#!/usr/bin/env bash
# Produce pass/fail Bevy screenshot evidence without manual window interaction.
set -euo pipefail

root=$(cd "$(dirname "$0")/.." && pwd)
kind=dark
output=""
build=1
seconds=60

usage() {
  cat <<'EOF'
usage: tools/bevy-headless.sh [shot-kind] [--output PATH] [--no-build] [--timeout SECONDS]

Runs a MISALIGNED_SHOT harness, verifies its PNG, prints its SHA-256, and exits
nonzero on any failure. Material-mode shots additionally require fog-audit
success. The running frontend reports its actual staged dialect; this wrapper
does not duplicate the screenshot-kind-to-view mapping.
EOF
}

while [ $# -gt 0 ]; do
  case "$1" in
    --output) shift; output=${1:-}; shift || true ;;
    --no-build) build=0; shift ;;
    --timeout) shift; seconds=${1:-60}; shift || true ;;
    -h|--help) usage; exit 0 ;;
    -*) echo "unknown option: $1" >&2; usage >&2; exit 2 ;;
    *) kind=$1; shift ;;
  esac
done

case "$seconds" in *[!0-9]*|"") echo "timeout must be seconds" >&2; exit 2 ;; esac
case "$kind" in
  zoomin|zoomout)
    echo "FAIL: shot '$kind' is an interaction probe, not screenshot evidence" >&2
    exit 2
    ;;
esac

cd "$root"
if [ "$build" -eq 1 ]; then
  cargo build --quiet -p misaligned-bevy --bin misaligned-bevy
fi
bin="$root/target/debug/misaligned-bevy"
[ -x "$bin" ] || { echo "FAIL: Bevy binary missing: $bin" >&2; exit 1; }

tmp=$(mktemp -d "${TMPDIR:-/tmp}/misaligned-bevy.XXXXXX")
trap 'rm -rf "$tmp"' EXIT
[ -n "$output" ] || output="$tmp/${kind}.png"
case "$output" in /*) ;; *) output="$root/$output" ;; esac
mkdir -p "$(dirname "$output")"

python3 - "$bin" "$kind" "$output" "$seconds" <<'PY'
import hashlib, os, pathlib, shutil, subprocess, sys

binary, kind, output, seconds = sys.argv[1], sys.argv[2], pathlib.Path(sys.argv[3]), int(sys.argv[4])
env = os.environ.copy()
env.update({
    "MISALIGNED_SHOT": kind,
    "MISALIGNED_SHOT_PATH": str(output),
    "MISALIGNED_WAKE": "off",
})
command = [binary]
if sys.platform.startswith("linux") and not (env.get("DISPLAY") or env.get("WAYLAND_DISPLAY")):
    xvfb = shutil.which("xvfb-run")
    if not xvfb:
        print("FAIL: no display and xvfb-run is unavailable", file=sys.stderr)
        sys.exit(1)
    command = [xvfb, "-a", *command]
try:
    result = subprocess.run(
        command,
        env=env,
        text=True,
        stdout=subprocess.PIPE,
        stderr=subprocess.STDOUT,
        timeout=seconds,
        check=False,
    )
except subprocess.TimeoutExpired as exc:
    print(f"FAIL: Bevy evidence timed out after {seconds}s", file=sys.stderr)
    if exc.stdout:
        print(exc.stdout, file=sys.stderr)
    sys.exit(1)
print(result.stdout, end="")
if result.returncode:
    print(f"FAIL: Bevy evidence exited {result.returncode}", file=sys.stderr)
    sys.exit(result.returncode)
prefix = f"bevy shot ready: kind={kind} dialect="
dialect_lines = [line.removeprefix(prefix) for line in result.stdout.splitlines() if line.startswith(prefix)]
if len(dialect_lines) != 1 or dialect_lines[0] not in {"DIGITAL", "REAL"}:
    print(f"FAIL: Bevy evidence did not report one valid staged dialect for shot '{kind}'", file=sys.stderr)
    sys.exit(1)
dialect = dialect_lines[0]
if dialect == "REAL" and "fog audit OK" not in result.stdout:
    print("FAIL: Bevy evidence did not report fog audit OK", file=sys.stderr)
    sys.exit(1)
if not output.is_file() or output.stat().st_size < 8:
    print(f"FAIL: screenshot missing or empty: {output}", file=sys.stderr)
    sys.exit(1)
data = output.read_bytes()
if data[:8] != b"\x89PNG\r\n\x1a\n":
    print(f"FAIL: screenshot is not a PNG: {output}", file=sys.stderr)
    sys.exit(1)
print(f"bevy evidence: OK shot={kind} dialect={dialect.lower()} path={output} sha256={hashlib.sha256(data).hexdigest()}")
PY