# Copyright 2021 The Go Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

# Library of useful bash functions and variables for presubmit checks.

RED=; GREEN=; YELLOW=; NORMAL=;
MAXWIDTH=0

if tput setaf 1 >& /dev/null; then
  RED=`tput setaf 1`
  GREEN=`tput setaf 2`
  YELLOW=`tput setaf 3`
  NORMAL=`tput sgr0`
  MAXWIDTH=$(( $(tput cols) - 2 ))
fi

EXIT_CODE=0

info() { echo -e "${GREEN}$@${NORMAL}" 1>&2; }
warn() { echo -e "${YELLOW}$@${NORMAL}" 1>&2; }
err() { echo -e "${RED}$@${NORMAL}" 1>&2; EXIT_CODE=1; }

die() {
  err $@
  exit 1
}

dryrun=false

# runcmd prints an info log describing the command that is about to be run, and
# then runs it. It sets EXIT_CODE to non-zero if the command fails, but does not exit
# the script.
runcmd() {
  msg="$@"
  if $dryrun; then
    echo -e "${YELLOW}dryrun${GREEN}\$ $msg${NORMAL}"
    return 0
  fi
  # Truncate command logging for narrow terminals.
  # Account for the 2 characters of '$ '.
  if [[ $MAXWIDTH -gt 0 && ${#msg} -gt $MAXWIDTH ]]; then
    msg="${msg::$(( MAXWIDTH - 3 ))}..."
  fi

  echo -e "$@\n" 1>&2;
  $@ || err "command failed"
}

# check_header checks that all given files contain the standard header for Go
# projects.
check_header() {
  if [[ "$@" != "" ]]; then
    for FILE in $@
    do
        line="$(head -4 $FILE)"
        if [[ ! $line == *"The Go Authors. All rights reserved."* ]] &&
         [[ ! $line == "// DO NOT EDIT. This file was copied from" ]]; then
              err "missing license header: $FILE"
        fi
    done
  fi
}

# ensure_go_binary verifies that a binary exists in $PATH corresponding to the
# given go-gettable URI. If no such binary exists, it is fetched via `go install`.
ensure_go_binary() {
  local binary=$(basename $1)
  if ! [ -x "$(command -v $binary)" ]; then
    info "Installing: $1"
    go install $1
  fi
}