#!/bin/bash
set -eo pipefail

# 检查环境变量
required_vars=("WEBDAV_URL" "WEBDAV_USERNAME" "WEBDAV_PASSWORD")
for var in "${required_vars[@]}"; do
    if [ -z "${!var}" ]; then
        echo "警告: 缺少必要环境变量 $var，将禁用备份功能"
        exec ./alist server --data /app/config
        exit 0
    fi
done

# 设置完整WebDAV路径
FULL_WEBDAV_URL="${WEBDAV_URL}${WEBDAV_BACKUP_PATH:+/$WEBDAV_BACKUP_PATH}"

# 恢复备份函数
restore_backup() {
    echo "尝试从WebDAV恢复最新备份..."
    python3 <<EOF
import os
import sys
import tarfile
import requests
from webdav3.client import Client
from tenacity import retry, stop_after_attempt, wait_fixed

# 配置WebDAV客户端
options = {
    'webdav_hostname': '$FULL_WEBDAV_URL',
    'webdav_login': '$WEBDAV_USERNAME',
    'webdav_password': '$WEBDAV_PASSWORD'
}

@retry(stop=stop_after_attempt(3), wait=wait_fixed(5))
def download_latest_backup():
    client = Client(options)
    try:
        backups = [f for f in client.list() if f.endswith('.tar.gz') and f.startswith('alist_backup_')]
        if not backups:
            print("未找到备份文件")
            return False
        
        latest = sorted(backups)[-1]
        print(f"找到最新备份: {latest}")
        
        # 下载备份
        temp_file = f"/tmp/{latest}"
        client.download_sync(remote_path=latest, local_path=temp_file)
        
        # 解压备份
        if os.path.exists("$DATA_DIR"):
            import shutil
            shutil.rmtree("$DATA_DIR")
        os.makedirs("$DATA_DIR", exist_ok=True)
        
        with tarfile.open(temp_file, "r:gz") as tar:
            tar.extractall("$DATA_DIR")
        
        os.remove(temp_file)
        print("备份恢复成功")
        return True
    except Exception as e:
        print(f"备份恢复失败: {str(e)}")
        raise

download_latest_backup()
EOF
}

# 首次启动恢复备份
restore_backup || echo "使用空数据目录启动"

# 启动AList和Aria2
./alist server --data /app/config &
aria2c --enable-rpc --rpc-listen-all --rpc-allow-origin-all --rpc-listen-port=6800 --daemon

# 同步函数
sync_data() {
    while true; do
        echo "$(date) 开始同步数据..."
        
        # 创建备份
        backup_file="/tmp/alist_backup_$(date +%Y%m%d_%H%M%S).tar.gz"
        tar -czf "$backup_file" -C "$DATA_DIR" .
        
        # 上传备份
        python3 <<EOF
import os
from webdav3.client import Client
from tenacity import retry, stop_after_attempt, wait_fixed

options = {
    'webdav_hostname': '$FULL_WEBDAV_URL',
    'webdav_login': '$WEBDAV_USERNAME',
    'webdav_password': '$WEBDAV_PASSWORD'
}

@retry(stop=stop_after_attempt(3), wait=wait_fixed(10))
def upload_and_clean():
    client = Client(options)
    try:
        # 上传新备份
        client.upload_sync(local_path='$backup_file', remote_path='${backup_file##*/}')
        print("备份上传成功")
        
        # 清理旧备份(保留最近5个)
        backups = [f for f in client.list() if f.endswith('.tar.gz') and f.startswith('alist_backup_')]
        if len(backups) > 5:
            for old_backup in sorted(backups)[:-5]:
                client.clean(old_backup)
                print(f"已删除旧备份: {old_backup}")
    except Exception as e:
        print(f"备份操作失败: {str(e)}")
        raise

upload_and_clean()
EOF
        
        rm -f "$backup_file"
        echo "下次同步将在 $SYNC_INTERVAL 秒后..."
        sleep "$SYNC_INTERVAL"
    done
}

# 启动同步进程
sync_data