#!/usr/bin/env bash
# bin/compile <build-dir> <cache-dir>

set -x

# clean up leaking environment
unset GIT_DIR

# config
SCONS_VERSION="1.2.0"
S3_BUCKET="heroku-buildpack-nodejs"

# parse and derive params
BUILD_DIR=$1
CACHE_DIR=$2
LP_DIR=`cd $(dirname $0); cd ..; pwd`
CACHE_STORE_DIR="$CACHE_DIR/node_modules/$NPM_VERSION"
CACHE_TARGET_DIR="$BUILD_DIR/node_modules"

function error() {
  echo " !     $*"
  exit 1
}

function mktmpdir() {
  dir=$(mktemp -t node-$1-XXXX)
  rm -rf $dir
  mkdir -p $dir
  echo $dir
}

function indent() {
  c='s/^/       /'
  case $(uname) in
    Darwin) sed -l "$c";;
    *)      sed -u "$c";;
  esac
}

function run_npm() {
  command="$1"
  HOME="$BUILD_DIR" $VENDORED_NODE/bin/node $VENDORED_NPM/cli.js $command 2>&1 | indent

  if [ "${PIPESTATUS[*]}" != "0 0" ]; then
    echo " !     Failed to $command dependencies with npm"
    exit 1
  fi
}

function manifest_versions() {
  curl "http://${S3_BUCKET}.s3.amazonaws.com/manifest.${1}" -s -o - | tr -s '\n' ' '
}

function resolve_version() {
  available_versions="$1"
  requested_version="$2"
  default_version="$3"

  if [ "$2" == "" ]; then
    echo $3
  else
    args=""
    for version in $available_versions; do args="${args} -v \"${version}\""; done
    for version in $requested_version; do args="${args} -r \"${version}\""; done
    eval $bootstrap_node/bin/node $LP_DIR/vendor/node-semver/bin/semver ${args} | tail -n1
  fi
}

function package_engine_version() {
  version=$(cat $BUILD_DIR/package.json | $bootstrap_node/bin/node $LP_DIR/vendor/json/json engines.$1)
  if [ $? == 0 ]; then
    echo $version
  fi
}

function package_resolve_version() {
  engine="$1"
  resolved_version=$(resolve_version "${engine_versions[$engine]}" "${engine_requests[$engine]}" "${engine_defaults[$engine]}")

  if [ "${resolved_version}" == "" ]; then
    error "Requested engine $engine version: ${REQUESTED_NODE_VERSION} does not match available versions: ${engine_versions[$engine]}"
  else
    echo $resolved_version
  fi
}

function package_download() {
  engine="$1"
  version="$2"
  location="$3"

  mkdir -p $location
  package="http://${S3_BUCKET}.s3.amazonaws.com/$engine-$version.tgz"
  echo "downloading $engine $version"
  curl $package -s -o - | tar xzf - -C $location
}

bootstrap_node=$(mktmpdir bootstrap_node)
package_download "nodejs" "0.4.7" $bootstrap_node

# make some associative arrays
declare -A engine_versions
declare -A engine_defaults
declare -A engine_requests

engine_defaults["node"]="0.4.7"
engine_defaults["npm"]="1.0.94"

engine_versions["node"]=$(manifest_versions "nodejs")
engine_requests["node"]=$(package_engine_version "node")

engine_versions["npm"]=$(manifest_versions "npm")
engine_requests["npm"]=$(package_engine_version "npm")

NODE_VERSION=$(package_resolve_version "node")
NPM_VERSION=$(package_resolve_version "npm")

# s3 packages
NODE_PACKAGE="http://${S3_BUCKET}.s3.amazonaws.com/nodejs-${NODE_VERSION}.tgz"
NPM_PACKAGE="http://${S3_BUCKET}.s3.amazonaws.com/npm-${NPM_VERSION}.tgz"
SCONS_PACKAGE="http://${S3_BUCKET}.s3.amazonaws.com/scons-${SCONS_VERSION}.tgz"

# vendor directories
VENDORED_NODE="$(mktmpdir node)"
VENDORED_NPM="$(mktmpdir npm)"
VENDORED_SCONS="$(mktmpdir scons)"

# download and unpack packages
echo "-----> Fetching Node.js binaries"
package_download "nodejs", "${NODE_VERSION}", "${VENDORED_NODE}"
package_download "npm", "${NPM_VERSION}", "${VENDORED_NPM}"
package_download "scons", "${SCONS_VERSION}", "${VENDORED_SCONS}"

# vendor node into the slug
PATH="$BUILD_DIR/bin:$PATH"
echo "-----> Vendoring node into slug"
mkdir -p "$BUILD_DIR/bin"
cp "$VENDORED_NODE/bin/node" "$BUILD_DIR/bin/node"

# setting up paths for building
PATH="$VENDORED_SCONS:$VENDORED_NODE/bin:$PATH"
INCLUDE_PATH="$VENDORED_NODE/include"
export CPATH="$INCLUDE_PATH"
export CPPPATH="$INCLUDE_PATH"

# unpack existing cache
if [ -d $CACHE_STORE_DIR ]; then

  # generate a place to put node_modules
  TEMP_NODE_MODULES_DIR=$(mktmpdir node_modules)

  # move existing node_modules out of the way
  if [ -d $CACHE_TARGET_DIR ]; then
    mv $CACHE_TARGET_DIR $TEMP_NODE_MODULES_DIR/
  fi

  # copy the cached node_modules in
  mkdir -p $CACHE_TARGET_DIR
  cp -R $CACHE_STORE_DIR/* $CACHE_TARGET_DIR/

  # move existing node_modules back into place
  if [ -d $TEMP_NODE_MODULES_DIR/node_modules ]; then
    cp -R $TEMP_NODE_MODULES_DIR/node_modules/* $CACHE_TARGET_DIR/
  fi

fi

# install dependencies with npm
echo "-----> Installing dependencies with npm"
cd $BUILD_DIR
HOME="$BUILD_DIR" $VENDORED_NODE/bin/node $VENDORED_NPM/cli.js prune 2>&1 | indent
HOME="$BUILD_DIR" $VENDORED_NODE/bin/node $VENDORED_NPM/cli.js install 2>&1 | indent
if [ "${PIPESTATUS[*]}" != "0 0" ]; then
  error "Failed to install dependencies with npm"
else
  echo "       Dependencies installed"
fi

echo "Dependencies installed" | indent

# repack cache with new assets
if [ -d $CACHE_TARGET_DIR ]; then
  rm -rf $CACHE_STORE_DIR
  mkdir -p $(dirname $CACHE_STORE_DIR)
  cp -a $CACHE_TARGET_DIR $CACHE_STORE_DIR
fi
