package com.todoroo.andlib.service;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;

public class TestDependencyInjector implements AbstractDependencyInjector {

    /**
     * Dependencies this class knows how to handle
     */
    private final HashMap<String, Object> injectables = new HashMap<String, Object>();
    
    private String name;
    
    public TestDependencyInjector(String name) {
        this.name = name;
    }

    public void addInjectable(String field, Object injection) {
        injectables.put(field, injection);
    }
    
    public Object getInjection(Object object, Field field) {
        if(injectables.containsKey(field.getName())) {
            return injectables.get(field.getName());
        }
        
        return null;
    }
    
    // --- static stuff
    
    /**
     * Install TestDependencyInjector above other injectors
     */
    public synchronized static TestDependencyInjector initialize(String name) {
        ArrayList<AbstractDependencyInjector> list = 
            new ArrayList<AbstractDependencyInjector>(Arrays.asList(DependencyInjectionService.getInstance().getInjectors()));
        for(Iterator<AbstractDependencyInjector> i = list.iterator(); i.hasNext(); ) {
            AbstractDependencyInjector injector = i.next();
            
            // if another one of these injectors already exists in the
            // stack, remove it
            if(injector instanceof TestDependencyInjector) {
                if(((TestDependencyInjector)injector).name.equals(name))
                    i.remove();
            }
        }
            
        TestDependencyInjector instance = new TestDependencyInjector(name);
        list.add(0, instance);
        DependencyInjectionService.getInstance().setInjectors(list.toArray(new AbstractDependencyInjector[list.size()]));
        return instance;
    }

}