package io.trygvis.engine;

import bitronix.tm.TransactionManagerServices;
import bitronix.tm.resource.jdbc.PoolingDataSource;
import com.googlecode.flyway.core.Flyway;
import com.googlecode.flyway.core.api.MigrationInfo;
import com.googlecode.flyway.core.api.MigrationInfoService;
import org.jbpm.bpmn2.handler.ServiceTaskHandler;
import org.jbpm.process.audit.AuditLoggerFactory;
import org.kie.api.KieBase;
import org.kie.api.runtime.Environment;
import org.kie.api.runtime.EnvironmentName;
import org.kie.api.runtime.process.ProcessInstance;
import org.kie.internal.KnowledgeBaseFactory;
import org.kie.internal.io.ResourceFactory;
import org.kie.internal.persistence.jpa.JPAKnowledgeService;
import org.kie.internal.runtime.StatefulKnowledgeSession;
import org.kie.internal.utils.KieHelper;
import org.slf4j.Logger;

import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.sql.DataSource;
import java.util.Date;

import static java.lang.String.format;
import static org.slf4j.LoggerFactory.getLogger;

public class CalamusJbpm {
    private final Logger log = getLogger(getClass());

    private final EntityManagerFactory emf;

    private final StatefulKnowledgeSession session;

    public static enum CalamusProcess {
        DEPLOY("io.trygvis.bpm.Deploy");

        private String name;

        CalamusProcess(String name) {
            this.name = name;
        }
    }

    public CalamusJbpm() {
        PoolingDataSource ds = new PoolingDataSource();
        ds.setUniqueName("jdbc/jbpm-ds");
        ds.setClassName(bitronix.tm.resource.jdbc.lrc.LrcXADataSource.class.getCanonicalName());
        ds.setMaxPoolSize(3);
        ds.setAllowLocalTransactions(true);
        ds.getDriverProperties().put("user", "jbpm");
        ds.getDriverProperties().put("password", "jbpm");
        ds.getDriverProperties().put("url", "jdbc:postgresql://localhost/jbpm");
        ds.getDriverProperties().put("driverClassName", org.postgresql.Driver.class.getCanonicalName());
        ds.init();

        runFlyway(log, ds, "", "public");

        emf = Persistence.createEntityManagerFactory("org.jbpm.persistence.jpa");
        Environment env = KnowledgeBaseFactory.newEnvironment();
        env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, emf);
        env.set(EnvironmentName.TRANSACTION_MANAGER, TransactionManagerServices.getTransactionManager());

        KieBase kieBase = new KieHelper()
                .addResource(ResourceFactory.newClassPathResource("Deploy.bpmn2"))
                .build();

        session = JPAKnowledgeService.newStatefulKnowledgeSession(kieBase, null, env);
        session.addEventListener(AuditLoggerFactory.newJPAInstance(env));

        session.getWorkItemManager().registerWorkItemHandler("Service Task", new ServiceTaskHandler());
        session.getWorkItemManager().registerWorkItemHandler("Upgrade App", new UpgradeAppWorkItemHandler());
        session.getWorkItemManager().registerWorkItemHandler("Restart App", new RestartAppWorkItemHandler());
    }

    public StatefulKnowledgeSession getSession() {
        return session;
    }

    public EntityManagerFactory getEntityManagerFactory() {
        return emf;
    }

    public void startProcess(CalamusProcess process) {
        ProcessInstance processInstance = session.startProcess(process.name);
    }

    private static void runFlyway(Logger log, DataSource dataSource, String prefix, String schema) {
        log.info("Running migrations for {}", schema);

        Flyway flyway = new Flyway();
        flyway.setDataSource(dataSource);
        flyway.setSchemas(schema);
        flyway.setLocations("db/" + prefix);
        flyway.setInitOnMigrate(true);
        MigrationInfoService info = flyway.info();
        log.info(format("%-15s %-10s %-19s %s", "Version", "State", "Installed on", "Description"));
        for (MigrationInfo mi : info.all()) {
            Date installedOn = mi.getInstalledOn();
            log.info(format("%-15s %-10s %-19s %s",
                    mi.getVersion(),
                    trimToEmpty(mi.getState().getDisplayName()),
                    installedOn != null ? new Date(installedOn.getTime()).toString() : "",
                    trimToEmpty(mi.getDescription())));
        }
        flyway.migrate();
    }

    private static String trimToEmpty(String string) {
        if (string == null) {
            return "";
        }

        return string.trim();
    }
}