:- use_module(library('http/xpce_httpd')).
:- use_module(plht).

:- dynamic published_dir/2.
:- dynamic published_pred/2.
:- dynamic index_file/1.
:- dynamic simple_mime/2.
:- dynamic processed_file/2.

published_dir('/doc','/usr/local/httpd/htdocs').
published_dir('/','/home/yannick/proj/LUSE/web/').
index_file('index.html').
index_file('index.plht').
simple_mime('.html','text/html').
simple_mime('.htm','text/html').
simple_mime('.txt','text/plain').
simple_mime('.gif','image/gif').
simple_mime('.jpg','image/jpeg').
simple_mime('.png','image/png').
processed_file('.plht',process_plht).

join_path(Dir,Fname,Path):-
	atom_concat(Dir,'/',Dir2),
	atom_concat(Dir2,Fname,Path).

%%% TODO:
%%%   doesn't allow things like /blah/foo.plht/mumble/schnuck
%%%   loop could have a "cycle" attribute
%%%     as in <pl:loop query="..." cycle_var="Color"
%%%				   cycle_list="['#ffffff','#cccccc']">

reply(Query):-
	member(path(Path),Query),
	published_dir(Path_Prefix,Real_Dir),
	atom_concat(Path_Prefix,Path_Suffix,Path),
	atom_concat(Real_Dir,Path_Suffix,Path1),
	absolute_file_name(Path1,Real_Path),
	atom_concat(Real_Dir,_,Real_Path),
	(   
	exists_file(Real_Path),
	publish_file(Real_Path,Query);
	exists_directory(Real_Path),
	index_file(I),
	join_path(Real_Path,I,Path2),
	    exists_file(Path2),
	    publish_file(Path2,Query)).

reply(Query):-
	member(path(Path),Query),
	published_pred(Path_Prefix,Pred),
	atom_concat(Path_Prefix,Path_Suffix,Path),
	call(Pred,[path_suffix(Path_Suffix)|Query]).
	    
publish_file(Real_Path,_):-
	simple_mime(Ext,Mimetype),
	atom_concat(_,Ext,Real_Path),
	format('Content-type: ~a\r\n\r\n',[Mimetype]),
	open(Real_Path,read,In),
	current_output(Out),
	copy_stream_data(In,Out),
	close(In).

publish_file(Real_Path,Query):-
	processed_file(Ext,Pred),
	atom_concat(_,Ext,Real_Path),
	call(Pred,Real_Path,Query).

%publish_file(Real_Path,Query):-
%	write('Content-type: text/plain\r\n\r\n'),
%	format('filename: ~q\n',[Real_Path]).



process_plht(Real_Path,Query):-
	hash_term(Real_Path,Hash),
	atom_concat(plht_,Hash,PredName),
	atom_concat(PredName,'.pl',FileName),
	(
	current_predicate(PredName/1),
	    time_file(FileName,TimePL),
	    time_file(Real_Path,TimePLHT),
	    TimePLHT<TimePL ;
	assert(doing(compile_plht(PredName,Real_Path,FileName))),
	 compile_plht(PredName,Real_Path,FileName),
	 retract(doing(compile_plht(PredName,Real_Path,FileName))),
	    consult(FileName)),
	format('Content-type: text/html\r\n\r\n'),
	call(PredName,Query).

flush_cache:-
	ignore((current_predicate(PredName/1),
	       atom_concat(plht_,_,PredName),
	       abolish(PredName/1),
	       fail)).

run_server(Port):-
	http_server(reply,[port(Port)]).