// SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#ifndef JFJOCH_JFJOCHREADERIMAGE_H
#define JFJOCH_JFJOCHREADERIMAGE_H

#include <vector>
#include <unordered_set>
#include <map>
#include <mutex>
#include <optional>

#include "../common/TopPixels.h"
#include "JFJochReaderDataset.h"
#include "../common/CrystalLattice.h"
#include "../common/Histogram.h"

constexpr static int32_t GAP_PXL_VALUE = INT32_MIN + 1;
constexpr static int32_t ERROR_PXL_VALUE = INT32_MIN;
constexpr static int32_t SATURATED_PXL_VALUE = INT32_MAX;

class JFJochReaderImage {
    std::shared_ptr<const JFJochReaderDataset> dataset;

    std::vector<int32_t> image; // Image in the reader must be 32-bit signed, uncompressed
    DataMessage message;

    std::unordered_set<int64_t> saturated_pixel;
    std::unordered_set<int64_t> error_pixel;
    std::vector<std::pair<int32_t, int32_t>> valid_pixel;

    // Fast stats without storing/sorting all valid pixels
    int32_t valid_min = 0;
    int32_t valid_max = 0;
    size_t valid_count = 0;
    bool has_valid = false;

    // For overlay: track top pixels with a tiny O(K) structure; export to vector for UI
    TopPixels top_pixels_acc{20};
    std::vector<std::pair<int32_t, int32_t>> top_pixels;

    // This histogram operates in square root of count from 0 to 10^20
    Histogram count_histogram{100000};

    constexpr static float auto_foreground_range = 99.0f;
    int32_t auto_foreground;
    void CalcAutoContrast();

    template <class T>
    void ProcessInputImage(const void* image, size_t npixel, int64_t sat_value, int64_t special_value);
    void ProcessInputImage(const CompressedImage& image);
public:
    JFJochReaderImage(const DataMessage &msg, const std::shared_ptr<const JFJochReaderDataset> &dataset);
    JFJochReaderImage(const JFJochReaderImage &other);

    const DataMessage &ImageData() const;
    DataMessage &ImageData();

    const std::vector<int32_t> &Image() const;
    const std::unordered_set<int64_t> &SaturatedPixels() const;
    const std::unordered_set<int64_t> &ErrorPixels() const;
    const JFJochReaderDataset &Dataset() const;

    std::optional<std::pair<int32_t, int32_t>> ValidMinMax() const;
    const std::vector<std::pair<int32_t, int32_t>> &GetTopPixels() const;

    void AddImage(const JFJochReaderImage& other);
    std::vector<float> GetAzInt1D() const;
    std::vector<float> GetAzInt1D_BinToQ() const;
    std::shared_ptr<JFJochReaderDataset> CreateMutableDataset();

    int32_t GetAutoContrastValue() const;

    std::vector<float> GetHistogram() const;
};

#endif //JFJOCH_JFJOCHREADERIMAGE_H