#include "string.hh"

#include "exception.hh"
#include "utils.hh"
#include "utf8_iterator.hh"

namespace Kakoune
{

bool operator<(StringView lhs, StringView rhs)
{
    int cmp = strncmp(lhs.data(), rhs.data(), (int)std::min(lhs.length(), rhs.length()));
    if (cmp == 0)
        return lhs.length() < rhs.length();
    return cmp < 0;
}

std::vector<String> split(StringView str, char separator, char escape)
{
    std::vector<String> res;
    auto it = str.begin();
    while (it != str.end())
    {
        res.emplace_back();
        String& element = res.back();
        while (it != str.end())
        {
            auto c = *it;
            if (c == escape and it + 1 != str.end() and *(it+1) == separator)
            {
                element += separator;
                it += 2;
            }
            else if (c == separator)
            {
                ++it;
                break;
            }
            else
            {
                element += c;
                ++it;
            }
        }
    }
    return res;
}

std::vector<StringView> split(StringView str, char separator)
{
    std::vector<StringView> res;
    auto beg = str.begin();
    for (auto it = beg; it != str.end(); ++it)
    {
        if (*it == separator)
        {
            res.emplace_back(beg, it);
            beg = it + 1;
        }
    }
    res.emplace_back(beg, str.end());
    return res;
}

String escape(StringView str, StringView characters, char escape)
{
    String res;
    for (auto& c : str)
    {
        if (contains(characters, c))
            res += escape;
        res += c;
    }
    return res;
}

String unescape(StringView str, StringView characters, char escape)
{
    String res;
    for (auto& c : str)
    {
        if (contains(characters, c) and not res.empty() and res.back() == escape)
            res.back() = c;
        else
            res += c;
    }
    return res;
}

int str_to_int(StringView str)
{
    int res = 0;
    if (sscanf(str.zstr(), "%i", &res) != 1)
        throw runtime_error(str + "is not a number");
    return res;
}

String to_string(int val)
{
    char buf[16];
    sprintf(buf, "%i", val);
    return buf;
}

bool subsequence_match(StringView str, StringView subseq)
{
    auto it = str.begin();
    for (auto& c : subseq)
    {
        if (it == str.end())
            return false;
        while (*it != c)
        {
            if (++it == str.end())
                return false;
        }
        ++it;
    }
    return true;
}

String expand_tabs(StringView line, CharCount tabstop, CharCount col)
{
    String res;
    using Utf8It = utf8::iterator<const char*>;
    for (Utf8It it = line.begin(); it.base() < line.end(); ++it)
    {
        if (*it == '\t')
        {
            CharCount end_col = (col / tabstop + 1) * tabstop;
            res += String{' ', end_col - col};
        }
        else
            res += *it;
    }
    return res;
}

std::vector<StringView> wrap_lines(StringView text, CharCount max_width)
{
    using Utf8It = utf8::iterator<const char*>;
    Utf8It word_begin{text.begin()};
    Utf8It word_end{word_begin};
    Utf8It end{text.end()};
    CharCount col = 0;
    std::vector<StringView> lines;
    Utf8It line_begin = text.begin();
    Utf8It line_end = line_begin;
    while (word_begin != end)
    {
        const CharCategories cat = categorize(*word_begin);
        do
        {
            ++word_end;
        } while (word_end != end and categorize(*word_end) == cat);

        col += word_end - word_begin;
        if ((word_begin != line_begin and col > max_width) or
            cat == CharCategories::EndOfLine)
        {
            lines.emplace_back(line_begin.base(), line_end.base());
            line_begin = (cat == CharCategories::EndOfLine or
                          cat == CharCategories::Blank) ? word_end : word_begin;
            col = word_end - line_begin;
        }
        if (cat == CharCategories::Word or cat == CharCategories::Punctuation)
            line_end = word_end;

        word_begin = word_end;
    }
    if (line_begin != word_begin)
        lines.emplace_back(line_begin.base(), word_begin.base());
    return lines;
}

}