#!/bin/bash

name="hugo-timestamp"
version="1.0"
read -r -d '' help_message <<-EOF
	Set a date/timestamp into a Hugo content files
	Usage: hugo-timestamp [OPTIONS] TARGET DATETIME
	Options:
	 -h, --help     print this message and exit
	 -q, --quiet    suppress error messages
	 -v, --verbose  show additional messages
	 -V, --version  print version number and exit
EOF

source /usr/local/lib/mylib.bash
. /usr/local/lib/myparse.bash

# error if no filenames given
if [[ ${#positional[@]} -lt 2 ]]; then
  usage_msg
fi

_ed_append_date() {
  ed -s "$1" <<EOF
/^title:
a
date: "$2"
.
w
q
EOF
}

_ed_overwrite_date() {
  ed -s "$1" <<EOF
g/^date:/c
i
date: "$2"
.
w
q
EOF
}

filename="${positional[0]}"
newdate="${positional[1]}"

# if filename does not exist
if [[ ! -f "$filename" ]]; then
  error_msg "No such file '$filename'"

# main routine
else

  # try read timestamp from file
  olddate="$(hugo-extract-timestamp "$filename")"

  # branch 1: has no timestamp so append one
  if [[ -z "$olddate" ]]; then
    if [[ "$verbose" -eq 1 ]]; then
      debug_msg "No date found, creating one"
    fi

    _ed_append_date "$filename" "$newdate"

  # branch 2: has a timestamp so replace it
  else
    if [[ "$verbose" -eq 1 ]]; then
      debug_msg "replacing ${olddate}"
    fi

    _ed_overwrite_date "$filename" "$newdate"
  fi
fi