#! /bin/bash
#
# Copyright 2019 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

usage() {
  cat >&2 <<EOF
Determine and print the 32- or 64-bit architecture of a device.

Usage:
  $0 --32    Select the 32-bit architecture
  $0 --64    Select the 64-bit architecture
EOF
  exit 1
}

if [[ $# -ne 1 ]]; then
  usage
fi

ARCHITECTURES_32="(arm|x86|mips|none)"
ARCHITECTURES_64="(arm64|x86_64|mips64|none)"

case "$1" in
  (--32)
    ARCHITECTURES_PATTERN="${ARCHITECTURES_32}"
    ;;
  (--64)
    ARCHITECTURES_PATTERN="${ARCHITECTURES_64}"
    ;;
  (*) usage;;
esac

# Need to be root to query /data/dalvik-cache
adb root > /dev/null
adb wait-for-device
ISA=
ISA_adb_invocation=
ISA_outcome=
# We iterate a few times to workaround an adb issue. b/32655576
for i in {1..10}; do
  ISA_adb_invocation=$(adb shell ls /data/dalvik-cache)
  ISA_outcome=$?
  ISA=$(echo $ISA_adb_invocation | grep -Ewo "${ARCHITECTURES_PATTERN}")
  if [[ -n "$ISA" ]]; then
    break;
  fi
done
if [[ -z "$ISA" ]]; then
  echo >&2 "Unable to determine architecture"
  # Print a few things for helping diagnosing the problem.
  echo >&2 "adb invocation output: $ISA_adb_invocation"
  echo >&2 "adb invocation outcome: $ISA_outcome"
  echo >&2 $(adb shell ls -F /data/dalvik-cache)
  echo >&2 $(adb shell ls /data/dalvik-cache)
  echo >&2 ${ARCHITECTURES_PATTERN}
  echo >&2 $(adb shell ls -F /data/dalvik-cache | grep -Ewo "${ARCHITECTURES_PATTERN}")
  exit 1
fi

echo "$ISA"