Flow.java

package azkaban.flow;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import azkaban.project.ProjectManager;
import azkaban.project.ResourceLoader;
import azkaban.utils.Props;

public class Flow {
    public enum State {
        READY, RUNNING, RUNNING_WITH_FAILURE, FAILED, SUCCEEDED
    }
    private final String id;
    private ArrayList<Node> startNodes;
    private ArrayList<Node> endNodes;
    
    private HashMap<String, Node> nodes = new HashMap<String, Node>();

    private HashMap<String, Edge> edges = new HashMap<String, Edge>();
    private HashMap<String, Set<Edge>> outEdges = new HashMap<String, Set<Edge>>();
    private HashMap<String, Set<Edge>> inEdges = new HashMap<String, Set<Edge>>();
    private HashMap<String, FlowProps> flowProps = new HashMap<String, FlowProps>(); 

    private ArrayList<String> errors;

    private boolean isLayedOut = false;
    
    public Flow(String id) {
        this.id = id;
    }
    
    public void initialize() {
        if (startNodes == null) {
            startNodes = new ArrayList<Node>();
            endNodes = new ArrayList<Node>();
            for (Node node : nodes.values()) {
                // If it doesn't have any incoming edges, its a start node
                if (!inEdges.containsKey(node.getId())) {
                    startNodes.add(node);
                }

                // If it doesn't contain any outgoing edges, its an end node.
                if (!outEdges.containsKey(node.getId())) {
                    endNodes.add(node);
                }
            }
            
            for (Node node: startNodes) {
                node.setLevel(0);
                recursiveSetLevels(node);
            }
        }
    }

    private void recursiveSetLevels(Node node) {
        Set<Edge> edges = outEdges.get(node.getId());
        if (edges != null) {
            for (Edge edge : edges) {
                Node nextNode = nodes.get(edge.getTargetId());
                edge.setSource(node);
                edge.setTarget(nextNode);
                
                // We pick whichever is higher to get the max distance from root.
                int level = Math.max(node.getLevel() + 1, nextNode.getLevel());
                nextNode.setLevel(level);
                recursiveSetLevels(nextNode);
            }
        }
    }

    public List<Node> getStartNodes() {
        return startNodes;
    }
    
    public List<Node> getEndNodes() {
        return endNodes;
    }
    
    public void addAllNodes(Collection<Node> nodes) {
        for (Node node: nodes) {
            addNode(node);
        }
    }

    public void addNode(Node node) {
        nodes.put(node.getId(), node);
    }

    public void addAllFlowProperties(Collection<FlowProps> props) {
        for (FlowProps prop : props) {
            flowProps.put(prop.getSource(), prop);
        }
    }

    public String getId() {
        return id;
    }

    public void addError(String error) {
        if (errors == null) {
            errors = new ArrayList<String>();
        }

        errors.add(error);
    }
    
    public List<String> getErrors() {
        return errors;
    }
    
    public boolean hasErrors() {
        return errors != null && !errors.isEmpty();
    }
    
    public Collection<Node> getNodes() {
        return nodes.values();
    }
    
    public Collection<Edge> getEdges() {
        return edges.values();
    }
    
    public void addAllEdges(Collection<Edge> edges) {
        for (Edge edge: edges) {
            addEdge(edge);
        }
    }

    public void addEdge(Edge edge) {
        String source = edge.getSourceId();
        String target = edge.getTargetId();
    
        if (edge.hasError()) {
            addError("Error on " + edge.getId() + ". " + edge.getError());
        }

        Set<Edge> sourceSet = getEdgeSet(outEdges, source);
        sourceSet.add(edge);
        
        Set<Edge> targetSet = getEdgeSet(inEdges, target);
        targetSet.add(edge);
        
        edges.put(edge.getId(), edge);
    }
    
    private Set<Edge> getEdgeSet(HashMap<String, Set<Edge>> map, String id) {
        Set<Edge> edges = map.get(id);
        if (edges == null) {
            edges = new HashSet<Edge>();
            map.put(id, edges);
        }
        
        return edges;
    }

    public Map<String,Object> toObject() {
        HashMap<String, Object> flowObj = new HashMap<String, Object>();
        flowObj.put("type", "flow");
        flowObj.put("id", getId());
        flowObj.put("props", objectizeProperties());
        flowObj.put("nodes", objectizeNodes());
        flowObj.put("edges", objectizeEdges());
        if (errors != null) {
            flowObj.put("errors", errors);
        }
        
        return flowObj;
    }
    
    private List<Object> objectizeProperties() {
        ArrayList<Object> result = new ArrayList<Object>();
        for (FlowProps props: flowProps.values()) {
            Object objProps = props.toObject();
            result.add(objProps);
        }
        
        return result;
    }

    private List<Object> objectizeNodes() {
        ArrayList<Object> result = new ArrayList<Object>();
        for (Node node : getNodes()) {
            Object nodeObj = node.toObject();
            result.add(nodeObj);
        }
        
        return result;
    }
    
    private List<Object> objectizeEdges() {
        ArrayList<Object> result = new ArrayList<Object>();
        for (Edge edge: getEdges()) {
            Object edgeObj = edge.toObject();
            result.add(edgeObj);
        }
        
        return result;
    }
    
    @SuppressWarnings("unchecked")
    public static Flow flowFromObject(Object object) {
        Map<String, Object> flowObject = (Map<String,Object>)object;
        
        String id = (String)flowObject.get("id");
        Flow flow = new Flow(id);
        
        // Loading projects
        List<Object> propertiesList = (List<Object>)flowObject.get("props");
        Map<String, FlowProps> properties = loadPropertiesFromObject(propertiesList);
        flow.addAllFlowProperties(properties.values());
        
        // Loading nodes
        List<Object> nodeList = (List<Object>)flowObject.get("nodes");
        Map<String, Node> nodes = loadNodesFromObjects(nodeList);
        flow.addAllNodes(nodes.values());
        
        // Loading edges
        List<Object> edgeList = (List<Object>)flowObject.get("edges");
        List<Edge> edges = loadEdgeFromObjects(edgeList, nodes);
        flow.addAllEdges(edges);
        
        return flow;
    }

    private static Map<String, Node> loadNodesFromObjects(List<Object> nodeList) {
        Map<String, Node> nodeMap = new HashMap<String, Node>();
        
        for (Object obj: nodeList) {
            Node node = Node.fromObject(obj);
            nodeMap.put(node.getId(), node);
        }
        
        return nodeMap;
    }

    private static List<Edge> loadEdgeFromObjects(List<Object> edgeList, Map<String, Node> nodes) {
        List<Edge> edgeResult = new ArrayList<Edge>();
        
        for (Object obj: edgeList) {
            Edge edge = Edge.fromObject(obj);
            edgeResult.add(edge);
        }
        
        return edgeResult;
    }

    private static Map<String, FlowProps> loadPropertiesFromObject(List<Object> propertyObjectList) {
        Map<String, FlowProps> properties = new HashMap<String, FlowProps>();

        for (Object propObj: propertyObjectList) {
            FlowProps prop = FlowProps.fromObject(propObj);
            properties.put(prop.getSource(), prop);
        }
        
        return properties;
    }

    public boolean isLayedOut() {
        return isLayedOut;
    }

    public void setLayedOut(boolean layedOut) {
        this.isLayedOut = layedOut;
    }

    /*package*/ Map<String, Node> getNodeMap() {
        return nodes;
    }
    
    /*package*/ Map<String, Set<Edge>> getOutEdgeMap() {
        return outEdges;
    }
    
    /*package*/ Map<String, Set<Edge>> getInEdgeMap() {
        return inEdges;
    }
}