Jungfraujoch/reader/JFJochCBFReader.h

// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#pragma once

#include <string>
#include <vector>

#include "JFJochReader.h"
#include "MiniCBF.h"

// Reads a rotation sweep straight from a directory of PILATUS miniCBF files - the form most
// facilities still archive - with no conversion step and no libcbf.
//
// The sweep's geometry comes from the first file's header; the rotation angle of each image comes
// from its own header, which costs only the bytes up to the binary separator. Images are decoded on
// demand, one per call, so any number of workers can read at once - there is no global lock as there
// is on the HDF5 path, HDF5 not being thread-safe.
//
// A raw CBF carries no analysis results, so this reader has no spots, no reflections and no snapshots;
// the dataset it builds is the geometry, the mask and nothing else, exactly as a plain DECTRIS file
// with no /entry/MX would give.
class JFJochCBFReader : public JFJochReader {
    std::vector<std::string> files_;
    std::shared_ptr<JFJochReaderDataset> dataset_;
    minicbf::Header header0_;

    bool LoadImage_i(std::shared_ptr<JFJochReaderDataset> &dataset,
                     DataMessage &message,
                     std::vector<uint8_t> &buffer,
                     int64_t image_number,
                     bool update_dataset) override;

    // Decodes one image into the caller's byte buffer (RawByteBuffer or std::vector<uint8_t>) and
    // returns the image that points at it. The compressed file is read through scratch, which the
    // caller keeps between frames.
    template <class Buffer>
    CompressedImage DecodeInto(int64_t image_number, Buffer &buffer, std::vector<uint8_t> &scratch) const;

public:
    ~JFJochCBFReader() override = default;

    // True if the path names something this reader can open: a miniCBF file, or a directory holding
    // at least one. Cheap - it reads a few kB at most.
    static bool CanRead(const std::string &path);

    // path is a directory of *.cbf, or one *.cbf inside the sweep to take the whole directory from.
    void ReadFiles(const std::string &path);

    [[nodiscard]] uint64_t GetNumberOfImages() const override;
    void Close() override;


    // Whether the sweep really has an image at this point. A deposited series can be missing frames,
    // and they are kept as gaps so that every image keeps the spindle angle its own header states;
    // ReadRawImage hands such a slot back as "nothing to read".
    [[nodiscard]] bool HasImage(int64_t image_number) const;

    bool ReadRawImage(int64_t image_number, JFJochReaderRawImage &image) override;
    [[nodiscard]] std::vector<SpotToSave> ReadSpots(int64_t image) const override;
};