#!/bin/bash

action=$1
name=$2
shift 2

if [[ -n ${name} && ${name} == --global ]]; then
  global=true
  name=''
else
  global=$(arguments get global $*)
fi

bootstrap=false
if [[ -z ${name} ]]; then
  bootstrap=true
  name='pipsi'
fi

# set paths, try variables pipsi itself uses first and fall-back to
# defaults; take the 'global' option into account
declare -a pipsi_opts=( )
pipsi_bin_dir="${PIPSI_BIN_DIR:-"${HOME}/.local/bin"}"
pipsi_home="${PIPSI_HOME:-"${HOME}/.local/venvs"}"
if [[ ${global} == true ]]; then
  pipsi_bin_dir="${PIPSI_GLOBAL_BIN_DIR:-"/usr/local/bin"}"
  pipsi_home="${PIPSI_GLOBAL_HOME:-"/usr/local/lib/pipsi"}"
  pipsi_opts+=( --bin-dir=${pipsi_bin_dir} --home=${pipsi_home} )
fi
pip="${pipsi_home}/${name}/bin/pip"

# if bin_dir or home are not writable, automatically attempt to elevate
# permissions using sudo
get_su() {
  su=''
  bake test -w "${pipsi_bin_dir}/" || su='sudo'
  bake test -w "${pipsi_home}/" || su='sudo'
  printf '%s' "${su}"
}

# return STATUS_MISSING if pipsi (local or global, according to option)
# is missing, return 0 otherwise
# note this is only useful in case of operating on pipsi itself, if any
# pipsi is available it is capable of installing packages either
# locally or globally
status_have_pipsi() {
  bake which pipsi &>/dev/null || return "${STATUS_MISSING}"
  if [[ ${global} == true ]]; then
    bake type -ap pipsi |grep -q '^/usr' || return "${STATUS_MISSING}"
  else
    bake type -ap pipsi |grep -q "^${HOME}" || return "${STATUS_MISSING}"
  fi
}

case "${action}" in
  desc)
    printf '%s\n' \
      'asserts presence of packages installed via pipsi' \
      '* pipsi                (install/upgrade pipsi itself)' \
      '* pipsi packge-name    (works on given package from pypi)' \
      '--global               (work on global packages instead of per-user)'
    ;;
  status)
    needs_exec "python3" || return "${STATUS_FAILED_PRECONDITION}"

    if ${bootstrap}; then  # operate on pipsi itself
      status_have_pipsi || {
        status="$?"
        needs_exec "curl" || return "${STATUS_FAILED_PRECONDITION}"
        needs_exec "git" || return "${STATUS_FAILED_PRECONDITION}"
        return "${status}"
      }
      # pipsi is available, fall back to common check for up-to-date
    else  # operate on provided packge
      bake which pipsi || return "${STATUS_FAILED_PRECONDITION}"

      # check output of `pipsi list` to see if package is installed
      [[ $(bake pipsi "${pipsi_opts[@]}" list) =~ "Package \"${name}\"" ]] \
        || return "${STATUS_MISSING}"
    fi

    # pipsi doesn't provide a way to check if packge is up-to-date,
    # so for now have to use `pip` directly
    ! bake "${pip}" list --outdated --format=legacy | egrep "^${name} " \
      || return "${STATUS_OUTDATED}"
    return "${STATUS_OK}"
    ;;
  install)
    su="$(get_su)"
    if ${bootstrap}; then  # operate on pipsi itself
      # escape the pipe as we want `bake` to evaluate it lazily
      # install pipsi from git master for now as release on pypi is
      # ancient, master contains many fixes and some new features
      bake curl -fsSL \
        https://raw.githubusercontent.com/mitsuhiko/pipsi/master/get-pipsi.py \
        \| "${su}" python3 - "${pipsi_opts[@]}" \
        --ignore-existing \
        --src 'git+https://github.com/mitsuhiko/pipsi.git#egg=pipsi'
    else  # operate on provided packge
      bake "${su}" pipsi "${pipsi_opts[@]}" install "${name}"
    fi
    bake "${pip}" install --upgrade pip setuptools
    ;;
  upgrade|delete)
    if [[ ${action} == delete ]]; then
      action="uninstall"
    fi
    bake "$(get_su)" pipsi "${pipsi_opts[@]}" "${action}" "${name}"
    ;;
  *) return 1 ;;
esac
