#!/bin/bash
#
# Presubmit checks for certificate-transparency-go.
#
# Checks for lint errors, spelling, licensing, correct builds / tests and so on.
# Flags may be specified to allow suppressing of checks or automatic fixes, try
# `scripts/presubmit.sh --help` for details.
#
# Globals:
#   GO_TEST_PARALLELISM: max processes to use for Go tests. Optional (defaults
#       to 10).
#   GO_TEST_TIMEOUT: timeout for 'go test'. Optional (defaults to 5m).
set -eu

check_pkg() {
  local cmd="$1"
  local pkg="$2"
  check_cmd "$cmd" "try running 'go get -u $pkg'"
}

check_cmd() {
  local cmd="$1"
  local msg="$2"
  if ! type -p "${cmd}" > /dev/null; then
    echo "${cmd} not found, ${msg}"
    return 1
  fi
}

usage() {
  echo "$0 [--coverage] [--fix] [--no-build] [--no-linters] [--no-generate]"
}

main() {
  local coverage=0
  local fix=0
  local run_build=1
  local run_lint=1
  local run_generate=1
  while [[ $# -gt 0 ]]; do
    case "$1" in
      --coverage)
        coverage=1
        ;;
      --fix)
        fix=1
        ;;
      --help)
        usage
        exit 0
        ;;
      --no-build)
        run_build=0
        ;;
      --no-linters)
        run_lint=0
        ;;
      --no-generate)
        run_generate=0
        ;;
      *)
        usage
        exit 1
        ;;
    esac
    shift 1
  done

  cd "$(dirname "$0")"  # at scripts/
  cd ..  # at top level

  go_srcs="$(find . -name '*.go' | \
    grep -v vendor/ | \
    grep -v mock_ | \
    grep -v .pb.go | \
    grep -v x509/ | \
    grep -v asn1/ | \
    tr '\n' ' ')"

  # Prevent the creation of proto files with .txt extensions.
  bad_protos="$(find . -name '*.pb.txt' -o -name '*.proto.txt' -print)"
  if [[ "${bad_protos}" != "" ]]; then
    echo "Text-based protos must use the .textproto extension:"
    echo $bad_protos
    exit 1
  fi

  if [[ "$fix" -eq 1 ]]; then
    check_pkg goimports golang.org/x/tools/cmd/goimports || exit 1

    echo 'running gofmt'
    gofmt -s -w ${go_srcs}
    echo 'running goimports'
    goimports -w ${go_srcs}
  fi

  if [[ "${run_build}" -eq 1 ]]; then
    echo 'running go build'
    go build ./...

    echo 'running go test'

    # Individual package profiles are written to "$profile.out" files under
    # /tmp/ct_profile.
    # An aggregate profile is created at /tmp/coverage.txt.
    mkdir -p /tmp/ct_profile
    rm -f /tmp/ct_profile/*

    for d in $(go list ./...); do
      # Create a different -coverprofile for each test (if enabled)
      local coverflags=
      if [[ ${coverage} -eq 1 ]]; then
        # Transform $d to a smaller, valid file name.
        # For example:
        # * github.com/google/certificate-transparency-go becomes c-t-go.out
        # * github.com/google/certificate-transparency-go/cmd/createtree/keys becomes
        #   c-t-go-cmd-createtree-keys.out
        local profile="${d}.out"
        profile="${profile#github.com/*/}"
        profile="${profile//\//-}"
        profile="${profile/certificate-transparency-go/c-t-go}"
        coverflags="-covermode=atomic -coverprofile='/tmp/ct_profile/${profile}'"
      fi

      # Do not run go test in the loop, instead echo it so we can use xargs to
      # add some parallelism.
      echo go test \
          -short \
          -timeout=${GO_TEST_TIMEOUT:-5m} \
          ${coverflags} \
          "$d"
    done | xargs -I '{}' -P ${GO_TEST_PARALLELISM:-10} bash -c '{}' || exit 1

    [[ ${coverage} -eq 1 ]] && \
      cat /tmp/ct_profile/*.out > coverage.txt
  fi

  if [[ "${run_lint}" -eq 1 ]]; then
    check_cmd golangci-lint \
      'have you installed github.com/golangci/golangci-lint?' || exit 1

    echo 'running golangci-lint'
    golangci-lint run --deadline=5m
    echo 'checking license headers'
    ./scripts/check_license.sh ${go_srcs}
  fi

  if [[ "${run_generate}" -eq 1 ]]; then
    check_cmd protoc 'have you installed protoc?'
    check_pkg mockgen github.com/golang/mock/mockgen || exit 1

    echo 'running go generate'
    go generate -run="protoc" ./...
    go generate -run="mockgen" ./...
  fi
}

main "$@"