string(key)));
        }
    }
}

std::string ReadFitsTask::description() {
    return fmt::format(
        "Read the specified fits file (or all fits files in specified folder): {}\n and "
        "write raw star data into: {}\nAll columns required for default rendering and "
        "filtering parameters will always be read but user can define additional filter "
        "columns to read.", _inFileOrFolderPath, _outFileOrFolderPath
    );
}

void ReadFitsTask::perform(const Task::ProgressCallback& onProgress) {
    onProgress(0.f);

    if (_singleFileProcess) {
        readSingleFitsFile(onProgress);
    }
    else {
        readAllFitsFilesFromFolder(onProgress);
    }

    onProgress(1.f);
}

void ReadFitsTask::readSingleFitsFile(const Task::ProgressCallback& progressCallback) {
    int32_t nValuesPerStar = 0;

    FitsFileReader fileReader(false);
    std::vector<float> fullData = fileReader.readFitsFile(
        _inFileOrFolderPath,
        nValuesPerStar,
        _firstRow,
        _lastRow,
        _filterColumnNames
    );

    progressCallback(0.8f);

    std::ofstream outFileStream(_outFileOrFolderPath, std::ofstream::binary);
    if (outFileStream.good()) {
        int32_t nValues = static_cast<int32_t>(fullData.size());
        LINFO(fmt::format("Writing {} values to file {}", nValues, _outFileOrFolderPath));
        LINFO("Number of values per star: " + std::to_string(nValuesPerStar));

        if (nValues == 0) {
            LERROR("Error writing file - No values were read from file.");
        }
        outFileStream.write(
            reinterpret_cast<const char*>(&nValues),
            sizeof(int32_t)
        );
        outFileStream.write(
            reinterpret_cast<const char*>(&nValuesPerStar),
            sizeof(int32_t)
        );

        size_t nBytes = nValues * sizeof(fullData[0]);
        outFileStream.write(reinterpret_cast<const char*>(fullData.data()), nBytes);

        outFileStream.close();
    }
    else {
        LERROR(fmt::format(
            "Error opening file: {} as output data file.", _outFileOrFolderPath
        ));
    }
}

void ReadFitsTask::readAllFitsFilesFromFolder(const Task::ProgressCallback&) {
    std::vector<std::vector<float>> octants(8);
    std::vector<bool> isFirstWrite(8, true);
    size_t finishedJobs = 0;
    int totalStars = 0;

    _firstRow = std::max(_firstRow, 1);

    // Create Threadpool and JobManager.
    LINFO("Threads in pool: " + std::to_string(_threadsToUse));
    ThreadPool threadPool(_threadsToUse);
    ConcurrentJobManager<std::vector<std::vector<float>>> jobManager(threadPool);

    // Get all files in specified folder.
    ghoul::filesystem::Directory currentDir(_inFileOrFolderPath);
    std::vector<std::string> allInputFiles = currentDir.readFiles();
    size_t nInputFiles = allInputFiles.size();
    LINFO("Files to read: " + std::to_string(nInputFiles));

    // Define what columns to read.
    _allColumnNames.clear();
    // Read in the order of table in file.
    std::vector<std::string> defaultColumnNames = {
        "ra",
        "ra_error",
        "dec",
        "dec_error",
        "parallax",
        "parallax_error",
        "pmra",
        "pmra_error",
        "pmdec",
        "pmdec_error",
        "phot_g_mean_mag",
        "phot_bp_mean_mag",
        "phot_rp_mean_mag",
        "bp_rp",
        "bp_g",
        "g_rp",
        "radial_velocity",
        "radial_velocity_error",
    };
    _allColumnNames.insert(
        _allColumnNames.end(),
        defaultColumnNames.begin(),
        defaultColumnNames.end()
    );
    // Append additional filter parameters to default rendering parameters.
    _allColumnNames.insert(
        _allColumnNames.end(),
        _filterColumnNames.begin(),
        _filterColumnNames.end()
    );

    std::string allNames = "Columns to read: \n";
    for (const std::string& colName : _allColumnNames) {
        allNames += colName + "\n";
    }
    LINFO(allNames);

    // Declare how many values to save for each star.
    int32_t nValuesPerStar = 24;
    size_t nDefaultColumns = defaultColumnNames.size();
    auto fitsFileReader = std::make_shared<FitsFileReader>(false);

    // Divide all files into ReadFilejobs and then delegate them onto several threads!
    while (!allInputFiles.empty()) {
        std::string fileToRead = allInputFiles.back();
        allInputFiles.erase(allInputFiles.end() - 1);

        // Add reading of file to jobmanager, which will distribute it to our threadpool.
        auto readFileJob = std::make_shared<gaia::ReadFileJob>(
            fileToRead,
            _allColumnNames,
            _firstRow,
            _lastRow,
            nDefaultColumns,
            nValuesPerStar,
            fitsFileReader
        );
        jobManager.enqueueJob(readFileJob);
    }

    LINFO("All files added to queue!");

    // Check for finished jobs.
    while (finishedJobs < nInputFiles) {
        if (jobManager.numFinishedJobs() > 0) {
            std::vector<std::vector<float>> newOctant =
                jobManager.popFinishedJob()->product();

            finishedJobs++;

            for (int i = 0; i < 8; ++i) {
                // Add read values to global octant and check if it's time to write!
                octants[i].insert(
                    octants[i].end(),
                    newOctant[i].begin(),
                    newOctant[i].end()
                );
                if ((octants[i].size() > MAX_SIZE_BEFORE_WRITE) ||
                    (finishedJobs == nInputFiles))
                {
                    // Write to file!
                    totalStars += writeOctantToFile(
                        octants[i],
                        i,
                        isFirstWrite,
                        nValuesPerStar
                    );

                    octants[i].clear();
                    octants[i].shrink_to_fit();
                }
            }
        }
    }
    LINFO(fmt::format("A total of {} stars were written to binary files.", totalStars));
}

int ReadFitsTask::writeOctantToFile(const std::vector<float>& octantData, int index,
                                    std::vector<bool>& isFirstWrite, int nValuesPerStar)
{
    std::string outPath = fmt::format("{}octant_{}.bin", _outFileOrFolderPath, index);
    std::ofstream fileStream(outPath, std::ofstream::binary | std::ofstream::app);
    if (fileStream.good()) {
        int32_t nValues = static_cast<int32_t>(octantData.size());
        LINFO("Write " + std::to_string(nValues) + " values to " + outPath);

        if (nValues == 0) {
            LERROR("Error writing file - No values were read from file.");
        }
        // If this is the first write then write number of values per star!
        if (isFirstWrite[index]) {
            LINFO("First write for Octant_" + std::to_string(index));
            fileStream.write(
                reinterpret_cast<const char*>(&nValuesPerStar),
                sizeof(int32_t)
            );
            isFirstWrite[index] = false;
        }

        size_t nBytes = nValues * sizeof(octantData[0]);
        fileStream.write(reinterpret_cast<const char*>(octantData.data()), nBytes);

        fileStream.close();

        // Return number of stars written.
        return nValues / nValuesPerStar;
    }
    else {
        LERROR(fmt::format("Error opening file: {} as output data file.", outPath));
        return 0;
    }
}

documentation::Documentation ReadFitsTask::Documentation() {
    using namespace documentation;
    return {
        "ReadFitsFile",
        "gaiamission_fitsfiletorawdata",
        {
            {
                "Type",
                new StringEqualVerifier("ReadFitsTask"),
                Optional::No
            },
            {
                KeyInFileOrFolderPath,
                new StringVerifier,
                Optional::No,
                "If SingleFileProcess is set to true then this specifies the path to a "
                "single FITS file that will be read. Otherwise it specifies the path to "
                "a folder with multiple FITS files that are to be read.",
            },
            {
                KeyOutFileOrFolderPath,
                new StringVerifier,
                Optional::No,
                "If SingleFileProcess is set to true then this specifies the name "
                "(including entire path) to the output file. Otherwise it specifies the "
                "path to the output folder which to export binary star data to.",
            },
            {
                KeySingleFileProcess,
                new BoolVerifier,
                Optional::Yes,
                "If true then task will read from a single FITS file and output a single "
                "binary file. If false then task will read all files in specified folder "
                "and output multiple files sorted by location."
            },
            {
                KeyThreadsToUse,
                new IntVerifier,
                Optional::Yes,
                "Defines how many threads to use when reading from multiple files."
            },
            {
                KeyFirstRow,
                new IntVerifier,
                Optional::Yes,
                "Defines the first row that will be read from the specified FITS "
                "file(s). If not defined then reading will start at first row.",
            },
            {
                KeyLastRow,
                new IntVerifier,
                Optional::Yes,
                "Defines the last row that will be read from the specified FITS file(s). "
                "If not defined (or less than FirstRow) then full file(s) will be read.",
            },
            {
                KeyFilterColumnNames,
                new StringListVerifier,
                Optional::Yes,
                "A list of strings with the names of all the additional columns that are "
                "to be read from the specified FITS file(s). These columns can be used "
                "for filtering while constructing Octree later.",
            },

        }
    };
}

} // namespace openspace