#ifndef INCLUDED_BOBCAT_STRING_
#define INCLUDED_BOBCAT_STRING_

#include <iostream>
#include <cstring>
#include <string>
#include <vector>
#include <algorithm>

namespace FBB
{

struct String
{
    enum Type
    {
        DQUOTE_UNTERMINATED,    // unterminated d-quoted element
        SQUOTE_UNTERMINATED,    // unterminated s-quoted element
        ESCAPED_END,            // word with plain \ at the end
        SEPARATOR, // separator encountered
        NORMAL, // normal string-element in the original string
        DQUOTE, // string-element originally surrounded by " chars
        SQUOTE, // string-element originally surrounded by ' chars
        END,    // end-of-string immediately encountered
    };

    enum SplitType
    {
        TOK,            // split acts like strtok (like addEmpty == false)
        TOKSEP,         // same, but return separators (like addEmpty == true)
        STR,            // split acts like strstr
        STRSEP,         // same, but return separators
    };

    struct Unescape
    {
        std::string str;
        size_t      length;
    };

    struct SplitPair: public std::pair<std::string, Type>
    {
        SplitPair();                                                    // .ih
        SplitPair(char ch, Type type);                                  // .ih
    };

    private:
        using SplitPairVector =  std::vector<SplitPair>;
        using ConstIter =  std::string::const_iterator;

        static size_t const s_nSplitTypeSize =
                                static_cast<size_t>(STRSEP) + 1;

        enum class CharType
        {
            DQUOTE,
            SQUOTE,
            SEPARATOR,
            ESCAPE,
            CHAR,
            EOS,
            size
        };

        static size_t const s_nCharTypes =
                                    static_cast<size_t>(CharType::size);

        enum State
        {
            START,
            SQSTRING,
            DQSTRING,
        };

        struct FSAData
        {
            State state;
            std::string separators;
            SplitPair entry;
            SplitPairVector *entries;
            ConstIter begin;
            ConstIter end;
        };

        static bool (*s_FSAtransition[][s_nCharTypes])(FSAData &);
        static void (*s_tuneToSplitType[s_nSplitTypeSize])(
                            SplitPairVector *entries);
        static std::string (*s_join[])(SplitPairVector const &, char);

    public:
        static constexpr Type *const noType = 0;

        static char const **argv(std::vector<std::string> const &lines);

        static int casecmp(std::string const &lhs,                      // .f
                           std::string const &rhs);

        static std::string escape(std::string const &str,
                            char const *series = "'\"\\");

        static std::string join(std::vector<std::string> const &words,  // 1
                                char sep);

        static std::string join(SplitPairVector const &entries,         // 2
                                char sep, bool all = true);

        static std::string lc(std::string const &str);


        static SplitPairVector split(std::string const &str,            // 1
                    SplitType stype, char const *separators = " \t");

        static SplitPairVector split(std::string const &str,            // 2
                    char const *separators = " \t",
                    bool addEmpty = false);


        static size_t split(SplitPairVector *entries,                   // 3
                    std::string const &str, SplitType stype,
                    char const *separators = " \t");

        static size_t split(SplitPairVector *entries,                   // 4
                    std::string const &str, char const *separators = " \t",
                    bool addEmpty = false);


        static std::vector<std::string> split(                          // 5
                        Type *type, std::string const &str, SplitType stype,
                    char const *separators = " \t");

        static std::vector<std::string> split(                          // 6
                    Type *type, std::string const &str,
                    char const *separators = " \t",
                    bool addEmpty = false);


        static size_t split(std::vector<std::string> *words,            // 7
                    std::string const &str, SplitType stype,
                    char const *separators = " \t");

        static size_t split(std::vector<std::string> *words,            // 8
                    std::string const &str, char const *separators = " \t",
                    bool addEmpty = false);


        static std::string trim(std::string const &str);
        static std::string uc(std::string const &str);

        static std::string unescape(std::string const &str);
        static Unescape unescape(ConstIter begin,                       // 2
                                 ConstIter const &end);

        static std::string urlDecode(std::string const &str);
        static std::string urlEncode(std::string const &str);

        template <std::unsigned_integral ValueType>
        static std::string to_string(ValueType value,                   // .f
                                     unsigned base = 10);   

    private:
        static void tolower(char &chr);                                 // .ih
        static void toupper(char &chr);                                 // .ih

        static FSAData process(SplitPairVector *entries, SplitType stype,
                               std::string const &str, char const *sep);

        static CharType peek(FSAData &data);
        static bool dqIn(FSAData &data);
        static bool sqIn(FSAData &data);
        static bool sepIn(FSAData &data);
        static bool escIn(FSAData &data);
        static bool chIn(FSAData &data);
        static bool eosIn(FSAData &data);
        static bool qEnd(FSAData &data);
        static bool eosSq(FSAData &data);
        static bool eosDq(FSAData &data);

        static void tok(SplitPairVector *entries);  // tuning members
        static void toksep(SplitPairVector *entries);
        static void str(SplitPairVector *entries);
        static void strsep(SplitPairVector *entries);   // see data.cc

        static std::string joinAll(SplitPairVector const &entries, char sep);
        static std::string joinIgnoreSEPARATOR(SplitPairVector const &entries,
                                               char sep);
};

#include "string.f"

} // FBB

#endif
