package org.simantics.graph.representation;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

public class TransferableGraphUtils {

	public static Collection<Identity> getRoots(TransferableGraph1 tg) {
		
		ArrayList<Identity> result = new ArrayList<Identity>();
		for(Identity id : tg.identities) {
			if(id.definition instanceof Root) result.add(id);
		}
		return result;
		
	}
	
	public static Identity findRootWithName(TransferableGraph1 tg, String name) {
		
		for(Identity id : tg.identities) {
			if(id.definition instanceof Root) {
				Root ext = (Root)id.definition;
				if(ext.name.equals(name)) return id;
			}
		}
		return null;
		
	}

	public static Identity findExternalWithName(TransferableGraph1 tg, String name) {
		
		for(Identity id : tg.identities) {
			if(id.definition instanceof External) {
				External ext = (External)id.definition;
				if(ext.name.equals(name)) return id;
			}
		}
		return null;
		
	}

	public static Identity findExternalWithNameAndParent(TransferableGraph1 tg, int parent, String name) {
		
		for(Identity id : tg.identities) {
			if(id.definition instanceof External) {
				External ext = (External)id.definition;
				if(ext.name.equals(name) && ext.parent == parent) return id;
			}
		}
		return null;
		
	}
	
	public static Identity findExternal(TransferableGraph1 tg, String uri) {
		
		Identity identity = findExternalWithName(tg, "http:/");
		if(identity == null) identity = findExternalWithName(tg, "");
		if(identity == null) identity = findRootWithName(tg, "");
		if("http:/".equals(uri)) return identity;
		String[] tokens = uri.substring("http://".length()).split("/");
		for(String token : tokens) {
			identity = findExternalWithNameAndParent(tg, identity.resource, token);
		}
		return identity;
		
	}
	
	public static Collection<Identity> getChildren(TransferableGraph1 tg, Identity parent) {
		ArrayList<Identity> result = new ArrayList<Identity>();
		System.err.println("children for " + parent.resource);
		for(Identity id : tg.identities) {
			if(id.definition instanceof Internal) {
				Internal internal = (Internal)id.definition;
				System.err.println("internal with parent " + internal.parent);
				if(internal.parent == parent.resource) result.add(id);
			}
		}
		findExternal(tg, "http://www.simantics.org/Layer0-1.1/ConsistsOf");
		for(int i=0;i<tg.statements.length;i+=4) {
			if(tg.statements[i] == parent.resource)
				System.err.println("related to parent  " + tg.statements[i+3]);
		}
		return result;
	}
	
	public static int getPossibleObject(TransferableGraph1 tg, Identity subject, String predicate) {
		Identity p = findExternal(tg, predicate);
		if(p == null) return 0;
		int result = 0;
		for(int i=0;i<tg.statements.length;i+=4) {
			if(tg.statements[i] == subject.resource && tg.statements[i+1] == p.resource) {
				if(result != 0) return 0;
				result = tg.statements[i+3];
			}
		}
		return result;
	}

	public static Map<Identity, String> getNames(TransferableGraph1 tg, Collection<Identity> ids) {
		Map<Identity, String> result = new HashMap<Identity, String>();
		for(Identity id : ids) {
			if(id.definition instanceof Internal) {
				Internal internal = (Internal)id.definition;
				result.put(id, internal.name);
			}
		}
		return result;
	}

	public static String getName(TransferableGraph1 tg, Identity id) {
		return getName(id);
	}

	public static String getName(Identity id) {
		if(id.definition instanceof Internal) {
			Internal internal = (Internal)id.definition;
			return internal.name;
		} else if(id.definition instanceof External) {
			External external = (External)id.definition;
			return external.name;
		} else if(id.definition instanceof Root) {
			Root root = (Root)id.definition;
			return root.name;
		} else  {
			Optional optional = (Optional)id.definition;
			return optional.name;
		}
	}

	public static String getRootType(Identity id) {
		if(id.definition instanceof Root) {
			Root root = (Root)id.definition;
			return root.type;
		} else  {
			throw new IllegalArgumentException("Expected root, got " + id);
		}
	}

	public static Value findValue(TransferableGraph1 tg, int subject) {
		for(Value v : tg.values) {
			if(v.resource == subject) return v;
		}
		return null;
	}
	
	public static String getURI(TransferableGraph1 tg, int id) {
	    return getURI(tg.resourceCount, tg.identities, id);
	}
	
	public static String getURI(int resourceCount, Identity[] identities, int id) {
	    for(Identity identity : identities) {
	        if(identity.resource == id) {
	            IdentityDefinition definition = identity.definition;
	            if(definition instanceof External) {
	                External def = (External)definition;
	                if(def.parent == -1) return "http:/";
	                else return getURI(resourceCount, identities, def.parent) + "/" + def.name;
	            } else if(definition instanceof Root) {
	            	Root def = (Root)definition;
	            	return def.name;
	            } else if (definition instanceof Internal) {
	                Internal def = (Internal)definition;
	                System.err.println("External URI error: parent was internal '" + def.name + "'");
	                return "";
	            } else {
	                return "";
	            }
	        }
	    }	    
	    return "<internal reference " + id + ">:";
	}
	
}