Make sure not to overwrite existing images when exporting results

ai_diffusion/model.py

@@ -500,6 +500,7 @@ def _save_job_result(model: Model, job: Job | None, index: int):
     prompt = util.sanitize_prompt(job.params.prompt)
     path = Path(model.document.filename)
     path = path.parent / f"{path.stem}-generated-{timestamp}-{index}-{prompt}.webp"
+    path = util.find_unused_path(path)
     base_image = model._get_current_image(Bounds(0, 0, *model.document.extent))
     result_image = job.results[index]
     base_image.draw_image(result_image, job.params.bounds.offset)

ai_diffusion/util.py

@@ -64,6 +64,18 @@ def sanitize_prompt(prompt: str):
     return "".join(c for c in prompt if c.isalnum() or c in " _-")
 
 
+def find_unused_path(path: Path):
+    """Finds an unused path by appending a number to the filename"""
+    if not path.exists():
+        return path
+    stem = path.stem
+    ext = path.suffix
+    i = 1
+    while (new_path := path.with_name(f"{stem}-{i}{ext}")).exists():
+        i += 1
+    return new_path
+
+
 def get_path_dict(paths: Sequence[str | Path]) -> dict:
     """Builds a tree like structure out of a list of paths"""
 

tests/test_util.py

@@ -1,7 +1,7 @@
 import pytest
 from tempfile import TemporaryDirectory
 from pathlib import Path
-from ai_diffusion.util import batched, get_path_dict, ZipFile
+from ai_diffusion.util import batched, sanitize_prompt, find_unused_path, get_path_dict, ZipFile
 
 
 def test_batched():
@@ -11,6 +11,22 @@ def test_batched():
     assert list(batched(iterable, n)) == expected_output
 
 
+def test_sanitize_prompt():
+    assert sanitize_prompt("") == "no prompt"
+    assert sanitize_prompt("a" * 50) == "a" * 40
+    assert sanitize_prompt("bla\nblub\n<x:2:4> (neg) [pos]") == "blablubx24 neg pos"
+
+
+def test_unused_path():
+    with TemporaryDirectory() as dir:
+        file = Path(dir) / "test.txt"
+        assert find_unused_path(file) == file
+        file.touch()
+        assert find_unused_path(file) == Path(dir) / "test-1.txt"
+        (Path(dir) / "test-1.txt").touch()
+        assert find_unused_path(file) == Path(dir) / "test-2.txt"
+
+
 def test_path_dict():
     paths = [
         "f1.txt",