def clear(np):
    for i in range(np.n):
        np[i] = (0, 0, 0)
    np.write()


def white(np, brightness=255):
    for i in range(np.n):
        np[i] = (brightness, brightness, brightness)
    np.write()

def demo(np):
    import utime

    n = np.n

    # cycle
    for i in range(4 * n):
        for j in range(n):
            np[j] = (0, 0, 0)
        np[i % n] = (255, 255, 255)
        np.write()
        utime.sleep_ms(25)

    # bounce
    for i in range(4 * n):
        for j in range(n):
            np[j] = (0, 0, 128)
        if (i // n) % 2 == 0:
            np[i % n] = (0, 0, 0)
        else:
            np[n - 1 - (i % n)] = (0, 0, 0)
        np.write()
        utime.sleep_ms(60)

    # fade in/out
    for i in range(0, 4 * 256, 8):
        for j in range(n):
            if (i // 256) % 2 == 0:
                val = i & 0xff
            else:
                val = 255 - (i & 0xff)
            np[j] = (val, 0, 0)
        np.write()

    # clear
    for i in range(n):
        np[i] = (0, 0, 0)
    np.write()

def slide(np):
    import utime

    position = 0
    add = False

    while True:

        position += 1
        n = np.n


        if position > n:
            position = 0

        brightness = 255

        for i in range(n):
            pos = i + position
            if pos >= n:
                pos = pos - n

            np[pos] = (brightness, brightness, brightness)

            if brightness < 10:
                add = True
            elif brightness > 250:
                add = False

            if add:
                brightness += 10
            else:
                brightness -= 10

        np.write()
        utime.sleep_ms(10)

def gradient_light(np, position=0):
    color = [122, 255, 0]
    value = 255/np.n*2
    add = [True, False, True]

    for pos in range(np.n):
        for i in range(len(color)):
            if color[i] < 10:
                add[i] = True
            elif color[i] > 245:
                add[i] = False

            if add[i]:
                color[i] += value
            else:
                color[i] -= value

        if position+pos >= np.n:
            pos = pos - np.n

        np[position+pos] = tuple(int(i) for i in color)

    np.write()

def gradient_light(np, position=0):
    color = [122, 255, 0]
    value = 255/np.n*2
    add = [True, False, True]

    for pos in range(np.n):
        for i in range(len(color)):
            if color[i] < value:
                add[i] = True
            elif color[i] > 255-value:
                add[i] = False

            if add[i]:
                color[i] += value
            else:
                color[i] -= value

        if position+pos >= np.n:
            pos = pos - np.n

        np[position+pos] = tuple(int(i) for i in color)

    np.write()

def gradient_colorfull(np, position=0):
    r = 255
    g = 0
    b = 0
    value = 255/np.n*3
    r_add = -1
    g_add = +1
    b_add = 0

    for pos in range(np.n):
        if r < value and r_add == -1:
            r_add = 0
        elif r > 255-value and r_add == +1:
            r_add = -1
            g_add = +1

        if g < value and g_add == -1:
            g_add = 0
        elif g > 255-value and g_add == +1:
            g_add = -1
            b_add = +1

        if b < value and b_add == -1:
            b_add = 0
        elif b > 255-value and b_add == +1:
            b_add = -1
            r_add = +1


        r += r_add * value
        g += g_add * value
        b += b_add * value
        if position+pos >= np.n:
            pos = pos - np.n

        np[position+pos] = (int(r), int(g), int(b))

    np.write()

def color_slide(np, gradient_f=gradient_colorfull):
    import utime

    position = 0

    n = np.n

    while True:
        position += 1

        if position > n:
            position = 0

        gradient_f(np, position=position)

        utime.sleep_ms(10)