/*
 * Copyright (C) 2013 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 foo.bar.printservice;

import android.content.Intent;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.print.PrintAttributes;
import android.print.PrintAttributes.Margins;
import android.print.PrintAttributes.MediaSize;
import android.print.PrintAttributes.Resolution;
import android.print.PrintJobId;
import android.print.PrintJobInfo;
import android.print.PrinterCapabilitiesInfo;
import android.print.PrinterId;
import android.print.PrinterInfo;
import android.printservice.PrintJob;
import android.printservice.PrintService;
import android.printservice.PrinterDiscoverySession;
import android.util.ArrayMap;
import android.util.Log;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class MyPrintService extends PrintService {

    private static final String LOG_TAG = "MyPrintService";

    private static final long STANDARD_DELAY_MILLIS = 10000000;

    static final String INTENT_EXTRA_ACTION_TYPE = "INTENT_EXTRA_ACTION_TYPE";
    static final String INTENT_EXTRA_PRINT_JOB_ID = "INTENT_EXTRA_PRINT_JOB_ID";

    static final int ACTION_TYPE_ON_PRINT_JOB_PENDING = 1;
    static final int ACTION_TYPE_ON_REQUEST_CANCEL_PRINT_JOB = 2;

    private static final Object sLock = new Object();

    private static MyPrintService sInstance;

    private Handler mHandler;

    private AsyncTask<ParcelFileDescriptor, Void, Void> mFakePrintTask;

    private FakePrinterDiscoverySession mSession;

    private final Map<PrintJobId, PrintJob> mProcessedPrintJobs =
            new ArrayMap<PrintJobId, PrintJob>();

    public static MyPrintService peekInstance() {
        synchronized (sLock) {
            return sInstance;
        }
    }

    @Override
    protected void onConnected() {
        Log.i(LOG_TAG, "#onConnected()");
        mHandler = new MyHandler(getMainLooper());
        synchronized (sLock) {
            sInstance = this;
        }
    }

    @Override
    protected void onDisconnected() {
        Log.i(LOG_TAG, "#onDisconnected()");
        if (mSession != null) {
            mSession.cancellAddingFakePrinters();
        }
        synchronized (sLock) {
            sInstance = null;
        }
    }

    @Override
    protected PrinterDiscoverySession onCreatePrinterDiscoverySession() {
        Log.i(LOG_TAG, "#onCreatePrinterDiscoverySession()");
        return new FakePrinterDiscoverySession();
    }

    @Override
    protected void onRequestCancelPrintJob(final PrintJob printJob) {
        Log.i(LOG_TAG, "#onRequestCancelPrintJob()");
        mProcessedPrintJobs.put(printJob.getId(), printJob);
        Intent intent = new Intent(this, MyDialogActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.putExtra(INTENT_EXTRA_PRINT_JOB_ID, printJob.getId());
        intent.putExtra(INTENT_EXTRA_ACTION_TYPE, ACTION_TYPE_ON_REQUEST_CANCEL_PRINT_JOB);
        startActivity(intent);
    }

    @Override
    public void onPrintJobQueued(final PrintJob printJob) {
        Log.i(LOG_TAG, "#onPrintJobQueued()");
        mProcessedPrintJobs.put(printJob.getId(), printJob);
        if (printJob.isQueued()) {
            printJob.start();
        }
        
        Intent intent = new Intent(this, MyDialogActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.putExtra(INTENT_EXTRA_PRINT_JOB_ID, printJob.getId());
        intent.putExtra(INTENT_EXTRA_ACTION_TYPE, ACTION_TYPE_ON_PRINT_JOB_PENDING);
        startActivity(intent);
    }

    void handleRequestCancelPrintJob(PrintJobId printJobId) {
        PrintJob printJob = mProcessedPrintJobs.get(printJobId);
        if (printJob == null) {
            return;
        }
        mProcessedPrintJobs.remove(printJobId);
        if (printJob.isQueued() || printJob.isStarted() || printJob.isBlocked()) {
            mHandler.removeMessages(MyHandler.MSG_HANDLE_DO_PRINT_JOB);
            mHandler.removeMessages(MyHandler.MSG_HANDLE_FAIL_PRINT_JOB);
            printJob.cancel();
        }
    }

    void handleFailPrintJobDelayed(PrintJobId printJobId) {
        Message message = mHandler.obtainMessage(
                MyHandler.MSG_HANDLE_FAIL_PRINT_JOB, printJobId);
        mHandler.sendMessageDelayed(message, STANDARD_DELAY_MILLIS);
    }

    void handleFailPrintJob(PrintJobId printJobId) {
        PrintJob printJob = mProcessedPrintJobs.get(printJobId);
        if (printJob == null) {
            return;
        }
        mProcessedPrintJobs.remove(printJobId);
        if (printJob.isQueued() || printJob.isStarted()) {
            printJob.fail(getString(R.string.fail_reason));
        }
    }

    void handleBlockPrintJobDelayed(PrintJobId printJobId) {
        Message message = mHandler.obtainMessage(
                MyHandler.MSG_HANDLE_BLOCK_PRINT_JOB, printJobId);
        mHandler.sendMessageDelayed(message, STANDARD_DELAY_MILLIS);
    }

    void handleBlockPrintJob(PrintJobId printJobId) {
        final PrintJob printJob = mProcessedPrintJobs.get(printJobId);
        if (printJob == null) {
            return;
        }

        if (printJob.isStarted()) {
            printJob.block("Gimme some rest, dude");
        }
    }

    void handleBlockAndDelayedUnblockPrintJob(PrintJobId printJobId) {
        handleBlockPrintJob(printJobId);

        Message message = mHandler.obtainMessage(
                MyHandler.MSG_HANDLE_UNBLOCK_PRINT_JOB, printJobId);
        mHandler.sendMessageDelayed(message, STANDARD_DELAY_MILLIS);
    }

    void handleUnblockPrintJob(PrintJobId printJobId) {
        final PrintJob printJob = mProcessedPrintJobs.get(printJobId);
        if (printJob == null) {
            return;
        }

        if (printJob.isBlocked()) {
            printJob.start();
        }
    }

    void handleQueuedPrintJobDelayed(PrintJobId printJobId) {
        final PrintJob printJob = mProcessedPrintJobs.get(printJobId);
        if (printJob == null) {
            return;
        }

        if (printJob.isQueued()) {
            printJob.start();
        }
        Message message = mHandler.obtainMessage(
                MyHandler.MSG_HANDLE_DO_PRINT_JOB, printJobId);
        mHandler.sendMessageDelayed(message, STANDARD_DELAY_MILLIS);
    }

    void handleQueuedPrintJob(PrintJobId printJobId) {
        final PrintJob printJob = mProcessedPrintJobs.get(printJobId);
        if (printJob == null) {
            return;
        }

        if (printJob.isQueued()) {
            printJob.start();
        }

        final PrintJobInfo info = printJob.getInfo();
        final File file = new File(getFilesDir(), info.getLabel() + ".pdf");

        mFakePrintTask = new AsyncTask<ParcelFileDescriptor, Void, Void>() {
            @Override
            protected Void doInBackground(ParcelFileDescriptor... params) {
                InputStream in = new BufferedInputStream(new FileInputStream(
                        params[0].getFileDescriptor()));
                OutputStream out = null;
                try {
                    out = new BufferedOutputStream(new FileOutputStream(file));
                    final byte[] buffer = new byte[8192];
                    while (true) {
                        if (isCancelled()) {
                            break;
                        }
                        final int readByteCount = in.read(buffer);
                        if (readByteCount < 0) {
                            break;
                        }
                        out.write(buffer, 0, readByteCount);
                    }
                } catch (IOException ioe) {
                    throw new RuntimeException(ioe);
                } finally {
                    if (in != null) {
                        try {
                            in.close();
                        } catch (IOException ioe) {
                            /* ignore */
                        }
                    }
                    if (out != null) {
                        try {
                            out.close();
                        } catch (IOException ioe) {
                            /* ignore */
                        }
                    }
                    if (isCancelled()) {
                        file.delete();
                    }
                }
                return null;
            }

            @Override
            protected void onPostExecute(Void result) {
                if (printJob.isStarted()) {
                    printJob.complete();
                }

                file.setReadable(true, false);

                // Quick and dirty to show the file - use a content provider instead.
                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setDataAndType(Uri.fromFile(file), "application/pdf");
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                startActivity(intent, null);

                mFakePrintTask = null;
            }

            @Override
            protected void onCancelled(Void result) {
                if (printJob.isStarted()) {
                    printJob.cancel();
                }
            }
        };
        mFakePrintTask.executeOnExecutor(AsyncTask.SERIAL_EXECUTOR,
                printJob.getDocument().getData());
    }

    private final class MyHandler extends Handler {
        public static final int MSG_HANDLE_DO_PRINT_JOB = 1;
        public static final int MSG_HANDLE_FAIL_PRINT_JOB = 2;
        public static final int MSG_HANDLE_BLOCK_PRINT_JOB = 3;
        public static final int MSG_HANDLE_UNBLOCK_PRINT_JOB = 4;

        public MyHandler(Looper looper) {
            super(looper);
        }

        @Override
        public void handleMessage(Message message) {
            switch (message.what) {
                case MSG_HANDLE_DO_PRINT_JOB: {
                    PrintJobId printJobId = (PrintJobId) message.obj;
                    handleQueuedPrintJob(printJobId);
                } break;

                case MSG_HANDLE_FAIL_PRINT_JOB: {
                    PrintJobId printJobId = (PrintJobId) message.obj;
                    handleFailPrintJob(printJobId);
                } break;

                case MSG_HANDLE_BLOCK_PRINT_JOB: {
                    PrintJobId printJobId = (PrintJobId) message.obj;
                    handleBlockPrintJob(printJobId);
                } break;

                case MSG_HANDLE_UNBLOCK_PRINT_JOB: {
                    PrintJobId printJobId = (PrintJobId) message.obj;
                    handleUnblockPrintJob(printJobId);
                } break;
            }
        }
    }

    private final class FakePrinterDiscoverySession extends  PrinterDiscoverySession {
        private final Handler mSesionHandler = new SessionHandler(getMainLooper());

        private final List<PrinterInfo> mFakePrinters = new ArrayList<PrinterInfo>();

        public FakePrinterDiscoverySession() {
            for (int i = 0; i < 10; i++) {
                String name = "Printer " + i;
                PrinterInfo printer = new PrinterInfo
                        .Builder(generatePrinterId(name), name, (i % 2 == 1)
                                ? PrinterInfo.STATUS_UNAVAILABLE : PrinterInfo.STATUS_IDLE)
                        .build();
                mFakePrinters.add(printer);
            }
        }

        @Override
        public void onDestroy() {
            Log.i(LOG_TAG, "FakePrinterDiscoverySession#onDestroy()");
            mSesionHandler.removeMessages(SessionHandler.MSG_ADD_FIRST_BATCH_FAKE_PRINTERS);
            mSesionHandler.removeMessages(SessionHandler.MSG_ADD_SECOND_BATCH_FAKE_PRINTERS);
        }

        @Override
        public void onStartPrinterDiscovery(List<PrinterId> priorityList) {
            Log.i(LOG_TAG, "FakePrinterDiscoverySession#onStartPrinterDiscovery()");
            Message message1 = mSesionHandler.obtainMessage(
                    SessionHandler.MSG_ADD_FIRST_BATCH_FAKE_PRINTERS, this);
            mSesionHandler.sendMessageDelayed(message1, 0);

            Message message2 = mSesionHandler.obtainMessage(
                    SessionHandler.MSG_ADD_SECOND_BATCH_FAKE_PRINTERS, this);
            mSesionHandler.sendMessageDelayed(message2, 10000);
        }

        @Override
        public void onStopPrinterDiscovery() {
            Log.i(LOG_TAG, "FakePrinterDiscoverySession#onStopPrinterDiscovery()");
            cancellAddingFakePrinters();
        }

        @Override
        public void onStartPrinterStateTracking(PrinterId printerId) {
            Log.i(LOG_TAG, "FakePrinterDiscoverySession#onStartPrinterStateTracking()");
            PrinterInfo printer = findPrinterInfo(printerId);
            if (printer != null) {
                PrinterCapabilitiesInfo capabilities =
                        new PrinterCapabilitiesInfo.Builder(printerId)
                    .setMinMargins(new Margins(200, 200, 200, 200))
                    .addMediaSize(MediaSize.ISO_A4, true)
                    .addMediaSize(MediaSize.ISO_A5, false)
                    .addResolution(new Resolution("R1", getString(
                            R.string.resolution_200x200), 200, 200), false)
                    .addResolution(new Resolution("R2", getString(
                            R.string.resolution_300x300), 300, 300), true)
                    .setColorModes(PrintAttributes.COLOR_MODE_COLOR
                            | PrintAttributes.COLOR_MODE_MONOCHROME,
                            PrintAttributes.COLOR_MODE_MONOCHROME)
                    .build();

                printer = new PrinterInfo.Builder(printer)
                    .setCapabilities(capabilities)
                    .build();

                List<PrinterInfo> printers = new ArrayList<PrinterInfo>();
                printers.add(printer);
                addPrinters(printers);
            }
        }

        @Override
        public void onValidatePrinters(List<PrinterId> printerIds) {
            Log.i(LOG_TAG, "FakePrinterDiscoverySession#onValidatePrinters()");
        }

        @Override
        public void onStopPrinterStateTracking(PrinterId printerId) {
            Log.i(LOG_TAG, "FakePrinterDiscoverySession#onStopPrinterStateTracking()");
        }

        private void addFirstBatchFakePrinters() {
            List<PrinterInfo> printers = mFakePrinters.subList(0, mFakePrinters.size() / 2);
            addPrinters(printers);
        }

        private void addSecondBatchFakePrinters() {
            List<PrinterInfo> printers = mFakePrinters.subList(0, mFakePrinters.size() / 2
                    /* mFakePrinters.size() / 2, mFakePrinters.size()*/);
            final int printerCount = mFakePrinters.size();
            for (int i = printerCount - 1; i >= 0; i--) {
                PrinterInfo printer = new PrinterInfo.Builder(mFakePrinters.get(i))
                        .setStatus(PrinterInfo.STATUS_UNAVAILABLE).build();
                printers.add(printer);
            }
            addPrinters(printers);
        }

        private PrinterInfo findPrinterInfo(PrinterId printerId) {
            List<PrinterInfo> printers = getPrinters();
            final int printerCount = getPrinters().size();
            for (int i = 0; i < printerCount; i++) {
                PrinterInfo printer = printers.get(i);
                if (printer.getId().equals(printerId)) {
                    return printer;
                }
            }
            return null;
        }

        private void cancellAddingFakePrinters() {
            mSesionHandler.removeMessages(SessionHandler.MSG_ADD_FIRST_BATCH_FAKE_PRINTERS);
            mSesionHandler.removeMessages(SessionHandler.MSG_ADD_SECOND_BATCH_FAKE_PRINTERS);
        }

        final class SessionHandler extends Handler {
            public static final int MSG_ADD_FIRST_BATCH_FAKE_PRINTERS = 1;
            public static final int MSG_ADD_SECOND_BATCH_FAKE_PRINTERS = 2;

            public SessionHandler(Looper looper) {
                super(looper);
            }

            @Override
            public void handleMessage(Message message) {
                switch (message.what) {
                    case MSG_ADD_FIRST_BATCH_FAKE_PRINTERS: {
                        addFirstBatchFakePrinters();
                    } break;

                    case MSG_ADD_SECOND_BATCH_FAKE_PRINTERS: {
                        addSecondBatchFakePrinters();
                    } break;
                }
            }
        }
    }
}