edit

#!/bin/bash

# this script edits a note, it inserts the file name into the first line
# after editing the file, it reads the first line and renames the file accordingly
# It takes two arguments: 1. the editor command and 2. the note to be edited

set -eu

EDITOR=$1
initial_path=$2
filename="$(basename "$initial_path")"
basename="${filename%.*}"


while true; do
  # insert the filename if it isn't already there
  #first_line="$(head --lines=1 -- "$initial_path")"
  #if [[ "$first_line" != "$basename" ]]; then
  #fi

  if [[ -f "$initial_path" ]]; then
    ed -s +1 "$initial_path" <<< $'i\n'"$basename"$'\n.\nw'
  fi

  # edit the file and read the first line
  $EDITOR "$initial_path"
  edited_line="$(head --lines=1 -- "$initial_path")"
  [[ -z "$edited_line" ]] && exit 1;
  ed -s +1 "$initial_path" <<< $'d\nw'

  if [[ "$basename" == "$edited_line" ]]; then
    break
  fi

  if [[ "$filename" == *.* ]]; then
    extension=".${filename##*.}"
  else
    extension=""
  fi
  chosen_path="$(dirname "$initial_path")/$edited_line${extension}"
  if [[ -e "$chosen_path" ]]; then
    { echo "i"
      echo "=== Error Message starts here ==="
      echo "The name '$edited_line' is already taken"
      echo "Please delete this error message then:"
      echo "- Save and quit to accept the original name"
      echo "- or, choose another name"
      echo "=== Error Message ends here ==="
      echo
      echo "."
      echo "w"
    } | ed -s +1 "$initial_path";
    continue
  fi
  if mv "$initial_path" "$chosen_path"; then
    break;
  else
    { echo "i"
      echo "Error: rename operation failed"
      echo "File name is reset to the initial name"
      echo "Choose another name or keep the original"
      echo "Make sure to remove this message once done"
      echo "."
      echo "w"
    } | ed -s +1 "$initial_path";
    continue
  fi
done