#!/bin/sh -eu
# Idea condensed from https://github.com/Shopify/comma

program=$(basename "$0")
requires="$(command -V nix-index nix-locate nix-shell fzf | awk '{ print $1, $3 }' | column -t)"

[ "${1:-}" = "--check" ] && printf '%s\n' "$requires" && exit;

{ [ "${1:-}" = "--help" ] || [ "$#" = 0 ]; } && printf \
"
Usage: %s [FLAGS]... [ARGUMENT]...

The wrapper $program shall search all nix
packages for a file and set up a nix shell for the
program that contains that file. The shell prints
all binaries in the package upon invocation.

  Command List:

   $program [ARGUMENT]...        Search for packages using file name argument.
   $program --help               Show this help menu.
   $program --check              Check dependencies.
" "$program" && exit;

databasePath=${XDG_DATA_HOME:-~/.local/share}/nix-index
nixLocate='nix-locate --db '"$databasePath"' --top-level --minimal --whole-name '"${1:-}"
attributes=$($nixLocate | while read -r attribute; do
  attributeName=${attribute%.*};
  printf '%s\n' "$attributeName";
done)

attribute=$(printf '%s' "$attributes" | fzf)
nix-shell --packages "$attribute" --command \
'
  printf "\n";
  ls $buildInputs/bin;
  printf "\n";
  tree -L 1 $buildInputs;
  return
';