#include <list>
#include "utf8.h"
#include <unordered_map>

struct context_occurrence
{
    unsigned int count{ 1 };
    std::unordered_map<utf8::utfchar32_t, unsigned int> counts;

    explicit context_occurrence(utf8::utfchar32_t character);
    void add(utf8::utfchar32_t character);

    std::unordered_map<utf8::utfchar32_t, unsigned int>::iterator begin();
    std::unordered_map<utf8::utfchar32_t, unsigned int>::iterator end();
};

struct context_model
{
    void add(utf8::utfchar32_t character);

    std::unordered_map<std::string, context_occurrence>::iterator begin();
    std::unordered_map<std::string, context_occurrence>::iterator end();

private:
    std::list<utf8::utfchar32_t> current_context;
    std::unordered_map<std::string, context_occurrence> occurrences;
};