Add GLOB.cassettes

monkestation/code/modules/cassettes/cassette_db/cassette_datum.dm

@@ -1,3 +1,6 @@
+/// An associative list of cassette IDs to cassette datums.
+GLOBAL_LIST_EMPTY_TYPED(cassettes, /datum/cassette)
+
 /datum/cassette
 	/// The name of the cassette.
 	var/name
@@ -21,6 +24,12 @@
 	front = new
 	back = new
 
+/datum/cassette/Destroy(force)
+	QDEL_NULL(author)
+	QDEL_NULL(front)
+	QDEL_NULL(back)
+	return ..()
+
 /// Imports cassette date from the old format.
 /datum/cassette/proc/import_old_format(list/data)
 	name = data["name"]
@@ -43,7 +52,8 @@
 			side.songs += new /datum/cassette_song(song_names[idx], song_urls[idx])
 
 /// Exports cassette date in the old format.
-/datum/cassette/proc/export_old_format()
+/datum/cassette/proc/export_old_format() as /list
+	RETURN_TYPE(/list)
 	. = list(
 		"name" = name,
 		"desc" = desc,
@@ -73,6 +83,12 @@
 		.["song_names"][side_name] = names
 		.["songs"][side_name] = urls
 
+/// Saves the cassette to the data folder, in JSON format.
+/datum/cassette/proc/save()
+	if(!id)
+		CRASH("Attempted to save cassette without an ID to disk")
+	rustg_file_write(json_encode(export_old_format(), JSON_PRETTY_PRINT), "data/cassette_storage/[id].json")
+
 /// Simple helper to get a side of the cassette.
 /// TRUE is front side, FALSE is back side.
 /datum/cassette/proc/get_side(front_side = TRUE) as /datum/cassette_side
@@ -91,6 +107,10 @@
 	/// The songs on this side of the cassette.
 	var/list/datum/cassette_song/songs = list()
 
+/datum/cassette_side/Destroy(force)
+	QDEL_LIST(songs)
+	return ..()
+
 /datum/cassette_song
 	/// The name of the song.
 	var/name
@@ -101,3 +121,20 @@
 	. = ..()
 	src.name = name
 	src.url = url
+
+/// Loads the cassette with the given ID from a JSON in the `data/cassette_storage` folder.
+/proc/load_cassette(id) as /datum/cassette
+	RETURN_TYPE(/datum/cassette)
+	if(!id)
+		return null
+	if(GLOB.cassettes[id])
+		return GLOB.cassettes[id]
+	var/cassette_file = "data/cassette_storage/[id].json"
+	if(!rustg_file_exists(cassette_file))
+		return null
+	var/list/cassette_json = json_decode(rustg_file_read(cassette_file))
+	var/datum/cassette/cassette_data = new
+	cassette_data.import_old_format(cassette_json)
+	cassette_data.id = id
+	GLOB.cassettes[id] = cassette_data
+	return cassette_data

monkestation/code/modules/cassettes/cassette_db/subsystem.dm

@@ -4,7 +4,6 @@ SUBSYSTEM_DEF(cassette_storage)
 	runlevels = RUNLEVEL_LOBBY | RUNLEVELS_DEFAULT
 	var/list/cassette_datums = list()
 
-
 /datum/controller/subsystem/cassette_storage/Initialize()
 	if(!length(GLOB.approved_ids))
 		GLOB.approved_ids = initialize_approved_ids()