//首頁加載的數(shù)據(jù)的遷移
class func loadHomeData(sinceId: Int64,maxId: Int64,finished: @escaping ([[String : Any]]?) -> ()) {
    let res = checkoutStatus(sinceId: sinceId, maxId: maxId)
    //if let result ',' 可以獲取到賦值的結果
    if let result = res, result.count > 0 {
        //有緩存數(shù)據(jù)  返回緩存數(shù)據(jù)
        //TODO: 待返回
        finished(result)
        return
    }
    
    //沒有緩存數(shù)據(jù), 請求網(wǎng)絡數(shù)據(jù)
    let urlString = "https://api.weibo.com/2/statuses/home_timeline.json"
    let parameters = ["access_token" : HMUserAccountViewModel.shared.access_token,
                      "max_id" : "\(maxId)",
        "since_id" : "\(sinceId)"]
    
    HMNetworkTools.shared.request(method: .GET, urlString: urlString, parameters: parameters, finished: { (responseObject,error) -> () in
        if error != nil {
            //告訴外界請求失敗 在閉包中如何完成失敗的回調
            //TODO: 完成失敗的回調
            finished(nil)
            return
        }
        
        //成功
        let dict = responseObject as! [String : Any]
        //嘗試轉換為字典類型的數(shù)組
        guard let array = dict["statuses"] as? [[String : Any]] else {
            finished(nil)
            return
        }
        
        
        //回調的網(wǎng)絡 請求的結果
        finished(array)
        //存儲到本地
        cacheStauts(array: array)
    })
}



//1.檢查本地是否有緩存數(shù)據(jù)
class func checkoutStatus(sinceId: Int64,maxId: Int64) -> [[String : Any]]? {
    //查詢的sql
    
    guard let userId = HMUserAccountViewModel.shared.userAccount?.uid else {
        return nil
    }
    
    //會將數(shù)據(jù)庫中所有的緩存數(shù)據(jù)都查找到
    var sql = "SELECT status FROM T_Status WHERE userId = \(userId) "
    //拼接sql
    //如果sinceId > 0 標識需要查找新數(shù)據(jù)
    if sinceId > 0 {
        //向上查找
        sql += "AND statusId > \(sinceId) "
    }
    
    if maxId > 0 {
        //向下查找
        sql += "AND statusId < \(maxId) "
    }
    
    //排序 降序
    sql += "ORDER BY statusId DESC "
    
    //限制條數(shù)
    sql += "LIMIT 100"
    
    print(sql)
    //實例化數(shù)據(jù)
    var array = [[String : Any]]()
    
    HMSQLiteTools.shared.queue.inDatabase { (db) in
        guard let res = db!.executeQuery(sql, withArgumentsIn: nil) else {
            //在閉包中不能夠return
            return
        }
        //逐條獲取數(shù)據(jù)
        while res.next() {
            //獲取status 二進制數(shù)據(jù)
            let jsonData = res.data(forColumn: "status")
            //轉換為json 字典
            let dict = try! JSONSerialization.jsonObject(with:jsonData!, options: [])
            array.append(dict as! [String : Any])
        }
    }
    
    return array
}

//2. 如果本地有緩存數(shù)據(jù) 就直接返回本地的緩存數(shù)據(jù),給用戶節(jié)省流量,讓用戶在沒有網(wǎng)絡的情況可以瀏覽之前的內(nèi)容

//3. 沒有緩存數(shù)據(jù)就請求網(wǎng)絡數(shù)據(jù) 返回網(wǎng)絡數(shù)據(jù)

//4. 獲取網(wǎng)絡數(shù)據(jù)之后就應該立即存儲網(wǎng)絡數(shù)據(jù)
/*
 statusId
 status
 userId
 */
class func cacheStauts(array: [[String : Any]]) {
    //獲取userId
    guard let userId = HMUserAccountViewModel.shared.userAccount?.uid else {
        print("用戶沒有登錄呢")
        return
    }
    
    //sql
    //如果在對應的主鍵下已經(jīng)存在數(shù)據(jù) 就執(zhí)行替換的操作
    let sql = "INSERT OR REPLACE INTO T_Status (statusId,status,userId) VALUES (?,?,?)"
    HMSQLiteTools.shared.queue.inTransaction { (db, rollback) in
        
        for item in array {
            let statusId = item["id"]!
            //數(shù)據(jù)庫中能夠存儲的數(shù)據(jù)不能夠是Foundation 需要將字典數(shù)據(jù)轉換二進制數(shù)據(jù)存儲到數(shù)據(jù)庫中
            //如果是字典數(shù)據(jù) 在讀取的時候會有問題
            let jsonData = try! JSONSerialization.data(withJSONObject: item, options: [])
            let res =  db!.executeUpdate(sql, withArgumentsIn: [statusId,jsonData,userId])
            if !res {
               //不成功就執(zhí)行回滾
                rollback?.pointee = true
                return
            }
        }
    }
}