DBHomework/editbook.cpp

#include "Session.h"
#include "Util.h"
#include "json.hpp"
#include "jsonfail.h"
using namespace std;
using json=nlohmann::json;

#define postval(NAME) string NAME=req.post[#NAME]
#define gpostval(NAME) NAME=new string;*NAME=req.post[#NAME]
#define tpostval(NAME) string* NAME=nullptr; do { if(postexist(#NAME)) { gpostval(NAME); } }while(0)

int main()
{
    Request req;
    Session se(req);
    Response res;
    json j;

    auto jsonfail=[&](int errcode,const string& detail="")
    {
        j["success"]=0;
        j["errcode"]=errcode;
        j["errmsg"]=string(GetErrMsg(errcode))+" : "+detail;
    };

    /// Used by Marco: tpostval(NAME)
    auto postexist=[&](const string& key)->bool
    {
        return req.post.find(key)!=req.post.end();
    };

    do
    {
        if(!se.isReady())
        {
            jsonfail(err_session);
            break;
        }
        if(se.isNew()||se.getUser().empty())
        {
            jsonfail(err_need_login);
            break;
        }

        if(req.requestMethod!="POST")
        {
            jsonfail(err_method_not_supported);
            break;
        }

        if(req.post["book_key"].empty())
        {
            jsonfail(err_missing_parameter);
            break;
        }

        postval(book_key);
        int book_key_real=ParseInt(book_key);
        if(book_key_real<0)
        {
            jsonfail(err_parameter,"Book Key Parse Error");
            break;
        }

        DBInfo db;
        MySQLConn conn;
        if(db.readConfig()<0)
        {
            jsonfail(err_config);
            break;
        }

        if(db.connectProxy(conn)<0)
        {
            jsonfail(err_connect);
            break;
        }

        /// Check Permission
        int permission_level;
        if(conn.exec(make_str("select permission_level from bs_user where username='",
                              se.getUser(),
                              "'"),
                     [&](MySQLResult& res)
                     {
                         res.stepRow([&](char** val,unsigned long* len)
                                     {
                                         permission_level=ParseInt(val[0]);
                                    });
                    })<0)
        {
            jsonfail(err_sql,"Step 1");
            break;
        }

        if(permission_level>1)
        {
            /// Permission Denied.
            jsonfail(err_permission_denied);
            break;
        }

        /// Try to verify book_key (class_id)
        int count_class_id_val;
        if(conn.exec(make_str("select count(class_id) from bs_book where class_id=",
                              book_key_real),
                     [&](MySQLResult& res)
                     {
                         res.stepRow([&](char** val,unsigned long* len)
                                     {
                                         count_class_id_val=ParseInt(val[0]);
                                     });
                     })<0)
        {
            jsonfail(err_sql,"Step 2");
            break;
        }

        if(count_class_id_val!=1)
        {
            /// Failed to verify
            jsonfail(err_data,"Cannot verify book key.");
            break;
        }

        /// Try to fetch values.
        tpostval(isbn);
        tpostval(bookname);
        tpostval(booktype);
        tpostval(author);
        tpostval(publisher);
        tpostval(pubdate);
        tpostval(status);

        if(status!=nullptr)
        {
            int _in_status=ParseInt(*status);
            if(_in_status<0)
            {
                jsonfail(err_parameter,"Status parse failed.");
                break;
            }

            /// Verify status
            int status_cnt;
            if(conn.exec(make_str("select count(status) from bs_meta_book where status=",
                                  _in_status),
                         [&](MySQLResult& res)
                         {
                             res.stepRow([&](char** val,unsigned long* len)
                                         {
                                             status_cnt=ParseInt(val[0]);
                                         });
                         })<0)
            {
                jsonfail(err_sql,"Step 3");
                break;
            }

            if(status_cnt!=1)
            {
                jsonfail(err_data,"Cannot verify status");
                break;
            }

            if(conn.exec(make_str("update bs_book set status=",_in_status),nullptr)<0)
            {
                jsonfail(err_sql,"Step 4 status");
                break;
            }

            if(conn.getAffectedRows()!=1)
            {
                jsonfail(err_sql_logic,"status");
                break;
            }
        }

        #define doUpdate(NAME,SETNAME) \
            if(NAME!=nullptr) \
            {\
                if((*NAME).empty()) \
                {\
                    *NAME="null";\
                }\
                else\
                {\
                    *NAME=make_str("'",(*NAME),"'");\
                }\
                if(conn.exec(make_str("update bs_book set ",SETNAME,"=",\
                                      *NAME,\
                                      " where class_id=",\
                                      book_key_real),nullptr)<0)\
                {\
                    jsonfail(err_sql,make_str("Step 4 ",SETNAME));\
                    break;\
                }\
                if(conn.getAffectedRows()!=1)\
                {\
                    jsonfail(err_sql_logic,SETNAME);\
                    break;\
                }\
            }

        doUpdate(isbn,"isbn");
        doUpdate(bookname,"name");
        doUpdate(booktype,"book_type");
        doUpdate(author,"author");
        doUpdate(publisher,"publisher");
        doUpdate(pubdate,"publish_time");

        j["success"]=1;
    }while(0);

    res.content.append(j.dump());
    res.show();

    return 0;
}