"""read_marker_id: template-correlation read of a marker's own small
"#<N>" id label (see map_vision.read_marker_id's own docstring for why
this is template correlation, not OCR -- same reasoning as
read_cell_label). Synthetic image, real font, no fixture screenshot or
the (slow) detection pipeline needed -- just render the label the way
the game does and check it round-trips.
"""
import numpy as np
from PIL import Image, ImageDraw, ImageFont

from fenigma import map_vision


def _render_label(text: str, height: int) -> Image.Image:
    """Cream glyph, heavy dark outline, same style glyph_template expects
    to correlate against -- see glyph_template's own docstring."""
    font = ImageFont.truetype(str(map_vision.FONT_PATH), height)
    pad = height
    im = Image.new("L", (height * 4 + pad, height * 2 + pad), 30)  # dark "photo" background
    ImageDraw.Draw(im).text((pad // 2, pad // 4), text, font=font, fill=230,
                            stroke_width=max(1, int(height * 0.10)), stroke_fill=0)
    return im


def test_reads_a_clean_id_label():
    # A marker box roughly where a real one measures (see read_marker_id's
    # own calibration note), with a rendered "#8" sitting where the game
    # draws it: above-left of the box.
    box_w, box_h = 40, 40
    label_h = int(0.45 * box_h)
    label_im = _render_label("#8", label_h)

    canvas = Image.new("L", (200, 200), 60)
    label_x, label_y = 60, 60
    canvas.paste(label_im, (label_x, label_y))
    gray = np.array(canvas)

    box_x = label_x + int(1.0 * box_w) - 5   # box sits to the right of/below the label
    box_y = label_y + int(0.45 * box_h)
    box = (box_x, box_y, box_w, box_h)

    assert map_vision.read_marker_id(gray, box) == "8"


def test_returns_none_on_a_blank_patch():
    gray = np.full((200, 200), 60, dtype=np.uint8)
    box = (100, 100, 40, 40)
    assert map_vision.read_marker_id(gray, box) is None


def test_returns_none_on_a_degenerate_box_at_the_image_edge():
    gray = np.full((200, 200), 60, dtype=np.uint8)
    box = (0, 0, 2, 2)  # crop region collapses to nothing usable
    assert map_vision.read_marker_id(gray, box) is None