package com.mukesh.aphabaticalview;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;

public class Alphbatical extends Activity {
    private ListView countryList;
    ListView sideList;
    boolean isReady = false, mainTouched, sideTouched;

    AbsListView.OnScrollListener mainListener, sideListener, slaveListener;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.home);

        sideList = (ListView) findViewById(R.id.sideIndex);
        countryList = (ListView) findViewById(R.id.list);

        //TODO
        addGlobalLayoutListener();
    }

    private void addGlobalLayoutListener() {
        findViewById(R.id.main).getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                if (isReady)
                    return;
                isReady = true;
                setEverything();
            }
        });
    }

    private void setEverything() {
        setMainListView();
        setSideListView();
    }

    //TODO
    private void stopScroll(AbsListView view) {
        try {
            Field field = android.widget.AbsListView.class.getDeclaredField("mFlingRunnable");
            field.setAccessible(true);
            Object flingRunnable = field.get(view);
            if (flingRunnable != null) {
                Method method = Class.forName("android.widget.AbsListView$FlingRunnable").getDeclaredMethod("endFling");
                method.setAccessible(true);
                method.invoke(flingRunnable);
            }
        } catch (Exception ignored) {
        }
    }

    private void setMainListView() {
        // TODO ADAPTER
        View v = new View(getApplicationContext());
        int height = countryList.getHeight();
        v.setLayoutParams(new AbsListView.LayoutParams(10, height));
        countryList.addFooterView(v, null, false);
        AllDataAdapter adapter = new AllDataAdapter(getApplicationContext(), R.layout.home_list, Whatever.getData());
        countryList.setAdapter(adapter);

        // TODO SCROLL LISTENER

        mainListener = new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView absListView, int i) {
                switch (i) {
                    case SCROLL_STATE_TOUCH_SCROLL:
                        mainTouched = true;
                        break;
                    case SCROLL_STATE_IDLE:
                        mainTouched = false;
                        sideList.setOnScrollListener(sideListener);
                        break;
                }
            }

            @Override
            public void onScroll(AbsListView absListView, int first, int visible, int all) {
                if (first == all - 1) {
                    countryList.setSelection(first - 1);
                    stopScroll(countryList);
                    return;
                }

                if (mainTouched) {
                    String character = ((Data) (countryList.getAdapter().getItem(countryList.getFirstVisiblePosition()))).title.substring(0, 1);
                    for (int i = 0; i < sideList.getAdapter().getCount(); i++) {
                        if ((sideList.getAdapter().getItem(i)).equals(character)) {

                            smoothScrollToPositionFromTop(sideList, i);
                            break;
                        }
                    }
                }
            }
        };

        countryList.setOnScrollListener(mainListener);
    }

    private void setSideListView() {
        final String[] alphabaticalList = {"All", "A", "B", "C", "D", "E",
                "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q",
                "R", "S", "T", "U", "V", "W", "X", "Y", "Z"};
        ArrayAdapter<String> alphabaticalListAdapter = new ArrayAdapter<String>(
                this, android.R.layout.simple_list_item_1, Arrays.asList(alphabaticalList));

        View v = new View(getApplicationContext());
        int height = sideList.getHeight();
        v.setLayoutParams(new AbsListView.LayoutParams(10, height));
        sideList.addFooterView(v, null, false);

        sideList.setAdapter(alphabaticalListAdapter);

        sideListener = new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView absListView, int i) {
                switch (i) {
                    case SCROLL_STATE_TOUCH_SCROLL:
                        sideTouched = true;
                        break;
                    case SCROLL_STATE_IDLE:
                        countryList.setOnScrollListener(mainListener);
                        sideTouched = false;
                        break;
                }
            }

            @Override
            public void onScroll(AbsListView absListView, int first, int visible, int all) {
                if (first == all - 1) {
                    sideList.setSelection(first - 1);
                    sideList.scrollBy(0, 0);
                    stopScroll(sideList);
                    return;
                }
                if (sideTouched) {
                    String character = ((String) absListView.getAdapter().getItem(first)).substring(0, 1);
                    for (int i = 0; i < countryList.getAdapter().getCount() - 1; i++) {
                        if (((Data) countryList.getAdapter().getItem(i)).title.substring(0, 1).equals(character)) {
                            smoothScrollToPositionFromTop(countryList, i);
                            break;
                        }
                    }
                }
            }
        };
        sideList.setOnScrollListener(sideListener);
    }

    public void smoothScrollToPositionFromTop(final AbsListView view, final int position) {
        View child = getChildAtPosition(view, position);

        if ((child != null) && ((child.getTop() == 0) || ((child.getTop() > 0) && !view.canScrollVertically(1)))) {
            return;
        }
        if (position < view.getFirstVisiblePosition()) {
            final int value = (position - view.getFirstVisiblePosition()) * view.getAdapter().getView(view.getFirstVisiblePosition(), null, view).getHeight();
            view.smoothScrollToPosition(value);
        }
//        else {

            view.setOnScrollListener(new AbsListView.OnScrollListener() {
                @Override
                public void onScrollStateChanged(final AbsListView view, final int scrollState) {
                    if (scrollState == SCROLL_STATE_IDLE) {
                        view.setOnScrollListener(null);

                        new Handler().post(new Runnable() {
                            @Override
                            public void run() {
                                view.setSelection(position);
                            }
                        });
                    }
                }

                @Override
                public void onScroll(final AbsListView view, final int firstVisibleItem, final int visibleItemCount,final int totalItemCount) {}
            });

            new Handler().post(new Runnable() {
                @Override
                public void run() {
                    view.smoothScrollToPositionFromTop(position, 0);
                }
            });
//        }
    }

    public static View getChildAtPosition(final AdapterView view, final int position) {
        final int index = position - view.getFirstVisiblePosition();
        if ((index >= 0) && (index < view.getChildCount())) {
            return view.getChildAt(index);
        } else {
            return null;
        }
    }
}