import pytest
import io
from PIL import Image
import blurhash
import numpy as np

def create_dummy_image(format="JPEG", mode="RGB", size=(100, 100), color=(255, 0, 0)):
    img = Image.new(mode, size, color)
    buf = io.BytesIO()
    img.save(buf, format=format)
    return buf.getvalue()

def test_blurhash_encode_jpeg():
    raw_bytes = create_dummy_image(format="JPEG", mode="RGB")
    img = Image.open(io.BytesIO(raw_bytes)).convert("RGB")
    thumb = img.resize((32, 32))
    hash_str = blurhash.encode(np.asarray(thumb), 4, 3)
    assert isinstance(hash_str, str)
    assert len(hash_str) > 5

def test_blurhash_encode_png_rgba():
    raw_bytes = create_dummy_image(format="PNG", mode="RGBA", color=(0, 255, 0, 128))
    img = Image.open(io.BytesIO(raw_bytes)).convert("RGB")
    thumb = img.resize((32, 32))
    hash_str = blurhash.encode(np.asarray(thumb), 4, 3)
    assert isinstance(hash_str, str)
    assert len(hash_str) > 5

def test_blurhash_encode_webp():
    raw_bytes = create_dummy_image(format="WEBP", mode="RGB", color=(0, 0, 255))
    img = Image.open(io.BytesIO(raw_bytes)).convert("RGB")
    thumb = img.resize((32, 32))
    hash_str = blurhash.encode(np.asarray(thumb), 4, 3)
    assert isinstance(hash_str, str)
    assert len(hash_str) > 5

def test_non_image_blurhash_is_none():
    non_image_bytes = b"%PDF-1.4 header dummy data"
    b_hash = None
    try:
        img = Image.open(io.BytesIO(non_image_bytes)).convert("RGB")
        b_hash = blurhash.encode(np.asarray(img.resize((32, 32))), 4, 3)
    except Exception:
        b_hash = None
    assert b_hash is None