package com.atlassian.pageobjects.binder;
   
   import com.atlassian.annotations.Internal;
   import com.atlassian.pageobjects.DelayedBinder;
   import com.atlassian.pageobjects.Page;
   import com.atlassian.pageobjects.PageBinder;
   import com.atlassian.pageobjects.ProductInstance;
   import com.atlassian.pageobjects.Tester;
   import com.atlassian.pageobjects.browser.Browser;
  import com.atlassian.pageobjects.browser.IgnoreBrowser;
  import com.atlassian.pageobjects.browser.RequireBrowser;
  import com.atlassian.pageobjects.inject.AbstractInjectionConfiguration;
  import com.atlassian.pageobjects.inject.ConfigurableInjectionContext;
  import com.atlassian.pageobjects.inject.InjectionConfiguration;
  import com.atlassian.pageobjects.inject.InjectionContext;
  import com.atlassian.pageobjects.util.BrowserUtil;
  import com.google.common.collect.ImmutableMap;
  import com.google.common.collect.Lists;
  import com.google.inject.AbstractModule;
  import com.google.inject.Binder;
  import com.google.inject.Binding;
  import com.google.inject.ConfigurationException;
  import com.google.inject.Guice;
  import com.google.inject.Injector;
  import com.google.inject.Key;
  import com.google.inject.Module;
  import com.google.inject.ProvisionException;
  import com.google.inject.util.Modules;
  import org.apache.commons.lang.ClassUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.annotation.Nonnull;
  import javax.annotation.concurrent.NotThreadSafe;
  import javax.inject.Inject;
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Constructor;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  
  import static com.google.common.base.Preconditions.checkArgument;
  import static com.google.common.base.Preconditions.checkNotNull;
  import static java.util.Arrays.asList;
  import static java.util.Collections.unmodifiableList;
  
  /**
   * Page navigator that builds page objects from classes, then injects them with dependencies and calls lifecycle methods.
   * <p/>
   * <p>The construction process is as follows:
   * <ol>
   * <li>Determine the actual class by checking for an override</li>
   * <li>Instantiate the class using a constructor that matches the passed arguments</li>
   * <li>Changes the tester to the corrent URL (if {@link #navigateToAndBind(Class, Object...)})</li>
   * <li>Inject all fields annotated with {@link Inject}, including private</li>
   * <li>Execute the supplied {@link PostInjectionProcessor}</li>
   * <li>Call all methods annotated with {@link WaitUntil}</li>
   * <li>Call all methods annotated with {@link ValidateState}</li>
   * <li>Call all methods annotated with {@link Init}</li>
   * </ol>
   * <p/>
   * <p>When going to a page via the {@link #navigateToAndBind(Class, Object...)} method, the page's URL is retrieved and navigated to
   * via {@link Tester#gotoUrl(String)} after construction and initializing but before {@link WaitUntil} methods are called.
   *
   * <p/>
   * This class also implements a mutable variant of {@link com.atlassian.pageobjects.inject.ConfigurableInjectionContext},
   * where injection configuration changes are applied in-place, by creating a new Guice injector.
   */
  @NotThreadSafe
  @Internal
  public final class InjectPageBinder implements PageBinder, ConfigurableInjectionContext
  {
      private final Tester tester;
      private final ProductInstance productInstance;
      private static final Logger log = LoggerFactory.getLogger(InjectPageBinder.class);
  
      private final Map<Class<?>, Class<?>> overrides = new HashMap<Class<?>, Class<?>>();
      private volatile Module module;
      private volatile Injector injector;
      private volatile List<Binding<PostInjectionProcessor>> postInjectionProcessors;
  
      public InjectPageBinder(ProductInstance productInstance, Tester tester, Module... modules)
      {
          checkNotNull(productInstance);
          checkNotNull(tester);
          checkNotNull(modules);
          this.tester = tester;
          this.productInstance = productInstance;
          this.module = Modules.override(modules).with(new ThisModule());
          this.injector = Guice.createInjector(module);
          initPostInjectionProcessors();
      }
  
      private void initPostInjectionProcessors()
      {
         List<Binding<PostInjectionProcessor>> procs = Lists.newArrayList();
         for (Binding binding : collectBindings().values())
         {
             if (PostInjectionProcessor.class.isAssignableFrom(binding.getKey().getTypeLiteral().getRawType()))
             {
                 procs.add(binding);
             }
         }
         postInjectionProcessors = unmodifiableList(procs);
     }
 
     private Map<Key<?>, Binding<?>> collectBindings()
     {
         ImmutableMap.Builder<Key<?>, Binding<?>> result = ImmutableMap.builder();
         Injector current = this.injector;
         while (current != null)
         {
             result.putAll(injector.getAllBindings());
             current = current.getParent();
         }
         return result.build();
     }
 
 
     /**
      * Injector used by this binder.
      *
      * @return injector used by this binder.
      * @deprecated take advantage of {@link InjectionContext} API instead. Scheduled for removal in 3.0
      */
     public Injector injector()
     {
         return injector;
     }
 
     public <P extends Page> P navigateToAndBind(Class<P> pageClass, Object... args)
     {
         checkNotNull(pageClass);
         DelayedBinder<P> binder = delayedBind(pageClass, args);
         P p = binder.get();
         visitUrl(p);
         return binder.bind();
     }
 
     public <P> P bind(Class<P> pageClass, Object... args)
     {
         checkNotNull(pageClass);
         return delayedBind(pageClass, args).bind();
     }
 
     public <P> DelayedBinder<P> delayedBind(Class<P> pageClass, Object... args)
     {
         return new InjectableDelayedBind<P>(asList(
                 new InstantiatePhase<P>(pageClass, args),
                 new InjectPhase<P>(),
                 new WaitUntilPhase<P>(),
                 new ValidateStatePhase<P>(),
                 new InitializePhase<P>()));
     }
 
     protected void visitUrl(Page p)
     {
         checkNotNull(p);
 
         tester.gotoUrl(normalisedBaseUrl() + normalisedPath(p));
     }
 
     public <P> void override(Class<P> oldClass, Class<? extends P> newClass)
     {
         checkNotNull(oldClass);
         checkNotNull(newClass);
         overrides.put(oldClass, newClass);
     }
 
     /**
      * Calls all methods with the given annotation, starting with methods found in the topmost superclass, then calling
      * more specific methods in subclasses. Note that this can mean that this will attempt to call the same method
      * multiple times - once per override in the hierarchy. Will call the methods even if they're private. Skips methods
      * if they are also annotated with {@link com.atlassian.pageobjects.browser.IgnoreBrowser} (or {@link com.atlassian.pageobjects.browser.RequireBrowser}) if the current {@link Browser}
      * matches (does not match) any of the browsers listed in that annotation.
      * @param instance the page object to check for the annotation
      * @param annotation the annotation to find
      * @throws InvocationTargetException if any matching method throws any exception.
      */
     private void callLifecycleMethod(Object instance, Class<? extends Annotation> annotation) throws InvocationTargetException
     {
         Class clazz = instance.getClass();
         List<Class> classes = ClassUtils.getAllSuperclasses(clazz);
         Collections.reverse(classes);
         classes.add(clazz);
 
         for (Class cl : classes)
         {
             for (Method method : cl.getDeclaredMethods())
             {
                 if (method.getAnnotation(annotation) != null)
                 {
                     Browser currentBrowser = BrowserUtil.getCurrentBrowser();
                     if (isIgnoredBrowser(method, method.getAnnotation(IgnoreBrowser.class), currentBrowser) ||
                             !isRequiredBrowser(method, method.getAnnotation(RequireBrowser.class), currentBrowser))
                     {
                         continue;
                     }
 
                     try
                     {
                         if (!method.isAccessible())
                         {
                             method.setAccessible(true);
                         }
 
                         method.invoke(instance);
                     }
                     catch (IllegalAccessException e)
                     {
                         throw new RuntimeException(e);
                     }
                 }
             }
         }
     }
 
     private boolean isRequiredBrowser(Method method, RequireBrowser requireBrowser, Browser currentBrowser)
     {
         if (requireBrowser == null)
             return true;
 
         for (Browser browser : requireBrowser.value())
         {
             if (browser != currentBrowser)
             {
                 log.info(method.getName() + " ignored, since it requires <" + browser + ">");
                 return false;
             }
         }
         return true;
     }
 
     private boolean isIgnoredBrowser(Method method, IgnoreBrowser ignoreBrowser, Browser currentBrowser)
     {
         if (ignoreBrowser == null)
             return false;
 
         for (Browser browser : ignoreBrowser.value())
         {
             if (browser == currentBrowser || browser == Browser.ALL)
             {
                 log.info(method.getName() + " ignored, reason: " + ignoreBrowser.reason());
                 return true;
             }
         }
         return false;
     }
 
     // -----------------------------------------------------------------------------------------------  InjectionContext
 
 
     @SuppressWarnings("ConstantConditions")
     @Override
     @Nonnull
     public <T> T getInstance(@Nonnull Class<T> type)
     {
         checkArgument(type != null, "type was null");
         try
         {
             return injector.getInstance(type);
         }
         catch (ProvisionException e)
         {
             throw new IllegalArgumentException(e);
         }
         catch (ConfigurationException e)
         {
             throw new IllegalArgumentException(e);
         }
     }
 
     @Override
     public void injectStatic(@Nonnull final Class<?> targetClass)
     {
         injector.createChildInjector(new AbstractModule()
         {
             @Override
             protected void configure()
             {
                 requestStaticInjection(targetClass);
             }
         });
     }
 
     @Override
     public void injectMembers(@Nonnull Object targetInstance)
     {
         injector.injectMembers(targetInstance);
     }
 
     @Override
     @Nonnull
     public InjectionConfiguration configure()
     {
         return new InjectConfiguration();
     }
 
     void reconfigure(Module module)
     {
         this.module = Modules.override(this.module).with(module);
         this.injector = Guice.createInjector(this.module);
         initPostInjectionProcessors();
     }
 
     /**
      * @return the base URL for the application with no trailing slash
      */
     private String normalisedBaseUrl()
     {
         final String baseUrl = productInstance.getBaseUrl();
         if (baseUrl.endsWith("/"))
         {
             return baseUrl.substring(0, baseUrl.length() - 1);
         }
 
         return baseUrl;
     }
 
     /**
      * @param p a Page
      * @return the path segment for a page with a leading slash
      */
     private String normalisedPath(Page p)
     {
         final String path = p.getUrl();
         if (!path.startsWith("/"))
         {
             return "/" + path;
         }
 
         return path;
     }
 
     // ---------------------------------------------------------------------------------------------------------- Phases
 
     private static interface Phase<T>
     {
         T execute(T pageObject);
     }
 
     private class InstantiatePhase<T> implements Phase<T>
     {
         private Class<T> pageClass;
         private final Object[] args;
 
         public InstantiatePhase(Class<T> pageClass, Object[] args)
         {
             this.pageClass = pageClass;
             this.args = args;
         }
 
         @SuppressWarnings("unchecked")
         public T execute(T t)
         {
             T instance;
             Class<T> actualClass = pageClass;
             if (overrides.containsKey(pageClass))
             {
                 actualClass = (Class<T>) overrides.get(pageClass);
             }
 
             try
             {
                 instance = instantiate(actualClass, args);
             }
             catch (InstantiationException e)
             {
                 throw new IllegalArgumentException(e);
             }
             catch (IllegalAccessException e)
             {
                 throw new IllegalArgumentException(e);
             }
             catch (InvocationTargetException e)
             {
                 throw new IllegalArgumentException(e.getCause());
             }
             return instance;
         }
 
         @SuppressWarnings("unchecked")
         private T instantiate(Class<T> clazz, Object[] args)
                 throws InstantiationException, IllegalAccessException, InvocationTargetException
         {
             if (args != null && args.length > 0)
             {
                 for (Constructor c : clazz.getConstructors())
                 {
                     Class[] paramTypes = c.getParameterTypes();
                     if (args.length == paramTypes.length)
                     {
                         boolean match = true;
                         for (int x = 0; x < args.length; x++)
                         {
                             if (args[x] != null && !ClassUtils.isAssignable(args[x].getClass(), paramTypes[x], true /*autoboxing*/))
                             {
                                 match = false;
                                 break;
                             }
                         }
                         if (match)
                         {
                             return (T) c.newInstance(args);
                         }
                     }
                 }
             }
             else
             {
                 try
                 {
                     return clazz.newInstance();
                 }
                 catch (InstantiationException ex)
                 {
                     throw new IllegalArgumentException("Error invoking default constructor", ex);
                 }
             }
             throw new IllegalArgumentException("Cannot find constructor on " + clazz + " to match args: " + asList(args));
         }
     }
 
     private class InjectPhase<T> implements Phase<T>
     {
         public T execute(T t)
         {
             autowireInjectables(t);
             T pageObject = t;
             for (Binding<PostInjectionProcessor> binding : postInjectionProcessors)
             {
                 pageObject = binding.getProvider().get().process(pageObject);
             }
             return pageObject;
         }
 
         private void autowireInjectables(final Object instance)
         {
             try
             {
                 injector.injectMembers(instance);
             }
             catch (ConfigurationException ex)
             {
                 throw new IllegalArgumentException(ex);
             }
         }
     }
 
     private class WaitUntilPhase<T> implements Phase<T>
     {
         public T execute(T pageObject)
         {
             try
             {
                 callLifecycleMethod(pageObject, WaitUntil.class);
             }
             catch (InvocationTargetException e)
             {
                 Throwable targetException = e.getTargetException();
                 if (targetException instanceof PageBindingWaitException)
                 {
                     throw (PageBindingWaitException) targetException;
                 }
                 else
                 {
                     throw new PageBindingWaitException(pageObject, targetException);
                 }
             }
             return pageObject;
         }
     }
 
     private class ValidateStatePhase<T> implements Phase<T>
     {
         public T execute(T pageObject)
         {
             try
             {
                 callLifecycleMethod(pageObject, ValidateState.class);
             }
             catch (InvocationTargetException e)
             {
                 Throwable targetException = e.getTargetException();
                 if (targetException instanceof InvalidPageStateException)
                 {
                     throw (InvalidPageStateException) targetException;
                 }
                 else
                 {
                     throw new InvalidPageStateException(pageObject, targetException);
                 }
             }
             return pageObject;
         }
     }
 
     private class InitializePhase<T> implements Phase<T>
     {
         public T execute(T pageObject)
         {
             try
             {
                 callLifecycleMethod(pageObject, Init.class);
             }
             catch (InvocationTargetException e)
             {
                 throw new PageBindingException(pageObject, e.getTargetException());
             }
             return pageObject;
         }
     }
 
     private class InjectableDelayedBind<T> implements DelayedBinder<T>
     {
         private final LinkedList<Phase<T>> phases;
         private T pageObject = null;
 
         public InjectableDelayedBind(List<Phase<T>> phases)
         {
             this.phases = new LinkedList<Phase<T>>(phases);
         }
 
         public boolean canBind()
         {
             try
             {
                 advanceTo(InitializePhase.class);
                 return true;
             }
             catch (PageBindingException ex)
             {
                 return false;
             }
         }
 
         private void advanceTo(Class<? extends Phase> phaseClass)
         {
             boolean found = false;
             for (Phase<T> phase : phases)
             {
                 if (phase.getClass() == phaseClass)
                 {
                     found = true;
                 }
             }
 
             if (found)
             {
                 while (!phases.isEmpty())
                 {
                     pageObject = phases.getFirst().execute(pageObject);
                     if (phases.removeFirst().getClass() == phaseClass)
                     {
                         break;
                     }
                 }
             }
             else
             {
                 log.debug("Already advanced to state: " + phaseClass.getName());
             }
         }
 
 
         public T get()
         {
             advanceTo(InstantiatePhase.class);
             return pageObject;
         }
 
         public DelayedBinder<T> inject()
         {
             advanceTo(InjectPhase.class);
             return this;
         }
 
         public DelayedBinder<T> waitUntil()
         {
             advanceTo(WaitUntilPhase.class);
             return this;
         }
 
         public DelayedBinder<T> validateState()
         {
             advanceTo(ValidateStatePhase.class);
             return this;
         }
 
         public T bind()
         {
             advanceTo(InitializePhase.class);
             return pageObject;
         }
     }
 
     private final class InjectConfiguration extends AbstractInjectionConfiguration
     {
 
         @Override
         @Nonnull
         public ConfigurableInjectionContext finish()
         {
             reconfigure(getModule());
             return InjectPageBinder.this;
         }
 
         Module getModule()
         {
             return new Module()
             {
                 @Override
                 @SuppressWarnings("unchecked")
                 public void configure(Binder binder)
                 {
                     for (InterfaceToImpl intToImpl : interfacesToImpls)
                     {
                         binder.bind((Class)intToImpl.interfaceType).to(intToImpl.implementation);
                     }
                     for (InterfaceToInstance intToInstance : interfacesToInstances)
                     {
                         binder.bind((Class)intToInstance.interfaceType).toInstance(intToInstance.instance);
                     }
                 }
             };
         }
     }
 
     private final class ThisModule extends AbstractModule
     {
 
         @Override
         protected void configure()
         {
             bind(PageBinder.class).toInstance(InjectPageBinder.this);
         }
     }
 }