#!/bin/bash

# ================= 配置 =================
WEBDAV_URL=${WEBDAV_URL%/}
WEBDAV_BACKUP_PATH=${WEBDAV_BACKUP_PATH:-""}
# 处理子路径
WEBDAV_BACKUP_PATH=${WEBDAV_BACKUP_PATH#/}
WEBDAV_BACKUP_PATH=${WEBDAV_BACKUP_PATH%/}

if [ -n "$WEBDAV_BACKUP_PATH" ]; then
    FULL_WEBDAV_URL="${WEBDAV_URL}/${WEBDAV_BACKUP_PATH}"
else
    FULL_WEBDAV_URL="${WEBDAV_URL}"
fi

SYNC_INTERVAL=${SYNC_INTERVAL:-60}
TARGET_FILENAME="accounts.json"
REMOTE_FILENAME="antigravity_accounts.json"
TEMP_DIR="/tmp/backup_temp"

# =======================================

log() { echo "[Backup] [$(date '+%H:%M:%S')] $1"; }
mkdir -p "$TEMP_DIR"

# 检查环境
if [[ -z "$WEBDAV_URL" ]]; then
    log "未设置 WEBDAV_URL，跳过备份"
    exit 0
fi

if ! command -v curl &> /dev/null; then
    apk add --no-cache curl || (apt-get update && apt-get install -y curl)
fi

# === 核心修复：智能寻找真正活跃的文件 ===
find_active_file() {
    FILE_ROOT="/app/$TARGET_FILENAME"
    FILE_DATA="/app/data/$TARGET_FILENAME"
    
    # 获取文件修改时间戳 (如果文件不存在则为0)
    TIME_ROOT=$(stat -c %Y "$FILE_ROOT" 2>/dev/null || echo 0)
    TIME_DATA=$(stat -c %Y "$FILE_DATA" 2>/dev/null || echo 0)
    
    # 比较哪个文件更新
    if [ "$TIME_ROOT" -gt "$TIME_DATA" ]; then
        echo "$FILE_ROOT"
    elif [ "$TIME_DATA" -gt 0 ]; then
        echo "$FILE_DATA"
    else
        # 如果都没有，尝试用 find 找 (兼容性兜底)
        find /app -name "$TARGET_FILENAME" -type f -not -path "*/node_modules/*" | head -n 1
    fi
}

# === 恢复功能 ===
restore() {
    log "正在从 WebDAV 恢复备份..."
    REMOTE_FILE="$FULL_WEBDAV_URL/$REMOTE_FILENAME"
    TEMP_FILE="$TEMP_DIR/restored.json"
    
    HTTP_CODE=$(curl -s -o "$TEMP_FILE" -w "%{http_code}" -u "$WEBDAV_USERNAME:$WEBDAV_PASSWORD" "$REMOTE_FILE")
    
    if [[ "$HTTP_CODE" == "200" ]] && [ -s "$TEMP_FILE" ]; then
        # 恢复策略：只恢复到 /app 根目录
        # 为什么？因为我们确定程序会优先读取根目录，或者在根目录生成
        # 如果程序之前在 data 目录，它找不到 data 里的文件通常会自动回落或重建
        
        DEST_PATH="/app/$TARGET_FILENAME"
        cp "$TEMP_FILE" "$DEST_PATH"
        log "✅ 备份已恢复到: $DEST_PATH"
        
        # 只有当 data 目录已经存在时，才顺便放一份进去，但不强求
        if [ -d "/app/data" ]; then
            cp "$TEMP_FILE" "/app/data/$TARGET_FILENAME"
        fi
    else
        log "📭 未找到远程备份或文件为空，将以新状态启动"
    fi
}

# === 循环备份功能 ===
loop() {
    log "启动智能增量备份 (间隔: ${SYNC_INTERVAL}秒)"
    
    # 尝试创建远程目录
    if [ -n "$WEBDAV_BACKUP_PATH" ]; then
        curl -s -o /dev/null -u "$WEBDAV_USERNAME:$WEBDAV_PASSWORD" -X MKCOL "$FULL_WEBDAV_URL/"
    fi
    
    while true; do
        sleep $SYNC_INTERVAL
        
        # 每次都重新判断哪个文件是最新的
        CURRENT_PATH=$(find_active_file)
        
        if [ -n "$CURRENT_PATH" ] && [ -f "$CURRENT_PATH" ]; then
            FILE_SIZE=$(wc -c < "$CURRENT_PATH")
            
            # 只有大于 10 字节才备份 (避免备份空的 [])
            if [ "$FILE_SIZE" -gt 10 ]; then
                # log "正在备份活跃文件: $CURRENT_PATH (大小: $FILE_SIZE)"
                
                HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" -u "$WEBDAV_USERNAME:$WEBDAV_PASSWORD" -T "$CURRENT_PATH" "$FULL_WEBDAV_URL/$REMOTE_FILENAME")
                
                if [[ "$HTTP_CODE" != "201" ]] && [[ "$HTTP_CODE" != "204" ]] && [[ "$HTTP_CODE" != "200" ]]; then
                    log "❌ 上传失败: HTTP $HTTP_CODE"
                else
                    # 成功时不刷屏，静默成功
                    : 
                fi
            else
                log "⚠️ 文件过小 ($FILE_SIZE bytes)，跳过备份以免覆盖数据"
            fi
        else
            log "等待 accounts.json 生成..."
        fi
    done
}

case "$1" in
    "restore") restore ;;
    "loop") loop ;;
    *) restore; loop ;;
esac