#ifndef CORE_ARRAY_STRING_HPP
#define CORE_ARRAY_STRING_HPP

#include "core/math/Math.hpp"
#include "core/utils/Check.hpp"
#include "core/utils/Error.hpp"
#include "core/utils/Meta.hpp"
#include "core/utils/Types.hpp"
#include "core/utils/Utility.hpp"

namespace Core {
    template<typename T>
    constexpr int stringLength(const T* c) {
        const T* i = c + 1;
        while(*(c++) != '\0') {}
        return static_cast<int>(c - i);
    }

    Error readUnicode(c32& u, const char*& s);

    class Char32String;

    class CharString {
    protected:
        i32 length;
        i32 capacity;
        u32 hash;
        char* data;

    public:
        CharString(char* buffer, i32 bufferSize);
        CharString(const CharString&) = delete;
        CharString& operator=(const CharString&) = delete;
        check_return Error copyFrom(const CharString& s);
        bool operator==(const char* s) const;
        bool operator==(const CharString& other) const;
        bool operator!=(const char* s) const;
        bool operator!=(const CharString& other) const;
        char operator[](int index) const;
        int getLength() const;
        int getCapacity() const;
        check_return Error append(char c);
        check_return Error append(signed char c);
        check_return Error append(unsigned char c);
        check_return Error append(wchar_t c);
        check_return Error append(c32 c);
        check_return Error append(const char* s);
        check_return Error append(const c32* s);
        check_return Error append(const signed char* s);
        check_return Error append(const unsigned char* s);
        check_return Error append(bool b);
        check_return Error append(Error e);

        template<typename T>
        check_return Error append(const T& t) {
            if constexpr(requires { t.toString(*this); }) {
                return t.toString(*this);
            } else {
                char buffer[64];
                CORE_RETURN_ERROR(Core::toString(t, buffer, CORE_SIZE(buffer)));
                return append(static_cast<const char*>(buffer));
            }
        }

        check_return Error toString(CharString& s) const;
        check_return Error toString(Char32String& s) const;
        void clear();
        u32 hashCode() const;
        check_return Error print() const;
        check_return Error printLine() const;

        template<typename... Args>
        check_return Error format(CharString& s, Args&&... args) {
            Error e = formatBuffer(s, 0, Core::forward<Args>(args)...);
            if(e == Error::NONE) {
                return copyFrom(s);
            } else if(e == Error::CAPACITY_REACHED) {
                (void)copyFrom(s);
            }
            return e;
        }

        bool startsWidth(const CharString& other, int from = 0) const;
        int search(const CharString& other, int from = 0) const;
        bool contains(const CharString& other, int from = 0) const;
        int search(char u, int from = 0) const;
        bool contains(char u, int from = 0) const;
        check_return Error substring(CharString& s, int from, int to) const;
        check_return Error substring(CharString& s, int from = 0) const;
        check_return Error replace(CharString& s, const CharString& search,
                                   const CharString& replace);
        void replace(char search, char replace);
        operator const char*() const;

    private:
        void addToHash(c32 u);

        template<typename T, typename... Args>
        check_return Error formatBuffer(CharString& s, int index, const T& t,
                                        Args&&... args) {
            while(index < length) {
                char u = data[index++];
                if(u == '#') {
                    if(index >= length ||
                       (index < length && data[index] != '#')) {
                        break;
                    }
                    index++;
                }
                CORE_RETURN_ERROR(s.append(u));
            }
            CORE_RETURN_ERROR(s.append(t));
            return formatBuffer(s, index, Core::forward<Args>(args)...);
        }

        check_return Error formatBuffer(CharString& s, int index);
    };

    class Char32String {
    protected:
        i32 length;
        i32 capacity;
        u32 hash;
        c32* data;

    public:
        Char32String(c32* buffer, i32 bufferSize);
        Char32String(const Char32String&) = delete;
        Char32String& operator=(const Char32String&) = delete;
        Error copyFrom(const Char32String& s);
        bool operator==(const c32* s) const;
        bool operator==(const Char32String& other) const;
        bool operator!=(const c32* s) const;
        bool operator!=(const Char32String& other) const;
        c32 operator[](int index) const;
        int getLength() const;
        int getCapacity() const;
        check_return Error append(char c);
        check_return Error append(signed char c);
        check_return Error append(unsigned char c);
        check_return Error append(wchar_t c);
        check_return Error append(c32 c);
        check_return Error append(const char* s);
        check_return Error append(const c32* s);
        check_return Error append(const signed char* s);
        check_return Error append(const unsigned char* s);
        check_return Error append(bool b);
        check_return Error append(Error e);

        template<typename T>
        check_return Error append(const T& t) {
            if constexpr(requires { t.toString(*this); }) {
                return t.toString(*this);
            } else {
                char buffer[64];
                CORE_RETURN_ERROR(Core::toString(t, buffer, CORE_SIZE(buffer)));
                return append(static_cast<const char*>(buffer));
            }
        }

        check_return Error toString(CharString& s) const;
        check_return Error toString(Char32String& s) const;
        void clear();
        u32 hashCode() const;
        check_return Error print() const;
        check_return Error printLine() const;

        template<typename... Args>
        check_return Error format(Char32String& s, Args&&... args) {
            Error e = formatBuffer(s, 0, Core::forward<Args>(args)...);
            if(e == Error::NONE) {
                return copyFrom(s);
            } else if(e == Error::CAPACITY_REACHED) {
                (void)copyFrom(s);
            }
            return e;
        }

        bool startsWidth(const Char32String& other, int from = 0) const;
        int search(const Char32String& other, int from = 0) const;
        bool contains(const Char32String& other, int from = 0) const;
        int search(c32 u, int from = 0) const;
        bool contains(c32 u, int from = 0) const;
        check_return Error substring(Char32String& s, int from, int to) const;
        check_return Error substring(Char32String& s, int from = 0) const;
        check_return Error replace(Char32String& s, const Char32String& search,
                                   const Char32String& replace);
        void replace(c32 search, c32 replace);
        operator const c32*() const;

    private:
        Error add(c32 c);
        void addToHash(c32 u);

        template<typename T, typename... Args>
        check_return Error formatBuffer(Char32String& s, int index, const T& t,
                                        Args&&... args) {
            while(index < length) {
                c32 u = data[index++];
                if(u == '#') {
                    if(index >= length ||
                       (index < length && data[index] != '#')) {
                        break;
                    }
                    index++;
                }
                CORE_RETURN_ERROR(s.append(u));
            }
            CORE_RETURN_ERROR(s.append(t));
            return formatBuffer(s, index, Core::forward<Args>(args)...);
        }

        check_return Error formatBuffer(Char32String& s, int index);
    };

    template<int N, typename C, typename B>
    class ArrayString final : public B {
        static_assert(N > 0, "size of array string must be positive");
        C data[static_cast<unsigned int>(N)];

    public:
        ArrayString() : B(data, N) {
        }

        ArrayString(const ArrayString& other) : B(data, N) {
            Core::memoryCopy(data, other.data, sizeof(data));
            B::length = other.length;
            B::hash = other.hash;
        }

        ArrayString& operator=(const ArrayString& other) {
            if(this != &other) {
                Core::memoryCopy(data, other.data, sizeof(data));
                B::length = other.length;
                B::hash = other.hash;
            }
            return *this;
        }

        template<typename... Args>
        check_return Error format(Args&&... args) {
            ArrayString s;
            return B::format(s, Core::forward<Args>(args)...);
        }

        check_return Error replace(const B& search, const B& replace) {
            ArrayString s;
            return B::replace(s, search, replace);
        }

        using B::replace;
    };

    template<typename String, typename Iterable>
    check_return Error toString(String& s, const Iterable& i) {
        CORE_RETURN_ERROR(s.append("["));
        auto current = i.begin();
        auto end = i.end();
        while(current != end) {
            CORE_RETURN_ERROR(s.append(*current));
            ++current;
            if(current != end) {
                CORE_RETURN_ERROR(s.append(", "));
            }
        }
        return s.append("]");
    }

    template<int N>
    using String8 = ArrayString<N, char, CharString>;

    template<int N>
    using String32 = ArrayString<N, c32, Char32String>;
}

inline bool operator==(const c32* cs, const Core::Char32String& s) {
    return s == cs;
}

inline bool operator!=(const c32* cs, const Core::Char32String& s) {
    return s != cs;
}

inline bool operator==(const char* cs, const Core::CharString& s) {
    return s == cs;
}

inline bool operator!=(const char* cs, const Core::CharString& s) {
    return s != cs;
}

#endif