CREATE TABLE IF NOT EXISTS actor (
	objectId TEXT,		-- UUIDv4 of the corresponding object
	preferredUsername TEXT,

	FOREIGN KEY (objectId) REFERENCES object(id),
	PRIMARY KEY (objectId)
);

CREATE TABLE IF NOT EXISTS object (
	id TEXT,		-- Dereferenceable link to the object
	type TEXT,		-- Object type, see <https://www.w3.org/TR/activitystreams-vocabulary/#object-types>

	name TEXT,		-- Title of the object
	attributedTo TEXT,	-- object ID of the actor to whom the object is attributed
	summary TEXT,		-- Natural language summary of the object
	content TEXT,		-- Text content or representation
	url TEXT,		-- A URL that represents the object
	mediaType TEXT,		-- MIME type of `content`
	icon TEXT,		-- URL of a 1:1 image that represents the object

	-- These four columns are unix timestamps. AP expects ISO timestamps
	startTime INTEGER,	-- When the object is said to have "begun," in some context
	endTime INTEGER,	-- When the object is said to "end," in some context
	published INTEGER,	-- When the object was first created
	updated INTEGER,	-- When the object was last updated

	FOREIGN KEY (attributedTo) REFERENCES object(id),
	PRIMARY KEY(id)
);

CREATE TABLE IF NOT EXISTS activity (
	objectId TEXT,

	-- All of these are object IDs, all of them are optional
	actor TEXT,		-- Actor "behind" the activity
	object TEXT,		-- Object encapsulated by the activity, if applicable
	origin TEXT,		-- Object the activity is "from"
	target TEXT,		-- Object the activity is "going to", or the encapsulated object is
	result TEXT,		-- Object describing the outcome
	instrument TEXT,	-- Object with which the activity was performed
	
	FOREIGN KEY (objectId) REFERENCES object(id),
	FOREIGN KEY (actor) REFERENCES object(id),
	FOREIGN KEY (object) REFERENCES object(id),
	FOREIGN KEY (origin) REFERENCES object(id),
	FOREIGN KEY (target) REFERENCES object(id),
	FOREIGN KEY (result) REFERENCES object(id),
	FOREIGN KEY (instrument) REFERENCES object(id),
	PRIMARY KEY (objectId)
);

CREATE TABLE IF NOT EXISTS object_contentMap (
	objectId INTEGER,	-- The object attaching `attachedId`
	key TEXT,		-- Langauge code
	content TEXT,		-- The content being mapped to by the key

	FOREIGN KEY(objectId) REFERENCES object(id),
	PRIMARY KEY(objectId, key)
);

CREATE TABLE IF NOT EXISTS object_attachment (
	objectId INTEGER,	-- The object attaching `attachedId`
	attachedId INTEGER,	-- The object attached by `objectId`

	FOREIGN KEY(objectId) REFERENCES object(id),
	FOREIGN KEY(attachedId) REFERENCES object(id),
	PRIMARY KEY(objectId, attachedId)
);

CREATE TABLE IF NOT EXISTS object_audience (
	objectId INTEGER,	-- Object identifying an audience
	audienceId INTEGER,	-- Audience being identified

	FOREIGN KEY(objectId) REFERENCES object(id),
	FOREIGN KEY(audienceId) REFERENCES object(id),
	PRIMARY KEY(objectId, audienceId)
);

CREATE TABLE IF NOT EXISTS object_replies (
	objectId INTEGER,	-- "original post," or whatever is being replied to
	responseId INTEGER,	-- The response to the original object

	FOREIGN KEY(objectId) REFERENCES object(id),
	FOREIGN KEY(responseId) REFERENCES object(id),
	PRIMARY KEY(objectId, responseId)
);

CREATE TABLE IF NOT EXISTS object_tags (
	taggerId INTEGER,
	taggedId INTEGER,

	FOREIGN KEY(taggerId) REFERENCES object(id),
	FOREIGN KEY(taggedId) REFERENCES object(id),
	PRIMARY KEY(taggerId, taggedId)
);