context.h

#pragma once

#include "huffman.h"
#include "quantization.h"
#include "dct.h"
#include "mcu.h"
#include "octet.h"
#include "block.h"

#include <cstddef>
#include <optional>
#include <unordered_map>

namespace jpeg::decoder {

enum class EEncodingType : Octet {
    Baseline = 0,
    Progressive = 1,
    Unknown = 2,
};

struct ChannelConfig {
    Octet id = 0;
    Octet horisontal_sampling = 0;
    Octet vertical_sampling = 0;
    Octet quantization_table = 0;
};

struct Context {
    size_t num_sections = 0;
    std::optional<size_t> start_section = std::nullopt;
    std::optional<size_t> end_section = std::nullopt;
    std::string comment;

    EEncodingType type = EEncodingType::Unknown;
    Vec2<size_t> size;
    Vec2<size_t> extended_size;
    std::unordered_map<Octet, ChannelConfig> channels_;
    mcu::McuConfig mcu_;

    std::array<std::optional<quantization::QuantizationTable>, 4> quantization_tables_;
    std::array<std::array<std::optional<huffman::HuffmanTable>, 4>, 2> huffman_tables_;

    std::unordered_map<Octet, std::vector<block::Block>> coefficients_;

public:
    huffman::HuffmanTable& GetHuffmanTable(dct::CoefficientType clazz, size_t id);
    huffman::HuffmanTable& GetHuffmanTable(PackedTuple<4, 4> spec);
    quantization::QuantizationTable& GetQuantizationTable(size_t id);
};

}  // namespace jpeg::decoder