#!/usr/bin/env bash

# Copyright 2016 The Fuchsia Authors
#
# Use of this source code is governed by a MIT-style
# license that can be found in the LICENSE file or at
# https://opensource.org/licenses/MIT

# Use this to use git bisect with prebuilt binary artifacts. To use, first copy the script somewhere
# outside of the source tree (so git bisect won't mess with it) then run the following commands:
#   git bisect start <bad> <good>
#   git bisect run PATH_TO/bisect-helper <optional additional args to run-zircon>
# The script will download the prebuilt zircon.bin associated with each commit, if it exists, and
# start it up in qemu. After qemu exits, the script will ask if the build is good or bad.  Type 'y'
# or 'n' and the bisect will proceed.

set -e

readonly SCRIPT_DIR="$1"

readonly TEMP_DIR="$(mktemp -d)"
trap "rm -rf -- "${TEMP_DIR}"" EXIT
readonly CURRENT_COMMIT="$(git rev-parse HEAD)"
readonly ZIRCON_BIN_URL="https://storage-download.googleapis.com/fuchsia-build/zircon/qemu-arm64/zircon.elf/${CURRENT_COMMIT}"
readonly DOWNLOAD_STATUS="$(curl -s -w %{http_code} --progress-bar --output "${TEMP_DIR}/zircon.elf" "${ZIRCON_BIN_URL}")"
if [[ "${DOWNLOAD_STATUS}" != 200 ]]; then
    echo "Could not find prebuilt at ${ZIRCON_BIN_URL}: ${DOWNLOAD_STATUS}"
    exit 125  # could not evaluate this commit, no prebuilt available
fi
"${SCRIPT_DIR}/run-zircon-arm64" -o "${TEMP_DIR}"

echo "Did it work? y/n"
read RESULT
if [[ "${RESULT}" == y ]]; then
    exit 0
else
    exit 1
fi