#!/bin/bash

# ============================================
# Docker 镜像加速器配置脚本
# 用于配置国内镜像源，加速 Docker 镜像拉取
# ============================================

set -e

echo "=========================================="
echo "配置 Docker 镜像加速器（国内镜像源）"
echo "=========================================="

# 检查是否为 root 用户
if [ "$EUID" -ne 0 ]; then 
    echo "❌ 错误: 请使用 root 用户或 sudo 运行此脚本"
    exit 1
fi

# Docker 配置文件路径
DOCKER_DAEMON_JSON="/etc/docker/daemon.json"
DOCKER_DAEMON_JSON_BACKUP="/etc/docker/daemon.json.backup.$(date +%Y%m%d_%H%M%S)"

# 国内镜像源列表（按优先级排序）
MIRRORS=(
    "https://docker.mirrors.ustc.edu.cn"
    "https://hub-mirror.c.163.com"
    "https://mirror.baidubce.com"
)

echo ""
echo "📋 配置信息："
echo "  配置文件: ${DOCKER_DAEMON_JSON}"
echo "  镜像源数量: ${#MIRRORS[@]}"
echo ""

# 备份现有配置
if [ -f "$DOCKER_DAEMON_JSON" ]; then
    echo "📦 备份现有配置..."
    cp "$DOCKER_DAEMON_JSON" "$DOCKER_DAEMON_JSON_BACKUP"
    echo "   ✓ 备份完成: ${DOCKER_DAEMON_JSON_BACKUP}"
else
    echo "📦 创建新配置文件..."
    mkdir -p /etc/docker
fi

# 创建新的配置
echo ""
echo "🔧 配置镜像加速器..."

# 检查是否已存在 registry-mirrors 配置
if [ -f "$DOCKER_DAEMON_JSON" ]; then
    # 如果文件存在，检查是否已有 registry-mirrors
    if grep -q "registry-mirrors" "$DOCKER_DAEMON_JSON"; then
        echo "  ⚠️  检测到已有 registry-mirrors 配置"
        echo "  📝 将更新为推荐的国内镜像源"
        
        # 使用 jq 更新配置（如果安装了 jq）
        if command -v jq &> /dev/null; then
            jq '.registry-mirrors = $mirrors' --argjson mirrors "$(printf '%s\n' "${MIRRORS[@]}" | jq -R . | jq -s .)" "$DOCKER_DAEMON_JSON" > "${DOCKER_DAEMON_JSON}.tmp"
            mv "${DOCKER_DAEMON_JSON}.tmp" "$DOCKER_DAEMON_JSON"
        else
            echo "  ⚠️  未安装 jq，将手动创建配置"
            # 创建新配置（保留其他配置项）
            python3 << EOF
import json
import sys

try:
    with open('${DOCKER_DAEMON_JSON}', 'r') as f:
        config = json.load(f)
except:
    config = {}

config['registry-mirrors'] = ${MIRRORS[@]@Q}

with open('${DOCKER_DAEMON_JSON}', 'w') as f:
    json.dump(config, f, indent=2)
EOF
        fi
    else
        # 追加 registry-mirrors 到现有配置
        python3 << EOF
import json

try:
    with open('${DOCKER_DAEMON_JSON}', 'r') as f:
        config = json.load(f)
except:
    config = {}

config['registry-mirrors'] = ${MIRRORS[@]@Q}

with open('${DOCKER_DAEMON_JSON}', 'w') as f:
    json.dump(config, f, indent=2)
EOF
    fi
else
    # 创建新配置文件
    cat > "$DOCKER_DAEMON_JSON" << EOF
{
  "registry-mirrors": [
    "https://docker.mirrors.ustc.edu.cn",
    "https://hub-mirror.c.163.com",
    "https://mirror.baidubce.com"
  ]
}
EOF
fi

echo "  ✓ 配置完成"

# 显示配置内容
echo ""
echo "📄 当前配置内容："
cat "$DOCKER_DAEMON_JSON" | python3 -m json.tool 2>/dev/null || cat "$DOCKER_DAEMON_JSON"
echo ""

# 重启 Docker 服务
echo "🔄 重启 Docker 服务..."
if systemctl is-active --quiet docker; then
    systemctl daemon-reload
    systemctl restart docker
    echo "  ✓ Docker 服务已重启"
else
    echo "  ⚠️  Docker 服务未运行，请手动启动: systemctl start docker"
fi

# 验证配置
echo ""
echo "🔍 验证配置..."
sleep 2
if docker info | grep -q "Registry Mirrors"; then
    echo "  ✓ 镜像加速器配置成功"
    echo ""
    echo "📋 已配置的镜像源："
    docker info | grep -A 10 "Registry Mirrors" | sed 's/^/    /'
else
    echo "  ⚠️  未检测到镜像加速器配置，请检查 Docker 服务状态"
fi

echo ""
echo "=========================================="
echo "✅ 配置完成！"
echo "=========================================="
echo ""
echo "💡 提示："
echo "  - 配置已保存到: ${DOCKER_DAEMON_JSON}"
echo "  - 备份文件: ${DOCKER_DAEMON_JSON_BACKUP}"
echo "  - 现在可以使用 docker pull 拉取镜像，将自动使用国内镜像源"
echo ""
echo "🧪 测试镜像拉取："
echo "  docker pull minio/minio:RELEASE.2025-04-22T22-12-26Z"
echo ""