-- SPDX-FileCopyrightText: © 2022—2026 Vladimir Zorin <vladimir@deviant.guru>
-- SPDX-License-Identifier: LicenseRef-OWL-1.0-or-later
-- Licensed under OWL v1.0+. See LICENSE.

local testimony = require("testimony")
local client = require("dns.client")
local cache = require("dns.cache")

local testify = testimony.new("== dns.client ==")

-- =========================================================================
-- Constructor
-- =========================================================================

testify:that("new: returns resolver with default config", function()
	local r, err = client.new({ servers = { "1.1.1.1" } })
	testimony.assert_not_nil(r, "expected resolver, got error: " .. (err or "nil"))
	testimony.assert_equal(5, r.cfg.timeout)
	testimony.assert_equal(2, r.cfg.retries)
	testimony.assert_equal(1, r.cfg.ndots)
	testimony.assert_equal(false, r.cfg.use_tcp)
	testimony.assert_equal(false, r.cfg.use_tls)
	testimony.assert_equal(false, r.cfg.use_0x20)
	testimony.assert_equal(4096, r.cfg.edns_buffer_size)
	r:close()
end)

testify:that("new: accepts all config options", function()
	local c = cache.new()
	local r, err = client.new({
		servers = { "8.8.8.8", "8.8.4.4" },
		timeout = 3,
		retries = 1,
		ndots = 2,
		search = { "corp.internal." },
		edns_buffer_size = 1232,
		use_0x20 = true,
		cache = c,
	})
	testimony.assert_not_nil(r, "expected resolver, got error: " .. (err or "nil"))
	testimony.assert_equal(3, r.cfg.timeout)
	testimony.assert_equal(1, r.cfg.retries)
	testimony.assert_equal(2, r.cfg.ndots)
	testimony.assert_equal(1232, r.cfg.edns_buffer_size)
	testimony.assert_equal(true, r.cfg.use_0x20)
	testimony.assert_equal(2, #r.cfg.servers)
	testimony.assert_equal(1, #r.cfg.search)
	r:close()
end)

testify:that("new: returns nil when servers missing", function()
	local r, err = client.new({})
	testimony.assert_nil(r)
	testimony.assert_match("servers", err)
end)

testify:that("new: returns nil when servers empty", function()
	local r, err = client.new({ servers = {} })
	testimony.assert_nil(r)
	testimony.assert_match("servers", err)
end)

-- =========================================================================
-- resolve() — Validation
-- =========================================================================

testify:that("resolve: rejects unknown string qtype", function()
	local r, err = client.new({ servers = { "1.1.1.1" } })
	testimony.assert_not_nil(r, "expected resolver, got error: " .. (err or "nil"))
	local answers, qerr = r:resolve("example.com", "BOGUS")
	testimony.assert_nil(answers)
	testimony.assert_match("unknown query type", qerr)
	r:close()
end)

-- =========================================================================
-- close()
-- =========================================================================

testify:that("close: is callable without error", function()
	local r, err = client.new({ servers = { "1.1.1.1" } })
	testimony.assert_not_nil(r, "expected resolver, got error: " .. (err or "nil"))
	r:close()
	-- Should not raise
end)

-- =========================================================================
-- parse_resolv_conf()
-- =========================================================================

testify:that("parse_resolv_conf: parses system resolv.conf", function()
	local result, err = client.parse_resolv_conf()
	testimony.assert_not_nil(result, "expected result, got error: " .. (err or "nil"))
	testimony.assert_not_nil(result.servers)
	testimony.assert_true(#result.servers > 0, "expected at least one nameserver")
	for _, s in ipairs(result.servers) do
		testimony.assert_not_nil(s.host, "expected host field in server entry")
	end
end)

testify:that("parse_resolv_conf: returns nil for nonexistent file", function()
	local result, err = client.parse_resolv_conf("/nonexistent/resolv.conf")
	testimony.assert_nil(result)
	testimony.assert_not_nil(err)
end)

testify:that("parse_resolv_conf: output accepted by new()", function()
	local sys, err = client.parse_resolv_conf()
	if not sys or #sys.servers == 0 then
		return
	end
	local r, rerr = client.new(sys)
	testimony.assert_not_nil(r, "expected resolver from resolv.conf, got error: " .. (rerr or "nil"))
	r:close()
end)

-- =========================================================================
-- Server normalization
-- =========================================================================

testify:that("new: normalizes string servers to tables", function()
	local r, err = client.new({ servers = { "1.1.1.1", "8.8.8.8" } })
	testimony.assert_not_nil(r, "expected resolver, got error: " .. (err or "nil"))
	testimony.assert_equal("1.1.1.1", r.cfg.servers[1].host)
	testimony.assert_equal("8.8.8.8", r.cfg.servers[2].host)
	testimony.assert_nil(r.cfg.servers[1].port)
	r:close()
end)

testify:that("new: accepts table servers with host and port", function()
	local r, err = client.new({ servers = { { host = "1.1.1.1", port = 5353 } } })
	testimony.assert_not_nil(r, "expected resolver, got error: " .. (err or "nil"))
	testimony.assert_equal("1.1.1.1", r.cfg.servers[1].host)
	testimony.assert_equal(5353, r.cfg.servers[1].port)
	r:close()
end)

testify:that("new: accepts mixed string and table servers", function()
	local r, err = client.new({ servers = { "1.1.1.1", { host = "8.8.8.8", port = 5353 } } })
	testimony.assert_not_nil(r, "expected resolver, got error: " .. (err or "nil"))
	testimony.assert_equal("1.1.1.1", r.cfg.servers[1].host)
	testimony.assert_nil(r.cfg.servers[1].port)
	testimony.assert_equal("8.8.8.8", r.cfg.servers[2].host)
	testimony.assert_equal(5353, r.cfg.servers[2].port)
	r:close()
end)

testify:that("new: rejects table server without host", function()
	local r, err = client.new({ servers = { { port = 5353 } } })
	testimony.assert_nil(r)
	testimony.assert_match("host", err)
end)

-- =========================================================================
-- Conclude
-- =========================================================================

testify:conclude()