import sys
from pathlib import Path
sys.path.insert(0, str(Path(__file__).resolve().parent))
import numpy as np
import pytest
from geometry import output_size, padded_size, tile_coordinates

@pytest.mark.parametrize('width,height', [(2048,2048),(2048,1365),(1024,683),(128,8),(1,1),(1,4096),(4096,1),(4096,4096)])
def test_tiles_cover_every_pixel_without_stretching(width, height):
    pw, ph = padded_size(width, height)
    coverage = np.zeros((ph // 8, pw // 8), dtype=np.uint8)
    coords = tile_coordinates(ph // 8, pw // 8, 64, 64, 8)
    assert coords
    for y,x in coords:
        assert x % 2 == y % 2 == 0
        assert coverage[y:y+64,x:x+64].shape == (64,64)
        coverage[y:y+64,x:x+64] += 1
    assert coverage.min() > 0

@pytest.mark.parametrize('width,height,size,expected', [(683,1024,'2×',(1366,2048)),(1,2048,'2048 px long edge',(1,2048)),(100,75,'4096 px long edge',(4096,3072)),(128,8,'4×',(512,32))])
def test_exact_output_dimensions(width,height,size,expected):
    assert output_size(width,height,size) == expected

def test_rejects_oversized_output():
    with pytest.raises(ValueError):
        output_size(4096,4096,'4×')


def test_final_tiles_are_anchored_at_border():
    coords = tile_coordinates(256,256,64,64,8)
    assert coords[-1] == (192,192)
    assert len(coords) == 25