import time
import queue
import unittest
from unittest.mock import patch, MagicMock

import hbd.dns as dns


class TestDNS(unittest.TestCase):

    def test_create_nsupdate_payload_ipv4(self):
        p = dns.create_nsupdate_payload("host", "1.2.3.4", "example")
        self.assertIn("update add host.dy.example 5 A 1.2.3.4", p)
        self.assertNotIn("AAAA", p)

    def test_create_nsupdate_payload_ipv6(self):
        p = dns.create_nsupdate_payload("host", "2001:db8::1", "example")
        self.assertIn("update add host.dy.example 5 AAAA 2001:db8::1", p)

    @patch("hbd.dns.Popen")
    def test_nsupdate_success(self, mock_popen):
        proc = MagicMock()
        proc.communicate.return_value = (b"status: NOERROR", None)
        mock_popen.return_value = proc

        err = dns.nsupdate(
            "host",
            "1.2.3.4",
            "example",
            nsupdate_bin="/usr/bin/nsupdate",
            rndc_key="/etc/rndc.key",
        )

        self.assertIsNone(err)
        mock_popen.assert_called_once_with(
            ["/usr/bin/nsupdate", "-k", "/etc/rndc.key", "-v"],
            shell=False,
            bufsize=0,
            stdin=dns.PIPE,
            stdout=dns.PIPE,
            stderr=dns.STDOUT,
        )

    @patch("hbd.dns.Popen")
    def test_nsupdate_failure(self, mock_popen):
        proc = MagicMock()
        proc.communicate.return_value = (b"some error", None)
        mock_popen.return_value = proc

        err = dns.nsupdate("host", "1.2.3.4", "example", nsupdate_bin="/usr/bin/nsupdate", rndc_key="/etc/rndc.key")
        self.assertIsNotNone(err)
        self.assertIn("some error", err)

    def test_dnsupdatethread_processes_queue(self):
        # patch nsupdate to succeed
        with patch("hbd.dns.nsupdate", return_value=None):
            logs = []

            def log(h, m):
                logs.append((h, m))

            emails = []

            def email(s, m):
                emails.append((s, m))

            class FakeHost:
                dnsQ = queue.Queue()

            class FakeHbd:
                Host = FakeHost

            # start the thread (daemon) that processes the queue
            t = dns.start_dns_thread(FakeHbd, {"dyndomains": ["example"]}, log=log, email=email)
            self.assertTrue(t.is_alive())

            # enqueue one item and wait for it to be processed (polling with timeout)
            FakeHbd.Host.dnsQ.put(("testhost", "1.2.3.4"))

            for _ in range(30):
                if logs:
                    break
                time.sleep(0.1)

            self.assertTrue(logs, "dnsupdatethread did not call log")
            self.assertTrue(any("changed address" in m or "DNS updated" in m for (_h, m) in logs))

    def test_dnsupdatethread_calls_email_on_failure(self):
        # patch nsupdate to fail with an error message
        with patch("hbd.dns.nsupdate", return_value="error: failed"):
            logs = []

            def log(h, m):
                logs.append((h, m))

            emails = []

            def email(s, m):
                emails.append((s, m))

            class FakeHost:
                dnsQ = queue.Queue()

            class FakeHbd:
                Host = FakeHost

            t = dns.start_dns_thread(FakeHbd, {"dyndomains": ["example"]}, log=log, email=email)
            # enqueue and wait for the email to be sent
            FakeHbd.Host.dnsQ.put(("testhost", "1.2.3.4"))

            for _ in range(30):
                if emails:
                    break
                time.sleep(0.1)

            self.assertTrue(emails, "dnsupdatethread did not call email on failure")
            self.assertTrue(any("nsupdate failed" in s or "nsupdate failed" in m or "error" in m for (s, m) in emails))

    @patch("hbd.dns.Popen")
    def test_nsupdate_raises_oserror(self, mock_popen):
        mock_popen.side_effect = OSError("noexec")
        err = dns.nsupdate("h", "1.2.3.4", "example", nsupdate_bin="/usr/bin/nsupdate", rndc_key="/etc/rndc.key")
        self.assertIsNotNone(err)
        self.assertIn("execution failed", err)


if __name__ == "__main__":
    unittest.main()