/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.inputmethod.latin;

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Looper;
import android.os.MessageQueue;
import android.preference.PreferenceManager;
import android.test.ServiceTestCase;
import android.text.InputType;
import android.text.SpannableStringBuilder;
import android.text.style.CharacterStyle;
import android.text.style.SuggestionSpan;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.inputmethod.EditorInfo;
import android.view.inputmethod.InputConnection;
import android.widget.FrameLayout;
import android.widget.TextView;

import com.android.inputmethod.keyboard.Key;
import com.android.inputmethod.keyboard.Keyboard;
import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;

import java.util.Locale;

public class InputTestsBase extends ServiceTestCase<LatinIME> {

    private static final String PREF_DEBUG_MODE = "debug_mode";

    // The message that sets the underline is posted with a 100 ms delay
    protected static final int DELAY_TO_WAIT_FOR_UNDERLINE = 200;

    protected LatinIME mLatinIME;
    protected Keyboard mKeyboard;
    protected MyTextView mTextView;
    protected View mInputView;
    protected InputConnection mInputConnection;

    // A helper class to ease span tests
    public static class SpanGetter {
        final SpannableStringBuilder mInputText;
        final CharacterStyle mSpan;
        final int mStart;
        final int mEnd;
        // The supplied CharSequence should be an instance of SpannableStringBuilder,
        // and it should contain exactly zero or one span. Otherwise, an exception
        // is thrown.
        public SpanGetter(final CharSequence inputText,
                final Class<? extends CharacterStyle> spanType) {
            mInputText = (SpannableStringBuilder)inputText;
            final CharacterStyle[] spans =
                    mInputText.getSpans(0, mInputText.length(), spanType);
            if (0 == spans.length) {
                mSpan = null;
                mStart = -1;
                mEnd = -1;
            } else if (1 == spans.length) {
                mSpan = spans[0];
                mStart = mInputText.getSpanStart(mSpan);
                mEnd = mInputText.getSpanEnd(mSpan);
            } else {
                throw new RuntimeException("Expected one span, found " + spans.length);
            }
        }
        public boolean isAutoCorrectionIndicator() {
            return (mSpan instanceof SuggestionSpan) &&
                    0 != (SuggestionSpan.FLAG_AUTO_CORRECTION & ((SuggestionSpan)mSpan).getFlags());
        }
        public String[] getSuggestions() {
            return ((SuggestionSpan)mSpan).getSuggestions();
        }
    }

    // A helper class to increase control over the TextView
    public static class MyTextView extends TextView {
        public Locale mCurrentLocale;
        public MyTextView(final Context c) {
            super(c);
        }
        public void onAttachedToWindow() {
            super.onAttachedToWindow();
        }
        public Locale getTextServicesLocale() {
            // This method is necessary because TextView is asking this method for the language
            // to check the spell in. If we don't override this, the spell checker will run in
            // whatever language the keyboard is currently set on the test device, ignoring any
            // settings we do inside the tests.
            return mCurrentLocale;
        }
    }

    public InputTestsBase() {
        super(LatinIME.class);
    }

    // TODO: Isn't there a way to make this generic somehow? We can take a <T> and return a <T>
    // but we'd have to dispatch types on editor.put...() functions
    protected boolean setBooleanPreference(final String key, final boolean value,
            final boolean defaultValue) {
        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(mLatinIME);
        final boolean previousSetting = prefs.getBoolean(key, defaultValue);
        final SharedPreferences.Editor editor = prefs.edit();
        editor.putBoolean(key, value);
        editor.commit();
        return previousSetting;
    }

    // returns the previous setting value
    protected boolean setDebugMode(final boolean value) {
        return setBooleanPreference(PREF_DEBUG_MODE, value, false);
    }

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        mTextView = new MyTextView(getContext());
        final int inputType = InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_FLAG_AUTO_CORRECT
                | InputType.TYPE_TEXT_FLAG_MULTI_LINE;
        mTextView.setInputType(inputType);
        mTextView.setEnabled(true);
        setupService();
        mLatinIME = getService();
        final boolean previousDebugSetting = setDebugMode(true);
        mLatinIME.onCreate();
        setDebugMode(previousDebugSetting);
        final EditorInfo ei = new EditorInfo();
        final InputConnection ic = mTextView.onCreateInputConnection(ei);
        final LayoutInflater inflater =
                (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        final ViewGroup vg = new FrameLayout(getContext());
        mInputView = inflater.inflate(R.layout.input_view, vg);
        mLatinIME.onCreateInputMethodInterface().startInput(ic, ei);
        mLatinIME.setInputView(mInputView);
        mLatinIME.onBindInput();
        mLatinIME.onCreateInputView();
        mLatinIME.onStartInputView(ei, false);
        mInputConnection = ic;
        changeLanguage("en_US");
    }

    // We need to run the messages added to the handler from LatinIME. The only way to do
    // that is to call Looper#loop() on the right looper, so we're going to get the looper
    // object and call #loop() here. The messages in the handler actually run on the UI
    // thread of the keyboard by design of the handler, so we want to call it synchronously
    // on the same thread that the tests are running on to mimic the actual environment as
    // closely as possible.
    // Now, Looper#loop() never exits in normal operation unless the Looper#quit() method
    // is called, which has a lot of bad side effects. We can however just throw an exception
    // in the runnable which will unwind the stack and allow us to exit.
    private final class InterruptRunMessagesException extends RuntimeException {
        // Empty class
    }
    protected void runMessages() {
        mLatinIME.mHandler.post(new Runnable() {
                @Override
                public void run() {
                    throw new InterruptRunMessagesException();
                }
            });
        try {
            Looper.loop();
        } catch (InterruptRunMessagesException e) {
            // Resume normal operation
        }
    }

    // type(int) and type(String): helper methods to send a code point resp. a string to LatinIME.
    protected void type(final int codePoint) {
        // onPressKey and onReleaseKey are explicitly deactivated here, but they do happen in the
        // code (although multitouch/slide input and other factors make the sequencing complicated).
        // They are supposed to be entirely deconnected from the input logic from LatinIME point of
        // view and only delegates to the parts of the code that care. So we don't include them here
        // to keep these tests as pinpoint as possible and avoid bringing it too many dependencies,
        // but keep them in mind if something breaks. Commenting them out as is should work.
        //mLatinIME.onPressKey(codePoint);
        for (final Key key : mKeyboard.mKeys) {
            if (key.mCode == codePoint) {
                final int x = key.mX + key.mWidth / 2;
                final int y = key.mY + key.mHeight / 2;
                mLatinIME.onCodeInput(codePoint, x, y);
                return;
            }
        }
        mLatinIME.onCodeInput(codePoint, Constants.NOT_A_COORDINATE, Constants.NOT_A_COORDINATE);
        //mLatinIME.onReleaseKey(codePoint, false);
    }

    protected void type(final String stringToType) {
        for (int i = 0; i < stringToType.length(); i = stringToType.offsetByCodePoints(i, 1)) {
            type(stringToType.codePointAt(i));
        }
    }

    protected void waitForDictionaryToBeLoaded() {
        int remainingAttempts = 300;
        while (remainingAttempts > 0 && mLatinIME.mSuggest.isCurrentlyWaitingForMainDictionary()) {
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                // Don't do much
            } finally {
                --remainingAttempts;
            }
        }
        if (!mLatinIME.mSuggest.hasMainDictionary()) {
            throw new RuntimeException("Can't initialize the main dictionary");
        }
    }

    protected void changeLanguage(final String locale) {
        mTextView.mCurrentLocale = LocaleUtils.constructLocaleFromString(locale);
        SubtypeSwitcher.getInstance().forceLocale(mTextView.mCurrentLocale);
        mLatinIME.loadKeyboard();
        mKeyboard = mLatinIME.mKeyboardSwitcher.getKeyboard();
        waitForDictionaryToBeLoaded();
    }

    protected void pickSuggestionManually(final int index, final String suggestion) {
        mLatinIME.pickSuggestionManually(index, new SuggestedWordInfo(suggestion, 1,
                SuggestedWordInfo.KIND_CORRECTION, "main"));
    }

    // Helper to avoid writing the try{}catch block each time
    protected static void sleep(final int milliseconds) {
        try {
            Thread.sleep(milliseconds);
        } catch (InterruptedException e) {}
    }
}