package com.zeapo.pwdstore.autofill;

import android.accessibilityservice.AccessibilityService;
import android.app.PendingIntent;
import android.content.ClipData;
import android.content.ClipboardManager;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.v7.app.AlertDialog;
import android.util.Log;
import android.view.WindowManager;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.accessibility.AccessibilityWindowInfo;
import android.widget.Toast;

import com.zeapo.pwdstore.R;
import com.zeapo.pwdstore.utils.PasswordItem;
import com.zeapo.pwdstore.utils.PasswordRepository;

import org.apache.commons.io.FileUtils;
import org.openintents.openpgp.OpenPgpError;
import org.openintents.openpgp.util.OpenPgpApi;
import org.openintents.openpgp.util.OpenPgpServiceConnection;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;

public class AutofillService extends AccessibilityService {
    private OpenPgpServiceConnection serviceConnection;
    private SharedPreferences settings;
    private AccessibilityNodeInfo info; // the original source of the event (the edittext field)
    private ArrayList<PasswordItem> items; // password choices
    private AlertDialog dialog;
    private AccessibilityWindowInfo window;
    private static boolean unlockOK = false; // if openkeychain user interaction was successful
    private CharSequence packageName;
    private boolean ignoreActionFocus = false;

    public final class Constants {
        public static final String TAG = "Keychain";
    }

    public static void setUnlockOK() { unlockOK = true; }

    @Override
    protected void onServiceConnected() {
        super.onServiceConnected();
        serviceConnection = new OpenPgpServiceConnection(AutofillService.this, "org.sufficientlysecure.keychain");
        serviceConnection.bindToService();
        settings = PreferenceManager.getDefaultSharedPreferences(this);
    }
    // TODO change search/search results (just use first result)
    @Override
    public void onAccessibilityEvent(AccessibilityEvent event) {
        // if returning to the source app from a successful AutofillActivity
        if (event.getEventType() == AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED
                && event.getPackageName().equals(packageName) && unlockOK) {
            decryptAndVerify();
        }

        // nothing to do if not password field focus, android version, or field is keychain app
        if (!event.isPassword()
                || Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR2
                || event.getPackageName().equals("org.sufficientlysecure.keychain")) {
            // the default keyboard showing/hiding is a window state changed event
            // on Android 5+ we can use getWindows() to determine when the original window is not visible
            // on Android 4.3 we have to use window state changed events and filter out the keyboard ones
            // there may be other exceptions...
            boolean dismiss;
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                dismiss = !getWindows().contains(window);
            } else {
                dismiss = !(event.getEventType() == AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED
                        && event.getPackageName().toString().contains("inputmethod"));
            }
            if (dismiss && dialog != null && dialog.isShowing()) {
                dialog.dismiss();
            }
            return;
        }

        if (dialog != null && dialog.isShowing()) {
            // if the view was clicked, the click event follows the focus event
            // since the focus event was already handled, ignore click event
            if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_CLICKED) {
                return;
            }
            // if past this point, a new dialog will be created, so dismiss the existing
            dialog.dismiss();
        }

        // ignore the ACTION_FOCUS from decryptAndVerify otherwise dialog will appear after Fill
        if (ignoreActionFocus) {
            ignoreActionFocus = false;
            return;
        }

        info = event.getSource();

        // save the dialog's corresponding window so we can use getWindows() above to check whether dismiss
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            window = info.getWindow();
        }

        // get the app name and find a corresponding password
        PackageManager packageManager = getPackageManager();
        ApplicationInfo applicationInfo;
        try {
            applicationInfo = packageManager.getApplicationInfo(event.getPackageName().toString(), 0);
        } catch (PackageManager.NameNotFoundException e) {
            applicationInfo = null;
        }
        final String appName = (applicationInfo != null ? packageManager.getApplicationLabel(applicationInfo) : "").toString();

        // if autofill_default is checked and prefs.getString DNE, 'Automatically match with password'/"first" otherwise "never"
        String defValue = settings.getBoolean("autofill_default", true) ? "first" : "never";
        SharedPreferences prefs = getSharedPreferences("autofill", Context.MODE_PRIVATE);
        String preference = prefs.getString(event.getPackageName().toString(), defValue);
        switch (preference) {
            case "first":
                items = recursiveFilter(appName, null);
                break;
            case "never":
                return;
            default:
                String path = PasswordRepository.getWorkTree() + "/" + preference + ".gpg";
                File file = new File(path);
                items = new ArrayList<>();
                items.add(PasswordItem.newPassword(file.getName(), file, PasswordRepository.getRepositoryDirectory(this)));
        }
        if (items.isEmpty()) {
            return;
        }

        if (dialog == null) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this, R.style.Theme_AppCompat_Dialog);
            builder.setNegativeButton("Cancel", null);
            builder.setPositiveButton("Fill", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    decryptAndVerify();
                }
            });
            builder.setNeutralButton("Settings", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // the user will have to return to the app themselves.
                    Intent intent = new Intent(AutofillService.this, AutofillPreferenceActivity.class);
                    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    intent.putExtra("packageName", info.getPackageName());
                    intent.putExtra("appName", appName);
                    startActivity(intent);
                }
            });
            dialog = builder.create();
            dialog.setIcon(R.drawable.ic_launcher);
            dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
            dialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);
            dialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
            dialog.getWindow().setLayout(WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT);
        }
        dialog.setTitle(items.get(0).toString());
        dialog.show();
    }

    private ArrayList<PasswordItem> recursiveFilter(String filter, File dir) {
        ArrayList<PasswordItem> items = new ArrayList<>();
        if (!PasswordRepository.isInitialized()) {
            PasswordRepository.initialize(this);
        }
        ArrayList<PasswordItem> passwordItems = dir == null ?
                PasswordRepository.getPasswords(PasswordRepository.getRepositoryDirectory(this)) :
                PasswordRepository.getPasswords(dir, PasswordRepository.getRepositoryDirectory(this));
        for (PasswordItem item : passwordItems) {
            if (item.getType() == PasswordItem.TYPE_CATEGORY) {
                items.addAll(recursiveFilter(filter, item.getFile()));
            }
            if (item.toString().toLowerCase().contains(filter.toLowerCase())) {
                items.add(item);
            }
        }
        return items;
    }

    @Override
    public void onInterrupt() {

    }

    public void decryptAndVerify() {
        unlockOK = false;
        packageName = info.getPackageName();
        Intent data = new Intent();
        data.setAction(OpenPgpApi.ACTION_DECRYPT_VERIFY);
        InputStream is = null;
        try {
            is = FileUtils.openInputStream(items.get(0).getFile());
        } catch (IOException e) {
            e.printStackTrace();
        }
        ByteArrayOutputStream os = new ByteArrayOutputStream();

        OpenPgpApi api = new OpenPgpApi(AutofillService.this, serviceConnection.getService());
        Intent result = api.executeApi(data, is, os);
        switch (result.getIntExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_ERROR)) {
            case OpenPgpApi.RESULT_CODE_SUCCESS: {
                try {
                    String[] passContent = os.toString("UTF-8").split("\n");

                    // if the user focused on something else, take focus back
                    // but this will open another dialog...hack to ignore this
                    ignoreActionFocus = info.performAction(AccessibilityNodeInfo.ACTION_FOCUS);
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                        Bundle args = new Bundle();
                        args.putCharSequence(AccessibilityNodeInfo.ACTION_ARGUMENT_SET_TEXT_CHARSEQUENCE,
                                passContent[0]);
                        info.performAction(AccessibilityNodeInfo.ACTION_SET_TEXT, args);
                    } else {
                        ClipboardManager clipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
                        ClipData clip = ClipData.newPlainText("autofill_pm", passContent[0]);
                        clipboard.setPrimaryClip(clip);
                        info.performAction(AccessibilityNodeInfo.ACTION_PASTE);

                        clip = ClipData.newPlainText("autofill_pm", "MyPasswordIsDaBest!");
                        clipboard.setPrimaryClip(clip);
                        if (settings.getBoolean("clear_clipboard_20x", false)) {
                            for (int i = 0; i < 19; i++) {
                                clip = ClipData.newPlainText(String.valueOf(i), String.valueOf(i));
                                clipboard.setPrimaryClip(clip);
                            }
                        }
                    }
                } catch (UnsupportedEncodingException e) {
                    Log.e(Constants.TAG, "UnsupportedEncodingException", e);
                }
                break;
            }
            case OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED: {
                Log.i("PgpHandler", "RESULT_CODE_USER_INTERACTION_REQUIRED");
                PendingIntent pi = result.getParcelableExtra(OpenPgpApi.RESULT_INTENT);
                // need to start a blank activity to call startIntentSenderForResult
                Intent intent = new Intent(AutofillService.this, AutofillActivity.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK
                        | Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
                intent.putExtra("pending_intent", pi);
                startActivity(intent);
                break;
            }
            case OpenPgpApi.RESULT_CODE_ERROR: {
                OpenPgpError error = result.getParcelableExtra(OpenPgpApi.RESULT_ERROR);
                Toast.makeText(AutofillService.this,
                        "Error from OpenKeyChain : " + error.getMessage(),
                        Toast.LENGTH_LONG).show();
                Log.e(Constants.TAG, "onError getErrorId:" + error.getErrorId());
                Log.e(Constants.TAG, "onError getMessage:" + error.getMessage());
                break;
            }
        }
    }
}