#!/bin/bash

name="verify-filter"
version="1.0"
read -r -d '' help_message <<-EOF
	Verify a PGP-signed file and print it
	Usage: pgpcat [OPTIONS] FILE
	Options:
	 -e, --exit               exit without printing FILE if verification fails
	 -f FILE, --file FILE     file to verify and print
	 -h, --help               print this message and exit
	 -q, --quiet              suppress error messages
	 -s SIG, --signature SIG  detached signature file; if unspecified,
	                          FILE should be armored clear-signed message
	 -v, --verbose            show additional messages
	 -V, --version            print version number and exit
EOF

source /usr/local/lib/mylib.bash

positional=()
fail_immediately=0
msgfile=
quiet=0
sigfile=
verbose=0

while [[ $# -gt 0 ]]; do
  case $1 in

  -e|--exit)
    debug_msg "Setting exit option to 1 (was ${fail_immediately})"
    fail_immediately=1
    shift
    ;;

  -f|--file)
    debug_msg "Setting file option to ${2} (was ${msgfile})"
    msgfile="$2"
    shift; shift
    ;;

  -h|--help)
    help_msg
    shift
    ;;

  -q|--quiet)
    debug_msg "Setting quiet option to 1 (was ${quiet})"
    quiet=1
    shift
    ;;

  -s|--signature)
    debug_msg "Setting signature option to ${2} (was ${sigfile})"
    sigfile="$2"
    shift; shift
    ;;

  -v|--verbose)
    debug_msg "Setting verbose option to 1 (was ${verbose})"
    verbose=1
    shift
    ;;

  -V|--version)
    version_msg
    ;;

  *)
    debug_msg "Argument '${1}' added to positional array"
    positional+=("$1")
    shift
    ;;
  esac
done

# handle input files
if [[ -z "$msgfile" ]]; then
  if [[ ${#positional[@]} -lt 1 ]]; then
    error_msg "Expected input file (given none)"
  else
    debug_msg "Moving a positional argument into file option (${#positional[0]})"
    msgfile="${positional[0]}"
    positional=("${positional[@]:1}")
  fi
fi

code=0
if [[ -z "$sigfile" ]]; then
  debug_msg "'${msgfile}' is armored clearsigned"
  if ! /usr/bin/local/verify --file "$msgfile"; then
    code=1
    nonfatal_error_msg "Can not verify file '${msgfile}'"

    if [[ "$fail_immediately" -eq 1 ]]; then
      exit "$code"
    fi
  fi
  /usr/bin/cat "$msgfile"
else
  debug_msg "'${msgfile}' is signed, '${sigfile}' is detached signature"
  if ! /usr/bin/local/verify --file "$msgfile" --signature "${sigfile}"; then
    code=1
    nonfatal_error_msg "Can not verify file '${msgfile}'"

    if [[ "$fail_immediately" -eq 1 ]]; then
      exit "$code"
    fi
  fi
  /usr/bin/cat "$msgfile"
fi

exit "$code"