#include "bodyparser.hh"
#include "pEpMIME_internal.hh"
#include "rules.hh"
#include "base64.hxx"
#include "quoted_printable.hxx"
#include <pEp/pEp_string.h>

#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/fusion/include/adapt_struct.hpp>

namespace qi = boost::spirit::qi;

    struct ContentType
    {
        std::string type;
        std::string subtype;
        std::vector<pEpMIME::NameValue> params;
        void tolower(); // only for ASCII chars, but that's sufficient here.
    };

    BOOST_FUSION_ADAPT_STRUCT(
        ContentType,
        (std::string, type)
        (std::string, subtype)
        (std::vector<pEpMIME::NameValue>, params)
    )

// that boost::fusion magic seems to work only in the actual TU
// so it has to be defined here, instead of at the end of pEpMIME_internal.cc  *sigh*
BOOST_FUSION_ADAPT_STRUCT(
    pEpMIME::NameValue,
    (std::string, name)
    (std::string, value)
)


void ascii_tolower(std::string& s)
{
    for(char& c : s)
    {
        if(c>='A' && c<='Z')
        {
            c += 32;
        }
    }
}

void ContentType::tolower()
{
    ascii_tolower(type);
    ascii_tolower(subtype);
}

std::ostream& operator<<(std::ostream& o, const ContentType& ct)
{
    return o << "CT:{" << ct.type << "/" << ct.subtype << ". params=" << ct.params << " } ";
}

  
namespace pEpMIME
{

char* base64_decode(const BodyLines& bl, size_t& output_size)
{
	size_t out_size = 0;
	for(const auto& line : bl)
	{
		out_size += (line.size()+3)/4 * 3;
	}
	
	char* out_string = new_string(nullptr, out_size);
	char* out_begin = out_string;
	char* out_end = out_string + out_size;
	
	base64::decode_iter( BodyIterator{bl}, BodyIterator{}, out_begin, out_end);
	output_size = out_begin - out_string;
	return out_string;
}

char* qp_decode(const BodyLines& bl, size_t& output_size)
{
	size_t out_size = 0;
	for(const auto& line : bl)
	{
		out_size += line.size();
	}
	
	char* out_string = new_string(nullptr, out_size);
	char* out_begin = out_string;
	char* out_end = out_string + out_size;
	
	qp::decode_iter( BodyIterator{bl}, BodyIterator{}, out_begin, out_end);
	output_size = out_begin - out_string;
	return out_string;
}



// Tokens from RFC 2045
Rule token = +( vchar - qi::char_("]()<>@,;:\\\"/?=["));

TRule<NameValue> parameter = token >> '=' >> (token | quoted_string.alias());
TRule<ContentType> content_type = token >> '/' >> token >> *( qi::omit[*cfws] >> ';' >> qi::omit[*cfws] >> parameter);


// parses the header and fill the parts in msg
void parse_body(message* msg, const HeaderSection& headers, const std::deque<sv>& body)
{
    if( header_value(headers, "MIME-Version") == "1.0" )  // TODO: According to RFC 2048 there can be comments in the header field value. -.-
    {
        // TODO: for whatever reason "string_view cts" does not work with qi::parse(). WTF!
        const std::string cts = header_value(headers, "Content-Type").to_string();
        ContentType ct;
        auto begin = cts.cbegin();
        
        const bool okay = qi::parse(begin, cts.cend(), content_type, ct);
        if(!okay)
        {
            throw std::runtime_error( "Cannot parse \"" + std::string{cts} + "\" as ContentType");
        }
        ct.tolower();
        std::cerr << ct << std::endl;
        
    }else{ // Non-MIME mail
        std::cerr << "<<< NO_MIME_MAIL >>>\n";
    }
}


} // end of namespace pEpMIME