#! /bin/bash

# This is a helper script for taking screenshot of the Agama installer
# running locally in Gnome kiosk.

set -e

# handle help option
if [ "$1" == "-h" ] || [ "$1" == "--help" ]; then
  echo "Usage: $0 [TARGET_FILE]"
  echo
  echo "Takes a screenshot of the Agama installer running locally."
  echo "The screenshot is saved in PNG format."
  echo
  echo "If TARGET_FILE is not specified it generates a random name in"
  echo "the current directory."
  echo
  echo "Options:"
  echo "  -h, --help   Show this help message and exit."
  exit 0
fi

# Gnome kiosk fails if the target file already exists,
# create the screenshot in a temporary directory and then move it
SCREENSHOT_DIR=$(mktemp -d -p /tmp "screenshot-XXXXXXX")
FILE="$SCREENSHOT_DIR/screenshot.png"

# see the DBus API description at
# https://gitlab.gnome.org/GNOME/gnome-kiosk/-/blob/main/dbus-interfaces/org.gnome.Shell.Screenshot.xml?ref_type=heads
# include cursor: false
# flash screen: false
gdbus call --session --dest org.gnome.Shell.Screenshot --object-path \
  /org/gnome/Shell/Screenshot --method org.gnome.Shell.Screenshot.Screenshot \
  false false "$FILE" >/dev/null

# move the file
if [ -n "$1" ]; then
  # if the script is called with an argument, use it as the target file
  TARGET_FILE="$1"
else
  # otherwise use a random name in the current directory
  TARGET_FILE=$(mktemp "agama-$(date +%Y-%m-%d)-XXXX.png")
fi

mv "$FILE" "$TARGET_FILE"
rm -rf "$SCREENSHOT_DIR"

echo "Screenshot saved to $TARGET_FILE"