Initial commit

app/app.py

@@ -0,0 +1,124 @@
+import asyncio
+import io
+import shutil
+import tempfile
+from distutils.dir_util import copy_tree
+from pathlib import Path
+
+from quart import Quart, abort, send_file, render_template, request
+from werkzeug.utils import secure_filename
+
+app = Quart(__name__, static_folder="static", template_folder="templates")
+
+
+# allow at most these many scad processes in parallel
+semaphore = asyncio.Semaphore(2)
+
+
+def package_path() -> Path:
+    return Path(__file__).parent
+
+
+class Generator:
+    GENERATOR_SCAD_FILE_NAME = "generator.scad"
+    GENERATED_STL_FILE_NAME = "generated.stl"
+
+    def __init__(self, name: str, tempdir: Path | str):
+        self._name = name
+        self._tempdir = Path(tempdir)
+
+    def _generate_scad_template(self) -> str:
+        return f"""
+            use <bottle-clip.scad>
+            $fn=180;
+            // one name tag for 0.5l Club Mate and similar bottles
+            bottle_clip(name="{self._name}", logo="thing-logos/fablab-cube2.dxf");
+        """
+
+    def _generate_files_in_temp_dir(self):
+        copy_tree(str(package_path() / "openscad"), str(self._tempdir))
+
+        with open(self._tempdir / self.GENERATOR_SCAD_FILE_NAME, "w") as f:
+            f.write(self._generate_scad_template())
+
+    async def generate_stl(self) -> str:
+        self._generate_files_in_temp_dir()
+
+        openscad_path = shutil.which("openscad")
+
+        if not openscad_path:
+            abort(500)
+
+        proc = await asyncio.create_subprocess_exec(
+            openscad_path,
+            self.GENERATOR_SCAD_FILE_NAME,
+            "-o",
+            self.GENERATED_STL_FILE_NAME,
+            # "--hardwarnings",
+            cwd=self._tempdir,
+        )
+
+        await proc.wait()
+
+        if proc.returncode != 0:
+            abort(500)
+
+        return self.GENERATED_STL_FILE_NAME
+
+
+@app.route("/generate/<name>")
+async def generate_rest(name: str):
+    async with semaphore:
+        with tempfile.TemporaryDirectory(prefix="fablab-bottle-clip-generator-") as tempdir:
+            generator = Generator(name, tempdir)
+
+            generated_stl_file_name = await generator.generate_stl()
+
+            # to be able to use send_file with a temporary directory, we need buffer the entire file in memory
+            # before the context manager gets to delete the dir
+            bytes_io = io.BytesIO()
+
+            with open(Path(tempdir) / generated_stl_file_name, "rb") as f:
+                while True:
+                    data = f.read(4096)
+                    if not data:
+                        break
+                    bytes_io.write(data)
+
+            # using secure_filename allows us to send the file to the user with some safe yet reasonably
+            # identifiable filename
+            return await send_file(
+                bytes_io,
+                mimetype="model/stl",
+                as_attachment=True,
+                attachment_filename=secure_filename(f"{name}.stl")
+            )
+
+
+# aside from the RESTful API above, we need a "traditional" HTML forms compatible end point
+@app.route("/generate")
+async def generate_form():
+    try:
+        name = request.args["name"]
+    except KeyError:
+        abort(400)
+        return
+
+    return await generate_rest(name)
+
+
+@app.route("/")
+async def index():
+    return await render_template("index.html")
+
+
+async def test():
+    with tempfile.TemporaryDirectory() as td:
+        generator = Generator("testabc", td)
+        generated_stl_file_name = await generator.generate_stl()
+        shutil.copy(Path(td) / generated_stl_file_name, ".")
+
+
+if __name__ == "__main__":
+    import asyncio
+    asyncio.run(test())