root/uri.cc

/*  This file is part of Alue, the multiprotocol Internet discussion daemon

    Copyright © 2009, 2010 Antti-Juhani Kaijanaho

    Alue is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Alue is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Alue.  If not, see <http://www.gnu.org/licenses/>.

 */

#include "util.hh"
#include "uri.hh"

#include <boost/lexical_cast.hpp>

const char uri::invalid::msgprefix[] = 
        "Uniform Resource Identifier (URI) invalid";

uri::uri(std::string str)
        : port(-1)
{
        using util::split1L;
        using util::split1R;

        scheme = split1L(str, ":");

        if (str.substr(0, 2) == "//")
        {
                str.erase(0, 2);
                std::string authority = split1R(str, "/");
                userinfo = split1L(authority, "@");
                host = split1R(authority, ":");
                if (!authority.empty())
                {
                        if (!util::is_number(authority))
                                throw invalid("invalid port");
                        port = boost::lexical_cast<int>(authority);
                }
        }

        path = split1R(str, "?");
        query = str;
}

std::string uri::percent_decode(std::string s)
{
        std::string rv;
        rv.reserve(s.length());
        for (size_t i = 0; i < s.length(); i++)
        {
                if (s[i] == '%')
                {
                        if (i + 2 >= s.length())
                                throw uri::invalid("percent encoding "
                                                   "truncated");
                        int val = 0;
                        for (size_t j = 1; j <= 2; j++)
                        {
                                val *= 16;
                                char c = s[i+j];
                                /**/ if ('0' <= c && c <= '9') val += c-'0';
                                else if ('a' <= c && c <= 'f') val += c-'a'+10;
                                else if ('A' <= c && c <= 'F') val += c-'A'+10;
                                else throw uri::invalid("percent encoding "
                                                        "invalid");
                        }
                        rv += char(val);
                        i += 2;
                }
                else
                        rv += s[i];
        }
        return rv;
}

std::string uri::percent_encode(std::string s)
{
        std::string rv;
        rv.reserve(s.length());
        for (size_t i = 0; i < s.length(); i++)
        {
                char c = s[i];
                if ( ('a' <= c && c <= 'z') ||
                     ('A' <= c && c <= 'Z') ||
                     ('0' <= c && c <= '9') ||
                     (c == '/') ||
                     c == '-' ||
                     c == '.' ||
                     c == '_' ||
                     c == '~')
                {
                        rv += c;
                        continue;
                } 
                rv += '%';
                static const char hexdig[] = "0123456789ABCDEF";
                rv += hexdig[c / 16];
                rv += hexdig[c % 16];
        }
        return rv;
}

void uri::replace_query_param(std::string name, std::string new_value)
{
        remove_query_param(name);
        if (!query.empty())
                query += '&';
        query += name + "=" + percent_encode(new_value);
}

void uri::replace_query_param(std::string name, int val)
{
        std::ostringstream os;
        os << val;
        replace_query_param(name, os.str());
}

void uri::remove_query_param(std::string name)
{
        for (size_t ix = 0; ix < query.length(); /**/)
        {
                size_t nix = query.find("&", ix+1);
                if (query.substr(ix, name.length()+1) == name + "=")
                        query.erase(ix, nix - ix);
                else
                {
                        ix = nix;
                        if (ix + 1 != 0) ix++;
                }
        }
        for (size_t i = 0; i < query.length(); i++)
        {
                if (i > 0 && query[i] == '&' && query[i-1] == '&')
                {
                        query.erase(i, 1);
                        i--;
                }

        }
        if (!query.empty() && query[query.length()-1] == '&')
                query.erase(query.length()-1, 1);
}

std::string uri::get_query_param(std::string name) const
{
        for (size_t ix = 0; ix < query.length(); /**/)
        {
                size_t nix = query.find("&", ix+1);
                size_t eq = ix+name.length();
                if (eq < query.length() && query[eq] == '=' &&
                    query.substr(ix, name.length()) == name)
                {
                        std::string rv = eq + 1 < query.length()
                                ? query.substr(eq + 1, nix - eq - 1)
                                : "";
                        return percent_decode(rv);
                }
                else
                {
                        ix = nix;
                        if (ix + 1 != 0) ix++;
                }
        }       
        return "";
}

std::string uri::to_string() const
{
        std::ostringstream os;
        if (!scheme.empty()) os << scheme << "://";
        if (!userinfo.empty()) os << userinfo << "@";
        if (!host.empty()) os << host;
        if (port >= 0) os << ":" << port;
        if (path.empty()) os << "/"; else os << path;
        if (!query.empty()) os << "?" << query;
        return os.str();
}