package tracker;

import java.io.File;
import java.util.HashMap;
import java.util.Map;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;

import com.querydsl.jpa.impl.JPAUpdateClause;

import entity.QUserPT;
import entity.TTorent;
import entity.TransRecord;
import entity.config;

public class Tracker implements TrackerInterface {
    private final EntityManagerFactory emf;

    // 默认构造：产线数据库
    public Tracker() {
        config cfg = new config();
        Map<String,Object> props = new HashMap<>();
        props.put("javax.persistence.jdbc.url",
                  "jdbc:mysql://" + cfg.SqlURL + "/" + cfg.Database);
        props.put("javax.persistence.jdbc.user", cfg.SqlUsername);
        props.put("javax.persistence.jdbc.password", cfg.SqlPassword);
        this.emf = Persistence.createEntityManagerFactory("myPersistenceUnit", props);
    }

    // 测试传入：测试库
    public Tracker(EntityManagerFactory emf) {
        this.emf = emf;
    }

    @Override
    public boolean AddUpLoad(String userid, int upload) {
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = em.getTransaction();
        try {
            tx.begin();
            QUserPT q = QUserPT.userPT;
            long updated = new JPAUpdateClause(em, q)
                .where(q.userid.eq(userid))
                .set(q.upload, q.upload.add(upload))
                .execute();
            tx.commit();
            // 成功时 updated>0 返回 false，失败时返回 true
            return updated <= 0;
        } catch(Exception e) {
            if (tx.isActive()) tx.rollback();
            return true;
        } finally {
            em.close();
        }
    }

    @Override
    public boolean ReduceUpLoad(String userid, int upload){
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = em.getTransaction();
        try {
            tx.begin();
            QUserPT q = QUserPT.userPT;
            long updated = new JPAUpdateClause(em, q)
                .where(q.userid.eq(userid))
                .set(q.upload, q.upload.subtract(upload))
                .execute();
            tx.commit();
            // 成功时 updated>0 返回 false，失败时返回 true
            return updated <= 0;
        } catch(Exception e) {
            if (tx.isActive()) tx.rollback();
            return true;
        } finally {
            em.close();
        }
    }

    @Override
    public boolean AddDownload(String userid, int download) {
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = em.getTransaction();
        try {
            tx.begin();
            QUserPT q = QUserPT.userPT;
            long updated = new JPAUpdateClause(em, q)
                .where(q.userid.eq(userid))
                .set(q.download, q.download.add(download))
                .execute();
            tx.commit();
            return updated <= 0;
        } catch(Exception e) {
            if (tx.isActive()) tx.rollback();
            return true;
        } finally {
            em.close();
        }
    }

    @Override
    public boolean ReduceDownload(String userid, int download) {
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = em.getTransaction();
        try {
            tx.begin();
            QUserPT q = QUserPT.userPT;
            long updated = new JPAUpdateClause(em, q)
                .where(q.userid.eq(userid))
                .set(q.download, q.download.subtract(download))
                .execute();
            tx.commit();
            return updated <= 0;
        } catch(Exception e) {
            if (tx.isActive()) tx.rollback();
            return true;
        } finally {
            em.close();
        }
    }

    @Override
    public boolean AddMagic(String userid, int magic) {
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = em.getTransaction();
        try {
            tx.begin();
            QUserPT q = QUserPT.userPT;
            long updated = new JPAUpdateClause(em, q)
                .where(q.userid.eq(userid))
                .set(q.magic, q.magic.add(magic))
                .execute();
            tx.commit();
            return updated <= 0;
        } catch(Exception e) {
            if (tx.isActive()) tx.rollback();
            return true;
        } finally {
            em.close();
        }
    }

    @Override
    public boolean ReduceMagic(String userid, int magic) {
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = em.getTransaction();
        try {
            tx.begin();
            QUserPT q = QUserPT.userPT;
            long updated = new JPAUpdateClause(em, q)
                .where(q.userid.eq(userid))
                .set(q.magic, q.magic.subtract(magic))
                .execute();
            tx.commit();
            return updated <= 0;
        } catch(Exception e) {
            if (tx.isActive()) tx.rollback();
            return true;
        } finally {
            em.close();
        }
    }


    @Override
    public int SaveTorrent(File TTorent){
        return 0;
    };//保存seedid对应的ttorent信息

    @Override
    public File GetTTorent(String seedid,String userid){
        return null;
    };//根据种子id获得ttorent信息然后构建Ttorent文件并返回,同时记录用户的下载行为


    @Override
    public int AddRecord(TransRecord rd){
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = em.getTransaction();
        try {
            tx.begin();
            em.persist(rd);
            tx.commit();
            // 持久化成功，返回1表示插入成功
            return 1;
        } catch (Exception e) {
            if (tx.isActive()) tx.rollback();
            return -1;
        } finally {
            em.close();
        }
    }
}