#!/usr/bin/env bash
# Runs the headless GDScript gameplay tests.
#
#   bash tests/run_tests.sh                 # everything
#   bash tests/run_tests.sh formation       # only tests matching a substring
#   JOBS=1 bash tests/run_tests.sh          # serial, for debugging a hang
#   VERBOSE=1 bash tests/run_tests.sh       # print passing tests' output too
#   IN_PLACE=1 bash tests/run_tests.sh      # run from the project dir itself
#   GODOT_BIN=/path/to/godot bash tests/run_tests.sh   # pick the binary
#
# There are two ways to get a Godot to run them with, picked automatically:
#
#   Termux    the Godot 4.7 Linux arm64 build installed inside the
#             proot-distro Ubuntu container, which is the only way to run
#             a desktop Godot on the phone at all.
#   WSL       the Windows Godot build off /mnt/c. A Linux `godot` on PATH
#             is used first if there is one.
#
# The platform decides which Godot runs and where the project is copied to.
# Everything else - the copy itself, the worker count, and
# tests/_run_inside.sh, which does the actual running - is shared.
#
# On Termux, three things make this fast, in descending order of how much
# they matter (measured, not guessed - see tests/_profile_startup.gd):
#
# 1. It runs from a COPY on Termux's own filesystem, not from the project
#    directory. The project lives under ~/storage/shared, which is Android's
#    FUSE bridge; read through proot on top of that, `load("res://world/Main.tscn")`
#    alone took 8.5s per test, against ~2s from a native path. Nearly every
#    test loads Main.tscn, and none of that time is gameplay. The copy is
#    ~1.4s for the whole suite and its .godot import cache is kept between
#    runs. WSL copies too, but to a native NTFS path rather than to ext4:
#    a Windows Godot reads C: at full speed and would read \\wsl$ slowly, so
#    the copy is for ISOLATION rather than for speed there. Six Godot
#    processes churning the project directory is six processes writing
#    .godot, creating and deleting files under PlanetSetups/, and doing it
#    in a working tree that git, an open editor and the player are also
#    using. Under that, single tests failed at random - a delete that did
#    not take, a scene that would not instantiate - never the same one
#    twice.
# 2. Tests run JOBS at a time. Each is its own Godot process - they call
#    quit() and stamp on the GameState autoload, so they cannot share one -
#    which makes the suite a pile of independent, single-core-bound jobs on
#    an 8-core phone.
# 3. The whole run happens in ONE `proot-distro login`. Entering the
#    container costs ~0.5s, which used to be paid once per test.
#
# Output is buffered per test and printed only for failures; six interleaved
# logs are unreadable.

set -uo pipefail

PROJECT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"

PLATFORM="termux"
if [[ -n "${WSL_DISTRO_NAME:-}" ]] || grep -qi microsoft /proc/version 2>/dev/null; then
	PLATFORM="wsl"
fi

# Finding a Godot on WSL. A Linux build on PATH wins - no interop, no drive
# letters - but there usually is not one, and the Windows build the editor
# already runs from is right there on /mnt/c. Two things about picking that
# one up:
#   - it must be the *_console.exe. The plain .exe is built as a Windows GUI
#     subsystem binary: it detaches from the terminal, so every test would
#     produce an empty log and the runner would call all of them failures.
#   - sort -V so 4.7.2 beats 4.6.1 when several versions are downloaded.
_find_godot_wsl() {
	local found
	found="$(command -v godot 2>/dev/null)"
	if [[ -n "$found" ]]; then
		echo "$found"
		return
	fi
	found="$(find /mnt/c/Users/*/Downloads /mnt/c/Users/*/AppData/Local/Programs \
			"/mnt/c/Program Files" -maxdepth 2 -name 'Godot_v*_console.exe' \
			2>/dev/null | sort -V | tail -1)"
	echo "$found"
}

# Worker count comes from FREE MEMORY, not core count. Each Godot instance is
# ~400MB and this phone shares its RAM with everything else running on it.
# Getting it wrong is bad in both directions:
#   - too many and the kernel SIGKILLs the runner mid-suite (exit 137), which
#     looks exactly like a hang
#   - too many under swap pressure and every worker thrashes: the same suite
#     measured 100-190s with memory free, and 888s while 9GB sat in swap
# One worker per ~900MB available, capped at 6, and forced to 1 once swap is
# more than half consumed - past that, parallelism costs more than it buys.
# Override with JOBS= when you know better.
_pick_jobs() {
	local avail swap_total swap_free n
	avail=$(awk '/MemAvailable/ {print int($2 / 1024)}' /proc/meminfo 2>/dev/null)
	swap_total=$(awk '/SwapTotal/ {print $2}' /proc/meminfo 2>/dev/null)
	swap_free=$(awk '/SwapFree/ {print $2}' /proc/meminfo 2>/dev/null)
	if [[ -z "$avail" ]]; then
		echo 2
		return
	fi
	if [[ -n "$swap_total" ]] && (( swap_total > 0 )) \
			&& (( (swap_total - swap_free) * 2 > swap_total )); then
		echo 1
		return
	fi
	n=$(( avail / 900 ))
	(( n < 1 )) && n=1
	(( n > 6 )) && n=6
	echo "$n"
}
JOBS="${JOBS:-$(_pick_jobs)}"
VERBOSE="${VERBOSE:-0}"
IN_PLACE="${IN_PLACE:-0}"

# Where the copy lives. Termux wants its own native filesystem; WSL wants a
# WINDOWS one, because the thing reading it is a Windows binary and $HOME is
# ext4 behind the \\wsl$ share. %LOCALAPPDATA% is the natural home for it;
# if that cannot be read, fall back to a sibling of the project - still on
# the same native drive, still outside the repo.
_default_work_dir() {
	if [[ "$PLATFORM" != "wsl" ]]; then
		echo "$HOME/.cache/spaceship-tests"
		return
	fi
	local win_local
	win_local="$(cmd.exe /c 'echo %LOCALAPPDATA%' 2>/dev/null | tr -d '\r')"
	if [[ -n "$win_local" && "$win_local" != *'%'* ]]; then
		local unix_local
		unix_local="$(wslpath -u "$win_local" 2>/dev/null)"
		if [[ -n "$unix_local" ]]; then
			echo "$unix_local/spaceship-tests"
			return
		fi
	fi
	echo "$(dirname "$PROJECT_DIR")/.spaceship-tests"
}
WORK_DIR="${WORK_DIR:-$(_default_work_dir)}"

if [[ -z "${GODOT_BIN:-}" ]]; then
	if [[ "$PLATFORM" == "wsl" ]]; then
		GODOT_BIN="$(_find_godot_wsl)"
		if [[ -z "$GODOT_BIN" ]]; then
			echo "no Godot found. Install one on PATH, or download a Windows" >&2
			echo "build and point GODOT_BIN at its *_console.exe." >&2
			exit 2
		fi
	else
		GODOT_BIN="/root/Godot_v4.7.1-stable_linux.arm64"
	fi
fi

filter="${1:-}"
tests=()
for path in "$PROJECT_DIR"/tests/test_*.gd; do
	name="$(basename "$path")"
	if [[ -z "$filter" || "$name" == *"$filter"* ]]; then
		tests+=("$name")
	fi
done

if (( ${#tests[@]} == 0 )); then
	echo "no tests match '$filter'"
	exit 2
fi

start=$(date +%s)

run_dir="$PROJECT_DIR"
if [[ "$IN_PLACE" != "1" ]]; then
	run_dir="$WORK_DIR"
	mkdir -p "$run_dir"
	# Clear last run's sources but keep .godot, so imports stay warm. Without
	# the clear, a test deleted from the project would live on in the copy and
	# keep being run.
	find "$run_dir" -mindepth 1 -maxdepth 1 ! -name '.godot' -exec rm -rf {} +
	# android/ and builds/ are export artefacts no test touches, and the .apk
	# is 30MB of nothing useful here.
	tar -C "$PROJECT_DIR" \
		--exclude=./.godot --exclude=./android --exclude=./builds --exclude='*.apk' \
		-cf - . 2>/dev/null | tar -C "$run_dir" -xf -
fi

if [[ "$PLATFORM" == "wsl" ]]; then
	bash "$run_dir/tests/_run_inside.sh" \
		"$GODOT_BIN" "$run_dir" "$JOBS" "$VERBOSE" "${tests[@]}"
else
	proot-distro login ubuntu -- bash "$run_dir/tests/_run_inside.sh" \
		"$GODOT_BIN" "$run_dir" "$JOBS" "$VERBOSE" "${tests[@]}"
fi
status=$?

echo "in $(( $(date +%s) - start ))s with JOBS=$JOBS"
exit $status