flake.nix

{
  description = "Singularity Analysis Engine development environment";

  # Configure binary caches for faster builds
  nixConfig = {
    extra-substituters = [
      "https://mikkihugo.cachix.org"
      "https://cache.nixos.org"
    ];
    extra-trusted-public-keys = [
      "mikkihugo.cachix.org-1:TJ+vwFP1XImrAATJbqWLaEvtzuWpui9hw5stDdeOTAE="
      "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
    ];
  };

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    rust-overlay.url = "github:oxalica/rust-overlay";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = {
    nixpkgs,
    rust-overlay,
    flake-utils,
  }:
    flake-utils.lib.eachDefaultSystem (system: let
      overlays = [(import rust-overlay)];
      pkgs = import nixpkgs {
        inherit system overlays;
      };

      # Rust toolchain - latest stable
      rustToolchain = pkgs.rust-bin.stable.latest.default.override {
        extensions = ["rust-src" "rust-analyzer"];
      };

      # Build inputs for the project
      buildInputs = with pkgs; [
        # Rust and cargo tools
        rustToolchain
        cargo-edit # cargo add/rm/upgrade
        cargo-watch # cargo watch for auto-recompilation
        cargo-audit # security audit
        cargo-outdated # check for outdated dependencies
        cargo-tarpaulin # code coverage
        cargo-nextest # better test runner
        cargo-machete # find unused dependencies
        cargo-deny # lint dependencies
        cargo-release # release automation
        cargo-udeps # find unused dependencies (build-time)
        cargo-expand # expand macros
        cargo-bloat # find what takes space in binary
        cargo-geiger # detect unsafe usage
        cargo-fuzz # fuzz testing
        cargo-llvm-lines # count LLVM IR lines
        sccache # compilation cache

        # Node.js for additional tooling (jscpd can be installed via npm)
        nodejs

        # Elixir and Erlang
        beam.packages.erlang_28.elixir_1_19 # Elixir 1.19 with Erlang/OTP 28
        beam.packages.erlang_28.erlang
        beam.packages.erlang_28.rebar3
        beam.packages.erlang_28.hex

        # Elixir tools from Nix (pre-built, no compilation needed)
        beam.packages.erlang_28.elixir-ls # Language server

        # Build dependencies for NIFs
        pkg-config
        openssl

        # Development tools
        git
        gnumake
        just # command runner (modern make alternative)
        gcc
        libiconv

        # Security and quality scanning
        gitleaks # secret scanning
        shellcheck # shell script linting

        # Optional: useful for development
        jq
        ripgrep
        fd
        bat
        eza
        tokei # code statistics
      ];

      # Set up environment variables
      shellHook = ''
        echo "🚀 Singularity Analysis Engine Development Environment"
        echo ""
        echo "📦 Versions:"
        echo "  • Rust: $(rustc --version | cut -d' ' -f2)"
        echo "  • Cargo: $(cargo --version | cut -d' ' -f2)"
        echo "  • Elixir: $(elixir --version | grep Elixir | cut -d' ' -f2)"
        echo "  • Erlang/OTP: $(erl -eval 'erlang:display(erlang:system_info(otp_release)), halt().' -noshell | tr -d '\"')"
        echo ""
        echo "🛠️  Rust Quality Tools:"
        echo "  • cargo-audit, cargo-deny, cargo-geiger (security)"
        echo "  • cargo-nextest, cargo-tarpaulin (testing & coverage)"
        echo "  • cargo-outdated, cargo-udeps, cargo-machete (dependencies)"
        echo "  • cargo-bloat, cargo-llvm-lines (performance analysis)"
        echo "  • cargo-expand, cargo-fuzz (advanced)"
        echo ""
        echo "💜 Elixir Quality Tools:"
        echo "  • credo, dialyzer, doctor (code quality)"
        echo "  • sobelow, mix_audit (security)"
        echo "  • excoveralls (coverage)"
        echo ""
        echo "🔒 Security & General:"
        echo "  • gitleaks (secret scanning)"
        echo "  • shellcheck (shell script linting)"
        echo "  • tokei (code statistics)"
        echo "  • jscpd (install: npm install -g jscpd)"
        echo ""
        echo "🚀 Quick Commands:"
        echo "  • make help          - Show all available targets"
        echo "  • make quality       - Run all quality checks"
        echo "  • make security      - Security scans"
        echo "  • make test          - Run all tests"
        echo "  • make coverage      - Generate coverage reports"
        echo "  • See QUALITY.md for detailed documentation"
        echo ""

        # Set up Rust environment
        export RUST_SRC_PATH="${rustToolchain}/lib/rustlib/src/rust/library"
        export RUST_BACKTRACE=1

        # Set up build cache
        export SCCACHE_DIR="$PWD/.sccache"
        export RUSTC_WRAPPER="${pkgs.sccache}/bin/sccache"

        # Elixir/Erlang environment
        export ERL_AFLAGS="-kernel shell_history enabled"
        export HEX_HOME="$PWD/.hex"
        export MIX_HOME="$PWD/.mix"

        # Create local directories if they don't exist
        mkdir -p .sccache .hex .mix

        # Install local hex and rebar if not present
        if ! compgen -G "$MIX_HOME/archives/hex-*" > /dev/null; then
          echo "📥 Installing local hex..."
          mix local.hex --force --if-missing
        fi

        if ! compgen -G "$MIX_HOME/elixir/*/rebar3" > /dev/null; then
          echo "📥 Installing local rebar..."
          mix local.rebar --force --if-missing
        fi
      '';
    in {
      devShells.default = pkgs.mkShell {
        inherit buildInputs;
        inherit shellHook;

        # Additional environment variables
        RUST_LOG = "debug";
        CARGO_HOME = "$PWD/.cargo";
      };

      # Also provide a minimal shell without the startup message
      devShells.minimal = pkgs.mkShell {
        inherit buildInputs;
        shellHook = ''
          export RUST_SRC_PATH="${rustToolchain}/lib/rustlib/src/rust/library"
          export RUST_BACKTRACE=1
          export SCCACHE_DIR="$PWD/.sccache"
          export RUSTC_WRAPPER="${pkgs.sccache}/bin/sccache"
          export ERL_AFLAGS="-kernel shell_history enabled"
          export HEX_HOME="$PWD/.hex"
          export MIX_HOME="$PWD/.mix"
          export RUST_LOG="debug"
          export CARGO_HOME="$PWD/.cargo"
          mkdir -p .sccache .hex .mix .cargo
        '';
      };
    });
}