#!/bin/bash
# Copyright 2014 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Download the newest version of Closure Compiler, build it and put into Chrome
# source tree. Also update externs/chrome_extensions.js.
#
# TODO(dbeam): we don't really need to build the compiler any more. We used to
# need to because we built a custom runner. We could probably just curl
# https://dl.google.com/closure-compiler/compiler-latest.zip and unzip. And get
# the externs from rawgit.com.

readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
readonly TEMP_DIR=$(mktemp -d)
readonly EXTERNS_DIR="${SCRIPT_DIR}/externs"
readonly README="${SCRIPT_DIR}/README.chromium"

cleanup() {
  rm -rf "${TEMP_DIR}"
}

get_sha1() {
  sha1sum "$1" | cut -d" " -f1
}

trap cleanup SIGINT SIGHUP SIGTERM

old_head=$(egrep -o "^Revision: [0-9a-f]{5,40}$" "${README}" | cut -d" " -f2)
old_extensions_sha1=$(get_sha1 "${EXTERNS_DIR}/chrome_extensions.js")
old_polymer_sha1=$(get_sha1 "${EXTERNS_DIR}/polymer-1.0.js")

cd "${TEMP_DIR}"

echo "Cloning Closure Compiler repo"
git clone --depth 1 https://github.com/google/closure-compiler.git

cd closure-compiler

new_head=$(git rev-parse HEAD)

if [[ "${new_head}" == "${old_head}" ]]; then
  echo "No closure-compiler changes since last roll. Nothing to do."
  cleanup
  exit 0
else
  head_range=$(cat <<EOT
Change log:
https://github.com/google/closure-compiler/compare/${old_head}...${new_head}
EOT
)
fi

check_jdk_version() {
  # Pretty contrived checks modeling how we write Maven XML files.
  if [ ! -r "$2" ]; then
    echo "Could not find $2" >&2
    exit 1
  elif ! fgrep -q '<jdk.version>'$1'</jdk.version>' "$2"; then
    echo "JDK version $1 must be specified in $2" >&2
    exit 1
  elif ! fgrep -q '<source>${jdk.version}</source>' "$2"; then
    echo "Java source must be specified to be \${jdk.version} in $2" >&2
    exit 1
  elif ! fgrep -q '<target>${jdk.version}</target>' "$2"; then
    echo "Java target must be specified to be \${jdk.version} in $2" >&2
    exit 1
  fi
}

echo "Checking JDK Version Used to Build"
check_jdk_version 1.7 pom.xml

echo "Building Closure Compiler"
mvn clean install -DskipTests=true --projects com.google.javascript:closure-compiler,com.google.javascript:closure-compiler-externs

if [[ "$?" -ne 0 ]]; then
  echo "Failed to build jar, copying nothing" >&2
  cleanup
  exit 1
fi

# TODO(dbeam): the Maven-built jar seems a little bigger than the ant version.
cp target/closure-compiler-1.0-SNAPSHOT.jar "${SCRIPT_DIR}/compiler/compiler.jar"

readonly WARNING="$(cat <<EOT
//    SSSSSSSSSSSSSSS TTTTTTTTTTTTTTTTTTTTTTT     OOOOOOOOO     PPPPPPPPPPPPPPPPP
//  SS:::::::::::::::ST:::::::::::::::::::::T   OO:::::::::OO   P::::::::::::::::P
// S:::::SSSSSS::::::ST:::::::::::::::::::::T OO:::::::::::::OO P::::::PPPPPP:::::P
// S:::::S     SSSSSSST:::::TT:::::::TT:::::TO:::::::OOO:::::::OPP:::::P     P:::::P
// S:::::S            TTTTTT  T:::::T  TTTTTTO::::::O   O::::::O  P::::P     P:::::P
// S:::::S                    T:::::T        O:::::O     O:::::O  P::::P     P:::::P
//  S::::SSSS                                                     P::::PPPPPP:::::P
//   SS::::::SSSSS       This file is generated. To update it,    P:::::::::::::PP
//     SSS::::::::SS          run roll_closure_compiler.          P::::PPPPPPPPP
//        SSSSSS::::S                                             P::::P
//             S:::::S        T:::::T        O:::::O     O:::::O  P::::P
//             S:::::S        T:::::T        O::::::O   O::::::O  P::::P
// SSSSSSS     S:::::S      TT:::::::TT      O:::::::OOO:::::::OPP::::::PP
// S::::::SSSSSS:::::S      T:::::::::T       OO:::::::::::::OO P::::::::P
// S:::::::::::::::SS       T:::::::::T         OO:::::::::OO   P::::::::P
//  SSSSSSSSSSSSSSS         TTTTTTTTTTT           OOOOOOOOO     PPPPPPPPPP
EOT
)"

(echo "${WARNING}" && cat contrib/externs/chrome_extensions.js) > "${EXTERNS_DIR}/chrome_extensions.js"
(echo "${WARNING}" && cat contrib/externs/polymer-1.0.js) > "${EXTERNS_DIR}/polymer-1.0.js"

new_extensions_sha1=$(get_sha1 "${EXTERNS_DIR}/chrome_extensions.js")
if [[ "${new_extensions_sha1}" != "${old_extensions_sha1}" ]]; then
  extensions_range="chrome_extensions.js: ${old_extensions_sha1} -> ${new_extensions_sha1}"
fi

new_polymer_sha1=$(get_sha1 "${EXTERNS_DIR}/polymer-1.0.js")
if [[ "${new_polymer_sha1}" != "${old_polymer_sha1}" ]]; then
  polymer_range="polymer-1.0.js: ${old_polymer_sha1} -> ${new_polymer_sha1}"
fi

echo
echo "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"
echo "@"
echo "@  ROLL RESULTS:"
echo "@"
echo "@  closure-compiler.git HEAD:"
echo "@    Old: ${old_head}"
echo "@    New: ${new_head}"
echo "@"
echo "@  externs/chrome_extensions.js SHA1:"
echo "@    Old: ${old_extensions_sha1}"
echo "@    New: ${new_extensions_sha1}"
echo "@"
echo "@  externs/polymer-1.0.js SHA1:"
echo "@    Old: ${old_polymer_sha1}"
echo "@    New: ${new_polymer_sha1}"
echo "@"
echo "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"
echo

sed -i "s/^Revision: ${old_head}$/Revision: ${new_head}/" "${README}"

echo "git commit -a -m 'Roll closure compiler"
echo
echo "${head_range}"
if [[ ! -z "${extensions_range}" ]]; then echo "${extensions_range}"; fi
if [[ ! -z "${polymer_range}" ]]; then echo "${polymer_range}"; fi
echo
echo "TBR="
echo "BUG='"
echo
echo "git cl upload"

cleanup