import sys
if "lib" not in sys.path:
    sys.path.insert(0, "lib")
if "../lib" not in sys.path:
    sys.path.insert(0, "../lib")
from ws2812 import WS2812B
import time

# --- Chase test: pregenerated double buffer per strip, show via head offset (same as rainbow) ---

# (pin, num_leds) per strip — same config as rainbow
STRIP_CONFIG = (
    (2, 291),
    (3, 290),
    (4, 283),
    (7, 278),
    (0, 275),
    (28, 278),
    (29, 283),
    (6, 290),
)

strips = []
sm = 0
for pin, num_leds in STRIP_CONFIG:
    print(pin, num_leds)
    ws = WS2812B(num_leds, pin, sm, brightness=1.0)
    strips.append(ws)
    sm += 1

cumulative_leds = [0]
for ws in strips[:-1]:
    cumulative_leds.append(cumulative_leds[-1] + ws.num_leds)
total_ring_leds = cumulative_leds[-1] + strips[-1].num_leds

# Chase: trail length (0 = single LED), color (R,G,B)
TRAIL_LEN = 8
CHASE_COLOR = (0, 255, 100)  # cyan-green


def make_chase_double(num_leds, cumulative_leds, total_ring_leds, color, trail_len=0):
    """Pregenerate strip double buffer: when head shows index b first, that pixel is at
    distance (2*cumulative_leds - b) % total_ring_leds from chase head. GRB order."""
    n = 2 * num_leds
    buf = bytearray(n * 3)
    for b in range(n):
        dist = (2 * cumulative_leds - b) % total_ring_leds
        if dist == 0:
            r, grn, b_ = color[0], color[1], color[2]
        elif trail_len and 0 < dist <= trail_len:
            fade = 1.0 - (dist / (trail_len + 1))
            r = int(color[0] * fade)
            grn = int(color[1] * fade)
            b_ = int(color[2] * fade)
        else:
            r = grn = b_ = 0
        o = b * 3
        buf[o] = grn
        buf[o + 1] = r
        buf[o + 2] = b_
    return buf


# Pregenerate one double buffer per strip
chase_buffers = [
    make_chase_double(ws.num_leds, cumulative_leds[i], total_ring_leds, CHASE_COLOR, TRAIL_LEN)
    for i, ws in enumerate(strips)
]

chase_pos = 0
while True:
    for i, strip in enumerate(strips):
        # head in [0, strip_len) so DMA read head..head+num_leds*3 stays in double buffer (same as rainbow)
        strip_len = strip.num_leds * 3
        head = (chase_pos + cumulative_leds[i]) * 3 % strip_len
        strip.show(chase_buffers[i], head)
    chase_pos = (chase_pos + 1) % total_ring_leds
    time.sleep_ms(20)