#!/usr/bin/env bash

set -euo pipefail

# Most of this comes from github.com/bazelbuild/bazel-gazelle/internal/gazelle.bash.in.
# It's very hacky.

# Copyright 2017 The Bazel Authors. All rights reserved.
#
# 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.

FIETSJE_SHORT_PATH=@@FIETSJE_SHORT_PATH@@
GOTOOL=@@GOTOOL@@

# find_runfile prints the location of a runfile in the source workspace,
# either by reading the symbolic link or reading the runfiles manifest.
function find_runfile {
  local runfile=$1
  if [ -f "$runfile" ]; then
    readlink "$runfile"
    return
  fi
  runfile=$(echo "$runfile" | sed -e 's!^\(\.\./\|external/\)!!')
  if grep -q "^$runfile" MANIFEST; then
    grep "^$runfile" MANIFEST | head -n 1 | cut -d' ' -f2
    return
  fi
  # printing nothing indicates failure
}

# bazel_build_get_path builds a given target and prints the absolute path
# to the generated binary. This only works for rules that produce a single file.
function bazel_build_get_path {
  local build_log=$(mktemp fietsje_build.XXXX.json --tmpdir)
  bazel build --build_event_json_file="$build_log" "$1"
  grep "^{\"id\":{\"targetCompleted\":{\"label\":\"$1\"" "$build_log" | \
    sed -e 's!^.*file://\([^"]*\).*$!\1!'
  rm -f "$build_log"
}

# set_goroot attempts to set GOROOT to the SDK used by rules_go. fietsje
# invokes tools inside the Go SDK for dependency management. It's good to
# use the SDK used by the workspace in case the Go SDK is not installed
# on the host system or is a different version.
function set_goroot {
  local gotool=$(find_runfile "$GOTOOL")
  if [ -z "$gotool" ]; then
    echo "$0: warning: could not locate GOROOT used by rules_go" >&2
    return
  fi
  export GOROOT=$(cd "$(dirname "$gotool")/.."; pwd)
  if type cygpath >/dev/null 2>&1; then
    # On Windows, convert the path to something usable outside of bash.
    GOROOT=$(cygpath -w "$GOROOT")
  fi
}

set_goroot
fietsje_short_path=$(find_runfile "$FIETSJE_SHORT_PATH")
if [ -z "$fietsje_short_path" ]; then
  echo "error: could not locate fietsje binary" >&2
  exit 1
fi
if [ -z "${BUILD_WORKSPACE_DIRECTORY-}" ]; then
  echo "error: BUILD_WORKSPACE_DIRECOTRY not set" >&2
  exit 1
fi
cd "$BUILD_WORKSPACE_DIRECTORY"
"$fietsje_short_path" -shelf_path third_party/go/shelf.pb.text -repositories_bzl third_party/go/repositories.bzl