package de.superx.bianalysis.metadata;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import org.apache.log4j.Logger;

import com.fasterxml.jackson.annotation.JsonIgnore;

import de.superx.bianalysis.FaultyMetadataException;
import de.superx.bianalysis.metadata.models.json.MetaDimension;
import de.superx.bianalysis.metadata.models.json.MetaDimensionAttribute;
import de.superx.bianalysis.metadata.models.json.MetaFact;
import de.superx.bianalysis.metadata.models.json.MetaMeasure;
import de.superx.bianalysis.metadata.models.json.MetaMeasureFilter;
import de.superx.bianalysis.metadata.models.json.MetaObject;

public class MetaImport extends MetaJson {

	public List<MetaFact> facts;

	private static Logger log = Logger.getLogger(MetaImport.class);

	@JsonIgnore
    private Map<String, MetaDimensionAttribute> keysForMeasureFilter = new HashMap<>();

	@JsonIgnore
	public List<MetaDimension> conformedDimensions;

	@JsonIgnore
	public void setConformedDimensions(List<MetaDimension> conformedDimensions){
	    this.conformedDimensions = conformedDimensions;
        if(this.conformedDimensions != null) {
			for (MetaDimension dim : this.conformedDimensions) {
			    for (MetaDimensionAttribute attr : dim.getAttributes()) {
			    	attr.setDimension(dim);
       	            keysForMeasureFilter.put(dim.getDimension()+"."+attr.getDimColumn(), attr);
			    }
			}
        }
	}

    @JsonIgnore
	@Override
    public void init() {
    	this.allMetaObj = new ArrayList<MetaObject>();
		for (MetaFact fact : this.facts) {
			allMetaObj.add(fact);
			for (MetaDimension dim : fact.getDimensions()) {
				allMetaObj.add(dim);
				if(dim.getRefTo() != null && !dim.getRefTo().isEmpty()) {
				    MetaDimension conformedDim = findByRef(dim);
			    	dim.setConformedDimension(conformedDim);
				}
				for (MetaDimensionAttribute attr : dim.getAttributes()) {
					allMetaObj.add(attr);
					if(attr.getRefTo() != null && !attr.getRefTo().isEmpty()) {
					    MetaDimension confDimension = dim.getConformedDimension();
					    if(confDimension == null) {
					       throw new FaultyMetadataException(
					             "The attribute with the id: '" + attr.getId() + "' " +
					             "references a conformed attribute '" +  attr.getRefTo() + "' " +
					             "but the dimension " + dim.getId() + " is missing a ref_to");
					    }
					    String dimTable = confDimension.getDimension();
					    MetaDimensionAttribute refAttribute = findByRefAttr(dimTable, attr); 
			    	    attr.setConformedDimensionAttribute(refAttribute);
					}
       	            keysForMeasureFilter.put(dim.getDimension()+"."+attr.getDimColumn(), attr);
				}
			}
			if(fact.getMeasures() != null) {
			   for (MetaMeasure measure : fact.getMeasures()) {
			   	allMetaObj.add(measure);
			   	MetaMeasureFilter filter = measure.getFilter();
			   	if(filter != null) {
			   	    if(filter.getDimensionRef() != null && !filter.getDimensionRef().isBlank()) {
			   	        MetaDimensionAttribute attr = keysForMeasureFilter.get(filter.getDimensionRef());
	                    if(attr == null) {
	                        throw new FaultyMetadataException("Could not resolve dimensionRef '" + filter.getDimensionRef() + 
	                                "' (" + file.getName() + " -> " + fact.getFacttable() + ")");
	                    }
			   	       	filter.setAttribute(attr);
			   	       	allMetaObj.add(filter);
			   	    } else if(filter.getFactColumnRef() != null && !filter.getFactColumnRef().isBlank()) {
			   	       	allMetaObj.add(filter);
			   	    }
			   	}
			   }
			}
		}
	}

	private MetaDimensionAttribute findByRefAttr(String dimensionTable, MetaDimensionAttribute attribute) {
	    String attributeColumn = attribute.getRefTo();
	    MetaDimensionAttribute confAttr = null;
	    for (MetaDimension confDim  : this.conformedDimensions) {
	        if(!confDim.getDimension().equals(dimensionTable)) {
	            continue;
	        }
	        for (MetaDimensionAttribute attr : confDim.getAttributes()) {
               if(attr.getDimColumn() != null && attr.getDimColumn().equals(attributeColumn)) {
                  confAttr = attr;
                  break;
               }
            }
        }
	    if(confAttr == null) {
            throw new FaultyMetadataException(
                    "Could not resolve attribute reference '" + attributeColumn + "' (" 
                    + file.getName() + " -> " 
                    + attribute.getDimension().getFact().getFacttable() + " -> "
                    + attribute.getDimension().getRefTo() + ")"
            );
	    }
        return confAttr;
    }


    @JsonIgnore
    private MetaDimension findByRef(MetaDimension dim) {
        String refTo = dim.getRefTo();
        MetaDimension resolvedRefTo = null;
        for (MetaDimension dimConf : this.conformedDimensions) {
            if (dimConf.getDimension() == null) {
                log.error("Missing dimension attribute for " + dimConf.getCaption());
                continue;
            }
            if (dimConf.getDimension().equals(refTo)) {
                resolvedRefTo = dimConf;
                break;
            }
        }
        if (resolvedRefTo == null) {
            throw new FaultyMetadataException("Could not resolve dimension reference '" + refTo + "' (" + file.getName() + " -> " + dim.getFact().getFacttable() + ")");
        }
        return resolvedRefTo;
    }

}