import json
import unittest

import lotus_mc_status as s


def packet(players: dict) -> bytes:
    body = json.dumps({"version": {"name": "1.21.1"}, "players": players}).encode()
    return s.varint(0) + s.varint(len(body)) + body


class FormatStatus(unittest.TestCase):
    def test_nobody(self):
        self.assertEqual(s.format_status(0, []), "Nobody online")

    def test_one(self):
        self.assertEqual(s.format_status(1, ["Honnehh"]), "1 online: Honnehh")

    def test_sorted_regardless_of_server_order(self):
        self.assertEqual(s.format_status(3, ["b_x", "C", "a"]), "3 online: a, b_x, C")

    def test_long_names_collapse_and_stay_within_the_limit(self):
        names = [f"Player{i}_abcdefghi"[:16] for i in range(10)]
        got = s.format_status(10, names)
        self.assertLessEqual(len(got), s.MAX_LEN)
        self.assertRegex(got, r"^10 online: .+ \+\d+ more$")
        shown = got.split(": ")[1].split(" +")[0].split(", ")
        self.assertEqual(int(got.split("+")[1].split()[0]), 10 - len(shown))

    def test_exact_fit_has_no_more_suffix(self):
        got = s.format_status(1, ["A" * 16], max_len=len("1 online: ") + 16)
        self.assertEqual(got, "1 online: " + "A" * 16)

    def test_more_players_than_the_sample(self):
        self.assertEqual(s.format_status(14, ["a", "b"]), "14 online: a, b +12 more")

    def test_placeholders_are_not_shown_as_players(self):
        self.assertEqual(s.format_status(2, ["Anonymous Player", "a"]), "2 online: a +1 more")
        self.assertEqual(s.format_status(1, ["§cinjected name"]), "1 online")

    def test_count_only_when_nothing_fits(self):
        self.assertEqual(s.format_status(2, ["abcdefgh"], max_len=9), "2 online")

    def test_duplicates_and_stale_extras_do_not_overcount(self):
        self.assertEqual(s.format_status(1, ["a", "a", "b"]), "1 online: a")


class ParseStatus(unittest.TestCase):
    def test_with_sample(self):
        p = packet({"max": 20, "online": 2, "sample": [{"name": "a", "id": "x"}, {"name": "b", "id": "y"}]})
        self.assertEqual(s.parse_status(p), (2, ["a", "b"]))

    def test_without_sample(self):
        self.assertEqual(s.parse_status(packet({"max": 20, "online": 0})), (0, []))

    def test_rejects_other_packets_and_truncation(self):
        with self.assertRaises(ValueError):
            s.parse_status(s.varint(1) + b"xx")
        with self.assertRaises(ValueError):
            s.parse_status(packet({"max": 20, "online": 0})[:-3])

    def test_varint_round_trip(self):
        for n in (0, 1, 127, 128, 300, 6087, 2097151):
            data = iter([s.varint(n)])
            buf = next(data)
            pos = [0]

            def read(k, buf=buf, pos=pos):
                out = buf[pos[0] : pos[0] + k]
                pos[0] += k
                return out

            self.assertEqual(s.read_varint(read), n)


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