#include "core/utils/ArrayString.hpp"

#include <limits.h>
#include <stdlib.h>
#include <uchar.h>

#include "core/data/Array.hpp"
#include "core/math/Math.hpp"
#include "core/utils/Error.hpp"
#include "core/utils/Utility.hpp"

using CharString = Core::CharString;
using Char32String = Core::Char32String;
using Error = Core::Error;
namespace ErrorCode = Core::ErrorCode;

constexpr size_t stringLength(const c32* c) {
    const c32* i = c + 1;
    while(*(c++) != '\0') {}
    return static_cast<size_t>(c - i);
}

static Error readUnicode(c32& u, const char*& s) {
    size_t limit = MB_CUR_MAX;
    size_t n = mbrtoc32(&u, s, limit, nullptr);
    if(n > limit) {
        return ErrorCode::INVALID_CHAR;
    }
    s += n;
    return ErrorCode::NONE;
}

using C32Buffer = Core::Array<char, MB_LEN_MAX + 1>;

static Error convertC32(C32Buffer& buffer, c32 c) {
    size_t n = c32rtomb(buffer.begin(), c, nullptr);
    if(n >= buffer.getLength()) {
        return ErrorCode::INVALID_CHAR;
    }
    buffer[n] = '\0';
    return ErrorCode::NONE;
}

CharString::CharString(char* buffer, size_t bufferSize)
    : length(0), capacity(bufferSize <= 0 ? 0 : bufferSize - 1), data(buffer) {
    data[0] = '\0';
}

Error CharString::copyFrom(const CharString& s) {
    clear();
    return s.toString(*this);
}

bool CharString::operator==(const char* s) const {
    return strcmp(data, s) == 0;
}

bool CharString::operator==(const CharString& other) const {
    return length == other.length && strcmp(data, other.data) == 0;
}

bool CharString::operator!=(const char* s) const {
    return !((*this) == s);
}

bool CharString::operator!=(const CharString& other) const {
    return !((*this) == other);
}

char CharString::operator[](size_t index) const {
    return data[index];
}

size_t CharString::getLength() const {
    return length;
}

size_t CharString::getCapacity() const {
    return capacity;
}

Error CharString::append(char c) {
    if(length >= capacity) {
        return ErrorCode::CAPACITY_REACHED;
    }
    data[length++] = c;
    data[length] = '\0';
    return ErrorCode::NONE;
}

Error CharString::append(signed char c) {
    return append(static_cast<char>(c));
}

Error CharString::append(unsigned char c) {
    return append(static_cast<char>(c));
}

Error CharString::append(wchar_t c) {
    return append(static_cast<c32>(c));
}

Error CharString::append(c32 c) {
    C32Buffer buffer;
    CORE_RETURN_ERROR(convertC32(buffer, c));
    return append(static_cast<const char*>(buffer.begin()));
}

Error CharString::append(const char* s) {
    // stringLength as s could be some part of data
    for(size_t i = strlen(s); i > 0; i--) {
        CORE_RETURN_ERROR(append(*(s++)));
    }
    return ErrorCode::NONE;
}

Error CharString::append(const c32* s) {
    // stringLength as s could be some part of data
    for(size_t i = stringLength(s); i > 0; i--) {
        CORE_RETURN_ERROR(append(*(s++)));
    }
    return ErrorCode::NONE;
}

Error CharString::append(const signed char* s) {
    return append(reinterpret_cast<const char*>(s));
}

Error CharString::append(const unsigned char* s) {
    return append(reinterpret_cast<const char*>(s));
}

Error CharString::append(bool b) {
    return b ? append("true") : append("false");
}

Error CharString::toString(CharString& s) const {
    size_t l = length; // length changes if &s == this
    for(size_t i = 0; i < l; i++) {
        CORE_RETURN_ERROR(s.append(data[i]));
    }
    return ErrorCode::NONE;
}

Error CharString::toString(Char32String& s) const {
    return s.append(static_cast<const char*>(data));
}

void CharString::clear() {
    length = 0;
    data[0] = '\0';
}

void CharString::print() const {
    Core::print(data);
}

void CharString::printLine() const {
    Core::printLine(data);
}

bool CharString::startsWith(const CharString& other, size_t from) const {
    return length >= from + other.getLength() &&
           strncmp(data + from, other.data, other.getLength()) == 0;
}

size_t CharString::search(const CharString& other, size_t from) const {
    char* f = strstr(data + from, other.data);
    return f == nullptr ? SIZE_MAX : static_cast<size_t>(f - data);
}

bool CharString::contains(const CharString& other, size_t from) const {
    return search(other, from) != SIZE_MAX;
}

size_t CharString::search(char u, size_t from) const {
    char* f = strchr(data + from, u);
    return f == nullptr ? SIZE_MAX : static_cast<size_t>(f - data);
}

bool CharString::contains(char u, size_t from) const {
    return search(u, from) != SIZE_MAX;
}

Error CharString::substring(CharString& s, size_t from, size_t to) const {
    s.clear();
    to = Math::min(to + 1, length);
    for(size_t i = from; i < to; i++) {
        CORE_RETURN_ERROR(s.append(data[i]));
    }
    return ErrorCode::NONE;
}

Error CharString::substring(CharString& s, size_t from) const {
    return substring(s, from, length - 1);
}

Error CharString::replace(CharString& s, const CharString& search,
                          const CharString& replace) {
    size_t i = 0;
    while(i < length) {
        if(startsWith(search, i)) {
            CORE_RETURN_ERROR(s.append(replace));
            i += search.getLength();
        } else {
            CORE_RETURN_ERROR(s.append(data[i]));
            i++;
        }
    }
    return copyFrom(s);
}

void CharString::replace(char search, char replace) {
    for(size_t i = 0; i < length; i++) {
        if(data[i] == search) {
            data[i] = replace;
        }
    }
}

CharString::operator const char*() const {
    return data;
}

Char32String::Char32String(c32* buffer, size_t bufferSize)
    : length(0), capacity(bufferSize <= 0 ? 0 : bufferSize - 1), data(buffer) {
    data[0] = '\0';
}

Error Char32String::copyFrom(const Char32String& s) {
    clear();
    return s.toString(*this);
}

bool Char32String::operator==(const c32* s) const {
    const c32* p = data;
    while(*s == *p && *s != '\0') {
        s++;
        p++;
    }
    return *s == *p;
}

bool Char32String::operator==(const Char32String& other) const {
    if(length != other.getLength()) {
        return false;
    }
    for(size_t i = 0; i < length; i++) {
        if(data[i] != other[i]) {
            return false;
        }
    }
    return true;
}

bool Char32String::operator!=(const c32* s) const {
    return !((*this) == s);
}

bool Char32String::operator!=(const Char32String& other) const {
    return !((*this) == other);
}

c32 Char32String::operator[](size_t index) const {
    return data[index];
}

size_t Char32String::getLength() const {
    return length;
}

size_t Char32String::getCapacity() const {
    return capacity;
}

Error Char32String::append(char c) {
    return append(static_cast<c32>(c));
}

Error Char32String::append(signed char c) {
    return append(static_cast<char>(c));
}

Error Char32String::append(unsigned char c) {
    return append(static_cast<char>(c));
}

Error Char32String::append(wchar_t c) {
    return append(static_cast<c32>(c));
}

Error Char32String::append(c32 c) {
    if(length >= capacity) {
        return ErrorCode::CAPACITY_REACHED;
    }
    data[length++] = c;
    data[length] = '\0';
    return ErrorCode::NONE;
}

Error Char32String::append(const char* s) {
    while(true) {
        c32 u = 0;
        CORE_RETURN_ERROR(readUnicode(u, s));
        if(u == 0) {
            return ErrorCode::NONE;
        }
        CORE_RETURN_ERROR(append(u));
    }
}

Error Char32String::append(const c32* s) {
    // stringLength as s could be some part of data
    for(size_t i = stringLength(s); i > 0; i--) {
        CORE_RETURN_ERROR(append(*(s++)));
    }
    return ErrorCode::NONE;
}

Error Char32String::append(const signed char* s) {
    return append(reinterpret_cast<const char*>(s));
}

Error Char32String::append(const unsigned char* s) {
    return append(reinterpret_cast<const char*>(s));
}

Error Char32String::append(bool b) {
    return b ? append("true") : append("false");
}

Error Char32String::toString(CharString& s) const {
    size_t l = length; // length changes if &s == this
    for(size_t i = 0; i < l; i++) {
        CORE_RETURN_ERROR(s.append(data[i]));
    }
    return ErrorCode::NONE;
}

Error Char32String::toString(Char32String& s) const {
    size_t l = length; // length changes if &s == this
    for(size_t i = 0; i < l; i++) {
        CORE_RETURN_ERROR(s.append(data[i]));
    }
    return ErrorCode::NONE;
}

void Char32String::clear() {
    length = 0;
    data[0] = '\0';
}

void Char32String::print() const {
    for(size_t i = 0; i < length; i++) {
        C32Buffer buffer;
        if(convertC32(buffer, data[i]).check()) {
            Core::print('?');
        } else {
            Core::print(buffer.begin());
        }
    }
}

void Char32String::printLine() const {
    print();
    Core::print('\n');
}

bool Char32String::startsWith(const Char32String& other, size_t from) const {
    if(from + other.getLength() > length) {
        return false;
    }
    for(size_t i = 0; i < other.getLength(); i++) {
        if(data[from + i] != other[i]) {
            return false;
        }
    }
    return true;
}

size_t Char32String::search(const Char32String& other, size_t from) const {
    for(size_t i = from; i < length; i++) {
        if(startsWith(other, i)) {
            return i;
        }
    }
    return SIZE_MAX;
}

bool Char32String::contains(const Char32String& other, size_t from) const {
    return search(other, from) != SIZE_MAX;
}

size_t Char32String::search(c32 u, size_t from) const {
    for(size_t i = from; i < length; i++) {
        if(data[i] == u) {
            return i;
        }
    }
    return SIZE_MAX;
}

bool Char32String::contains(c32 u, size_t from) const {
    return search(u, from) != SIZE_MAX;
}

Error Char32String::substring(Char32String& s, size_t from, size_t to) const {
    s.clear();
    to = Math::min(to + 1, length);
    for(size_t i = from; i < to; i++) {
        CORE_RETURN_ERROR(s.append(data[i]));
    }
    return ErrorCode::NONE;
}

Error Char32String::substring(Char32String& s, size_t from) const {
    return substring(s, from, length - 1);
}

Error Char32String::replace(Char32String& s, const Char32String& search,
                            const Char32String& replace) {
    size_t i = 0;
    while(i < length) {
        if(startsWith(search, i)) {
            CORE_RETURN_ERROR(s.append(replace));
            i += search.getLength();
        } else {
            CORE_RETURN_ERROR(s.append(data[i]));
            i++;
        }
    }
    return copyFrom(s);
}

void Char32String::replace(c32 search, c32 replace) {
    for(size_t i = 0; i < length; i++) {
        if(data[i] == search) {
            data[i] = replace;
        }
    }
}

Char32String::operator const c32*() const {
    return data;
}