#!/bin/sh
# Alpine apk 镜像源：按序探测可用镜像，避免单点 403 // Logan.Li
set -eu

ALPINE_VER=$(cut -d. -f1,2 /etc/alpine-release)
ARCH=$(apk --print-arch 2>/dev/null || echo "x86_64")

probe() {
    local host=$1
    local url="https://${host}/alpine/v${ALPINE_VER}/main/${ARCH}/APKINDEX.tar.gz"
    if wget -q --spider "$url" 2>/dev/null; then
        return 0
    fi
    if curl -fsSI --connect-timeout 8 "$url" >/dev/null 2>&1; then
        return 0
    fi
    return 1
}

write_repos() {
    local host=$1
    printf 'https://%s/alpine/v%s/main\nhttps://%s/alpine/v%s/community\n' \
        "$host" "$ALPINE_VER" "$host" "$ALPINE_VER" > /etc/apk/repositories
}

for host in mirrors.aliyun.com mirrors.cloud.tencent.com mirrors.ustc.edu.cn dl-cdn.alpinelinux.org; do
    if probe "$host"; then
        write_repos "$host"
        echo "[apk-mirror] alpine v${ALPINE_VER} ${ARCH} -> ${host}"
        exit 0
    fi
    echo "[apk-mirror] skip ${host} (unreachable)" >&2
done

echo "[apk-mirror] no mirror available for alpine v${ALPINE_VER}" >&2
exit 1