#!/usr/bin/env bash
# Raw full-root PNG grab of the headless display.
#
# This is deliberately the *uncropped* root window, because
# `tools/re-capture/bin/screenshot` is a wrapper that calls this one as its raw
# grabber and then crops to the game surface — xenia's window is a GTK window
# whose menu bar pushes the 1280x720 game image down ~25 px, and every pixel
# oracle in the toolkit was measured against the bare game image. That wrapper
# directory is first on PATH, so scripts calling `screenshot` get the cropped
# game surface and this stays the honest raw grab underneath it.
#
#   screenshot [out.png]     default: $HOME/shots/shot-NNNN.png
set -u

OUT="${1:-}"
if [ -z "$OUT" ]; then
  dir="${HOME:-/tmp}/shots"; mkdir -p "$dir"
  n_file="$dir/.counter"
  n=$(( $(cat "$n_file" 2>/dev/null || echo 0) + 1 )); echo "$n" > "$n_file"
  OUT="$dir/shot-$(printf '%04d' "$n").png"
fi
mkdir -p "$(dirname "$OUT")"

if ! xdpyinfo >/dev/null 2>&1; then
  echo "screenshot: no display on ${DISPLAY:-<unset>}" >&2
  exit 1
fi

# ImageMagick first. `import` talks X11 directly and captures a window that is
# mid-redraw without tearing the way a video grabber can.
if command -v import >/dev/null 2>&1 && import -silent -window root "$OUT" 2>/dev/null; then
  echo "$OUT"; exit 0
fi

# Fallback: ffmpeg's x11grab. Needs an explicit size, so read it off the server
# rather than assuming the geometry.
if command -v ffmpeg >/dev/null 2>&1; then
  size=$(xdpyinfo | awk '/dimensions:/{print $2; exit}')
  if ffmpeg -loglevel error -y -f x11grab -draw_mouse 0 \
            -video_size "$size" -i "$DISPLAY" -frames:v 1 "$OUT" 2>/dev/null; then
    echo "$OUT"; exit 0
  fi
fi

# Last resort: xwd, which is always present with x11-utils.
if command -v xwd >/dev/null 2>&1 && command -v convert >/dev/null 2>&1; then
  xwd -root -silent | convert xwd:- "$OUT" && { echo "$OUT"; exit 0; }
fi

echo "screenshot: no working capture backend" >&2
exit 1