// SPDX-FileCopyrightText: 2024 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#pragma once

#include <map>
#include <memory>
#include <optional>
#include <string>
#include <vector>

#include "JFJochReader.h"
#include "JFJochReaderSpots.h"
#include "HDF5ImageSource.h"
#include "HDF5MetadataSource.h"
#include "../writer/HDF5Objects.h"
#include "../image_analysis/IntegrationOutcome.h"

// Composes one shared raw-image source with one or more metadata sources ("snapshots") over the
// same images: the original _master.h5 plus optional reprocessing _process.h5 results. The active
// snapshot supplies the dataset and per-image metadata; the image source always supplies pixels,
// so switching snapshots never reloads image data.
class JFJochHDF5Reader : public JFJochReader {
    HDF5ImageSource image_source_;
    std::map<std::string, std::shared_ptr<HDF5MetadataSource> > snapshots_;
    std::shared_ptr<HDF5MetadataSource> active_metadata_;
    std::string active_snapshot_;
    size_t number_of_images = 0;

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

    HDF5ImageLocator::Location GetImageLocation(int64_t image_number) const;

public:
    ~JFJochHDF5Reader() override = default;

    void ReadFile(const std::string &filename);

    uint64_t GetNumberOfImages() const override;

    void Close() override;

    std::vector<HDF5DataSourceMessage> GetHDF5DataSource(
        uint64_t first_image = 0,
        std::optional<uint64_t> image_count = {}
    ) const;

    std::vector<IntegrationOutcome> ReadReflections(size_t start_image = 0, std::optional<size_t> end_image = {}) const;

    std::vector<SpotToSave> ReadSpots(int64_t image) const override;
    // True if the loaded file stores spot-finding results; false for a plain DECTRIS dataset (no
    // /entry/MX), so callers can find spots instead of reusing absent ones.
    [[nodiscard]] bool HasStoredSpots() const;

    CompressedImage ReadCalibration(std::vector<uint8_t> &tmp, const std::string &name) const;

    std::shared_ptr<JFJochReaderRawImage> GetRawImage(int64_t image_number) override;

    // Metadata snapshots over the same images. The original file is registered as "Original" on
    // ReadFile and is the initial active snapshot; reprocessing results can be added later.
    void RegisterSnapshot(const std::string &name, const std::string &master_path);
    void RemoveSnapshot(const std::string &name);   // "Original" cannot be removed
    void SetActiveSnapshot(const std::string &name);
    std::vector<std::string> SnapshotNames() const;
    std::string ActiveSnapshot() const;

    // All snapshot datasets (name -> dataset), for overlaying every run's plots at once.
    std::vector<std::pair<std::string, std::shared_ptr<const JFJochReaderDataset>>> AllSnapshotDatasets() const;
};