import io
import json
from pathlib import Path
import pytest
from PIL import Image
from backend.rendering import normalize_image_isolated
from backend.validation import InvalidAsset, IMAGE_ERRORS

def encoded(size=(64, 64), color=(60, 100, 180, 255), **kwargs):
    buffer=io.BytesIO()
    Image.new('RGBA',size,color).save(buffer,'PNG',**kwargs)
    return buffer.getvalue()

@pytest.mark.parametrize('raw,code',[
    (b'<svg><script>alert(1)</script></svg>','decode'),
    (encoded((16, 200)),'aspect'),
    (encoded((8, 8)),'dimensions'),
    (encoded(color=(0, 0, 0, 0)),'transparent'),
])
def test_worker_returns_actionable_allowlisted_errors(tmp_path,raw,code):
    output=tmp_path/'safe.png'
    with pytest.raises(InvalidAsset,match='^'+__import__('re').escape(IMAGE_ERRORS[code])+'$'):
        normalize_image_isolated(raw,output)
    assert not output.exists()

def test_worker_keeps_server_pixel_limit(tmp_path):
    # Browser preparation does not relax direct API upload limits.
    with pytest.raises(InvalidAsset,match='safe image limits'):
        normalize_image_isolated(encoded((4001,4000)),tmp_path/'too-large.png')

def test_worker_rejects_animation(tmp_path):
    b=io.BytesIO();a=Image.new('RGBA',(64,64),'red');z=Image.new('RGBA',(64,64),'blue')
    a.save(b,'PNG',save_all=True,append_images=[z],duration=100,loop=0)
    with pytest.raises(InvalidAsset,match='Animated images'):
        normalize_image_isolated(b.getvalue(),tmp_path/'animated.png')

def test_worker_preserves_orientation_and_removes_metadata(tmp_path):
    b=io.BytesIO();im=Image.new('RGB',(32,64),'red');exif=Image.Exif();exif[274]=6;exif[270]='private fixture metadata'
    im.save(b,'JPEG',exif=exif)
    output=tmp_path/'safe.png';result=normalize_image_isolated(b.getvalue(),output)
    assert (result['width'],result['height'])==(64,32)
    with Image.open(output) as image:assert image.format=='PNG' and not image.info

def test_unrecognized_worker_diagnostic_is_never_returned(tmp_path,monkeypatch):
    def fake(args,cwd,env,**kwargs):
        (Path(cwd)/'process.log').write_text(json.dumps({'ok':False,'code':'/private/user-secret'}))
    monkeypatch.setattr('backend.rendering.bounded_run',fake)
    with pytest.raises(InvalidAsset,match='^'+__import__('re').escape(IMAGE_ERRORS['decode'])+'$'):
        normalize_image_isolated(b'bad',tmp_path/'safe.png')