"""The lgbot plugin's frame logic (tick) against a fake minqlx: deaths, gaps, targets, acceleration."""
import importlib.util, logging, math, os, sys, types, unittest

PLUGIN = os.path.join(os.path.dirname(os.path.abspath(__file__)), "..", "home", "minqlx-plugins", "lgbot.py")
BOT_ID = 90071996842377216
HUMAN_ID = 76561198000000000


class V:
    def __init__(self, x, y, z):
        self.x, self.y, self.z = x, y, z


class FakePlayer:
    def __init__(self, cid, name, steam_id, pos):
        self.id, self.clean_name, self.steam_id = cid, name, steam_id
        self.team, self.is_alive, self.health = "free", True, 100
        self.pos, self.vel = list(pos), [0.0, 0.0, 0.0]
        self.sets = []

    def position(self):
        return V(*self.pos)

    def velocity(self, **kw):
        if kw:
            self.vel = [kw.get("x", self.vel[0]), kw.get("y", self.vel[1]), kw.get("z", self.vel[2])]
            self.sets.append(tuple(self.vel))
            return True
        return V(*self.vel)


class World:
    """Stands in for the server: players, cvars, a clock; moves players by their velocity."""

    def __init__(self):
        self.players, self.cvars, self.now = [], {}, 1000.0

    def frame(self, plugin, dt=0.025):
        self.now += dt
        plugin.handle_frame()
        for p in self.players:
            p.pos[0] += p.vel[0] * 0.85 * dt   # friction eats ~15%, like the measured server
            p.pos[1] += p.vel[1] * 0.85 * dt
            p.vel[0] *= 0.85
            p.vel[1] *= 0.85


def load(world):
    fake = types.ModuleType("minqlx")

    class Plugin:
        def __init__(self):
            self.logger = logging.getLogger("lgbot-test")

        def set_cvar_once(self, name, value):
            world.cvars.setdefault(name, value)

        def get_cvar(self, name):
            return world.cvars.get(name)

        def add_hook(self, event, fn):
            pass

        def players(self):
            return list(world.players)

    def log_exception(plugin=None):
        raise  # surface plugin errors in the test

    fake.Plugin, fake.log_exception = Plugin, log_exception
    sys.modules["minqlx"] = fake
    try:
        spec = importlib.util.spec_from_file_location("lgbot_under_test", PLUGIN)
        mod = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(mod)
    finally:
        del sys.modules["minqlx"]
    mod.time = types.SimpleNamespace(time=lambda: world.now)
    plugin = mod.lgbot()
    plugin.strafer.rng.seed(11) if hasattr(plugin.strafer.rng, "seed") else None
    return mod, plugin


def sideways_sign(bot, human):
    # sign of the bot's velocity across the bot->human line
    dx, dy = human.pos[0] - bot.pos[0], human.pos[1] - bot.pos[1]
    return 1 if (-dy * bot.vel[0] + dx * bot.vel[1]) > 0 else -1


class Tick(unittest.TestCase):
    def setUp(self):
        self.w = World()
        self.bot = FakePlayer(0, "lgbot", BOT_ID, (0, 0, 0))
        self.human = FakePlayer(1, "player", HUMAN_ID, (450, 0, 0))
        self.w.players = [self.bot, self.human]
        self.w.cvars["lgbot_move"] = "5"
        self.mod, self.plugin = load(self.w)

    def run_frames(self, n):
        for _ in range(n):
            self.w.frame(self.plugin)

    def test_steers_when_human_in_range(self):
        self.run_frames(40)
        self.assertTrue(self.bot.sets)

    def test_human_named_lgbot_is_left_alone(self):
        self.bot.steam_id = HUMAN_ID
        self.run_frames(40)
        self.assertEqual(self.bot.sets, [])

    def test_strafes_both_ways_after_respawn(self):
        self.run_frames(80)
        self.bot.is_alive = False
        self.run_frames(400)                      # 10 s dead
        self.bot.is_alive = True
        self.bot.pos = [0, 0, 0]
        signs = []
        for _ in range(400):
            self.w.frame(self.plugin)
            signs.append(sideways_sign(self.bot, self.human))
        self.assertLess(max(signs.count(1), signs.count(-1)) / 400.0, 0.75)

    def test_strafes_both_ways_after_walking_in(self):
        self.human.pos = [3000, 0, 0]             # far: AI walks
        self.run_frames(400)
        self.human.pos = [450, 0, 0]
        signs = []
        for _ in range(400):
            self.w.frame(self.plugin)
            signs.append(sideways_sign(self.bot, self.human))
        self.assertLess(max(signs.count(1), signs.count(-1)) / 400.0, 0.75)

    def test_velocity_changes_like_a_player_not_instantly(self):
        self.run_frames(400)
        sets = self.bot.sets
        comp = self.mod.FRICTION_COMP
        biggest = max(math.hypot(b[0] - a[0] * 0.85, b[1] - a[1] * 0.85) for a, b in zip(sets, sets[1:]))
        # per frame: at most the acceleration step (plus friction compensation), never a 640 u/s flip
        self.assertLess(biggest, self.mod.ACCEL * 0.025 * comp + 0.15 * 320 * comp + 1)

    def test_no_target_means_no_steering(self):
        self.human.team = "spectator"
        self.run_frames(40)
        self.assertEqual(self.bot.sets, [])


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