feat(nix): migrate to flake and remove default.nix (#1019)

Signed-off-by: en <54501296+2hexed@users.noreply.github.com>

README.md

@@ -48,8 +48,7 @@ Before getting started, you'll want to install:
 - Git
 - mold (optional, faster compilation)
 
-> A **default.nix** is available for Nix users!
-> Run `nix-shell` to activate mise.
+> **Flake** is available for Nix users! Run `nix develop` to enter the dev shell.
 
 As a heads-up, the development environment uses the following ports:
 

default.nix

@@ -1,43 +0,0 @@
-{ pkgs ? import (fetchTarball {
-    url = "https://github.com/NixOS/nixpkgs/archive/77ef7a29d276c6d8303aece3444d61118ef71ac2.tar.gz";
-    sha256 = "0pm4l48jq8plzrrrisimahxqlcpx7qqq9c99hylmf7p3zlc3phsy";
-  }) {},
-}:
-
-let
-  nix-ld-libs = pkgs.buildEnv {
-    name = "nix-ld-libs";
-    paths = with pkgs; [
-      stdenv.cc.cc.lib
-      zlib
-      openssl.out
-      dav1d
-    ];
-    pathsToLink = [ "/lib" ];
-  };
-
-in pkgs.mkShell {
-  packages = with pkgs; [
-    mise
-    cargo-binstall
-    (writeShellScriptBin "fish" ''
-      exec ${pkgs.fish}/bin/fish -C 'mise activate fish | source' "$@"
-    '')
-  ];
-
-  buildInputs = with pkgs; [
-    pkg-config
-    openssl.dev
-    dav1d
-  ];
-
-  shellHook = ''
-    export TMPDIR=/tmp
-    export NIX_LD="${pkgs.stdenv.cc.libc}/lib/ld-linux-x86-64.so.2"
-    export NIX_LD_LIBRARY_PATH="${nix-ld-libs}/lib"
-    export LD_LIBRARY_PATH="${nix-ld-libs}/lib''${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
-
-    export MISE_NODE_COMPILE=false
-    eval "$(mise activate bash)"
-  '';
-}

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1790185690,
+        "narHash": "sha256-xJ+X4hBtOcAFGBOe5nAMyMUeF9foJBmIOu3NjBqBycU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4975466d324710c576dc11ad614684e6bd8cad8e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,58 @@
+{
+  description = "Development environment for stoatchat";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs }:
+    let
+      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
+      forEachSystem = nixpkgs.lib.genAttrs supportedSystems;
+    in
+    {
+      devShells = forEachSystem (system:
+        let
+          pkgs = import nixpkgs { inherit system; };
+
+          nix-ld-libs = pkgs.buildEnv {
+            name = "nix-ld-libs";
+            paths = with pkgs; [
+              stdenv.cc.cc.lib
+              zlib
+              openssl.out
+              dav1d
+            ];
+            pathsToLink = [ "/lib" ];
+          };
+        in
+        {
+          default = pkgs.mkShell {
+            packages = with pkgs; [
+              mise
+              cargo-binstall
+              pkg-config
+              openssl
+              openssl.dev
+              meson
+              ninja
+              mold
+              nasm
+            ];
+
+            shellHook = ''
+              # Crucial for rust openssl-sys compilation via cargo
+              export PKG_CONFIG_PATH="\({pkgs.openssl.dev}/lib/pkgconfig:\){pkgs.dav1d}/lib/pkgconfig\({PKG_CONFIG_PATH:+:\)PKG_CONFIG_PATH}"
+              export OPENSSL_DIR="${pkgs.openssl.dev}"
+              export OPENSSL_LIB_DIR="${pkgs.openssl.out}/lib"
+
+              export MISE_NODE_COMPILE=false
+              if command -v mise &> /dev/null; then
+                eval "$(mise activate bash)"
+              fi
+            '';
+          };
+        }
+      );
+    };
+}