#!/bin/bash
set -e

WEBDAV_URL="${WEBDAV_URL}"
WEBDAV_USERNAME="${WEBDAV_USERNAME}" 
WEBDAV_PASSWORD="${WEBDAV_PASSWORD}"
DB_PATH="${DB_PATH:-/app/db}"
BACKUP_PATH="${BACKUP_PATH:-/app/backup}"
BACKUP_FILENAME="${BACKUP_FILENAME:-tgdrive_db_backup.tar.gz}"
REMOTE_BACKUP_DIR="${REMOTE_BACKUP_DIR:-tgdrive_backup}"
CONFIG_FILE="/app/config/sync_config"
PYTHON_CMD="/app/venv/bin/python3"

mkdir -p ${BACKUP_PATH}
mkdir -p /app/logs

log() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $1" >> /app/logs/sync.log 2>/dev/null || true
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $1"
}

mkdir -p /app/logs 2>/dev/null || true
touch /app/logs/sync.log 2>/dev/null || true

if [ ! -f "$CONFIG_FILE" ]; then
    log "创建初始配置文件"
    mkdir -p /app/config 2>/dev/null || true
    echo "LAST_SYNC=0" > "$CONFIG_FILE" 2>/dev/null || true
fi

if [ -f "$CONFIG_FILE" ]; then
    source "$CONFIG_FILE" 2>/dev/null || true
fi

if [ -z "$WEBDAV_URL" ] || [ -z "$WEBDAV_USERNAME" ] || [ -z "$WEBDAV_PASSWORD" ]; then
    log "错误: WebDAV配置不完整，请设置WEBDAV_URL, WEBDAV_USERNAME, WEBDAV_PASSWORD环境变量"
    exit 1
fi

backup_db() {
    log "开始备份数据库..."
    if [ -d "$DB_PATH" ]; then
        if [[ "$DB_PATH" == "/app/db" ]]; then
            tar -czf "${BACKUP_PATH}/${BACKUP_FILENAME}" -C /app db
        else
            tar -czf "${BACKUP_PATH}/${BACKUP_FILENAME}" -C $(dirname "$DB_PATH") $(basename "$DB_PATH")
        fi
        log "数据库已备份到 ${BACKUP_PATH}/${BACKUP_FILENAME}"
        return 0
    else
        log "警告: 数据库目录不存在"
        return 1
    fi
}

upload_to_webdav() {
    log "开始上传备份到WebDAV (目标目录: ${REMOTE_BACKUP_DIR})..."
    
    $PYTHON_CMD -c "
import webdav3.client as wc
import os

options = {
    'webdav_hostname': '$WEBDAV_URL',
    'webdav_login': '$WEBDAV_USERNAME',
    'webdav_password': '$WEBDAV_PASSWORD',
    'webdav_timeout': 30
}

client = wc.Client(options)

# 检查远程目录是否存在
if not client.check('$REMOTE_BACKUP_DIR'):
    client.mkdir('$REMOTE_BACKUP_DIR')

# 上传文件
local_path = '${BACKUP_PATH}/${BACKUP_FILENAME}'
remote_path = '$REMOTE_BACKUP_DIR/${BACKUP_FILENAME}'

if os.path.exists(local_path):
    try:
        client.upload_sync(remote_path=remote_path, local_path=local_path)
        print('上传成功')
    except Exception as e:
        print(f'上传失败: {e}')
else:
    print('本地备份文件不存在')
"
    
    if [ $? -eq 0 ]; then
        log "备份已成功上传到WebDAV (${REMOTE_BACKUP_DIR}/${BACKUP_FILENAME})"
        echo "LAST_SYNC=$(date +%s)" > "$CONFIG_FILE"
        return 0
    else
        log "上传到WebDAV失败"
        return 1
    fi
}

download_from_webdav() {
    log "开始从WebDAV下载备份 (源目录: ${REMOTE_BACKUP_DIR})..."
    
    $PYTHON_CMD -c "
import webdav3.client as wc
import os

options = {
    'webdav_hostname': '$WEBDAV_URL',
    'webdav_login': '$WEBDAV_USERNAME',
    'webdav_password': '$WEBDAV_PASSWORD',
    'webdav_timeout': 30
}

client = wc.Client(options)

# 检查远程文件是否存在
remote_path = '$REMOTE_BACKUP_DIR/${BACKUP_FILENAME}'
local_path = '${BACKUP_PATH}/${BACKUP_FILENAME}'

if client.check(remote_path):
    try:
        client.download_sync(remote_path=remote_path, local_path=local_path)
        print('下载成功')
    except Exception as e:
        print(f'下载失败: {e}')
else:
    print('远程备份文件不存在')
"
    
    if [ $? -eq 0 ]; then
        log "备份已成功从WebDAV (${REMOTE_BACKUP_DIR}/${BACKUP_FILENAME}) 下载"
        return 0
    else
        log "从WebDAV下载备份失败"
        return 1
    fi
}

restore_db() {
    log "开始恢复数据库到 ${DB_PATH}..."
    
    if [ -f "${BACKUP_PATH}/${BACKUP_FILENAME}" ]; then
        if [ -d "$DB_PATH" ] && [ "$(ls -A $DB_PATH 2>/dev/null)" ]; then
            local timestamp=$(date +%Y%m%d%H%M%S)
            if [[ "$DB_PATH" == "/app/db" ]]; then
                tar -czf "${BACKUP_PATH}/db_before_restore_${timestamp}.tar.gz" -C /app db 2>/dev/null || log "无法创建当前数据库备份，继续恢复..."
            else
                tar -czf "${BACKUP_PATH}/db_before_restore_${timestamp}.tar.gz" -C $(dirname "$DB_PATH") $(basename "$DB_PATH") 2>/dev/null || log "无法创建当前数据库备份，继续恢复..."
            fi
            log "尝试备份当前数据库到 ${BACKUP_PATH}/db_before_restore_${timestamp}.tar.gz"
        fi
        
        # 创建临时恢复目录
        mkdir -p /tmp/tgdrive_restore 2>/dev/null || true
        
        # 解压备份文件到临时目录
        tar -xzf "${BACKUP_PATH}/${BACKUP_FILENAME}" -C /tmp/tgdrive_restore 2>/dev/null || {
            log "解压备份文件失败，可能是格式不正确"
            rm -rf /tmp/tgdrive_restore 2>/dev/null || true
            return 1
        }
        
        # 确保数据库目录存在
        mkdir -p "$DB_PATH" 2>/dev/null || true
        
        # 清空数据库目录内容（逐个文件删除而不是删除整个目录）
        find "$DB_PATH" -mindepth 1 -delete 2>/dev/null || log "无法清空数据库目录，将尝试直接覆盖..."
        
        # 复制恢复的文件到数据库目录
        if [ -d "/tmp/tgdrive_restore/db" ]; then
            cp -rf /tmp/tgdrive_restore/db/* "$DB_PATH"/ 2>/dev/null || {
                log "复制恢复文件失败，尝试使用rsync..."
                which rsync >/dev/null 2>&1 && rsync -a /tmp/tgdrive_restore/db/ "$DB_PATH"/ 2>/dev/null
            }
        else
            log "备份中找不到db目录，尝试直接复制临时目录内容..."
            cp -rf /tmp/tgdrive_restore/* "$DB_PATH"/ 2>/dev/null || {
                log "复制恢复文件失败，尝试使用rsync..."
                which rsync >/dev/null 2>&1 && rsync -a /tmp/tgdrive_restore/ "$DB_PATH"/ 2>/dev/null
            }
        fi
        
        rm -rf /tmp/tgdrive_restore 2>/dev/null || true
        
        log "数据库已尝试恢复到 ${DB_PATH}"
        return 0
    else
        log "错误: 备份文件不存在，无法恢复数据库"
        return 1
    fi
}

case "$1" in
    backup)
        backup_db && upload_to_webdav
        ;;
    restore)
        download_from_webdav && restore_db
        ;;
    sync)
        current_time=$(date +%s)
        download_from_webdav
        
        if { [ ! -d "$DB_PATH" ] || [ ! "$(ls -A $DB_PATH 2>/dev/null)" ]; } && [ -f "${BACKUP_PATH}/${BACKUP_FILENAME}" ]; then
            log "检测到本地数据库不存在或为空，开始恢复..."
            restore_db
        fi
        
        backup_db && upload_to_webdav
        ;;
    *)
        echo "用法: $0 {backup|restore|sync}"
        echo "  backup  - 备份数据库并上传到WebDAV"
        echo "  restore - 从WebDAV下载备份并恢复数据库"
        echo "  sync    - 同步数据库（双向）"
        exit 1
        ;;
esac

exit 0