package eu.dnetlib.manager.wf.workflows.graph;

import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Service;

import com.google.common.collect.Sets;

import eu.dnetlib.errors.WorkflowManagerException;
import eu.dnetlib.manager.wf.model.GraphArc;
import eu.dnetlib.manager.wf.model.GraphParameter;
import eu.dnetlib.manager.wf.model.GraphParameterValue;
import eu.dnetlib.manager.wf.workflows.util.NodeHelper;

@Service
public class GraphLoader {

	private static final Log log = LogFactory.getLog(GraphLoader.class);

	private final String regExRef = "\\$\\{(\\w*)\\}";

	final Pattern pattern = Pattern.compile(regExRef, Pattern.MULTILINE);

	@Autowired
	private NodeHelper nodeHelper;

	@Autowired
	private Environment env;

	public Graph loadGraph(final List<eu.dnetlib.manager.wf.model.GraphNode> workflowGraph, final Map<String, String> globalParams)
		throws WorkflowManagerException {
		final Graph graph = new Graph();

		for (final eu.dnetlib.manager.wf.model.GraphNode node : workflowGraph) {
			final String nodeName = node.getName();
			final String nodeType = node.getType();
			final boolean isStart = node.isStart();
			final boolean isJoin = node.isJoin();

			final Map<String, GraphNodeParameter> params = calculateParamsForNode(node, globalParams);

			if (isStart) {
				graph.addNode(GraphNode.newStartNode(nodeName, nodeType, params));
			} else if (isJoin) {
				graph.addNode(GraphNode.newJoinNode(nodeName, nodeType, params));
			} else {
				graph.addNode(GraphNode.newNode(nodeName, nodeType, params));
			}

			if (graph.getArcs() != null) {
				for (final GraphArc a : node.getArcs()) {
					final String arcName = a.getName();
					final String to = a.getTo();
					graph.addArc(new Arc(StringUtils.isNotBlank(arcName) ? arcName : Arc.DEFAULT_ARC, nodeName, to));
				}
			}

			graph.addNode(GraphNode.newSuccessNode());
		}

		checkValidity(graph);

		return graph;
	}

	public Map<String, GraphNodeParameter> calculateParamsForNode(final eu.dnetlib.manager.wf.model.GraphNode node, final Map<String, String> globalParams) {

		final Map<String, GraphNodeParameter> params = new HashMap<>();

		if (node.getParams() != null) {
			for (final GraphParameter p : node.getParams()) {

				final String pName = p.getName();

				final GraphNodeParameter pValue = calculateSimpleValue(p, globalParams);

				if (pValue != null) {
					params.put(pName, pValue);
				} else if (p.getMap() != null) {

					final Map<String, GraphNodeParameter> map = p.getMap()
						.entrySet()
						.stream()
						.collect(Collectors.toMap(e -> e.getKey(), e -> {
							final GraphNodeParameter gnp = calculateSimpleValue(e.getValue(), globalParams);
							if (gnp == null) {
								final String msg = String.format("missing value for param: \"%s\"", e.getKey());
								log.debug(msg);
								return GraphNodeParameter.newNullParam();
							}
							return gnp;
						}));
					params.put(pName, GraphNodeParameter.newMapParam(map));
				} else if (p.getValues() != null) {
					final List<GraphNodeParameter> list = p.getValues()
						.stream()
						.map(e -> calculateSimpleValue(e, globalParams))
						.collect(Collectors.toList());
					params.put(pName, GraphNodeParameter.newListParam(list));
				}
			}
		}

		return params;
	}

	private GraphNodeParameter calculateSimpleValue(final GraphParameterValue graphValue, final Map<String, String> globalParams) {
		String value = graphValue.getValue();
		final String ref = graphValue.getRef();
		final String prop = graphValue.getProperty();
		final String envRef = graphValue.getEnv();

		if (StringUtils.isNotBlank(ref) && StringUtils.isNotBlank(globalParams.get(ref))) {
			return GraphNodeParameter.newSimpleParam(globalParams.get(ref));
		} else if (StringUtils.isNotBlank(envRef)) {
			return GraphNodeParameter.newEnvParam(envRef);
		} else if (StringUtils.isNotBlank(value)) {
			final Matcher matcher = pattern.matcher(value);
			while (matcher.find()) {
				final String rName = matcher.group(1);
				final String rValue = globalParams.get(rName);
				if (StringUtils.isBlank(rValue)) { return null; }
				value = value.replaceAll(Pattern.quote(matcher.group(0)), rValue);
				System.out.println("NEW VALUE " + value);
			}
			return GraphNodeParameter.newSimpleParam(value);
		} else if (StringUtils.isNotBlank(prop)) {
			return GraphNodeParameter.newSimpleParam(env.getProperty(prop));
		} else {
			return null;
		}

	}

	private void checkValidity(final Graph graph) throws WorkflowManagerException {

		final Set<String> nodesFromArcs = new HashSet<>();

		boolean foundSuccess = false;
		boolean foundStart = false;

		for (final Arc arc : graph.getArcs()) {
			if (StringUtils.isBlank(arc.getFrom()) || StringUtils.isBlank(arc.getFrom())) {
				throw new WorkflowManagerException("Invalid arc: missing from e/o to");
			}
			if (StringUtils.equals(arc.getTo(), GraphNode.SUCCESS_NODE)) {
				foundSuccess = true;
			}
			nodesFromArcs.add(arc.getFrom());
			nodesFromArcs.add(arc.getTo());
		}

		if (!foundSuccess) { throw new WorkflowManagerException("Arc to success not found"); }

		final Set<String> diff = Sets.symmetricDifference(graph.nodeNames(), nodesFromArcs);
		if (!diff.isEmpty()) { throw new WorkflowManagerException("Missing or invalid nodes in arcs: " + diff); }

		for (final GraphNode n : graph.nodes()) {
			if (StringUtils.isBlank(n.getName())) { throw new WorkflowManagerException("Invalid node: missing name"); }
			if (n.isStart()) {
				foundStart = true;
			}
			if (!this.nodeHelper.isValidType(n.getType())) { throw new WorkflowManagerException("Invalid node type: " + n.getType()); }
		}
		if (!foundStart) { throw new WorkflowManagerException("Start node not found"); }
	}

}