//
// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//

#ifndef BOOST_BEAST_HTTP_DETAIL_RFC7230_IPP
#define BOOST_BEAST_HTTP_DETAIL_RFC7230_IPP

#include <boost/beast/core/string.hpp>
#include <iterator>
#include <utility>

namespace boost {
namespace beast {
namespace http {
namespace detail {

bool
is_digit(char c)
{
    return c >= '0' && c <= '9';
}

char
is_alpha(char c)
{
    static char constexpr tab[] = {
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 0
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 16
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 32
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 48
        0, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 64
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 0,  0, 0, 0, 0, // 80
        0, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 96
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 0,  0, 0, 0, 0, // 112
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 128
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 144
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 160
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 176
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 192
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 208
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 224
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0  // 240
    };
    BOOST_STATIC_ASSERT(sizeof(tab) == 256);
    return tab[static_cast<unsigned char>(c)];
}

char
is_text(char c)
{
    // TEXT = <any OCTET except CTLs, but including LWS>
    static char constexpr tab[] = {
        0, 0, 0, 0,  0, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0, // 0
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 16
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 32
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 48
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 64
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 80
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 96
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 0, // 112
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 128
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 144
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 160
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 176
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 192
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 208
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 224
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1  // 240
    };
    BOOST_STATIC_ASSERT(sizeof(tab) == 256);
    return tab[static_cast<unsigned char>(c)];
}

char
is_token_char(char c)
{
    /*
        tchar = "!" | "#" | "$" | "%" | "&" |
                "'" | "*" | "+" | "-" | "." |
                "^" | "_" | "`" | "|" | "~" |
                DIGIT | ALPHA
    */
    static char constexpr tab[] = {
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 0
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 16
        0, 1, 0, 1,  1, 1, 1, 1,  0, 0, 1, 1,  0, 1, 1, 0, // 32
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 0, 0,  0, 0, 0, 0, // 48
        0, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 64
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 0,  0, 0, 1, 1, // 80
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 96
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 0,  1, 0, 1, 0, // 112
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 128
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 144
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 160
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 176
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 192
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 208
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 224
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0  // 240
    };
    BOOST_STATIC_ASSERT(sizeof(tab) == 256);
    return tab[static_cast<unsigned char>(c)];
}

char
is_qdchar(char c)
{
    /*
        qdtext = HTAB / SP / "!" / %x23-5B ; '#'-'[' / %x5D-7E ; ']'-'~' / obs-text
    */
    static char constexpr tab[] = {
        0, 0, 0, 0,  0, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0, // 0
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 16
        1, 1, 0, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 32
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 48
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 64
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  0, 1, 1, 1, // 80
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 96
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 0, // 112
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 128
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 144
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 160
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 176
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 192
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 208
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 224
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1  // 240
    };
    BOOST_STATIC_ASSERT(sizeof(tab) == 256);
    return tab[static_cast<unsigned char>(c)];
}

char
is_qpchar(char c)
{
    /*
        quoted-pair = "\" ( HTAB / SP / VCHAR / obs-text )
        obs-text = %x80-FF
    */
    static char constexpr tab[] = {
        0, 0, 0, 0,  0, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0, // 0
        0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, // 16
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 32
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 48
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 64
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 80
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 96
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 0, // 112
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 128
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 144
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 160
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 176
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 192
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 208
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, // 224
        1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1  // 240
    };
    BOOST_STATIC_ASSERT(sizeof(tab) == 256);
    return tab[static_cast<unsigned char>(c)];
}

// converts to lower case,
// returns 0 if not a valid text char
//
char
to_value_char(char c)
{
    // TEXT = <any OCTET except CTLs, but including LWS>
    static unsigned char constexpr tab[] = {
          0,   0,   0,   0,   0,   0,   0,   0,   0,   9,   0,   0,   0,   0,   0,   0, // 0
          0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, // 16
         32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47, // 32
         48,  49,  50,  51,  52,  53,  54,  55,  56,  57,  58,  59,  60,  61,  62,  63, // 48
         64,  97,  98,  99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, // 64
        112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122,  91,  92,  93,  94,  95, // 80
         96,  97,  98,  99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, // 96
        112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126,   0, // 112
        128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, // 128
        144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, // 144
        160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, // 160
        176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, // 176
        192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, // 192
        208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, // 208
        224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, // 224
        240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255  // 240
    };
    BOOST_STATIC_ASSERT(sizeof(tab) == 256);
    return static_cast<char>(tab[static_cast<unsigned char>(c)]);
}

// VFALCO TODO Make this return unsigned?
std::int8_t
unhex(char c)
{
    static signed char constexpr tab[] = {
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 16
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 32
         0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1, // 48
        -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 64
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 80
        -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 96
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 112
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 128
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 144
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 160
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 176
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 192
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 208
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 224
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1  // 240
    };
    BOOST_STATIC_ASSERT(sizeof(tab) == 256);
    return tab[static_cast<unsigned char>(c)];
}

template <class ForwardIt>
void
skip_ows(ForwardIt& it, ForwardIt end)
{
    while(it != end)
    {
        if(*it != ' ' && *it != '\t')
            break;
        ++it;
    }
}

template <class ForwardIt>
void
skip_token(ForwardIt& it, ForwardIt last)
{
    while(it != last && is_token_char(*it))
        ++it;
}

string_view
trim(string_view s)
{
    auto first = s.begin();
    auto last = s.end();
    skip_ows(first, last);
    while(first != last)
    {
        auto const c = *std::prev(last);
        if(c != ' ' && c != '\t')
            break;
        --last;
    }
    if(first == last)
        return {};
    return {&*first,
        static_cast<std::size_t>(last - first)};
}


BOOST_BEAST_DECL
void
param_iter::
increment()
{
/*
    param-list      = *( OWS ";" OWS param )
    param           = token OWS [ "=" OWS ( token / quoted-string ) ]
    quoted-string   = DQUOTE *( qdtext / quoted-pair ) DQUOTE
    qdtext          = HTAB / SP / "!" / %x23-5B ; '#'-'[' / %x5D-7E ; ']'-'~' / obs-text
    quoted-pair     = "\" ( HTAB / SP / VCHAR / obs-text )
    obs-text        = %x80-FF
*/
    auto const err =
        [&]
        {
            it = first;
        };
    v.first = {};
    v.second = {};
    detail::skip_ows(it, last);
    first = it;
    if(it == last)
        return err();
    if(*it != ';')
        return err();
    ++it;
    detail::skip_ows(it, last);
    if(it == last)
        return err();
    // param
    if(! detail::is_token_char(*it))
        return err();
    auto const p0 = it;
    skip_token(++it, last);
    auto const p1 = it;
    v.first = { &*p0, static_cast<std::size_t>(p1 - p0) };
    detail::skip_ows(it, last);
    if(it == last)
        return;
    if(*it == ';')
        return;
    if(*it != '=')
        return err();
    ++it;
    detail::skip_ows(it, last);
    if(it == last)
        return;
    if(*it == '"')
    {
        // quoted-string
        auto const p2 = it;
        ++it;
        for(;;)
        {
            if(it == last)
                return err();
            auto c = *it++;
            if(c == '"')
                break;
            if(detail::is_qdchar(c))
                continue;
            if(c != '\\')
                return err();
            if(it == last)
                return err();
            c = *it++;
            if(! detail::is_qpchar(c))
                return err();
        }
        v.second = { &*p2, static_cast<std::size_t>(it - p2) };
    }
    else
    {
        // token
        if(! detail::is_token_char(*it))
            return err();
        auto const p2 = it;
        skip_token(++it, last);
        v.second = { &*p2, static_cast<std::size_t>(it - p2) };
    }
}

bool
opt_token_list_policy::operator()(value_type& v,
    char const*& it, string_view s) const
{
    v = {};
    auto need_comma = it != s.data();
    for(;;)
    {
        detail::skip_ows(it, (s.data() + s.size()));
        if(it == (s.data() + s.size()))
        {
            it = nullptr;
            return true;
        }
        auto const c = *it;
        if(detail::is_token_char(c))
        {
            if(need_comma)
                return false;
            auto const p0 = it;
            for(;;)
            {
                ++it;
                if(it == (s.data() + s.size()))
                    break;
                if(! detail::is_token_char(*it))
                    break;
            }
            v = string_view{p0,
                static_cast<std::size_t>(it - p0)};
            return true;
        }
        if(c != ',')
            return false;
        need_comma = false;
        ++it;
    }
}

} // detail
} // http
} // beast
} // boost

#endif // BOOST_BEAST_HTTP_DETAIL_RFC7230_IPP