#!/env/bin/env bash

set -euo pipefail

intro-prompt() (
  cat <<...
--------------------------------------------------------------------------------

This YAMLScript Exercism exercise requires the YAMLScript version $version
interpreter command file to be installed here:

  $prefix/bin/ys

You can install it by pressing Enter now, or by running this command:

  $make install-ys

This should only take a few seconds and you only need to do this once.
Other exercises will use the same file.

See https://yamlscript.org/doc/install/ for more YAMLScript installation info.

--------------------------------------------------------------------------------

Would you like to install the 'ys' file now?

...

  printf "Press Enter to install. Ctl-C to Quit."; read -r
)

main() {
  setup "$@"

  install-from-local

  $auto && intro-prompt

  installed || install-from-release || true
  installed || install-from-build || true
  installed ||
    die "Installing '$installed' failed. Giving up." \
        "Consider filing an issue at: $gh_issue_url"

  echo
  echo 'Success!'
  echo "$installed is now installed."
  echo
}

installed() {
  [[ -f $installed ]]
}

install-from-local() {
  local path
  path=$(command -v "$ysfq") || true
  if [[ -f $path ]]; then
    mkdir -p "$bin"
    cp "$path" "$bin"/
    ln -fs "$ysfq" "$bin/ys-0"
    ln -fs "$ysfq" "$bin/ys"
    (installed && $auto) && exit
    true
  fi
}

install-from-release() (
  set -x
  curl -s https://yamlscript.org/install |
    BIN=1 VERSION="$version" PREFIX="$prefix" bash
)

install-from-build() (
  cat <<...

The binary release installation failed.
We can attempt to build and install $ysfq now.
This can take from 1 to 5 minutes to complete.

...

  printf "Press Enter to install. Ctl-C to Quit."; read -r

  [[ -d /tmp && -w /tmp ]] ||
    die "Can't write to /tmp" \
        'Giving up.'

  set -x

  rm -fr "$yamlscript_clone"

  git clone --branch="$version" "$yamlscript_repo" "$yamlscript_clone"

  "$make" -C "$yamlscript_clone/ys" install PREFIX="$prefix"
)

setup() {
  version=$1
  prefix=$2
  make=$3
  auto=false
  [[ ${4-} ]] && auto=true

  [[ $version =~ ^0\.1\.[0-9]+$ ]] ||
    die "Invalid YS_VERSION '$version'"

  bin=$prefix/bin
  ysfq=ys-$version
  installed=$bin/$ysfq

  if installed; then
    echo "'$installed' is already installed."
    exit
  fi

  yamlscript_repo=https://github.com/yaml/yamlscript
  yamlscript_clone=/tmp/yamlscript-exercism
  gh_issue_url=https://github.com/exercism/yamlscript/issues
}

die() {
  printf '%s\n' "$@" >&2
  exit 1
}

main "$@"