buildscript {
    repositories {
        google()
        jcenter()
        maven {url 'https://developer.huawei.com/repo/'}
    }
    dependencies {
        classpath "com.android.tools.build:gradle:4.1.1"
        classpath 'com.huawei.agconnect:agcp:1.4.2.300'
        // NOTE: Do not place your app dependencies here; they belong
        // in the individual module build.gradle files.
    }
}
allprojects {
    repositories {
        google()
        jcenter()
        maven {url 'https://developer.huawei.com/repo/'}
    }
}

dependencies {

    // Import the base SDK.
    implementation 'com.huawei.hms:ml-computer-voice-tts:2.1.0.300'
    // Import the bee voice package.
    implementation 'com.huawei.hms:ml-computer-voice-tts-model-bee:2.1.0.300'
    // Import the eagle voice package.
    implementation 'com.huawei.hms:ml-computer-voice-tts-model-eagle:2.1.0.300'
    // Import a PDF file analyzer.
    implementation 'com.itextpdf:itextg:5.5.10'
}

private void initTts() {
    // Set authentication information for your app to download the model package from the server of Huawei.
    MLApplication.getInstance().setApiKey(AGConnectServicesConfig.
            fromContext(getApplicationContext()).getString("client/api_key"));
    // Create a TTS engine by using MLTtsConfig.
    mlTtsConfigs = new MLTtsConfig()
            // Set the text converted from speech to English.
            .setLanguage(MLTtsConstants.TTS_EN_US)
            // Set the speaker with the English male voice (eagle).
            .setPerson(MLTtsConstants.TTS_SPEAKER_OFFLINE_EN_US_MALE_EAGLE)
            // Set the speech speed whose range is (0, 5.0]. 1.0 indicates a normal speed.
            .setSpeed(.8f)
            // Set the volume whose range is (0, 2). 1.0 indicates a normal volume.
            .setVolume(1.0f)
            // Set the TTS mode to on-device.
            .setSynthesizeMode(MLTtsConstants.TTS_OFFLINE_MODE);
    mlTtsEngine = new MLTtsEngine(mlTtsConfigs);
    // Update the configuration when the engine is running.
    mlTtsEngine.updateConfig(mlTtsConfigs);
    // Pass the TTS callback function to the TTS engine to perform TTS.
    mlTtsEngine.setTtsCallback(callback);
    // Create an on-device TTS model manager.
    manager = MLLocalModelManager.getInstance();
    isPlay = false;
}

MLTtsCallback callback = new MLTtsCallback() {
    @Override   
    public void onError(String taskId, MLTtsError err) {
        // Processing logic for TTS failure.
    }
    @Override
    public void onWarn(String taskId, MLTtsWarn warn) {
        // Alarm handling without affecting service logic.
    }
    @Override
    // Return the mapping between the currently played segment and text. start: start position of the audio segment in the input text; end (excluded): end position of the audio segment in the input text.
    public void onRangeStart(String taskId, int start, int end) {
        // Process the mapping between the currently played segment and text.
    }
    @Override
    // taskId: ID of a TTS task corresponding to the audio.
    // audioFragment: audio data.
    // offset: offset of the audio segment to be transmitted in the queue. One TTS task corresponds to a TTS queue.
    // range: text area where the audio segment to be transmitted is located; range.first (included): start position; range.second (excluded): end position.
    public void onAudioAvailable(String taskId, MLTtsAudioFragment audioFragment, int offset,
                                 Pair<Integer, Integer> range, Bundle bundle) {
        // Audio stream callback API, which is used to return the synthesized audio data to the app.
    }
    @Override
    public void onEvent(String taskId, int eventId, Bundle bundle) {
        // Callback method of a TTS event. eventId indicates the event name.
        boolean isInterrupted;
        switch (eventId) {
            case MLTtsConstants.EVENT_PLAY_START:
                // Called when playback starts.
                break;
            case MLTtsConstants.EVENT_PLAY_STOP:
                // Called when playback stops.
                isInterrupted = bundle.getBoolean(MLTtsConstants.EVENT_PLAY_STOP_INTERRUPTED);
                break;
            case MLTtsConstants.EVENT_PLAY_RESUME:
                // Called when playback resumes.
                break;
            case MLTtsConstants.EVENT_PLAY_PAUSE:
                // Called when playback pauses.
                break;
            // Pay attention to the following callback events when you focus on only the synthesized audio data but do not use the internal player for playback.
            case MLTtsConstants.EVENT_SYNTHESIS_START:
                // Called when TTS starts.
                break;
            case MLTtsConstants.EVENT_SYNTHESIS_END:
                // Called when TTS ends.
                break;
            case MLTtsConstants.EVENT_SYNTHESIS_COMPLETE:
                // TTS is complete. All synthesized audio streams are passed to the app.
                isInterrupted = bundle.getBoolean(MLTtsConstants.EVENT_SYNTHESIS_INTERRUPTED);
                break;
            default:
                break;
        }
    }
};

private String loadText(String path) {
    String result = "";
    try {
        PdfReader reader = new PdfReader(path);
        result = result.concat(PdfTextExtractor.getTextFromPage(reader,
                mCurrentPage.getIndex() + 1).trim() + System.lineSeparator());
        reader.close();
    } catch (IOException e) {
        showToast(e.getMessage());
    }
    // Obtain the position of the header.
    int header = result.indexOf(System.lineSeparator());
    // Obtain the position of the footer.
    int footer = result.lastIndexOf(System.lineSeparator());
    if (footer != 0){
        // Do not display the text in the header and footer.
        return result.substring(header, footer - 5);
    }else {
        return result;
    }
}

// Create an MLTtsLocalModel instance to set the speaker so that the language model corresponding to the speaker can be downloaded through the model manager.
MLTtsLocalModel model = new MLTtsLocalModel.Factory(MLTtsConstants.TTS_SPEAKER_OFFLINE_EN_US_MALE_EAGLE).create();
manager.isModelExist(model).addOnSuccessListener(new OnSuccessListener<Boolean>() {
    @Override
    public void onSuccess(Boolean aBoolean) {
        // If the model is not downloaded, call the download API. Otherwise, call the TTS API of the on-device engine.
        if (aBoolean) {
            String source = loadText(mPdfPath);
            // Call the speak API to perform TTS. source indicates the text to be synthesized.
            mlTtsEngine.speak(source, MLTtsEngine.QUEUE_APPEND);
            if (isPlay){
                // Pause playback.
                mlTtsEngine.pause();
                tv_speak.setText("speak");
            }else {
                // Resume playback.
                mlTtsEngine.resume();
                tv_speak.setText("pause");
            }
            isPlay = !isPlay;
        } else {
            // Call the API for downloading the on-device TTS model.
            downloadModel(MLTtsConstants.TTS_SPEAKER_OFFLINE_EN_US_MALE_EAGLE);
            showToast("The offline model has not been downloaded!");
        }
    }
}).addOnFailureListener(new OnFailureListener() {
    @Override
    public void onFailure(Exception e) {
        showToast(e.getMessage());
    }
});

@Override
protected void onDestroy() {
    super.onDestroy();
    try {
        if (mParcelFileDescriptor != null) {
            mParcelFileDescriptor.close();
        }
        if (mCurrentPage != null) {
            mCurrentPage.close();
        }
        if (mPdfRenderer != null) {
            mPdfRenderer.close();
        }
        if (mlTtsEngine != null){
            mlTtsEngine.shutdown();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}