#!/usr/bin/env bash
set -euo pipefail
cd "$(dirname "$0")/.."

test_name="dependency-cache-test-$$"
site_directory="${UCE_TEST_SITE_DIRECTORY:-site}"
source_dir="$site_directory/$test_name"
bin_directory="${BIN_DIRECTORY:-}"
if [[ -z "$bin_directory" && -r /etc/uce/settings.cfg ]]; then
	bin_directory=$(awk -F= '/^[[:space:]]*BIN_DIRECTORY[[:space:]]*=/ {gsub(/^[[:space:]]+|[[:space:]]+$/, "", $2); print $2; exit}' /etc/uce/settings.cfg)
fi
bin_directory="${bin_directory:-/tmp/uce/work}"
cache_dir=""
http_host="${UCE_TEST_HTTP_HOST:-uce.openfu.com}"

cleanup() {
	rm -rf "$source_dir"
	if [[ -n "$cache_dir" ]]; then
		rm -rf "$cache_dir"
	fi
}
trap cleanup EXIT
mkdir -p "$source_dir"
cache_dir="$bin_directory$(realpath "$source_dir")"

printf '%s\n' \
	'#ifndef UCE_DEPENDENCY_CACHE_CHILD' \
	'#define UCE_DEPENDENCY_CACHE_CHILD' \
	'String dependency_cache_marker() { return("dependency-marker-a"); }' \
	'#endif' >"$source_dir/child.uce"
printf '%s\n' \
	'#load "child.uce"' \
	'CLI(Request& context) { print(dependency_cache_marker(), ":", request_perf()["worker_pid"].to_string()); }' \
	'RENDER(Request& context) { print(dependency_cache_marker(), ":", request_perf()["worker_pid"].to_string()); }' >"$source_dir/parent.uce"

assert_marker() {
	local path="$1"
	local expected="$2"
	local output
	output=$(scripts/uce-cli "/$test_name/$path.uce")
	if [[ "$output" != *"$expected"* ]]; then
		echo "$path returned stale module; expected $expected: $output" >&2
		exit 1
	fi
}

http_marker() {
	curl -fsS -H "Host: $http_host" "http://127.0.0.1/$test_name/parent.uce"
}

assert_marker parent dependency-marker-a
if [[ "$(http_marker)" != *"dependency-marker-a"* ]]; then
	echo "HTTP warm-up did not return dependency-marker-a" >&2
	exit 1
fi

sed -i 's/dependency-marker-a/dependency-marker-b/' "$source_dir/child.uce"
started_at=$(date +%s%N)
http_during_rebuild=$(http_marker)
elapsed_ms=$(( ($(date +%s%N) - started_at) / 1000000 ))
if [[ "$http_during_rebuild" != *"dependency-marker-a"* && "$http_during_rebuild" != *"dependency-marker-b"* ]]; then
	echo "HTTP rebuild request returned neither complete artifact: $http_during_rebuild" >&2
	exit 1
fi
if (( elapsed_ms >= 2000 )); then
	echo "HTTP request spent ${elapsed_ms}ms rebuilding a stale artifact" >&2
	exit 1
fi
assert_marker parent dependency-marker-b

# A proactive rebuild owns these same per-unit locks. While it publishes fresh
# artifacts, requests must use the last complete artifacts instead of waiting
# across the transitive graph. Atomic publication keeps those artifacts safe.
parent_wasm="$cache_dir/parent.uce.wasm"
child_wasm="$cache_dir/child.uce.wasm"
(
	exec 8>"$parent_wasm.lock"
	exec 9>"$child_wasm.lock"
	flock 8
	flock 9
	sleep 3
) &
rebuild_lock_pid=$!
sleep 0.2
sed -i 's/dependency-marker-b/dependency-marker-d/' "$source_dir/child.uce"
started_at=$(date +%s%N)
http_during_lock=$(http_marker)
elapsed_ms=$(( ($(date +%s%N) - started_at) / 1000000 ))
if [[ "$http_during_lock" != *"dependency-marker-b"* ]]; then
	echo "HTTP request did not serve the last complete artifact during rebuild: $http_during_lock" >&2
	exit 1
fi
if (( elapsed_ms >= 2000 )); then
	echo "HTTP request waited ${elapsed_ms}ms for an active transitive rebuild" >&2
	exit 1
fi
started_at=$(date +%s%N)
assert_marker parent dependency-marker-d
elapsed_ms=$(( ($(date +%s%N) - started_at) / 1000000 ))
if (( elapsed_ms < 2000 )); then
	echo "CLI request returned before the locked rebuild published the current artifact (${elapsed_ms}ms)" >&2
	exit 1
fi
wait "$rebuild_lock_pid"

# Warm every configured worker, then replace the artifact while retaining its
# whole-second mtime. The worker cache must notice the nanosecond/ctime change.
for _ in {1..16}; do assert_marker parent dependency-marker-d; done
sed 's/dependency-marker-d/dependency-marker-c/' "$source_dir/child.uce" >"$source_dir/alternate-child.uce"
sed 's/child.uce/alternate-child.uce/' "$source_dir/parent.uce" >"$source_dir/alternate.uce"
assert_marker alternate dependency-marker-c
alternate_wasm="$cache_dir/alternate.uce.wasm"
parent_mtime=$(stat -c %Y "$parent_wasm")
cp "$alternate_wasm" "$parent_wasm"
touch -d "@$parent_mtime" "$parent_wasm"
rm -f "$cache_dir/parent.uce.cwasm"
for _ in {1..16}; do assert_marker parent dependency-marker-c; done

worker_count=$(awk -F= '/^[[:space:]]*WORKER_COUNT[[:space:]]*=/ {gsub(/^[[:space:]]+|[[:space:]]+$/, "", $2); print $2; exit}' /etc/uce/settings.cfg 2>/dev/null || true)
worker_count="${worker_count:-4}"
worker_pids=""
for _ in {1..48}; do
	output=$(scripts/uce-cli "/$test_name/parent.uce")
	worker_pids+="${output##*:}"$'\n'
done
unique_workers=$(printf '%s' "$worker_pids" | sed '/^$/d' | sort -u | wc -l)
if (( unique_workers > worker_count )); then
	echo "worker pool recycled during 48 requests: $unique_workers PIDs for $worker_count workers" >&2
	exit 1
fi

echo "dependency invalidation passed"