Registry.java

package ru.ltst.u2020mvp.base.mvp;

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.IdRes;

import java.util.Arrays;
import java.util.HashMap;

import butterknife.ButterKnife;
import ru.ltst.u2020mvp.ui.ActivityHierarchyServer;
import ru.ltst.u2020mvp.util.Strings;
import timber.log.Timber;

import static ru.ltst.u2020mvp.util.Strings.COLON;
import static ru.ltst.u2020mvp.util.Strings.DOT;

public class Registry {
    private static final HashMap<String, Entry> registers = new HashMap<>();
    public static final ActivityHierarchyServer.Empty SERVER = new ActivityHierarchyServer.Empty() {
        @Override
        public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
            final String key = getKey(activity);
            final Entry entry = registers.get(key);
            Timber.d("%s onActivityCreated", key);
            if (entry != null && savedInstanceState != null) {
                entry.presenter.onRestore(savedInstanceState);
            }
        }

        @Override
        @SuppressWarnings("unchecked")
        public void onActivityStarted(Activity activity) {
            final String key = getKey(activity);
            final Entry entry = registers.get(key);
            Timber.d("%s onActivityStarted", key);
            if (entry != null) {
                final BaseView view = ButterKnife.findById(activity, entry.viewId);
                entry.presenter.takeView(view);
            }
        }

        @Override
        @SuppressWarnings("unchecked")
        public void onActivityStopped(Activity activity) {
            final String key = getKey(activity);
            final Entry entry = registers.get(key);
            Timber.d("%s onActivityStopped", key);
            if (entry != null) {
                final BaseView view = ButterKnife.findById(activity, entry.viewId);
                entry.presenter.dropView(view);
            }
        }

        @Override
        public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
            final String key = getKey(activity);
            final Entry entry = registers.get(key);
            Timber.d("%s onActivitySaveInstanceState", key);
            if (entry != null) {
                entry.presenter.onSave(outState);
            }
        }

        @Override
        public void onActivityDestroyed(Activity activity) {
            final String key = getKey(activity);
            Timber.d("%s onActivityDestroyed", key);
            registers.remove(key);
        }
    };

    public static <V extends BaseView> void add(Activity activity, @IdRes int viewId, BasePresenter<V> presenter) {
        registers.put(getKey(activity), new Entry<>(viewId, presenter));
    }

    private static String getKey(Activity activity) {
        StringBuilder builder = new StringBuilder();
        builder.append(activity.getClass().getName());
        if (activity instanceof BaseActivity) {
            final String uniqueKey = ((BaseActivity) activity).uniqueKey();
            if (!uniqueKey.isEmpty()) {
                builder.append(Strings.DOT).append(uniqueKey);
            }
        } else {
            final String action = activity.getIntent().getAction();
            if (action != null) {
                builder.append(DOT).append(action);
            }
            final Uri data = activity.getIntent().getData();
            if (data != null) {
                builder.append(DOT).append(data.toString());
            }
            final Bundle extras = activity.getIntent().getExtras();
            if (extras != null) {
                for (String key : extras.keySet()) {
                    Object value = extras.get(key);
                    if (value == null) continue;
                    String valueString;
                    if (value.getClass().isArray()) {
                        valueString = Arrays.toString((Object[]) value);
                    } else {
                        valueString = value.toString();
                    }

                    builder.append(DOT);
                    builder.append(key).append(COLON);
                    builder.append(valueString);
                }
            }
        }
        return builder.toString();
    }

    private static class Entry<V extends BaseView> {
        @IdRes
        public final int viewId;
        public final BasePresenter<V> presenter;

        public Entry(int viewId, BasePresenter<V> presenter) {
            this.viewId = viewId;
            this.presenter = presenter;
        }
    }
}