migrate to uv2nix

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

flake.nix

@@ -22,10 +22,6 @@
   inputs = {
     flake-utils.url = "github:numtide/flake-utils";
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable-small";
-    poetry2nix = {
-      url = "github:nix-community/poetry2nix";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
     pre-commit-hooks = {
       url = "github:cachix/pre-commit-hooks.nix";
       inputs = {
@@ -34,6 +30,27 @@
         # flake-compat.follows = "flake-compat";
       };
     };
+    pyproject-nix = {
+      url = "github:pyproject-nix/pyproject.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    uv2nix = {
+      url = "github:pyproject-nix/uv2nix";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+        pyproject-nix.follows = "pyproject-nix";
+      };
+    };
+
+    pyproject-build-systems = {
+      url = "github:pyproject-nix/build-system-pkgs";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+        pyproject-nix.follows = "pyproject-nix";
+        uv2nix.follows = "uv2nix";
+      };
+    };
   };
 
   outputs =
@@ -41,39 +58,90 @@
       self,
       nixpkgs,
       flake-utils,
-      poetry2nix,
+      uv2nix,
+      pyproject-nix,
+      pyproject-build-systems,
       ...
     }@inputs:
     flake-utils.lib.eachDefaultSystem (
       system:
       let
-        # see https://github.com/nix-community/poetry2nix/tree/master#api for more functions and examples.
-        pkgs = nixpkgs.legacyPackages.${system}.extend poetry2nix.overlays.default;
+        inherit (nixpkgs) lib;
 
-        overrides = pkgs.poetry2nix.overrides.withDefaults (
-          _final: _prev: {
-            # prefer binary wheels instead of source distributions for rust based dependencies
-            # avoids needing to build them from source. technically a security risk
-            #polars = prev.polars.override { preferWheel = true; };
-            #ruff = prev.ruff.override { preferWheel = true; };
-            #greenlet = prev.greenlet.override { preferWheel = true; };
-            #sqlalchemy = prev.sqlalchemy.override { preferWheel = true; };
-          }
-        );
+        # Load a uv workspace from a workspace root.
+        # Uv2nix treats all uv projects as workspace projects.
+        workspace = uv2nix.lib.workspace.loadWorkspace { workspaceRoot = ./.; };
 
-        poetryConfig = {
-          inherit overrides;
-          projectDir = self;
-          python = pkgs.python312;
+        # Create package overlay from workspace.
+        overlay = workspace.mkPyprojectOverlay {
+          # Prefer prebuilt binary wheels as a package source.
+          # Sdists are less likely to "just work" because of the metadata missing from uv.lock.
+          # Binary wheels are more likely to, but may still require overrides for library dependencies.
+          sourcePreference = "wheel";
+          #sourcePreference = "sdist";
+          # Optionally customise PEP 508 environment
+          # environ = {
+          #   platform_release = "5.10.65";
+          # };
+        };
+
+        # Extend generated overlay with build fixups
+        #
+        # Uv2nix can only work with what it has, and uv.lock is missing essential metadata to perform some builds.
+        # This is an additional overlay implementing build fixups.
+        # See:
+        # - https://pyproject-nix.github.io/uv2nix/FAQ.html
+        pyprojectOverrides = _final: _prev: {
+          # Implement build fixups here.
+          # Note that uv2nix is _not_ using Nixpkgs buildPythonPackage.
+          # It's using https://pyproject-nix.github.io/pyproject.nix/build.html
+        };
+
+        # This example is only using x86_64-linux
+        pkgs = nixpkgs.legacyPackages.${system};
+
+        # Use Python 3.12 from nixpkgs
+        python = pkgs.python312;
+
+        # Construct package set
+        pythonSet =
+          # Use base package set from pyproject.nix builders
+          (pkgs.callPackage pyproject-nix.build.packages {
+            inherit python;
+          }).overrideScope
+            (
+              lib.composeManyExtensions [
+                pyproject-build-systems.overlays.default
+                overlay
+                pyprojectOverrides
+              ]
+            );
+
+        uv-shell = import ./uv-shell.nix {
+          inherit
+            lib
+            pkgs
+            python
+            workspace
+            pythonSet
+            ;
         };
       in
       rec {
-        inherit pkgs;
-        packages = {
-          flupdt = pkgs.poetry2nix.mkPoetryApplication poetryConfig // {
-            develop = false;
+        # Package a virtual environment as our main application.
+        #
+        # Enable no optional dependencies for production build.
+        packages = rec {
+          flupdt = pythonSet.mkVirtualEnv "flupdt-env" workspace.deps.default;
+          default = flupdt;
+        };
+
+        # Make hello runnable with `nix run`
+        apps = {
+          default = {
+            type = "app";
+            program = "${packages.default}/bin/flupdt";
           };
-          default = self.packages.${system}.flupdt;
         };
 
         formatter = pkgs.nixfmt-rfc-style;
@@ -82,10 +150,10 @@
           inherit
             self
             pkgs
-            poetryConfig
             inputs
             system
             checks
+            uv-shell
             ;
         };
         checks = import ./checks.nix { inherit inputs system formatter; };