#!/usr/bin/env bash

# Given a to a link plugin on GitHub, add the plugin to nixpkgs
#  - Run from the `nixpkgs` repository
#  - Provide plugin names in the author/plugin format
# Requires git and nix to be in the environment
# Example usage:
#   vim-plugin-add.sh nvim-lua/plenary.nvim letieu/btw.nvim

set -eu

msg() { echo ' ' "$@"; }
err() { msg "$@" >&2;}
dbg() { if [ "${DEBUG:-false}" = true ]; then echo; echo "  DEBUG:" "$@"; echo; fi; }

nix_build_vimplug() {
   for p; do
      nix build --quiet --no-link .#vimPlugins."$p"
   done
}

nix_test_build() {
   if nix_build_vimplug "$1"; then
      msg
      msg "Build of $1 succeeded!"
      return 0
   else
      msg
      msg "Build of $1 failed."
      return 1
   fi
}

if [ $# -lt 1 ]; then
   err 'Please pass the plugins you want to add as arguments, like so:'
   err "$0 Zeioth/compiler.nvim jmbuhr/otter.nvim"
   exit 1
fi
if ! git remote get-url origin | grep --silent -P 'nixpkgs.git$'; then
   err 'Please execute this from the root of the nixpkgs repository'
   exit 1
fi
if [ "$(git rev-parse --abbrev-ref HEAD)" != "master" ]; then
   msg 'WARNING: currently not on master branch!'
fi

nixpkgs_dir="$(git rev-parse --show-toplevel)"
nixpkgs_vim_plugin_dir=pkgs/applications/editors/vim/plugins
tmp_dir="$(mktemp -d)"
tmp_generated_nix="$(mktemp)"
tmp_ending_nix="$(mktemp)"
urls=()

for p; do
   msg "Adding $p"

   # set basic variables
   plugin_name="${p##*/}"
   plugin_author="${p%/*}"
   repo_url="https://github.com/$p"
   nixpkgs_plugin_name="$(tr . - <<< "$plugin_name")" # the plugin name, as nixpkgs will know it
   plugin_repo_tmp_dir="$tmp_dir/$plugin_name"

   # get info from plugin repository
   dbg "Getting plugin git repository"
   git clone --quiet --depth=1 "$repo_url" "$plugin_repo_tmp_dir"
   cd "$plugin_repo_tmp_dir"
   git_rev_hash="$(git rev-parse HEAD)"
   git_date_version="$(git show -s --format=%cs "$git_rev_hash")"
   rm -rf .git
   repo_hash="$(nix hash path .)"

   # add the plugin with vim-plugins-updater
   dbg "Running vimPluginsUpdater"
   cd "$nixpkgs_dir"
   rm -rf "$plugin_repo_tmp_dir"
   git checkout --quiet -b "$plugin_name"
   dbg "actually running the updater"
   # nix-shell -p vimPluginsUpdater --command "vim-plugins-updater add $p"
   vim-plugins-updater add "$p"

   # Append the new plugin to generated.nix
   dbg "Writing generated.nix"
   cd ./"$nixpkgs_vim_plugin_dir"
   head -n -2 generated.nix > "$tmp_generated_nix"
   editor_start_line="$(wc -l "$tmp_generated_nix")"
   cat <<- EOF > "$tmp_ending_nix"
	  $nixpkgs_plugin_name = buildVimPlugin {
	    pname = "$nixpkgs_plugin_name";
	    version = "$git_date_version";
	    src = fetchFromGitHub {
	      owner = "$plugin_author";
	      repo = "$plugin_name";
	      rev = "$git_rev_hash";
	      sha256 = "$repo_hash";
	    };
	    meta.homepage = "$repo_url";
	  };


	}
	EOF
   cat "$tmp_generated_nix" "$tmp_ending_nix" > generated.nix

   first=true
   until nix_test_build "$nixpkgs_plugin_name" && ! $first; do
      if [ $first = true ]; then
         msg "Please make any needed changes and then exit to automatically commit continue."
         msg "Such as adding dependencies to $nixpkgs_vim_plugin_dir/overrides.nix"
         msg "Exit to commit and push your changes"
         first=false
      fi

      $SHELL
   done
   git commit -a --amend
   git push --set-upstream origin "$plugin_name" --force
   git switch -
   # shellcheck disable=SC2016
   urls+=("https://$(git remote get-url origin | sed -r 's/^[^@]+@//g; s_:_/_g; s_\.git$__g')/pull/new/$plugin_name")
   echo
done

echo "Pull Request URLs:"
for url in "${urls[@]}"; do
   echo " - $url"
done

# Cleanup
rm -rf "$tmp_dir" "$tmp_ending_nix" "$tmp_generated_nix"

# vim: sw=3 ts=3 et