{
  pkgs,
  lib,
  config,
  inputs,
  ...
}:

let
  pkgs-unstable = import inputs.nixpkgs-unstable { system = pkgs.stdenv.system; };
  commonLibs = with pkgs; [ alsa-lib ];

  extraPackages = with pkgs; [
    d2
    pkg-config
    protobuf
    cargo-cross
    # opusic-sys (via symphonia-adapter-libopus) compiles libopus from source
    # with CMake, using the gnumake generator from stdenv. Do NOT add ninja:
    # its mere presence flips cmake's generator (Make -> Ninja), which then
    # conflicts with any build dir already cached under the other generator
    # ("Does not match the generator used previously"). Keeping only cmake
    # makes the generator deterministic.
    cmake
    # Stream-URL sidecar for the ytdy provider: YouTube caps tokenless
    # stream URLs at ~1 MiB and yt-dlp is the only maintained cipher
    # solver (architecture/youtube-rustypipe.md, D2-revised).
    yt-dlp
    # Web client toolchain (architecture/web-client.md): trunk builds
    # cbd-web to wasm, wasm-bindgen-cli must match the crate version,
    # binaryen provides wasm-opt for release builds.
    trunk
    wasm-bindgen-cli
    binaryen
  ];
in
{
  imports = [
    ./devenv-rust.nix
    ./devenv-docs.nix
  ];

  # The wasm target for cbd-web; merges with the languages.rust
  # settings in devenv-rust.nix.
  languages.rust.targets = [ "wasm32-unknown-unknown" ];

  env = {
    LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath commonLibs;
  };

  # https://devenv.sh/packages/
  packages = commonLibs ++ extraPackages;

  # https://devenv.sh/processes/
  # processes.cargo-watch.exec = "cargo-watch";

  # https://devenv.sh/services/
  # services.postgres.enable = true;

  # https://devenv.sh/scripts/
  scripts.hello.exec = ''
    echo Welcome to rust devenv
  '';

  # Builds the web client bundle (cbd-web/dist), which crabidy-server
  # embeds on its next build (architecture/web-client.md). RUSTFLAGS is
  # cleared because the mold linker flag from the native toolchain
  # (RUSTFLAGS wins over target-specific config) breaks rust-lld.
  scripts.build-web.exec = ''
    cd "$DEVENV_ROOT/cbd-web" && RUSTFLAGS="" trunk build --release "$@"
  '';
  # Dev loop: live-reloading trunk server proxying gRPC-web to a
  # locally running crabidy-server.
  scripts.serve-web.exec = ''
    cd "$DEVENV_ROOT/cbd-web" && RUSTFLAGS="" trunk serve "$@"
  '';
  # Generates the CLI shell completions and man pages into dist/ by building
  # the native binaries with CBD_ASSET_DIR set (architecture/cli.md D7). Each
  # binary's build.rs copies its assets into $CBD_ASSET_DIR when present, so
  # dist/completions/** and dist/man/*.1 appear after this runs. Unlike
  # build-web (a wasm build) this is a native build, so RUSTFLAGS is left
  # alone — the mold linker flag is correct for the native toolchain.
  scripts.gen-cli-assets.exec = ''
    cd "$DEVENV_ROOT" && CBD_ASSET_DIR="$DEVENV_ROOT/dist" cargo build "$@"
  '';
  # The build-feature matrix (architecture/build-features.md D11,
  # quality/build-features.md G6/G7). Feature combinations are where cfg rot
  # hides: a curated set catches what matters without a powerset sweep. Every
  # entry must be clippy-clean under -D warnings; the two extremes (defaults
  # and nothing) also run their tests.
  scripts.check-features.exec = ''
    set -euo pipefail
    cd "$DEVENV_ROOT"
    clippy() {
      echo "==> clippy $*"
      cargo clippy --all-targets "$@" -- -D warnings
    }
    test_it() {
      echo "==> test $*"
      cargo test "$@"
    }

    # The two extremes, tests included.
    clippy -p crabidy-server
    test_it -p crabidy-server
    clippy -p crabidy-server --no-default-features
    test_it -p crabidy-server --no-default-features

    # Each provider on its own: nothing else may be needed to compile it.
    for feature in tidal youtube fyyd abs soundcloud jamendo rss fs; do
      clippy -p crabidy-server --no-default-features --features "$feature"
    done

    # Each non-provider axis dropped from an otherwise full build.
    clippy -p crabidy-server --no-default-features --features all-providers,spectrum,web-ui
    clippy -p crabidy-server --no-default-features --features all-providers,opus,web-ui
    clippy -p crabidy-server --no-default-features --features all-providers,opus,spectrum
    # The local-files appliance and the streaming box from the docs.
    clippy -p crabidy-server --no-default-features --features fs,opus
    clippy -p crabidy-server --no-default-features --features tidal,web-ui,opus,spectrum

    # The other feature-carrying crates.
    clippy -p audio-player --no-default-features
    clippy -p cbd-tui --no-default-features
    test_it -p cbd-tui --no-default-features
    clippy -p cbd --no-default-features
    clippy -p cbd --no-default-features --features fs,opus,notifications

    echo "all feature combinations are clean"
  '';

  enterShell = "";

  # https://devenv.sh/tasks/
  # tasks = {
  #   "myproj:setup".exec = "mytool build";
  #   "devenv:enterShell".after = [ "myproj:setup" ];
  # };

  # https://devenv.sh/tests/
  enterTest = ''
    echo "Running tests"
  '';
  # https://devenv.sh/git-hooks/
  git-hooks.hooks = {
    nixfmt.enable = true;
    taplo.enable = true;
    markdownlint.enable = true;
    shellcheck.enable = true;
  };

  # https://devenv.sh/integrations/claude-code/
  # Claude Code integration: writes .claude/{settings,commands,agents}. We keep
  # ownership of .mcp.json (skills wiring), so stop devenv from writing it.
  claude.code.enable = true;
  claude.code.mcpServers = lib.mkForce { };
  claude.code.hooks.git-hooks-run.command = ''
    f=$(${pkgs.jq}/bin/jq -r '.tool_input.file_path // empty')
    if [ -n "$f" ]; then
      cd "''${CLAUDE_PROJECT_DIR:-.}"
      ${lib.getExe config.git-hooks.package} run --files "$f"
    fi
  '';

  # See full reference at https://devenv.sh/reference/options/
}