#!/usr/bin/env bash
# Capture host-free UI screenshots of the native Linux client under a virtual X
# display. Mirrors the iOS harness (clients/apple/tools/screenshots.sh): one app
# launch per scene (PUNKTFUNK_SHOT_SCENE), the app renders a mock-populated REAL
# view and prints `PF_SHOT_READY`, then we grab the X root window. No host, GPU, or
# live stream — only the chrome scenes (the stream page needs a live connector).
#
#   cargo build --release -p punktfunk-client-linux
#   bash clients/linux/tools/screenshots.sh            # → clients/linux/screenshots/<scene>.png
#   bash clients/linux/tools/screenshots.sh hosts pair # a subset
#
# Env knobs: BIN (client binary), OUT (output dir), GEOMETRY (Xvfb WxHxDepth),
# SETTLE (extra seconds after PF_SHOT_READY), SHOT_DISPLAY (X display), GSK_RENDERER
# (gl|ngl|cairo — gl/llvmpipe by default for full libadwaita fidelity).
set -euo pipefail

here="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)" # clients/linux
BIN="${BIN:-$here/../../target/release/punktfunk-client}"
OUT="${OUT:-$here/screenshots}"
# The client window maps at its 1100x720 default; with no WM under Xvfb it lands at the
# top-left, so keep the root just larger so the full window (incl. its CSD shadow) is
# captured by a root grab with only a thin margin to crop.
GEOMETRY="${GEOMETRY:-1280x800x24}"
SETTLE="${SETTLE:-1.2}"
SHOT_DISPLAY="${SHOT_DISPLAY:-:99}"

if [ "$#" -gt 0 ]; then SCENES=("$@"); else SCENES=(hosts settings trust pair); fi

[ -x "$BIN" ] || {
	echo "client binary not found: $BIN (build it first: cargo build --release -p punktfunk-client-linux)" >&2
	exit 1
}

# Isolated scratch HOME: the client generates its identity here on first run, and the
# saved-hosts grid is read from client-known-hosts.json, so seed mock hosts for the
# `hosts` scene (the dialogs/settings build their own mock state in-app).
WORK="$(mktemp -d)"
export HOME="$WORK"
mkdir -p "$HOME/.config/punktfunk"
cat >"$HOME/.config/punktfunk/client-known-hosts.json" <<'JSON'
{
  "hosts": [
    { "name": "Living Room PC", "addr": "192.168.1.42", "port": 9777,
      "fp_hex": "9f8e7d6c5b4a39281706f5e4d3c2b1a0998877665544332211ffeeddccbbaa00",
      "paired": true },
    { "name": "Office", "addr": "192.168.1.50", "port": 9777,
      "fp_hex": "a1b2c3d4e5f60718293a4b5c6d7e8f90112233445566778899aabbccddeeff00",
      "paired": false }
  ]
}
JSON

# Software-rendered X session — no GPU/Wayland. GL/llvmpipe runs the real NGL renderer
# (cairo is documented-incomplete for 3D-transformed content / libadwaita transitions).
unset WAYLAND_DISPLAY
export DISPLAY="$SHOT_DISPLAY"
export GDK_BACKEND=x11
export LIBGL_ALWAYS_SOFTWARE=1
export GALLIUM_DRIVER="${GALLIUM_DRIVER:-llvmpipe}"
export GSK_RENDERER="${GSK_RENDERER:-gl}"

Xvfb "$SHOT_DISPLAY" -screen 0 "$GEOMETRY" -nolisten tcp >"$WORK/xvfb.log" 2>&1 &
XVFB_PID=$!
cleanup() {
	kill "$XVFB_PID" 2>/dev/null || true
	rm -rf "$WORK"
}
trap cleanup EXIT

# Wait for the display to accept connections.
for _ in $(seq 1 50); do
	if command -v xdpyinfo >/dev/null 2>&1; then
		xdpyinfo -display "$SHOT_DISPLAY" >/dev/null 2>&1 && break
	else
		[ -e "/tmp/.X11-unix/X${SHOT_DISPLAY#:}" ] && break
	fi
	sleep 0.1
done

capture() {
	local out="$1"
	if command -v import >/dev/null 2>&1; then
		import -silent -window root "$out"
	elif command -v scrot >/dev/null 2>&1; then
		scrot -o "$out"
	else
		echo "no screenshot tool — install imagemagick or scrot" >&2
		return 1
	fi
}

mkdir -p "$OUT"
rc=0
for scene in "${SCENES[@]}"; do
	: >"$WORK/log"
	PUNKTFUNK_SHOT_SCENE="$scene" "$BIN" >"$WORK/log" 2>&1 &
	pid=$!
	ready=0
	for _ in $(seq 1 200); do # up to ~20s
		if grep -q "PF_SHOT_READY" "$WORK/log"; then
			ready=1
			break
		fi
		if ! kill -0 "$pid" 2>/dev/null; then break; fi
		sleep 0.1
	done
	if [ "$ready" = 1 ]; then
		sleep "$SETTLE"
		if capture "$OUT/$scene.png"; then
			echo "✓ $scene → $OUT/$scene.png"
		else
			rc=1
		fi
	else
		echo "✗ $scene: client never signalled PF_SHOT_READY" >&2
		sed 's/^/    /' "$WORK/log" >&2 || true
		rc=1
	fi
	kill "$pid" 2>/dev/null || true
	wait "$pid" 2>/dev/null || true
done

exit "$rc"