#!/bin/sh

# Display help message
usage() {
  echo "Open the most recent file or the list of old files edited by vim."
  echo ""
  echo "Usage: ${0##*/} [OPTION]"
  echo ""
  echo "Options:"
  echo "                  : Open the most recent old file in Vim."
  echo "  -h, --help      : Show this help message."
  echo "  -l, --list      : Show all recent files and select by number."
  echo ""
  echo "Examples:"
  echo "  ${0##*/}        # Open the most recent file."
  echo "  ${0##*/} -l     # Show all recent files and select by number."
  exit 0
}

# Function to open files in vim
openfiles() {
  files="$1"
  if [ -n "$files" ]; then
    # Convert newlines to spaces for vim arguments
    file_args=$(echo "$files" | tr '\n' ' ')
    vim $file_args
  fi
}

# List and handle oldfiles
list_oldfiles() {
  # Fetch the oldfiles list from Vim
  # Use vim's :oldfiles command and capture output
  temp_file="/tmp/vim_oldfiles_$$.txt"
  vim -u NONE -c "redir >> $temp_file | oldfiles | redir END | q" 2>/dev/null

  # Parse vim's oldfiles output (format: " 1: /path/to/file")
  oldfiles=$(cat "$temp_file" 2>/dev/null |
    sed -n 's/^[[:space:]]*[0-9]*:[[:space:]]*\(.*\)$/\1/p' |
    grep -v '^$')

  rm -f "$temp_file" 2>/dev/null

  # Exit if no oldfiles are found
  [ -z "$oldfiles" ] && {
    echo "No recent files found in Vim." >&2
    exit 1
  }

  case "$1" in
  -h | --help)
    usage
    ;;
  -l | --list)
    # Filter valid files first
    paths_file="/tmp/vim_file_paths_$$.txt"

    echo "$oldfiles" | while IFS= read -r file; do
      [ -f "$file" ] && printf "%s\n" "$file"
    done >"$paths_file"

    # Count valid files
    valid_count=$(wc -l <"$paths_file" 2>/dev/null | tr -d ' ')

    # Exit if no valid files exist
    [ -z "$valid_count" ] || [ "$valid_count" -eq 0 ] && {
      echo "No valid files found." >&2
      rm -f "$paths_file" 2>/dev/null
      exit 1
    }

    # Display numbered file list
    file_num=1
    while IFS= read -r file; do
      printf "%d: %s\n" "$file_num" "$file"
      file_num=$((file_num + 1))
    done <"$paths_file"

    echo ""
    printf "Select file number (1-%d) or 'q' to quit: " "$valid_count"
    read selection

    # Handle quit
    [ "$selection" = "q" ] || [ "$selection" = "Q" ] && {
      rm -f "$paths_file" 2>/dev/null
      exit 0
    }

    # Validate selection
    if [ -n "$selection" ] && [ "$selection" -ge 1 ] && [ "$selection" -le "$valid_count" ] 2>/dev/null; then
      selected_file=$(sed -n "${selection}p" "$paths_file")
      rm -f "$paths_file" 2>/dev/null
      openfiles "$selected_file"
    else
      echo "Invalid selection." >&2
      rm -f "$paths_file" 2>/dev/null
      exit 1
    fi
    ;;
  *)
    # Open the most recent file
    for file in $oldfiles; do
      if [ -f "$file" ]; then
        openfiles "$file"
        exit 0
      fi
    done
    echo "No valid recent files found." >&2
    exit 1
    ;;
  esac
}

# Parse command-line arguments
list_oldfiles "$@"