#!/bin/bash
# Copyright 2015 The Vanadium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

NATTEMPTS="${NATTEMPTS:-3}"

retry() {
  for attempt in $(seq 1 "${NATTEMPTS}"); do
    "$@" && break
    if [[ "${attempt}" == "${NATTEMPTS}" ]]; then
      echo "\"$@\" failed ${NATTEMPTS} times in a row."
      echo "This can happen if servers are unavailable,"
      echo "and is most likely a temporary problem."
      echo "Please try again later."
      exit 1
    fi
    echo "\"$@\" failed, trying again."
    sleep 1
  done
}

must() {
  "$@"
  if [[ "$?" -ne 0 ]]; then
    exit 1
  fi
}

run() {
  echo ">> $@"
  local OUTPUT
  OUTPUT=$("$@" 2>&1)
  if [[ "$?" -eq 0 ]]; then
    echo ">> OK"
    return 0
  else
    echo ">> FAILED"
    echo "${OUTPUT}"
    return 1
  fi
}

check_environment() {
  # Check that the JIRI_ROOT environment variable is set.
  if [[ -z "${JIRI_ROOT}" ]]; then
    echo "The JIRI_ROOT environment variable is not set."
    echo "Set the environment variable and re-run."
    exit 1
  fi

  # Check that the JIRI_ROOT environment variable does not contain spaces.
  # Note: This limitation is inherited from Autotools.
  local -r PATTERN="[ ']"
  if [[ "${JIRI_ROOT}" =~ "${PATTERN}" ]]; then
    echo "The JIRI_ROOT environment variable cannot contain"
    echo "space characters."
    exit 1
  fi

  # Check that the JIRI_ROOT path does not exist.
  if [[ -e "${JIRI_ROOT}" ]]; then
    echo "The JIRI_ROOT path already exists: ${JIRI_ROOT}"
    echo "Remove it or choose a different path and re-run."
    exit 1
  fi

  # Check that the "jiri" command is not already in PATH.
  local -r JIRI_CMD=$(which jiri)
  if [[ -n "${JIRI_CMD}" ]]; then
    echo "Your PATH already contains the 'jiri' command: ${JIRI_CMD}"
    echo "Remove it from the PATH and re-run."
    exit 1
  fi

  # Check that the host OS and package manager is supported.
  case $(uname -s) in
    "Linux")
      apt-get -v &> /dev/null
      if [[ "$?" -ne 0 ]]; then
        echo "Could not find the apt-get package manager."
        exit 1
      fi
      ;;
    "Darwin")
      brew -v &> /dev/null
      if [[ "$?" -ne 0 ]]; then
        echo "Could not find the brew package manager."
        exit 1
      fi
      ;;
    *)
      echo "Operating system $(uname -s) is not supported."
      exit 1
  esac

  # Check that Go compiler version 1.5 or newer exists on the host.
  local -r GO_VERSION=$(go version 2> /dev/null)
  local -r RESULT="$?"
  local -a TOKENS=(${GO_VERSION})
  TOKENS=($(echo "${TOKENS[2]}" | tr '.' ' '))
  if [[ "${RESULT}" -ne 0 ]] || [[ "${TOKENS[0]}" -eq "go1" && "${TOKENS[1]}" -lt 5 ]]; then
    echo "Go compiler version 1.5 or newer is required for installation."
    echo "Install it and re-run."
    exit 1
  fi

  # Check that GOPATH does not contain v.io packages.
  local -r VANADIUM_PACKAGES=$(go list v.io/... 2> /dev/null)
  if [[ -n "${VANADIUM_PACKAGES}" ]]; then
    echo "Your GOPATH already contains v.io packages."
    echo "Remove these from your GOPATH and re-run."
    exit 1
  fi

  # Check that git exists on the host.
  local -r GIT_VERSION=$(git version 2> /dev/null)
  if [[ "$?" -ne 0 ]]; then
    echo "The 'git' command does not exist in your PATH."
    echo "Add it to the PATH and re-run."
    exit 1
  fi
}

main() {
  check_environment

  trap "rm -rf ${JIRI_ROOT}" INT TERM EXIT

  # Create initial directories.
  must run mkdir -p "${JIRI_ROOT}/devtools/bin"

  # Clone the manifest repository.
  retry run git clone https://vanadium.googlesource.com/manifest "${JIRI_ROOT}/.manifest"

  # Get and install the jiri tool.
  GOPATH="${JIRI_ROOT}/tmp" retry run go get -d v.io/jiri
  GOPATH="${JIRI_ROOT}/tmp" must run go build -o "${JIRI_ROOT}/devtools/bin/jiri" v.io/jiri
  rm -rf "${JIRI_ROOT}/tmp"

  # Install all Vanadium repositories and tools.
  local -r VANADIUM_MANIFEST="${VANADIUM_MANIFEST:-default}"
  retry "${JIRI_ROOT}/devtools/bin/jiri" update -manifest="${VANADIUM_MANIFEST}"

  echo "Recommended for contributors:"
  echo "Add ${JIRI_ROOT}/devtools/bin to your PATH."

  trap - EXIT
}

main "$@"