#!/bin/bash

# Utlity functions

info() {
  printf "%s\\n" "$@"
}

fatal() {
  printf "**********\\n"
  printf "Fatal Error: %s\\n" "$@"
  printf "**********\\n"
  exit 1
}

# Get system architecture
#
# This is used to get the target architecture for docker image.
# For crossing building, we need a way to specify the target
# architecutre manually.
function get_arch() {
  local arch
  case $(uname -m) in
    x86_64)
      arch="amd64"
      ;;
    ppc64le)
      arch="ppc64le"
      ;;
    s390x)
      arch="s390x"
      ;;
    aarch64)
      arch="arm64"
      ;;
    armv7l)
      arch="arm32v7"
      ;;
    *)
      echo "$0 does not support architecture $arch ... aborting"
      exit 1
      ;;
  esac

  echo "$arch"
}

# Get corresponding variants based on the architecture.
# All supported variants of each supported architecutre are listed in a
# file - 'architectures'. Its format is:
#   <architecutre 1> <supported variant 1 >,<supported variant 2>...
#   <architecutre 2> <supported variant 1 >,<supported variant 2>...
function get_variants() {
  local dir
  dir=${1:-.}
  shift

  local arch
  local availablevariants
  local variantsfilter
  local variants

  arch=$(get_arch)
  variantsfilter=("$@")
  IFS=' ' read -ra availablevariants <<<"$(grep "^$arch" "$dir/architectures" | sed -E 's/'"$arch"'[[:space:]]*//' | sed -E 's/,/ /g')"

  if [ ${#variantsfilter[@]} -gt 0 ]; then
    for variant1 in "${availablevariants[@]}"; do
      for variant2 in "${variantsfilter[@]}"; do
        if [[ "$variant1" == "$variant2" ]]; then
          variants+=("$variant1")
        fi
      done
    done

    if [ ${#variants[@]} -gt 0 ]; then
      echo "${variants[@]}"
    fi
  else
    echo "${availablevariants[@]}"
  fi
}

# Get supported architectures for a specific version and variant
#
# Get default supported architectures from 'architectures'. Then go to the version folder
# to see if there is a local architectures file. The local architectures will override the
# default architectures. This will give us some benefits:
# - a specific version may or may not support some architectures
# - if there is no specialization for a version, just don't provide local architectures
function get_supported_arches() {
  local version
  local variant
  local arches
  local lines
  local line
  version="$1"
  shift
  variant="$1"
  shift

  # Get default supported arches
  lines=$(grep "$variant" "$(dirname "$version")"/architectures 2>/dev/null | cut -d' ' -f1)

  # Get version specific supported architectures if there is specialized information
  if [ -a "$version"/architectures ]; then
    lines=$(grep "$variant" "$version"/architectures 2>/dev/null | cut -d' ' -f1)
  fi

  while IFS='' read -r line; do
    arches+=("$line")
  done <<<"$lines"

  echo "${arches[@]}"
}

# Get configuration values from the config file
#
# The configuration entries are simple key/value pairs which are whitespace separated.
function get_config() {
  local dir
  dir=${1:-.}
  shift

  local name
  name=$1
  shift

  local value
  value=$(grep "^$name" "$dir/config" | sed -E 's/'"$name"'[[:space:]]*//')
  echo "$value"
}

# Get available versions for a given path
#
# If full or partial versions are provided then they are processed and
# validated. e.g. "6 chakracore" returns "6 chakracore/8" since it processed the
# chakracore entry and found it to be a fork rather than a complete version.
#
# The result is a list of valid versions.
function get_versions() {
  local prefix
  prefix=${1:-.}
  shift

  local versions
  local dirs=("$@")
  if [ ${#dirs[@]} -eq 0 ]; then
    IFS=' ' read -ra dirs <<<"$(echo "${prefix%/}/"*/)"
  fi

  for dir in "${dirs[@]}"; do
    if [ -a "$dir/config" ]; then
      local subdirs
      IFS=' ' read -ra subdirs <<<"$(get_versions "${dir#./}")"
      for subdir in "${subdirs[@]}"; do
        versions+=("$subdir")
      done
    elif [ -a "$dir/Dockerfile" ]; then
      versions+=("${dir#./}")
    fi
  done

  if [ ${#versions[@]} -gt 0 ]; then
    echo "${versions[@]%/}"
  fi
}

function get_fork_name() {
  local version
  version=$1
  shift

  IFS='/' read -ra versionparts <<<"$version"
  if [ ${#versionparts[@]} -gt 1 ]; then
    echo "${versionparts[0]}"
  fi
}

function get_full_version() {
  local version
  version=$1
  shift

  grep -m1 'ENV NODE_VERSION ' "$version/Dockerfile" | cut -d' ' -f3
}

function get_major_minor_version() {
  local version
  version=$1
  shift

  local fullversion
  fullversion=$(get_full_version "$version")

  echo "$(echo "$fullversion" | cut -d'.' -f1).$(echo "$fullversion" | cut -d'.' -f2)"
}

function get_tag() {
  local version
  version=$1
  shift

  local versiontype
  versiontype=${1:-full}
  shift

  local tagversion
  if [ "$versiontype" = full ]; then
    tagversion=$(get_full_version "$version")
  elif [ "$versiontype" = majorminor ]; then
    tagversion=$(get_major_minor_version "$version")
  fi

  local tagparts
  IFS=' ' read -ra tagparts <<<"$(get_fork_name "$version") $tagversion"
  IFS='-'
  echo "${tagparts[*]}"
  unset IFS
}

function sort_versions() {
  local versions=("$@")
  local sorted
  local lines
  local line

  IFS=$'\n'
  lines="${versions[*]}"
  unset IFS

  while IFS='' read -r line; do
    sorted+=("$line")
  done <<<"$(echo "$lines" | grep "^[0-9]" | sort -r)"

  while IFS='' read -r line; do
    sorted+=("$line")
  done <<<"$(echo "$lines" | grep -v "^[0-9]" | sort -r)"

  echo "${sorted[@]}"
}