-- pieces of levels

Chunk = {
	-- set of all chunks in the level.
	-- chunks are the keys, for easier removal.
	all = {},
}
Chunk.__index = Chunk

--[[
instance fields:

[string] filename
[Rect or nil] box
[table or nil] data
	data loaded from the chunks file. may be nil.
[table or nil] loaded
	entities that exist in the chunk.
]]

-- CLASS METHODS

-- box == nil for global chunks
function Chunk:new(filename, box)
	local o = { filename = filename, box = box }
	setmetatable(o, self)
	self.all[o] = true
end

function Chunk:getExportList()
	local r = {}
	for chunk in pairs(self.all) do
		table.insert(r, {chunk.filename, chunk.box})
	end
	return r
end

-- INSTANCE METHODS

function Chunk:containsPoint(pt)
	return self.box == nil or self.box:containsPoint(pt)
end

function Chunk:load()
	if self.loaded then
		return
	end
	logPrint("loading chunk "..self.filename)
	self.data = dofile(level_current.."/chunks/"..self.filename)
	self.loaded = { rooms = {}, collisions = {} }
	LevelTiles = self.data.tiles
	indexLevelTiles()
	optimizeTileObjects(self.loaded.collisions)

	for _, v in ipairs(self.data.rooms or {}) do
		local room = Collision:new(v[1],v[2],v[3],v[4])
		table.insert(self.data.rooms, room)
		table.insert(LoadedObjects.Rooms, room)
	end
	logPrint("loaded chunk with "..#self.loaded.collisions.." collisions")
end

function Chunk:save(chunkdir)
	return love.filesystem.write(chunkdir.."/"..self.filename, "return "..serialize_lua_value(self.data))
end