/*
 * Copyright (c) 2015 EMC Corporation
 * All Rights Reserved
 */
package com.emc.storageos.workflow;

import java.io.Serializable;
import java.util.Map;

import com.emc.storageos.svcs.errorhandling.model.ServiceCoded;
import com.emc.storageos.workflow.Workflow.StepState;
import com.emc.storageos.workflow.Workflow.StepStatus;

/**
 * A nested rollback handler for rollback of entire Workflows. It calls the original handler
 * as needed and handles the completion of the parent Workflow.
 */
class NestedWorkflowRollbackHandler implements Workflow.WorkflowRollbackHandler, Serializable {
    static final Integer NUMBER_OF_ADDED_ARGS = 2;  // number of arguments added for our handler

    // There may be a nested (i.e. previous) handler that our handler needs to call. If so,
    // it will be placed in the args here.
    static int indexOfNestedHandler(Object[] args) {
        return (args.length - 2);  // next to last argument in list
    }

    // The parentStepId will be in the args at this position. We will need to fire a workflow
    // step completer on the parent step id.
    static int indexOfParentStepId(Object[] args) {
        return (args.length - 1);	// the very last argument
    }

    @Override
    public void initiatingRollback(Workflow workflow, Object[] args) {
        Workflow.WorkflowRollbackHandler originalHandler =
                (Workflow.WorkflowRollbackHandler) args[indexOfNestedHandler(args)];
        if (originalHandler != null) {
            originalHandler.initiatingRollback(workflow, args);
        }
    }

    @Override
    public void rollbackComplete(Workflow workflow, Object[] args) {
        Workflow.WorkflowRollbackHandler originalHandler =
                (Workflow.WorkflowRollbackHandler) args[indexOfNestedHandler(args)];
        if (originalHandler != null) {
            originalHandler.initiatingRollback(workflow, args);
        }
        Map<String, StepStatus> stepToStepStatus = workflow.getStepStatusMap();
        boolean rollbackError = false;
        StringBuilder builder = new StringBuilder();
        for (StepStatus stepStatus : stepToStepStatus.values()) {
            if (stepStatus.description.startsWith("Rollback ") && stepStatus.state == StepState.ERROR) {
                if (builder.length() > 0) {
                    builder.append("\n");
                }
                builder.append(stepStatus.message);
                rollbackError = true;
            }
        }
        String parentStepId = (String) args[indexOfParentStepId(args)];
        if (rollbackError) {
            ServiceCoded coded = WorkflowException.exceptions.innerWorkflowRollbackError(workflow.getWorkflowURI().toString(),
                    builder.toString());
            WorkflowStepCompleter.stepFailed(parentStepId, coded);
        } else {
            WorkflowStepCompleter.stepSucceded(parentStepId);
        }
    }
}