-- LUALOCALS < ---------------------------------------------------------
local error, io, ipairs, minetest, pairs, string, type
    = error, io, ipairs, minetest, pairs, string, type
local io_open, string_format, string_gsub
    = io.open, string.format, string.gsub
-- LUALOCALS > ---------------------------------------------------------

local include = ...
local mediacache = include("mediacache")

local function getdir(s)
	if not minetest.mkdir(s) then return error(string_format("failed to mkdir %q", s)) end
	return s
end

local function cpfile(src, dst)
	local done = io_open(dst, "rb")
	if done then
		done:close()
		return true
	end
	local sf = io_open(src, "rb")
	if not sf then return error(string_format("failed to read %q", src)) end
	local df = io_open(dst, "wb")
	if not sf then return error(string_format("failed to write %q", dst)) end
	while true do
		local chunk = sf:read(65536)
		if not chunk then
			sf:close()
			df:close()
			return true
		end
		df:write(chunk)
	end
end

local function ripmedia(reffed, thing, dest, rel, test)
	test = test or function(a, b) return a == b end
	if type(thing) == "string" then
		for _, s in ipairs(string_gsub(thing, "[\\[:,=&{]", "^"):split("^")) do
			for k, v in pairs(mediacache) do
				if test(s, k) then
					local fulldest = getdir(dest .. "/" .. rel) .. "/" .. k
					cpfile(v, fulldest)
					reffed[fulldest] = true
				end
			end
		end
	elseif type(thing) == "table" then
		if thing.name then return ripmedia(reffed, thing.name, dest, rel, test) end
		for _, v in pairs(thing) do
			ripmedia(reffed, v, dest, rel, test)
		end
	end
end

return getdir, ripmedia