# devenv.nix — required by devenv v2+.
#
# IHP's flake module (flake.nix) provides the full devenv shell via
# `inputs.devenv.flakeModule`: Haskell toolchain, PostgreSQL, ghcid,
# and RunDevServer. This file satisfies devenv v2's file-presence
# requirement and adds project-specific overrides on top.
#
# Duplicates the settings from flake.nix devenv.shells.default so they
# are applied under both devenv v1 (flake path) and devenv v2 (this file).
{ pkgs, lib, config, inputs, ... }:
# devenv.nix — devenv v2 shell configuration.
#
# `devenv shell` reads only this file (not flake.nix's devenv.shells.default).
# IHP's flake module configures devenv.shells.default — that is only visible
# to `nix develop`.  This file therefore duplicates the IHP-critical parts so
# that `devenv shell` also has a working Haskell + IHP_LIB environment.
#
# devenv.yaml registers IHP as a devenv input (pinned rev matching flake.lock)
# and applies IHP's nixpkgs overlay, making pkgs.ghc the IHP Haskell package
# set (ihp, ihp-hspec, ghcid, etc.).
{
  # ── Resource limits (constrained host: 2 CPU / ~3.8 GiB RAM) ─────────────
  # -A32m: smaller minor heap; -M2g: hard heap ceiling.
  # -N1 omitted: requires -threaded, which breaks IHP tools.
  # GHC parallel module compilation is capped via -j4 in .ghci.
  env.GHCRTS = "-A32m -M2g";

  # ── IHP environment variables ─────────────────────────────────────────────
  # IHP_LIB is read by .ghci (applicationGhciConfig) and by scripts/compile-check.
  # IHP is the legacy name used by older Makefiles.
  env.IHP_LIB = "${inputs.ihp.packages.${pkgs.stdenv.system}.ihp-env-var-backwards-compat}";
  env.IHP     = "${inputs.ihp.packages.${pkgs.stdenv.system}.ihp-env-var-backwards-compat}";

  # ── Haskell toolchain ─────────────────────────────────────────────────────
  # IHP's nixpkgs overlay (applied via devenv.yaml overlays) makes pkgs.ghc
  # the IHP-augmented Haskell package set.  pkgs.ghc.ghc is the GHC compiler.
  languages.haskell.enable = true;
  languages.haskell.package = pkgs.ghc.ghc.withPackages (p: with p; [
    p.ihp
    # Project runtime dependencies (mirrors flake.nix haskellPackages)
    http-conduit
    aeson
    string-conversions
    cryptohash-sha256
    base16-bytestring
    random-bytestring
    yaml
    network-uri
    # Dev / test tools
    cabal-install
    hlint
    hspec
    p.ihp-hspec
  ]);
  # ghcid is used by scripts/compile-check-core; not auto-added by devenv.
  # LSP disabled — heavy binary not needed for CI-style compile checks.
  languages.haskell.lsp.enable = false;

  # ── Extra packages ────────────────────────────────────────────────────────
  packages = [
    pkgs.ghc.ghcid
    pkgs.nodePackages.tailwindcss
  ];

  # ── Processes ─────────────────────────────────────────────────────────────
  # Tailwind CSS watcher — not part of IHP's core devenv module.
  processes.tailwind.exec = "tailwindcss -c tailwind/tailwind.config.js -i ./tailwind/app.css -o static/app.css --watch=always";
}