setup.bash

#!/usr/bin/env bash

set -euo pipefail

HELP="
Usage:

bash [--github | --gitlab] $0 PLUGIN_NAME TOOL_TEST GH_USER AUTHOR_NAME TOOL_GH TOOL_PAGE LICENSE

All arguments are optional and will be interactively prompted when not given.

PLUGIN_NAME.
   A name for your new plugin always starting with \`asdf-\` prefix.

TOOL_TEST.
   A shell command used to test correct installation.
   Normally this command is something taking \`--version\` or \`--help\`.

GH_USER.
   Your GitHub/GitLab username.

AUTHOR_NAME.
   Your name, used for licensing.

TOOL_GH.
   The tool's GitHub homepage. Default installation process will try to use
   this to access GitHub releases.

TOOL_PAGE.
   Documentation site for tool usage, mostly informative for users.

LICENSE.
   A license keyword.
   https://help.github.com/en/github/creating-cloning-and-archiving-repositories/licensing-a-repository#searching-github-by-license-type
"
HELP_PLUGIN_NAME="Name for your plugin, starting with \`asdf-\`, eg. \`asdf-foo\`"
HELP_TOOL_CHECK="Shell command for testing correct tool installation. eg. \`foo --version\` or \`foo --help\`"
HELP_TOOL_REPO="The tool's GitHub homepage."
HELP_TOOL_HOMEPAGE="The tool's documentation homepage if necessary."

ask_for() {
  local prompt="$1"
  local default_value="${2:-}"
  local alternatives="${3:-"[$default_value]"}"
  local value=""

  while [ -z "$value" ]; do
    echo "$prompt" >&2
    if [ "[]" != "$alternatives" ]; then
      echo -n "$alternatives " >&2
    fi
    echo -n "> " >&2
    read -r value
    echo >&2
    if [ -z "$value" ] && [ -n "$default_value" ]; then
      value="$default_value"
    fi
  done

  printf "%s\n" "$value"
}

download_license() {
  local keyword file
  keyword="$1"
  file="$2"

  curl -qsL "https://raw.githubusercontent.com/github/choosealicense.com/gh-pages/_licenses/${keyword}.txt" |
    extract_license >"$file"
}

extract_license() {
  awk '/^---/{f=1+f} f==2 && /^$/ {f=3} f==3'
}

test_url() {
  curl -fqsL -I "$1" | head -n 1 | grep 200 >/dev/null
}

ask_license() {
  local license keyword

  printf "%s\n" "Please choose a LICENSE keyword." >&2
  printf "%s\n" "See available license keywords at" >&2
  printf "%s\n" "https://help.github.com/en/github/creating-cloning-and-archiving-repositories/licensing-a-repository#searching-github-by-license-type" >&2

  while true; do
    license="$(ask_for "License keyword:" "apache-2.0" "mit/[apache-2.0]/agpl-3.0/unlicense")"
    keyword=$(echo "$license" | tr '[:upper:]' '[:lower:]')

    url="https://choosealicense.com/licenses/$keyword/"
    if test_url "$url"; then
      break
    else
      printf "Invalid license keyword: %s\n" "$license"
    fi
  done

  printf "%s\n" "$keyword"
}

set_placeholder() {
  local name value out file tmpfile
  name="$1"
  value="$2"
  out="$3"

  git grep -P -l -F --untracked "$name" -- "$out" |
    while IFS=$'\n' read -r file; do
      tmpfile="$file.sed"
      sed "s#$name#$value#g" "$file" >"$tmpfile" && mv "$tmpfile" "$file"
    done
}

setup_github() {
  local cwd out tool_name tool_repo check_command author_name github_username tool_homepage ok primary_branch

  cwd="$PWD"
  out="$cwd/out"

  # ask for arguments not given via CLI
  tool_name="${1:-$(ask_for "$HELP_PLUGIN_NAME")}"
  tool_name="${tool_name/asdf-/}"
  check_command="${2:-$(ask_for "$HELP_TOOL_CHECK" "$tool_name --help")}"

  github_username="${3:-$(ask_for "Your GitHub username")}"
  author_name="${4:-$(ask_for "Your name" "$(git config user.name 2>/dev/null)")}"

  tool_repo="${5:-$(ask_for "$HELP_TOOL_REPO" "https://github.com/$github_username/$tool_name")}"
  tool_homepage="${6:-$(ask_for "$HELP_TOOL_HOMEPAGE" "$tool_repo")}"
  license_keyword="${7:-$(ask_license)}"
  license_keyword="$(echo "$license_keyword" | tr '[:upper:]' '[:lower:]')"

  primary_branch="main"

  cat <<-EOF
Setting up plugin: asdf-$tool_name

author:        $author_name
plugin repo:   https://github.com/$github_username/asdf-$tool_name
license:       https://choosealicense.com/licenses/$license_keyword/


$tool_name github:   $tool_repo
$tool_name docs:     $tool_homepage
$tool_name test:     \`$check_command\`

After confirmation, the \`$primary_branch\` will be replaced with the generated
template using the above information. Please ensure all seems correct.
EOF

  ok="${8:-$(ask_for "Type \`yes\` if you want to continue.")}"
  if [ "yes" != "$ok" ]; then
    printf "Nothing done.\n"
  else
    (
      set -e
      # previous cleanup to ensure we can run this program many times
      git branch template 2>/dev/null || true
      git checkout -f template
      git worktree remove -f out 2>/dev/null || true
      git branch -D out 2>/dev/null || true

      # checkout a new worktree and replace placeholders there
      git worktree add --detach out

      cd "$out"
      git checkout --orphan out
      git rm -rf "$out" >/dev/null
      git read-tree --prefix="" -u template:template/

      download_license "$license_keyword" "$out/LICENSE"
      sed -i '1s;^;TODO: INSERT YOUR NAME & COPYRIGHT YEAR\n;g' "$out/LICENSE"

      set_placeholder "<YOUR TOOL>" "$tool_name" "$out"
      set_placeholder "<TOOL HOMEPAGE>" "$tool_homepage" "$out"
      set_placeholder "<TOOL REPO>" "$tool_repo" "$out"
      set_placeholder "<TOOL CHECK>" "$check_command" "$out"
      set_placeholder "<YOUR NAME>" "$author_name" "$out"
      set_placeholder "<YOUR GITHUB USERNAME>" "$github_username" "$out"
      set_placeholder "<PRIMARY BRANCH>" "$primary_branch" "$out"

      git add "$out"
      # remove GitLab specific files
      git rm -rf "$out/.gitlab" "$out/.gitlab-ci.yml" "$out/README-gitlab.md" "$out/contributing-gitlab.md"
      # rename GitHub specific files to final filenames
      git mv "$out/README-github.md" "$out/README.md"
      git mv "$out/contributing-github.md" "$out/contributing.md"
      git commit -m "Generate asdf-$tool_name plugin from template."

      cd "$cwd"
      git branch -M out "$primary_branch"
      git worktree remove -f out
      git checkout -f "$primary_branch"

      printf "All done.\n"
      printf "Your %s branch has been reset to an initial commit.\n" "$primary_branch"
      printf "Push to origin/%s with \`git push --force-with-lease\`\n" "$primary_branch"

      printf "Review these TODO items:\n"
      git grep -P -n -C 3 "TODO"
    ) || cd "$cwd"
  fi
}

setup_gitlab() {
  local cwd out tool_name tool_repo check_command author_name github_username gitlab_username tool_homepage ok primary_branch

  cwd="$PWD"
  out="$cwd/out"

  # ask for arguments not given via CLI
  tool_name="${1:-$(ask_for "$HELP_PLUGIN_NAME")}"
  tool_name="${tool_name/asdf-/}"
  check_command="${2:-$(ask_for "$HELP_TOOL_CHECK" "$tool_name --help")}"

  gitlab_username="$(ask_for "Your GitLab username")"
  author_name="${4:-$(ask_for "Your name" "$(git config user.name 2>/dev/null)")}"

  github_username="${3:-$(ask_for "Tool GitHub username")}"
  tool_repo="${5:-$(ask_for "$HELP_TOOL_REPO" "https://github.com/$github_username/$tool_name")}"
  tool_homepage="${6:-$(ask_for "$HELP_TOOL_HOMEPAGE" "$tool_repo")}"
  license_keyword="${7:-$(ask_license)}"
  license_keyword="$(echo "$license_keyword" | tr '[:upper:]' '[:lower:]')"

  primary_branch="main"

  cat <<-EOF
Setting up plugin: asdf-$tool_name

author:        $author_name
plugin repo:   https://gitlab.com/$gitlab_username/asdf-$tool_name
license:       https://choosealicense.com/licenses/$license_keyword/


$tool_name github:   $tool_repo
$tool_name docs:     $tool_homepage
$tool_name test:     \`$check_command\`

After confirmation, the \`$primary_branch\` will be replaced with the generated
template using the above information. Please ensure all seems correct.
EOF

  ok="${8:-$(ask_for "Type \`yes\` if you want to continue.")}"
  if [ "yes" != "$ok" ]; then
    printf "Nothing done.\n"
  else
    (
      set -e
      # previous cleanup to ensure we can run this program many times
      git branch template 2>/dev/null || true
      git checkout -f template
      git worktree remove -f out 2>/dev/null || true
      git branch -D out 2>/dev/null || true

      # checkout a new worktree and replace placeholders there
      git worktree add --detach out

      cd "$out"
      git checkout --orphan out
      git rm -rf "$out" >/dev/null
      git read-tree --prefix=/ -u template:template/

      download_license "$license_keyword" "$out/LICENSE"

      set_placeholder "<YOUR TOOL>" "$tool_name" "$out"
      set_placeholder "<TOOL HOMEPAGE>" "$tool_homepage" "$out"
      set_placeholder "<TOOL REPO>" "$tool_repo" "$out"
      set_placeholder "<TOOL CHECK>" "$check_command" "$out"
      set_placeholder "<YOUR NAME>" "$author_name" "$out"
      set_placeholder "<YOUR GITHUB USERNAME>" "$github_username" "$out"
      set_placeholder "<YOUR GITLAB USERNAME>" "$gitlab_username" "$out"
      set_placeholder "<PRIMARY BRANCH>" "$primary_branch" "$out"

      git add "$out"
      # remove GitHub specific files
      git rm -rf "$out/.github" "$out/README-github.md" "$out/contributing-github.md"
      # rename GitLab specific files to final filenames
      git mv "$out/README-gitlab.md" "$out/README.md"
      git mv "$out/contributing-gitlab.md" "$out/contributing.md"
      git commit -m "Generate asdf-$tool_name plugin from template."

      cd "$cwd"
      git branch -M out "$primary_branch"
      git worktree remove -f out
      git checkout -f "$primary_branch"

      printf "All done.\n"
      printf "Your %s branch has been reset to an initial commit.\n" "$primary_branch"
      printf "You might want to push using \`--force-with-lease\` to origin/%s\n" "$primary_branch"

      printf "Showing pending TODO tags that you might want to review\n"
      git grep -P -n -C 3 "TODO"
    ) || cd "$cwd"
  fi
}

case "${1:-}" in
"-h" | "--help" | "help")
  printf "%s\n" "$HELP"
  exit 0
  ;;
"--gitlab")
  shift
  setup_gitlab "$@"
  ;;
"--github")
  shift
  setup_github "$@"
  ;;
*)
  setup_github "$@"
  ;;
esac