#!/usr/bin/env bash
# Capture an area or the whole desktop and open it in Satty for annotation.
set -euo pipefail
umask 077

fail() {
    echo "ferese-screenshot: $*" >&2
    if command -v notify-send >/dev/null; then
        notify-send --app-name=Ferese --urgency=critical 'Screenshot failed' "$*" || true
    fi
    exit 1
}

mode=area
case ${1:-} in
    '') ;;
    --full) mode=full; shift ;;
    --help|-h)
        echo 'Usage: ferese-screenshot [--full]'
        echo 'Select an area, or use --full for the whole desktop, then edit in Satty.'
        exit 0
        ;;
    *) fail 'Usage: ferese-screenshot [--full]' ;;
esac
(($# == 0)) || fail 'Usage: ferese-screenshot [--full]'

for tool in grim satty wl-copy flock; do
    command -v "$tool" >/dev/null || fail "Required command not found: $tool"
done
: "${XDG_RUNTIME_DIR:?A Wayland login session is required}"
exec 9>"$XDG_RUNTIME_DIR/ferese-screenshot.lock"
flock -n 9 || exit 0

capture_args=()
if [[ $mode == area ]]; then
    command -v slurp >/dev/null || fail 'Required command not found: slurp'
    # Escape cancels without creating a file or changing the clipboard.
    geometry=$(slurp) || exit 0
    [[ -n $geometry ]] || exit 0
    capture_args=(-g "$geometry")
fi
pictures=$(xdg-user-dir PICTURES 2>/dev/null) || pictures="$HOME/Pictures"
directory=${pictures:-$HOME/Pictures}/Screenshots
mkdir -p -- "$directory" || fail 'Could not create the screenshot directory.'
file=$(mktemp "$directory/Screenshot-$(date +%Y-%m-%d_%H-%M-%S)-XXXXXX.png") || fail 'Could not create the screenshot file.'
input=''
trap '[[ -z $input ]] || rm -f -- "$input"; [[ -s $file ]] || rm -f -- "$file"' EXIT
input=$(mktemp "$XDG_RUNTIME_DIR/ferese-screenshot-XXXXXX.png") || fail 'Could not create the temporary capture.'
grim "${capture_args[@]}" "$input" || fail 'Could not capture the screen. Log back into Ferese after enabling screen capture.'
# Enter saves the annotated image and copies it; Escape discards the capture.
exec 9>&-
satty --filename "$input" --output-filename "$file" \
    --fullscreen current-screen \
    --copy-command 'wl-copy --type image/png' \
    --save-after-copy \
    --actions-on-enter save-to-file,save-to-clipboard,exit \
    --actions-on-escape exit || fail 'Could not open the screenshot in Satty.'
if [[ -s $file ]]; then
    printf '%s\n' "$file"
fi