-- SPDX-FileCopyrightText: © 2026 Vladimir Zorin <vladimir@deviant.guru>
-- SPDX-License-Identifier: OWL-1.0 or later

local testimony = require("testimony")
local std = require("std")
local mneme = require("mneme")
local sleep = function(sec)
	os.execute("sleep " .. sec)
end

local testify = testimony.new("== mneme: TTL and expiry ==")

local tmp_path = function()
	return "/tmp/mneme_ttl_" .. std.nanoid() .. ".mneme"
end

testify:that("set with TTL, get before expiry succeeds", function()
	local path = tmp_path()
	local db = mneme.open(path, { sync = "none" })
	local ks = db:keyspace("t")

	ks:set("session", "data", { ttl = 60 })
	local val = ks:get("session")
	testimony.assert_equal("data", val)

	db:close()
	std.fs.remove(path)
end)

testify:that("set with TTL=1, get after expiry returns nil", function()
	local path = tmp_path()
	local db = mneme.open(path, { sync = "none" })
	local ks = db:keyspace("t")

	ks:set("ephemeral", "gone_soon", { ttl = 1 })

	-- Immediately should be available
	testimony.assert_equal("gone_soon", ks:get("ephemeral"))

	-- Wait for expiry
	sleep(2)

	-- Should be expired now
	local val = ks:get("ephemeral")
	testimony.assert_nil(val)

	db:close()
	std.fs.remove(path)
end)

testify:that("ttl() returns remaining seconds", function()
	local path = tmp_path()
	local db = mneme.open(path, { sync = "none" })
	local ks = db:keyspace("t")

	ks:set("k", "v", { ttl = 60 })
	local remaining = ks:ttl("k")
	testimony.assert_not_nil(remaining)
	testimony.assert_true(remaining > 55 and remaining <= 60)

	db:close()
	std.fs.remove(path)
end)

testify:that("ttl() returns nil for key without TTL", function()
	local path = tmp_path()
	local db = mneme.open(path, { sync = "none" })
	local ks = db:keyspace("t")

	ks:set("no_ttl", "forever")
	local remaining = ks:ttl("no_ttl")
	testimony.assert_nil(remaining)

	db:close()
	std.fs.remove(path)
end)

testify:that("persist() removes TTL", function()
	local path = tmp_path()
	local db = mneme.open(path, { sync = "none" })
	local ks = db:keyspace("t")

	ks:set("k", "v", { ttl = 2 })
	testimony.assert_not_nil(ks:ttl("k"))

	ks:persist("k")
	testimony.assert_nil(ks:ttl("k"))

	-- Should survive past original TTL
	sleep(3)
	testimony.assert_equal("v", ks:get("k"))

	db:close()
	std.fs.remove(path)
end)

testify:that("purge_expired removes expired keys", function()
	local path = tmp_path()
	local db = mneme.open(path, { sync = "none" })
	local ks = db:keyspace("t")

	ks:set("live", "yes", { ttl = 60 })
	ks:set("dead1", "no", { ttl = 1 })
	ks:set("dead2", "no", { ttl = 1 })
	ks:set("permanent", "always")

	sleep(2)

	local purged = ks:purge_expired()
	testimony.assert_equal(2, purged)

	-- Live and permanent keys still exist
	testimony.assert_equal("yes", ks:get("live"))
	testimony.assert_equal("always", ks:get("permanent"))

	-- Dead keys are gone even from scan
	testimony.assert_equal(2, ks:count())

	db:close()
	std.fs.remove(path)
end)

testify:that("scan skips expired keys", function()
	local path = tmp_path()
	local db = mneme.open(path, { sync = "none" })
	local ks = db:keyspace("t")

	ks:set("a", "alive")
	ks:set("b", "expired", { ttl = 1 })
	ks:set("c", "alive")

	sleep(2)

	local keys = {}
	for k in ks:scan() do
		table.insert(keys, k)
	end

	testimony.assert_equal(2, #keys)
	testimony.assert_equal("a", keys[1])
	testimony.assert_equal("c", keys[2])

	db:close()
	std.fs.remove(path)
end)

testify:conclude()