// SPDX-License-Identifier: MPL-2.0
#include "aare/RawFile.hpp"
#include "aare/DetectorGeometry.hpp"
#include "aare/PixelMap.hpp"
#include "aare/algorithm.hpp"
#include "aare/defs.hpp"
#include "aare/logger.hpp"

#include <fmt/format.h>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

namespace aare {

RawFile::RawFile(const std::filesystem::path &fname, const std::string &mode)
    : m_master(fname),
      m_geometry(m_master.geometry(), m_master.pixels_x(), m_master.pixels_y(),
                 m_master.udp_interfaces_per_module(), m_master.quad()) {
    m_mode = mode;

    if (mode == "r") {
        if (m_master.roi()) {
            m_geometry.update_geometry_with_roi(m_master.roi().value());
        }
        open_subfiles();
    } else {
        throw std::runtime_error(LOCATION +
                                 " Unsupported mode. Can only read RawFiles.");
    }
}

Frame RawFile::read_frame() { return get_frame(m_current_frame++); }

Frame RawFile::read_frame(size_t frame_number) {
    seek(frame_number);
    return read_frame();
}

void RawFile::read_into(std::byte *image_buf, size_t n_frames) {
    // TODO: implement this in a more efficient way

    for (size_t i = 0; i < n_frames; i++) {
        this->get_frame_into(m_current_frame++, image_buf);
        image_buf += bytes_per_frame();
    }
}

void RawFile::read_into(std::byte *image_buf) {
    return get_frame_into(m_current_frame++, image_buf);
}

void RawFile::read_into(std::byte *image_buf, DetectorHeader *header) {

    return get_frame_into(m_current_frame++, image_buf, header);
}

void RawFile::read_into(std::byte *image_buf, size_t n_frames,
                        DetectorHeader *header) {
    // return get_frame_into(m_current_frame++, image_buf, header);

    for (size_t i = 0; i < n_frames; i++) {
        this->get_frame_into(m_current_frame++, image_buf, header);
        image_buf += bytes_per_frame();
        if (header)
            header += m_geometry.n_modules_in_roi();
    }
}

size_t RawFile::bytes_per_frame() {
    return m_geometry.pixels_x() * m_geometry.pixels_y() * m_master.bitdepth() /
           bits_per_byte;
}
size_t RawFile::pixels_per_frame() {
    // return m_rows * m_cols;
    return m_geometry.pixels_x() * m_geometry.pixels_y();
}

DetectorType RawFile::detector_type() const { return m_master.detector_type(); }

void RawFile::seek(size_t frame_index) {
    // check if the frame number is greater than the total frames
    // if frame_number == total_frames, then the next read will throw an
    // error
    if (frame_index > total_frames()) {
        throw std::runtime_error(
            fmt::format("frame number {} is greater than total frames {}",
                        frame_index, total_frames()));
    }
    m_current_frame = frame_index;
}

size_t RawFile::tell() { return m_current_frame; }

size_t RawFile::total_frames() const { return m_master.frames_in_file(); }
size_t RawFile::rows() const { return m_geometry.pixels_y(); }
size_t RawFile::cols() const { return m_geometry.pixels_x(); }
size_t RawFile::bitdepth() const { return m_master.bitdepth(); }
xy RawFile::geometry() const {
    return xy{static_cast<uint32_t>(m_geometry.modules_y()),
              static_cast<uint32_t>(m_geometry.modules_x())};
}

size_t RawFile::n_modules() const { return m_geometry.n_modules(); };
size_t RawFile::n_modules_in_roi() const {
    return m_geometry.n_modules_in_roi();
};

void RawFile::open_subfiles() {
    if (m_mode == "r")
        for (size_t i : m_geometry.get_modules_in_roi()) {
            auto pos = m_geometry.get_module_geometries(i);
            m_subfiles.emplace_back(std::make_unique<RawSubFile>(
                m_master.data_fname(i, 0), m_master.detector_type(), pos.height,
                pos.width, m_master.bitdepth(), pos.row_index, pos.col_index));
        }
    else {
        throw std::runtime_error(LOCATION +
                                 "Unsupported mode. Can only read RawFiles.");
    }
}

DetectorHeader RawFile::read_header(const std::filesystem::path &fname) {
    DetectorHeader h{};
    FILE *fp = fopen(fname.string().c_str(), "r");
    if (!fp)
        throw std::runtime_error(
            fmt::format("Could not open: {} for reading", fname.string()));

    size_t const rc = fread(reinterpret_cast<char *>(&h), sizeof(h), 1, fp);
    if (rc != 1)
        throw std::runtime_error(LOCATION + "Could not read header from file");
    if (fclose(fp)) {
        throw std::runtime_error(LOCATION + "Could not close file");
    }

    return h;
}

RawMasterFile RawFile::master() const { return m_master; }

Frame RawFile::get_frame(size_t frame_index) {
    auto f = Frame(m_geometry.pixels_y(), m_geometry.pixels_x(),
                   Dtype::from_bitdepth(m_master.bitdepth()));
    std::byte *frame_buffer = f.data();
    get_frame_into(frame_index, frame_buffer);
    return f;
}

size_t RawFile::bytes_per_pixel() const { return m_master.bitdepth() / 8; }

void RawFile::get_frame_into(size_t frame_index, std::byte *frame_buffer,
                             DetectorHeader *header) {
    LOG(logDEBUG) << "RawFile::get_frame_into(" << frame_index << ")";
    if (frame_index >= total_frames()) {
        throw std::runtime_error(LOCATION + "Frame number out of range");
    }
    std::vector<size_t> frame_numbers(m_geometry.n_modules_in_roi());
    std::vector<size_t> frame_indices(m_geometry.n_modules_in_roi(),
                                      frame_index);

    // sync the frame numbers

    if (m_geometry.n_modules() != 1) { // if we have more than one module
        for (size_t part_idx = 0; part_idx != m_geometry.n_modules_in_roi();
             ++part_idx) {
            frame_numbers[part_idx] =
                m_subfiles[part_idx]->frame_number(frame_index);
        }

        // 1. if frame number vector is the same break
        while (!all_equal(frame_numbers)) {

            // 2. find the index of the minimum frame number,
            auto min_frame_idx = std::distance(
                frame_numbers.begin(),
                std::min_element(frame_numbers.begin(), frame_numbers.end()));

            // 3. increase its index and update its respective frame number
            frame_indices[min_frame_idx]++;

            // 4. if we can't increase its index => throw error
            if (frame_indices[min_frame_idx] >= total_frames()) {
                throw std::runtime_error(LOCATION +
                                         "Frame number out of range");
            }

            frame_numbers[min_frame_idx] =
                m_subfiles[min_frame_idx]->frame_number(
                    frame_indices[min_frame_idx]);
        }
    }

    if (m_master.geometry().col == 1) {
        // get the part from each subfile and copy it to the frame
        for (size_t part_idx = 0; part_idx != m_geometry.n_modules_in_roi();
             ++part_idx) {
            auto corrected_idx = frame_indices[part_idx];

            // This is where we start writing
            auto offset = (m_geometry
                                   .get_module_geometries(
                                       m_geometry.get_modules_in_roi(part_idx))
                                   .origin_y *
                               m_geometry.pixels_x() +
                           m_geometry
                               .get_module_geometries(
                                   m_geometry.get_modules_in_roi(part_idx))
                               .origin_x) *
                          m_master.bitdepth() / 8;

            if (m_geometry
                    .get_module_geometries(
                        m_geometry.get_modules_in_roi(part_idx))
                    .origin_x != 0)
                throw std::runtime_error(
                    LOCATION +
                    " Implementation error. x pos not 0."); // TODO: origin
                                                            // can still
                                                            // change if roi
                                                            // changes
            // TODO! What if the files don't match?
            m_subfiles[part_idx]->seek(corrected_idx);
            m_subfiles[part_idx]->read_into(frame_buffer + offset, header);
            if (header)
                ++header;
        }

    } else {
        // TODO! should we read row by row?

        // create a buffer large enough to hold a full module
        auto bytes_per_part = m_master.pixels_y() * m_master.pixels_x() *
                              m_master.bitdepth() /
                              8; // TODO! replace with image_size_in_bytes

        auto *part_buffer = new std::byte[bytes_per_part];

        // TODO! if we have many submodules we should reorder them on the
        // module level

        for (size_t part_idx = 0; part_idx != m_geometry.n_modules_in_roi();
             ++part_idx) {
            auto pos = m_geometry.get_module_geometries(
                m_geometry.get_modules_in_roi(part_idx));
            auto corrected_idx = frame_indices[part_idx];

            m_subfiles[part_idx]->seek(corrected_idx);
            m_subfiles[part_idx]->read_into(part_buffer, header);
            if (header)
                ++header;

            for (size_t cur_row = 0; cur_row < static_cast<size_t>(pos.height);
                 cur_row++) {

                auto irow = (pos.origin_y + cur_row);
                auto icol = pos.origin_x;
                auto dest = (irow * this->m_geometry.pixels_x() + icol);
                dest = dest * m_master.bitdepth() / 8;
                memcpy(frame_buffer + dest,
                       part_buffer +
                           cur_row * pos.width * m_master.bitdepth() / 8,
                       pos.width * m_master.bitdepth() / 8);
            }
        }
        delete[] part_buffer;
    }
}

std::vector<Frame> RawFile::read_n(size_t n_frames) {
    // TODO: implement this in a more efficient way
    std::vector<Frame> frames;
    for (size_t i = 0; i < n_frames; i++) {
        frames.push_back(this->get_frame(m_current_frame));
        m_current_frame++;
    }
    return frames;
}

size_t RawFile::frame_number(size_t frame_index) {
    if (frame_index >= m_master.frames_in_file()) {
        throw std::runtime_error(LOCATION + " Frame number out of range");
    }
    return m_subfiles[0]->frame_number(frame_index);
}

} // namespace aare
