Chris@10: :- module(urispace,[init/0]).
Chris@10: 
Chris@10: :- use_module(library('http/thread_httpd')).
Chris@27: :- use_module(library('http/http_cors')).
Chris@10: :- use_module(library('semweb/rdf_db')).
Chris@10: :- use_module(log).
Chris@10: :- use_module(chord_parser).
Chris@10: 
Chris@10: :- style_check(-discontiguous).
Chris@10: 
Chris@27: :- set_setting_default(http:cors, [*]).
Chris@27: 
Chris@27: 
Chris@10: server(Port, Options) :-
Chris@10:         http_server(reply,[ port(Port),timeout(20)| Options]).
Chris@10: 
Chris@10: 
Chris@10: namespace('http://dbtune.org/chord').
Chris@10: 
Chris@10: /**
Chris@10:  * Handles documents
Chris@10:  */
Chris@10: reply(Request) :-
Chris@10: 	member(path(Path),Request),
Chris@10: 	atom_concat(SymbolT,'.rdf',Path),
Chris@10: 	atom_concat('/',Symbol,SymbolT),
Chris@27:         cors_enable,
Chris@10: 	!,
Chris@10: 	(parse(Symbol,RDF) ->
Chris@10: 		(
Chris@10: 		current_output(S),
Chris@10: 		set_stream(S,encoding(utf8)),
Chris@10: 		format('Content-type: application/rdf+xml; charset=UTF-8~n~n', []),
Chris@10: 		rdf_write_xml(S,RDF));
Chris@10: 		(
Chris@10: 		throw(http_reply(server_error('The specified chord symbol is not valid~n~n')))
Chris@10: 		)).
Chris@10: 
Chris@10: /**
Chris@10:  * Sends back towards a png representation of the chord
Chris@10:  */
Chris@10: reply(Request) :-
Chris@10: 	member(path(Path),Request),
Chris@10: 	member(accept(AcceptHeader),Request),
Chris@10: 	log:log('Accept header: ~w ',[AcceptHeader]),
Chris@10: 	accept_png(AcceptHeader),
Chris@10: 	!,
Chris@10: 	atom_concat('/',Symbol,Path),
Chris@27:         cors_enable,
Chris@10: 	(parse(Symbol,RDF) ->
Chris@10: 		(
Chris@10: 		member(rdf(_,'http://xmlns.com/foaf/0.1/depiction',Pic),RDF),
Chris@10: 		throw(http_reply(see_other(Pic),[])));
Chris@10: 		(
Chris@10: 		throw(http_reply(server_error('The specified chord symbol is not valid~n~n')))
Chris@10: 		)).
Chris@10: accept_png('image/png').
Chris@10: 
Chris@10: 
Chris@10: 
Chris@10: /**
Chris@10:  * Sends back 303 to RDF document describing the resource
Chris@10:  */
Chris@10: reply(Request) :-
Chris@10: 	member(path(Path),Request),
Chris@10: 	%member(accept(AcceptHeader),Request),
Chris@10: 	accept_rdf(AcceptHeader),
Chris@10: 	!,
Chris@10: 	namespace(NS),
Chris@10: 	format(atom(Redirect),'~w~w.rdf',[NS,Path]),
Chris@10: 	log:log('Sending a 303 towards ~w',Redirect),
Chris@27:         cors_enable,
Chris@10: 	throw(http_reply(see_other(Redirect),[])).
Chris@10: 
Chris@10: accept_rdf('application/rdf+xml').
Chris@10: accept_rdf('text/xml').
Chris@10: accept_rdf(AcceptHeader) :-
Chris@10: 	sub_atom(AcceptHeader,_,_,_,'application/rdf+xml').
Chris@10: accept_rdf(AcceptHeader) :-
Chris@10:         sub_atom(AcceptHeader,_,_,_,'text/xml').
Chris@10: accept_rdf(_).
Chris@10: 
Chris@10: 
Chris@10: 
Chris@10: /**
Chris@10:  * Sends back towards the default representation of the resource
Chris@10:  * (usually html)
Chris@10:  */
Chris@10: 
Chris@10: html('http://www4.wiwiss.fu-berlin.de/rdf_browser/?browse_uri=').
Chris@10: reply(Request) :-
Chris@10:         member(path(Path),Request),
Chris@10:         !,
Chris@10:         html(Html),namespace(Namespace),
Chris@10: 	format(atom(Redirect),'~w~w~w',[Html,Namespace,Path]),
Chris@10: 	log:log('Sending a 303 towards ~w',Redirect),
Chris@27:         cors_enable,
Chris@10:         throw(http_reply(see_other(Redirect),[])).
Chris@10: 
Chris@10: port(1111).
Chris@10: init :- 
Chris@10:         port(P),
Chris@10:         server(P,[]),
Chris@10:         nl,
Chris@10:         writeln(' - Server launched'),nl.
Chris@10: 
Chris@10: :-
Chris@10:  nl,writeln('----------------'),nl,
Chris@10:  writeln(' - Launch the server on port 1111 by running ?-init.'),
Chris@10:  nl,writeln('----------------'),nl.
Chris@10: 
Chris@10: