Daniel@0: /* Part of DML (Digital Music Laboratory)
Daniel@0: 	Copyright 2014-2015 Samer Abdallah, University of London
Daniel@0: 	 
Daniel@0: 	This program is free software; you can redistribute it and/or
Daniel@0: 	modify it under the terms of the GNU General Public License
Daniel@0: 	as published by the Free Software Foundation; either version 2
Daniel@0: 	of the License, or (at your option) any later version.
Daniel@0: 
Daniel@0: 	This program is distributed in the hope that it will be useful,
Daniel@0: 	but WITHOUT ANY WARRANTY; without even the implied warranty of
Daniel@0: 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Daniel@0: 	GNU General Public License for more details.
Daniel@0: 
Daniel@0: 	You should have received a copy of the GNU General Public
Daniel@0: 	License along with this library; if not, write to the Free Software
Daniel@0: 	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
Daniel@0: */
Daniel@0: 
Daniel@0: :- module(api_archive, [ locator_uri/2, with_input_from_uri/2, uri_absolute_path/2, archive_file/3, archive_file/2 ]).
Daniel@0: 
Daniel@0: :- use_module(library(http/http_dispatch)).
Daniel@0: :- use_module(library(http/http_parameters)).
Daniel@0: :- use_module(library(xmlarchive)).
Daniel@0: :- use_module(library(httpfiles)).
Daniel@0: :- use_module(library(fileutils)).
Daniel@0: :- use_module(library(insist)).
Daniel@0: 
Daniel@0: :- set_prolog_flag(double_quotes,string).
Daniel@0: :- rdf_register_prefix(file,'file://').
Daniel@0: :- http_handler(api(archive/get), archive_get, []).
Daniel@0: :- setting(archive:root,string,"~/lib/dml-archive","Directory containing accessible files").
Daniel@0: 
Daniel@0: user:file_search_path(archive,Path) :- setting(archive:root,DD), expand_file_name(DD,[Path]).
Daniel@0: 
Daniel@0: archive_get(Request) :-
Daniel@0:    http_parameters(Request, [uri(URI, [optional(false), description("URI of archive entry")])]),
Daniel@0:    file_name_extension(_,Ext,URI),
Daniel@0:    with_input_from_uri(URI,reply_from_stream(Ext)).
Daniel@0: 
Daniel@0: uri_absolute_path(URI,Path) :- var(Path), !,
Daniel@0:    insist(string_concat("file://",LocString,URI)),
Daniel@0:    absolute_file_name(archive(LocString),Path,[access(read)]).
Daniel@0: uri_absolute_path(URI,Path) :-
Daniel@0:    file_search_path(archive,Root),
Daniel@0:    atom_concat(Root,Rel,Path),
Daniel@0:    atom_concat('file:/',Rel,URI).
Daniel@0: 
Daniel@0: :- meta_predicate with_input_from_uri(+,1).
Daniel@0: with_input_from_uri(URI,Goal) :-
Daniel@0:    insist(string_concat("file://",LocString,URI)),
Daniel@0:    (  sub_string(LocString,PathLen,1,FragLen,"#")
Daniel@0:    -> sub_string(LocString,0,PathLen,_,Path),
Daniel@0:       sub_atom(LocString,_,FragLen,0,Frag),
Daniel@0:       absolute_file_name(archive(Path),ArchivePath,[access(read)]),
Daniel@0:       with_archive_stream(ArchivePath,Frag,Goal)
Daniel@0:    ;  absolute_file_name(archive(LocString),AbsPath,[access(read)]),
Daniel@0:       with_stream(S, open(AbsPath,read,S), call(Goal,S))
Daniel@0:    ).
Daniel@0: 
Daniel@0: reply_from_stream(Ext,Stream) :- reply_stream(Stream,Ext).
Daniel@0: 
Daniel@0: locator_uri(file(Parts), URI) :- atomic_list_concat(['file:/'|Parts],'/',URI).
Daniel@0: locator_uri(archive_entry(ArchivePath,EntryName), URI) :- 
Daniel@0:    atomic_list_concat(['file://',ArchivePath,'#',EntryName],URI).
Daniel@0: 
Daniel@0: %% archive_file(+Ext:atom, +In:path, -Out:uri) is det.
Daniel@0: %% archive_file(+In:path,-Out:uri) is det.
Daniel@0: %
Daniel@0: %  This procedure finds a permanent home for the file In, moving it into
Daniel@0: %  the directory tree managed by the archive, giving it a unique file name,
Daniel@0: %  and returning the URI of the location.
Daniel@0: %
Daniel@0: %  !! could add extension if necessary
Daniel@0: archive_file(In,Out) :- archive_file('',In,Out).
Daniel@0: archive_file(Ext,In,Out) :-
Daniel@0:    get_time(Time),
Daniel@0:    format_time(atom(Dir),'auto/%Y%m%d',Time),
Daniel@0:    expand_file_search_path(archive(Dir),FullDir),
Daniel@0:    (  exists_directory(FullDir) -> true
Daniel@0:    ;  make_directory(FullDir)
Daniel@0:    ),
Daniel@0:    once( ( repeat, random_name(Ext,8,Str),
Daniel@0:            directory_file_path(FullDir,Str,Path),
Daniel@0:            \+exists_file(Path) )),
Daniel@0:    rename_file(In,Path),
Daniel@0:    uri_absolute_path(Out,Path).
Daniel@0: 
Daniel@0: random_name(Ext,Len,String) :-
Daniel@0:    length(Chars,Len),
Daniel@0:    maplist(web_storage:random_char,Chars),
Daniel@0:    format(string(String),'~s~s',[Chars,Ext]).
Daniel@0: 
Daniel@0: