try:
    from rpi_ws281x import Color
except (ImportError, RuntimeError):
    from mock_rpi_ws281x import Color
from config import PANEL_PIXEL_COUNT, DISPLAY_MAX_X, DISPLAY_MAX_Y
from fonts import FONT_7X5

# Set by main.py after strip is created
strip = None


def _pixel_index(x, y):
    if x % 2 == 1:
        y = PANEL_PIXEL_COUNT - 1 - y
    return y + (x * PANEL_PIXEL_COUNT)


def set_pixel(x, y, r, g, b):
    if x < 0 or y < 0 or x > DISPLAY_MAX_X or y > DISPLAY_MAX_Y:
        return
    strip.setPixelColor(_pixel_index(x, y), Color(r, g, b))


def get_pixel_color(x, y):
    """Returns (r, g, b) tuple."""
    if x < 0 or y < 0 or x > DISPLAY_MAX_X or y > DISPLAY_MAX_Y:
        return (0, 0, 0)
    c = strip.getPixelColor(_pixel_index(x, y))
    return ((c >> 16) & 0xFF, (c >> 8) & 0xFF, c & 0xFF)


def fill_pixels(x1, y1, x2, y2, r, g, b):
    if x1 > x2:
        x1, x2 = x2, x1
    if y1 > y2:
        y1, y2 = y2, y1
    for y in range(y1, y2 + 1):
        for x in range(x1, x2 + 1):
            set_pixel(x, y, r, g, b)


def shift_rectangle_left(x1, y1, x2, y2, shift_by):
    if not shift_by:
        return
    if x1 > x2:
        x1, x2 = x2, x1
    if y1 > y2:
        y1, y2 = y2, y1
    for y in range(y1, y2 + 1):
        if y < 0 or y > DISPLAY_MAX_Y:
            continue
        for x in range(x1, x2 + 1):
            src_x = x1 + (x - x1)
            dest_x = src_x - shift_by
            color = (0, 0, 0)
            if 0 <= src_x <= DISPLAY_MAX_X:
                color = get_pixel_color(src_x, y)
            if 0 <= dest_x <= DISPLAY_MAX_X:
                set_pixel(dest_x, y, *color)
    for y in range(y1, y2 + 1):
        if y < 0 or y > DISPLAY_MAX_Y:
            continue
        for x in range(x2 - shift_by + 1, x2 + 1):
            if 0 <= x <= DISPLAY_MAX_X:
                set_pixel(x, y, 0, 0, 0)


def draw_character_part(row_data, width, r, g, b, start_x, start_y):
    for col in range(width):
        if row_data[col]:
            px = col + start_x
            py = start_y
            if 0 <= px <= DISPLAY_MAX_X and 0 <= py <= DISPLAY_MAX_Y:
                set_pixel(px, py, r, g, b)


def draw_character(char_data, height, width, r, g, b, cursor):
    """Draws one character at cursor position, advances cursor.x by width+1."""
    for row in range(height):
        draw_character_part(char_data[row], width, r, g, b, cursor['x'], row + cursor['y'])
    cursor['x'] += width + 1