"""Unit tests for the WLED native realtime UDP packet builder."""

import numpy as np

from ledgrab.core.devices.wled_realtime_client import (
    DEFAULT_REALTIME_TIMEOUT,
    WledRealtimeClient,
    _clamp_timeout,
)


def _rgb(n: int) -> np.ndarray:
    return np.arange(n * 3, dtype=np.uint8).reshape(n, 3)


def test_drgb_small_rgb_strip():
    c = WledRealtimeClient("1.2.3.4", timeout_secs=2)
    pixels = _rgb(10)
    packets = c.build_packets(pixels)
    assert len(packets) == 1
    p = packets[0]
    assert p[0] == 2  # DRGB
    assert p[1] == 2  # timeout seconds
    assert len(p) == 2 + 10 * 3
    assert p[2:] == pixels.tobytes()


def test_drgbw_sets_explicit_white_zero():
    c = WledRealtimeClient("1.2.3.4", rgbw=True, timeout_secs=5)
    pixels = np.full((4, 3), 200, dtype=np.uint8)
    packets = c.build_packets(pixels)
    assert len(packets) == 1
    p = packets[0]
    assert p[0] == 3  # DRGBW
    assert p[1] == 5
    assert len(p) == 2 + 4 * 4
    body = np.frombuffer(p[2:], dtype=np.uint8).reshape(4, 4)
    assert (body[:, 0:3] == 200).all()
    assert (body[:, 3] == 0).all()  # white channel zeroed


def test_dnrgb_chunks_large_rgb_strip():
    c = WledRealtimeClient("1.2.3.4", timeout_secs=3)
    n = 1000  # > 490 -> DNRGB, > 489 per chunk -> 3 packets (489+489+22)
    pixels = _rgb(n)
    packets = c.build_packets(pixels)
    assert len(packets) == 3
    # Each packet starts with [4][timeout][start_hi][start_lo]
    starts = []
    total_leds = 0
    for p in packets:
        assert p[0] == 4  # DNRGB
        assert p[1] == 3  # timeout
        start = (p[2] << 8) | p[3]
        starts.append(start)
        leds = (len(p) - 4) // 3
        total_leds += leds
    assert starts == [0, 489, 978]
    assert total_leds == n


def test_dnrgb_reassembles_to_original():
    c = WledRealtimeClient("1.2.3.4", timeout_secs=1)
    n = 700
    pixels = _rgb(n)
    out = bytearray()
    for p in c.build_packets(pixels):
        out += p[4:]
    assert bytes(out) == pixels.tobytes()


def test_empty_frame_no_packets():
    c = WledRealtimeClient("1.2.3.4")
    assert c.build_packets(np.zeros((0, 3), dtype=np.uint8)) == []


def test_timeout_clamped_to_wire_range():
    assert _clamp_timeout(0) == 1
    assert _clamp_timeout(-5) == 1
    assert _clamp_timeout(255) == 255
    assert _clamp_timeout(1000) == 255
    assert WledRealtimeClient("h", timeout_secs=0).timeout_secs == 1


def test_rgbw_over_capacity_falls_back_to_dnrgb():
    # 400 RGBW LEDs (> 367) can't use DRGBW; falls back to DNRGB (RGB).
    c = WledRealtimeClient("1.2.3.4", rgbw=True, timeout_secs=2)
    packets = c.build_packets(_rgb(400))
    assert all(p[0] == 4 for p in packets)  # DNRGB


def test_default_timeout_constant():
    assert DEFAULT_REALTIME_TIMEOUT == 2
    assert WledRealtimeClient("h").timeout_secs == 2