#!/usr/bin/env bash
###
### a simple complement to bild which only deals with launching repls
###
### > repl <target..>
###
### Starts a repl/shell for one or more targets. (Currently, all targets must
### have the same extension for this to work.)
###
### Repls started with this script should bind to `localhost:$PORT`.
help() {
    sed -rn 's/^### ?//;T;p' "$0"
}
if [[ $# == 0 ]] || [[ "$1" == "-h" ]]; then
    help
    exit 1
fi
##
  set -e
  targets=${@:?}
  json=$(bild --json ${targets[@]})
  langdeps=$(jq --raw-output '.langdeps | join(" ")' <<< $json)
  sysdeps=$(jq --raw-output '.sysdeps | join(" ")' <<< $json)
  exts=$(jq --raw-output '.namespace.ext' <<< $json | sort | uniq)
  flags=()
  for lib in ${sysdeps[@]}; do
    flags+=(--packages "(import $BIZ_ROOT/Biz/Bild.nix {}).private.nixpkgs.${lib}")
  done
  case $exts in
    Hs)
      if [ -z ${var+PORT} ]; then
        echo "warn:  repl:  ghci does not support binding to a port"
      fi
      nix-shell \
        "${flags[@]}" \
        --packages "(import $BIZ_ROOT/Biz/Bild.nix {}).private.ghcWith (h: with h; [$langdeps])" \
        --command "ghci -i$BIZ_ROOT -ghci-script $BIZ_ROOT/.ghci ${targets[@]}"
      ;;
    Scm)
      for lib in ${langdeps[@]}; do
        flags+=(--packages "(import $BIZ_ROOT/Biz/Bild.nix {}).private.nixpkgs.guile-${lib}")
      done
      nix-shell \
        "${flags[@]}" \
        --packages "(import $BIZ_ROOT/Biz/Bild.nix {}).private.nixpkgs.guile_3_0" \
        --command "guile -L $BIZ_ROOT -C $BIZ_ROOT/_/int --r7rs --listen=${PORT:-37146}"
      ;;
    Lisp)
      nix-shell \
        "${flags[@]}" \
        --packages "(import $BIZ_ROOT/Biz/Bild.nix {}).private.sbclWith (p: with p; [asdf swank $langdeps])" \
        --command "sbcl --eval '(require :asdf)' --eval '(require :swank)' --eval '(swank:create-server :port ${PORT:-4005})' --load $targets"
      ;;
    Rs)
      nix-shell \
        "${flags[@]}" \
        --packages "(import $BIZ_ROOT/Biz/Bild.nix {}).private.nixpkgs.rustc"
      ;;
    *)
      echo "unsupported targets: ${targets[@]}"
      exit 1
      ;;
  esac
##