-- 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 testify = testimony.new("== mneme: MVCC origin tracking ==")

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

local function setup()
	local path = tmp_path()
	local db = mneme.open(path, { sync = "none" })
	local txn = db:txn_begin(false)
	local info = db:info()
	return db, txn, info.keyspace_root_pgno, path
end

local function teardown(db, path)
	db:close()
	std.fs.remove(path)
end

testify:that("freeing same-txn allocated page does not add to pending retire", function()
	local db, txn, _, path = setup()

	local pgno = txn:page_alloc()
	testimony.assert_not_nil(pgno)
	testimony.assert_not_nil(txn:page_free(pgno))

	local meta = txn:meta()
	testimony.assert_not_nil(meta)
	testimony.assert_not_nil(txn:commit())

	teardown(db, path)
end)

testify:that("same-txn overflow replacement commits cleanly", function()
	local db, txn, root, path = setup()

	local v1 = string.rep("A", 5000)
	local v2 = string.rep("B", 6000)

	root = txn:btree_put(root, "big", v1)
	testimony.assert_not_nil(root)
	root = txn:btree_put(root, "big", v2)
	testimony.assert_not_nil(root)
	local got = txn:btree_get(root, "big")
	testimony.assert_equal(v2, got)

	testimony.assert_not_nil(txn:commit())

	local rtxn = db:txn_begin(true)
	local reread = rtxn:btree_get(root, "big")
	testimony.assert_equal(v2, reread)
	rtxn:abort()

	teardown(db, path)
end)

testify:that("branch split path with later branch split commits cleanly", function()
	local db, txn, root, path = setup()

	for i = 1, 1200 do
		local k = string.format("k:%06d", i)
		local v = string.rep(string.char(65 + (i % 26)), 40)
		root = txn:btree_put(root, k, v)
		testimony.assert_not_nil(root)
	end

	for i = 1, 1200 do
		local k = string.format("k:%06d", i)
		local got = txn:btree_get(root, k)
		testimony.assert_not_nil(got)
	end

	testimony.assert_not_nil(txn:commit())
	teardown(db, path)
end)

testify:conclude()