package com.qqflow.engine.domain.flow.statemachine;

import com.qqflow.engine.domain.flow.enums.ProcessEvent;
import com.qqflow.engine.domain.flow.enums.ProcessStatus;
import org.springframework.context.annotation.Configuration;
import org.springframework.statemachine.config.EnableStateMachineFactory;
import org.springframework.statemachine.config.StateMachineConfigurerAdapter;
import org.springframework.statemachine.config.builders.StateMachineStateConfigurer;
import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;

import java.util.EnumSet;

@Configuration
@EnableStateMachineFactory
public class ProcessInstanceStateMachineConfig extends StateMachineConfigurerAdapter<ProcessStatus, ProcessEvent> {

    @Override
    public void configure(StateMachineStateConfigurer<ProcessStatus, ProcessEvent> states) throws Exception {
        states.withStates()
                .initial(ProcessStatus.PENDING_RECEIVE)
                .states(EnumSet.allOf(ProcessStatus.class));
    }

    @Override
    public void configure(StateMachineTransitionConfigurer<ProcessStatus, ProcessEvent> transitions) throws Exception {
        this.configureActiveTransitions(transitions);
        this.configureTerminalTransitions(transitions);
    }

    private void configureActiveTransitions(StateMachineTransitionConfigurer<ProcessStatus, ProcessEvent> transitions) throws Exception {
        transitions
                .withExternal()
                .source(ProcessStatus.PENDING_RECEIVE).target(ProcessStatus.PENDING).event(ProcessEvent.RECEIVE)
                .and()
                .withExternal()
                .source(ProcessStatus.PENDING).target(ProcessStatus.APPROVED).event(ProcessEvent.APPROVE)
                .and()
                .withExternal()
                .source(ProcessStatus.PENDING).target(ProcessStatus.REJECTED).event(ProcessEvent.REJECT)
                .and()
                .withExternal()
                .source(ProcessStatus.PENDING).target(ProcessStatus.RETURNED).event(ProcessEvent.RETURN)
                .and()
                .withExternal()
                .source(ProcessStatus.RETURNED).target(ProcessStatus.PENDING).event(ProcessEvent.RECEIVE);
    }

    private void configureTerminalTransitions(StateMachineTransitionConfigurer<ProcessStatus, ProcessEvent> transitions) throws Exception {
        transitions
                .withExternal()
                .source(ProcessStatus.APPROVED).target(ProcessStatus.COMPLETED).event(ProcessEvent.COMPLETE)
                .and()
                .withExternal()
                .source(ProcessStatus.PENDING_RECEIVE).target(ProcessStatus.REVOKED).event(ProcessEvent.REVOKE)
                .and()
                .withExternal()
                .source(ProcessStatus.PENDING).target(ProcessStatus.REVOKED).event(ProcessEvent.REVOKE)
                .and()
                .withExternal()
                .source(ProcessStatus.RETURNED).target(ProcessStatus.REVOKED).event(ProcessEvent.REVOKE)
                .and()
                .withExternal()
                .source(ProcessStatus.PENDING_RECEIVE).target(ProcessStatus.TERMINATED).event(ProcessEvent.TERMINATE)
                .and()
                .withExternal()
                .source(ProcessStatus.PENDING).target(ProcessStatus.TERMINATED).event(ProcessEvent.TERMINATE);
    }
}