feat: first functioning code

app.py

@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+import os
+from pathlib import Path
+
+from flask import Flask, jsonify, request, send_from_directory
+
+from compiler import CompileError, compile_graph
+
+
+def create_app() -> Flask:
+    app = Flask(
+        __name__,
+        static_folder="static",
+        static_url_path="/",
+    )
+
+    @app.get("/")
+    def spa_index():
+        static_dir = Path(app.static_folder or "static")
+        return send_from_directory(static_dir, "index.html")
+
+    @app.get("/<path:path>")
+    def spa_assets(path: str):
+        static_dir = Path(app.static_folder or "static")
+        file_path = static_dir / path
+        if file_path.exists() and file_path.is_file():
+            return send_from_directory(static_dir, path)
+        return send_from_directory(static_dir, "index.html")
+
+    @app.post("/api/compile")
+    def api_compile():
+        payload = request.get_json(silent=True)
+        if not isinstance(payload, dict):
+            return jsonify({"ok": False, "error": "request body must be a JSON object"}), 400
+
+        graph = payload.get("graph")
+        if not isinstance(graph, dict):
+            return jsonify({"ok": False, "error": "missing 'graph' object"}), 400
+
+        try:
+            yml = compile_graph(graph)
+        except CompileError as e:
+            return jsonify({"ok": False, "error": str(e)}), 400
+        except Exception:
+            return jsonify({"ok": False, "error": "internal error"}), 500
+
+        return jsonify({"ok": True, "yaml": yml})
+
+    return app
+
+
+if __name__ == "__main__":
+    port = int(os.environ.get("PORT", "7860"))
+    app = create_app()
+    app.run(host="0.0.0.0", port=port, debug=True)