#!/bin/bash
set -euo pipefail

# Check that app/ in this checkout matches app/ in the commit being built.
#
# The build-and-deploy scripts run the build scripts and config from the local
# checkout but build source files from the tip of the remote branch, so a stale
# checkout can silently build with the wrong Gecko version or omni patches.

SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
ROOT_DIR="$(dirname "$(dirname "$SCRIPT_DIR")")"

if [ -z "${1:-}" ]; then
	echo "Usage: $0 commit-hash" >&2
	exit 1
fi
hash=$1

cd "$ROOT_DIR"

if ! git cat-file -e "$hash^{commit}" 2>/dev/null; then
	git fetch -q origin
fi
if ! git cat-file -e "$hash^{commit}" 2>/dev/null; then
	echo "Commit $hash not found locally after fetching -- aborting" >&2
	exit 1
fi

if ! git diff --quiet HEAD "$hash" -- app/; then
	echo >&2
	echo "app/ files in this checkout differ from app/ in $hash:" >&2
	echo >&2
	git --no-pager diff --stat HEAD "$hash" -- app/ >&2
	echo >&2
	echo "Update this checkout (e.g., 'git pull') and try again" >&2
	exit 1
fi