#include <opkele/types.h>
#include <opkele/exception.h>
#include <opkele/util.h>

namespace opkele {
    using std::unary_function;

    struct __om_copier : public unary_function<const string&,void> {
	public:
	    const basic_fields& from;
	    basic_fields& to;

	    __om_copier(basic_fields& t,const basic_fields& f)
		: from(f), to(t) { }

	    result_type operator()(argument_type f) {
		to.set_field(f,from.get_field(f)); }
    };

    basic_fields::basic_fields(const basic_fields& x) {
	x.copy_to(*this);
    }
    void basic_fields::copy_to(basic_fields& x) const {
	x.reset_fields();
	for_each(fields_begin(),fields_end(),
		__om_copier(x,*this) );
    }
    void basic_fields::append_to(basic_fields& x) const {
	for_each(fields_begin(),fields_end(),
		__om_copier(x,*this) );
    }

    struct __om_query_builder : public unary_function<const string&,void> {
	public:
	    const basic_fields& om;
	    bool first;
	    string& rv;
	    const char *pfx;

	    __om_query_builder(const char *p,string& r,const basic_fields& m)
		: om(m), first(true), rv(r), pfx(p) {
		    for_each(om.fields_begin(),om.fields_end(),*this);
		}
	    __om_query_builder(const char *p,string& r,const basic_fields& m,const string& u)
		: om(m), first(true), rv(r), pfx(p) {
		    basic_fields::fields_iterator i=om.fields_begin(),
			ie=om.fields_end();
		    rv = u;
		    if(i!=ie) {
			if(rv.find('?')==string::npos)
			    rv += '?';
			else
			    first = false;
			for_each(i,ie,*this);
		    }
		}

	    result_type operator()(argument_type f) {
		if(first)
		    first = false;
		else
		    rv += '&';
		if(pfx) rv += pfx;
		rv+= f;
		rv += '=';
		rv += util::url_encode(om.get_field(f));
	    }
    };

    string basic_fields::append_query(const string& url,const char *pfx) const {
	string rv;
	return __om_query_builder(pfx,rv,*this,url).rv;
    }
    string basic_fields::query_string(const char *pfx) const {
	string rv;
	return __om_query_builder(pfx,rv,*this).rv;
    }

    void basic_fields::reset_fields() {
	throw not_implemented(OPKELE_CP_ "reset_fields() not implemented");
    }
    void basic_fields::set_field(const string&,const string&) {
	throw not_implemented(OPKELE_CP_ "set_field() not implemented");
    }
    void basic_fields::reset_field(const string&) {
	throw not_implemented(OPKELE_CP_ "reset_field() not implemented");
    }

    void basic_fields::from_query(const string& qs) {
	for(string::size_type p=0,np;;p=np+1) {
	    np = qs.find('&',p);
	    string::size_type eq = qs.find('=',p);
	    if(eq==string::npos) break;
	    if(np==string::npos) {
		set_field(
			util::url_decode(qs.substr(p,eq-p)),
			util::url_decode(qs.substr(eq+1)) );
		break;
	    }else if(eq<np) {
		set_field(
			util::url_decode(qs.substr(p,eq-p)),
			util::url_decode(qs.substr(eq+1,np-eq-1)) );
	    }
	}
    }


    bool fields_t::has_field(const string& n) const {
	return find(n)!=end();
    }
    const string& fields_t::get_field(const string& n) const {
	const_iterator i=find(n);
	if(i==end())
	    throw failed_lookup(OPKELE_CP_ n+": no such field");
	return i->second;
    }

    fields_t::fields_iterator fields_t::fields_begin() const {
	return util::map_keys_iterator<const_iterator,string,const string&,const string*>(begin(),end());
    }
    fields_t::fields_iterator fields_t::fields_end() const {
	return util::map_keys_iterator<const_iterator,string,const string&,const string*>(end(),end());
    }

    void fields_t::reset_fields() {
	clear();
    }
    void fields_t::set_field(const string& n,const string& v) {
	(*this)[n]=v;
    }
    void fields_t::reset_field(const string& n) {
	erase(n);
    }

}