#!/bin/bash
set -euo pipefail

MIRRORS=(
  "https://docker.1ms.run"
  "https://docker.xuanyuan.me"
  "https://docker.m.daocloud.io"
  "https://dockerproxy.com"
  "https://docker.nju.edu.cn"
)

DAEMON_JSON="/etc/docker/daemon.json"

if [ "$EUID" -ne 0 ]; then
  echo "Please run as root (sudo)." >&2
  exit 1
fi

# Backup existing config
if [ -f "$DAEMON_JSON" ]; then
  cp "$DAEMON_JSON" "${DAEMON_JSON}.bak.$(date +%s)"
fi

# Build mirrors JSON array
MIRRORS_JSON=$(printf '%s\n' "${MIRRORS[@]}" | jq -R . | jq -s .)

# Merge with existing config if present
if [ -f "$DAEMON_JSON" ]; then
  jq --argjson mirrors "$MIRRORS_JSON" '. + {"registry-mirrors": $mirrors}' "$DAEMON_JSON" > "${DAEMON_JSON}.new"
else
  jq -n --argjson mirrors "$MIRRORS_JSON" '{"registry-mirrors": $mirrors}' > "${DAEMON_JSON}.new"
fi

mv "${DAEMON_JSON}.new" "$DAEMON_JSON"
echo "Wrote $DAEMON_JSON"

systemctl daemon-reload
systemctl restart docker

echo "Docker mirrors configured. Verify: docker info | grep -A5 Mirrors"