#!/bin/bash

# omarchy:summary=Save incoming Taildrop files and announce them
# omarchy:args=[--once] [directory]
# omarchy:examples=omarchy tailscale receive | omarchy tailscale receive --once ~/Desktop

set -euo pipefail

once=false
if [[ ${1:-} == "--once" ]]; then
  once=true
  shift
fi

dir="${1:-${XDG_DOWNLOAD_DIR:-$HOME/Downloads}}"

# Taildrop lands in a staging directory next door rather than straight in the
# downloads directory: waiting for a delivery can take hours, and everything
# else that shows up meanwhile is somebody else's file. Same filesystem, so
# handing the finished file over is a rename.
staging="$dir/.omarchy-taildrop"
mkdir -p "$staging"

# Take the name by linking to it rather than by looking and then renaming.
# link(2) refuses an existing name, so nothing can land on the chosen one in
# the gap between the two. Staging shares the filesystem with the downloads
# directory, so the link always resolves and unlinking the staged name
# finishes the move. Prints the name it took.
claim_path() {
  local staged="$1" name="${staged##*/}" base ext candidate index=0

  base="${name%.*}"
  ext="${name#"$base"}"
  [[ -z $base ]] && { base="$name"; ext=""; }

  while (( index < 1000 )); do
    if (( index == 0 )); then
      candidate="$dir/$name"
    else
      candidate="$dir/$base-$index$ext"
    fi

    if ln -- "$staged" "$candidate" 2>/dev/null; then
      rm -f -- "$staged"
      printf '%s\n' "$candidate"
      return 0
    fi

    # Only a taken name is worth another spin. Anything else failed the link
    # itself, and the file keeps its place in staging for the next run.
    [[ -e $candidate ]] || return 1

    ((index++))
  done

  return 1
}

announce() {
  local path="$1"
  local name="${path##*/}"
  local args=("Received $name" "Saved to ${dir/#$HOME/~}" -u critical)

  case "${name,,}" in
  *.png | *.jpg | *.jpeg | *.gif | *.webp | *.avif | *.bmp | *.tif | *.tiff)
    args+=(--image "$path")
    ;;
  *)
    args+=(-g 󰒊)
    ;;
  esac

  # Announcing is best-effort: the file is already delivered, and under `set -e`
  # a notification outage would otherwise kill the long-running receiver.
  omarchy-notification-send "${args[@]}" --exec xdg-open "$path" || true
}

deliver() {
  local staged target

  while IFS= read -r staged; do
    target=$(claim_path "$staged") || continue
    announce "$target"
  done < <(find "$staging" -mindepth 1 -maxdepth 1)
}

# Anything left staged by an interrupted run still deserves delivering.
deliver

while true; do
  if ! tailscale file get --wait --conflict=rename "$staging"; then
    $once && exit 1
    sleep 10
    continue
  fi

  deliver
  $once && exit 0
done