#!/bin/bash
set -u

timestamp() {
	date -u +"%Y-%m-%dT%H:%M:%SZ"
}

log() {
	printf '[%s] %s\n' "$(timestamp)" "$1"
}

section() {
	printf '\n==================================================\n'
	printf '%s\n' "$1"
	printf '%s\n' '--------------------------------------------------'
}

fail() {
	log "[ERROR] $1"
	exit 1
}

# 當 workflow 被取消時，立即結束，避免健康檢查持續重試。
on_terminate() {
	log "[WARN] 收到取消訊號，停止健康檢查。"
	exit 130
}

trap on_terminate TERM INT

HEALTH_CODE="${HEALTH_CODE:-200}"

section "參數檢查"
if [ -z "${CHECK_URL:-}" ] || [ "$CHECK_URL" = "null" ]; then
	fail "CHECK_URL 不可為空。"
fi

if [ -z "$HEALTH_CODE" ] || [ "$HEALTH_CODE" = "null" ]; then
	fail "HEALTH_CODE 不可為空。"
fi

case "$CHECK_URL" in
	http://*|https://*) ;;
	*)
		fail "CHECK_URL 只允許 http:// 或 https://。"
		;;
esac

log "[INFO] CHECK_URL=$CHECK_URL"
log "[INFO] HEALTH_CODE=$HEALTH_CODE"

section "取得狀態碼"
log "[INFO] 開始檢查：$CHECK_URL"

while true; do
	printf '[%s] [INFO] GET %s ... ' "$(timestamp)" "$CHECK_URL"

	status_code="$(curl -sS --proto '=http,https' --proto-redir '=http,https' --max-time 60 --url "$CHECK_URL" -o /dev/null -w '%{http_code}' || true)"
	if [ -z "$status_code" ]; then
		status_code="000"
	fi

	printf '%s\n' "$status_code"

	if [ "$status_code" = "$HEALTH_CODE" ]; then
		log "[OK] 狀態碼符合預期：$status_code"
		break
	fi

	log "[WARN] 目前狀態碼 $status_code，預期 $HEALTH_CODE，60 秒後重試。"
	sleep 60
done

section "完成"
log "[INFO] 輸出 status_code=$status_code"
if [ -n "${GITHUB_OUTPUT:-}" ]; then
	echo "status_code=$status_code" >> "$GITHUB_OUTPUT"
else
	log "[WARN] GITHUB_OUTPUT 未設定，略過寫入輸出檔。"
fi