#include <deque>
#include <string>
#include "leveldb/status.h"
#include "leveldb/write_batch.h"
#include "port/port_stdcxx.h"
#include "util/mutexlock.h"
#include "util/serialize_value.h"
// #include "fielddb/field_db.h"

#ifndef REQUEST_H
#define REQUEST_H
namespace fielddb {
using namespace leveldb;
// 在taskqueue中的Request，由taskqueue最开始的线程处理一批Request
// 这个思路与write写入的思路类似
class FieldDB;
class Request {
public:
    friend class FieldDB;
    enum RequestType {
        FieldsReq_t,
        ValueReq_t,
        iCreateReq_t,
        iDeleteReq_t,
        DeleteReq_t,
    };

public:
    // Request(std::string *Key,std::string *Value,port::Mutex *mu):
    //     Key(Key),Value(Value),hasFields(false),cond_(mu) { }
    // Request(std::string *Key,FieldArray *Fields,port::Mutex *mu):
    //     Key(Key),Fields(Fields),hasFields(true),cond_(mu) { }
    Request(RequestType type,port::Mutex *mu):
        type_(type),cond_(mu),done(false) { parent = this; };

    virtual ~Request();

    inline bool isFieldsReq() { return type_ == FieldsReq_t; }
    // inline bool isValueReq() { return type_ == ValueReq_t; }
    inline bool isiCreateReq() { return type_ == iCreateReq_t; }
    inline bool isiDeleteReq() { return type_ == iDeleteReq_t; }
    inline bool isDeleteReq() { return type_ == DeleteReq_t; }

    //用于含有Fields的
    virtual void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
                WriteBatch &MetaBatch,fielddb::FieldDB *DB);
    //主要用于icreate和idelete在队列中的注册当前状态
    virtual void Prepare(FieldDB *DB);
    virtual void Finalize(FieldDB *DB);

    virtual void PendReq(Request *req);
    bool isPending();
// protected:
    bool done;
    Status s;
    port::CondVar cond_;
    RequestType type_;
    Request *parent;
};

//含有field的put
class FieldsReq : public Request {
public:
    FieldsReq(std::string *Key,FieldArray *Fields,port::Mutex *mu):
        Key(Key),Fields(Fields),Request(FieldsReq_t,mu) { };

    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
        WriteBatch &MetaBatch,fielddb::FieldDB *DB) override;

    std::string *Key;
    FieldArray *Fields;
};

//不含有field的put，但是计划被弃用了
// class ValueReq : public Request {
// public:
//     ValueReq(std::string *Key,std::string *Value,port::Mutex *mu):
//         Key(Key),Value(Value),Request(ValueReq_t,mu) { };

//     std::string *Key;
//     std::string *Value;
// };

//TODO:下面的Field什么的可能通过传引用的方式会更加好？

//创建索引的request
class iCreateReq : public Request {
public:
    iCreateReq(std::string *Field,port::Mutex *mu):
        Field(Field),Request(iCreateReq_t, mu) { };

    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
        WriteBatch &MetaBatch,fielddb::FieldDB *DB) override;
    void Prepare(FieldDB *DB) override;
    void Finalize(FieldDB *DB) override;
        
    std::string *Field;
    std::deque<Request *> pending_list;
};

//删除索引的request
class iDeleteReq : public Request {
public:
    iDeleteReq(std::string *Field,port::Mutex *mu):
        Field(Field),Request(iDeleteReq_t, mu) { };

    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
        WriteBatch &MetaBatch,fielddb::FieldDB *DB) override;
    void Prepare(FieldDB *DB) override;
    void Finalize(FieldDB *DB) override;
    
    std::string *Field;
    std::deque<Request *> pending_list;
};

//删除key的request
class DeleteReq : public Request {
public:
    DeleteReq(std::string *Key,port::Mutex *mu):
        Key(Key),Request(DeleteReq_t,mu) { };

    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
        WriteBatch &MetaBatch,fielddb::FieldDB *DB) override;

    std::string *Key;
};

}

#endif