/*
    Copyright 2013-2015 appPlant UG

    Licensed to the Apache Software Foundation (ASF) under one
    or more contributor license agreements.  See the NOTICE file
    distributed with this work for additional information
    regarding copyright ownership.  The ASF licenses this file
    to you 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 de.appplant.cordova.emailcomposer;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.res.AssetManager;
import android.content.res.Resources;
import android.net.Uri;
import android.os.Build;
import android.text.Html;
import android.util.Base64;
import android.util.Log;

import org.apache.cordova.CordovaPlugin;
import org.apache.cordova.CallbackContext;
import org.apache.cordova.PluginResult;

@SuppressWarnings("Convert2Diamond")
public class EmailComposer extends CordovaPlugin {

    //
    static private final String STORAGE_FOLDER = "/email_composer";

    // The callback context used when calling back into JavaScript
    private CallbackContext command;

    /**
     * Executes the request.
     *
     * This method is called from the WebView thread.
     * To do a non-trivial amount of work, use:
     *     cordova.getThreadPool().execute(runnable);
     *
     * To run on the UI thread, use:
     *     cordova.getActivity().runOnUiThread(runnable);
     *
     * @param action   The action to execute.
     * @param args     The exec() arguments in JSON form.
     * @param callback The callback context used when calling
     *                 back into JavaScript.
     * @return         Whether the action was valid.
     */
    @Override
    public boolean execute (String action, JSONArray args,
                            CallbackContext callback) throws JSONException {

        this.command = callback;

        if ("open".equals(action)) {
            open(args);

            return true;
        }

        if ("isAvailable".equals(action)) {
            isAvailable();

            return true;
        }

        // Returning false results in a "MethodNotFound" error.
        return false;
    }

    /**
     * Tells if the device has the capability to send emails.
     */
    private void isAvailable () {
        cordova.getThreadPool().execute(new Runnable() {
            public void run() {
                Boolean available   = isEmailAccountConfigured();
                PluginResult result = new PluginResult(PluginResult.Status.OK, available);

                command.sendPluginResult(result);
            }
        });
    }

    /**
     * Sends an intent to the email app.
     *
     * @param args
     *      The email properties like subject or body
     *
     * @throws JSONException
     */
    private void open (JSONArray args) throws JSONException {
        JSONObject properties = args.getJSONObject(0);
        Intent draft = getDraftWithProperties(properties);

        final Intent chooser = Intent.createChooser(draft, "Open with");
        final EmailComposer plugin = this;

        cordova.getThreadPool().execute(new Runnable() {
            public void run() {
                cordova.startActivityForResult(
                        plugin, chooser, 0);
            }
        });
    }

    /**
     * The intent with the containing email properties.
     *
     * @param params
     *      The email properties like subject or body
     * @return
     *      The resulting intent
     *
     * @throws JSONException
     */
    private Intent getDraftWithProperties (JSONObject params) throws JSONException {
        Intent mail = new Intent(Intent.ACTION_SEND_MULTIPLE);
        String app  = params.optString("app", null);

        if (params.has("subject"))
            setSubject(params.getString("subject"), mail);
        if (params.has("body"))
            setBody(params.getString("body"), params.optBoolean("isHtml"), mail);
        if (params.has("to"))
            setRecipients(params.getJSONArray("to"), mail);
        if (params.has("cc"))
            setCcRecipients(params.getJSONArray("cc"), mail);
        if (params.has("bcc"))
            setBccRecipients(params.getJSONArray("bcc"), mail);
        if (params.has("attachments"))
            setAttachments(params.getJSONArray("attachments"), mail);

        if (app != null && isAppInstalled(app)) {
            mail.setPackage(app);
        }

        mail.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

        return mail;
    }

    /**
     * Setter for the subject.
     *
     * @param subject
     *      The subject
     * @param draft
     *      The intent
     */
    private void setSubject (String subject, Intent draft) {
        draft.putExtra(Intent.EXTRA_SUBJECT, subject);
    }

    /**
     * Setter for the body.
     *
     * @param body
     *      The body
     * @param isHTML
     *      Indicates the encoding
     *      (HTML or plain text)
     * @param draft
     *      The intent
     */
    private void setBody (String body, Boolean isHTML, Intent draft) {
        if (isHTML) {
            draft.putExtra(Intent.EXTRA_TEXT, Html.fromHtml(body));
            draft.setType("text/html");

            if (Build.VERSION.SDK_INT > 15) {
                draft.putExtra(Intent.EXTRA_HTML_TEXT, body);
            }
        } else {
            draft.putExtra(Intent.EXTRA_TEXT, body);
            draft.setType("text/plain");
        }
    }

    /**
     * Setter for the recipients.
     *
     * @param recipients
     *      List of email addresses
     * @param draft
     *      The intent
     *
     * @throws JSONException
     */
    private void setRecipients (JSONArray recipients, Intent draft) throws JSONException {
        String[] receivers = new String[recipients.length()];

        for (int i = 0; i < recipients.length(); i++) {
            receivers[i] = recipients.getString(i);
        }

        draft.putExtra(Intent.EXTRA_EMAIL, receivers);
    }

    /**
     * Setter for the cc recipients.
     *
     * @param recipients
     *      List of email addresses
     * @param draft
     *      The intent
     *
     * @throws JSONException
     */
    private void setCcRecipients (JSONArray recipients, Intent draft) throws JSONException {
        String[] receivers = new String[recipients.length()];

        for (int i = 0; i < recipients.length(); i++) {
            receivers[i] = recipients.getString(i);
        }

        draft.putExtra(Intent.EXTRA_CC, receivers);
    }

    /**
     * Setter for the bcc recipients.
     *
     * @param recipients
     *      List of email addresses
     * @param draft
     *      The intent
     *
     * @throws JSONException
     */
    private void setBccRecipients (JSONArray recipients, Intent draft) throws JSONException {
        String[] receivers = new String[recipients.length()];

        for (int i = 0; i < recipients.length(); i++) {
            receivers[i] = recipients.getString(i);
        }

        draft.putExtra(Intent.EXTRA_BCC, receivers);
    }

    /**
     * Setter for the attachments.
     *
     * @param attachments
     *      List of URIs
     * @param draft
     *      The intent
     *
     * @throws JSONException
     */
    private void setAttachments (JSONArray attachments, Intent draft) throws JSONException {
        ArrayList<Uri> uris = new ArrayList<Uri>();

        for (int i = 0; i < attachments.length(); i++) {
            Uri uri = getUriForPath(attachments.getString(i));

            uris.add(uri);
        }

        draft.putParcelableArrayListExtra(Intent.EXTRA_STREAM, uris);
    }

    /**
     * The URI for an attachment path.
     *
     * @param path
     *      The given path to the attachment
     *
     * @return
     *      The URI pointing to the given path
     */
    private Uri getUriForPath (String path) {
        if (path.startsWith("res:")) {
            return getUriForResourcePath(path);
        } else if (path.startsWith("file:///")) {
            return getUriForAbsolutePath(path);
        } else if (path.startsWith("file://")) {
            return getUriForAssetPath(path);
        } else if (path.startsWith("base64:")) {
            return getUriForBase64Content(path);
        }

        return Uri.parse(path);
    }

    /**
     * The URI for a file.
     *
     * @param path
     *      The given absolute path
     *
     * @return
     *      The URI pointing to the given path
     */
    private Uri getUriForAbsolutePath (String path) {
        String absPath = path.replaceFirst("file://", "");
        File file      = new File(absPath);

        if (!file.exists()) {
            Log.e("EmailComposer", "File not found: " + file.getAbsolutePath());
        }

        return Uri.fromFile(file);
    }

    /**
     * The URI for an asset.
     *
     * @param path
     *      The given asset path
     *
     * @return
     *      The URI pointing to the given path
     */
    @SuppressWarnings("ResultOfMethodCallIgnored")
    private Uri getUriForAssetPath (String path) {
        String resPath  = path.replaceFirst("file:/", "www");
        String fileName = resPath.substring(resPath.lastIndexOf('/') + 1);
        File dir        = cordova.getActivity().getExternalCacheDir();

        if (dir == null) {
            Log.e("EmailComposer", "Missing external cache dir");
            return Uri.EMPTY;
        }

        String storage  = dir.toString() + STORAGE_FOLDER;
        File file       = new File(storage, fileName);

        new File(storage).mkdir();

        try {
            AssetManager assets = cordova.getActivity().getAssets();

            FileOutputStream outStream = new FileOutputStream(file);
            InputStream inputStream    = assets.open(resPath);

            copyFile(inputStream, outStream);
            outStream.flush();
            outStream.close();
        } catch (Exception e) {
            Log.e("EmailComposer", "File not found: assets/" + resPath);
            e.printStackTrace();
        }

        return Uri.fromFile(file);
    }

    /**
     * The URI for a resource.
     *
     * @param path
     *      The given relative path
     *
     * @return
     *      The URI pointing to the given path
     */
    @SuppressWarnings("ResultOfMethodCallIgnored")
    private Uri getUriForResourcePath (String path) {
        String resPath   = path.replaceFirst("res://", "");
        String fileName  = resPath.substring(resPath.lastIndexOf('/') + 1);
        String resName   = fileName.substring(0, fileName.lastIndexOf('.'));
        String extension = resPath.substring(resPath.lastIndexOf('.'));
        File dir         = cordova.getActivity().getExternalCacheDir();

        if (dir == null) {
            Log.e("EmailComposer", "Missing external cache dir");
            return Uri.EMPTY;
        }

        String storage   = dir.toString() + STORAGE_FOLDER;
        int resId        = getResId(resPath);
        File file        = new File(storage, resName + extension);

        if (resId == 0) {
            Log.e("EmailComposer", "File not found: " + resPath);
        }

        new File(storage).mkdir();

        try {
            Resources res = cordova.getActivity().getResources();
            FileOutputStream outStream = new FileOutputStream(file);
            InputStream inputStream    = res.openRawResource(resId);

            copyFile(inputStream, outStream);
            outStream.flush();
            outStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return Uri.fromFile(file);
    }

    /**
     * The URI for a base64 encoded content.
     *
     * @param content
     *      The given base64 encoded content
     *
     * @return
     *      The URI including the given content
     */
    @SuppressWarnings("ResultOfMethodCallIgnored")
    private Uri getUriForBase64Content (String content) {
        String resName = content.substring(content.indexOf(":") + 1, content.indexOf("//"));
        String resData = content.substring(content.indexOf("//") + 2);
        File dir       = cordova.getActivity().getExternalCacheDir();
        byte[] bytes;

        try {
            bytes = Base64.decode(resData, 0);
        } catch (Exception ignored) {
            Log.e("EmailComposer", "Invalid Base64 string");
            return Uri.EMPTY;
        }

        if (dir == null) {
            Log.e("EmailComposer", "Missing external cache dir");
            return Uri.EMPTY;
        }

        String storage = dir.toString() + STORAGE_FOLDER;
        File file      = new File(storage, resName);

        new File(storage).mkdir();

        try {
            FileOutputStream outStream = new FileOutputStream(file);

            outStream.write(bytes);
            outStream.flush();
            outStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return Uri.fromFile(file);
    }

    /**
     * Writes an InputStream to an OutputStream
     *
     * @param in
     *      The input stream
     * @param out
     *      The output stream
     */
    private void copyFile (InputStream in, OutputStream out) throws IOException {
        byte[] buffer = new byte[1024];
        int read;

        while((read = in.read(buffer)) != -1){
            out.write(buffer, 0, read);
        }
    }

    /**
     * @return
     *      The resource ID for the given resource.
     */
    private int getResId (String resPath) {
        Resources res = cordova.getActivity().getResources();
        int resId;

        String pkgName  = getPackageName();
        String dirName  = "drawable";
        String fileName = resPath;

        if (resPath.contains("/")) {
            dirName  = resPath.substring(0, resPath.lastIndexOf('/'));
            fileName = resPath.substring(resPath.lastIndexOf('/') + 1);
        }

        String resName = fileName.substring(0, fileName.lastIndexOf('.'));

        resId = res.getIdentifier(resName, dirName, pkgName);

        if (resId == 0) {
            resId = res.getIdentifier(resName, "drawable", pkgName);
        }

        return resId;
    }

    /**
     * If email apps are available.
     *
     * @return
     *      true if available, otherwise false
     */
    private Boolean isEmailAccountConfigured () {
        Uri uri           = Uri.fromParts("mailto","max@mustermann.com", null);
        Intent intent     = new Intent(Intent.ACTION_SENDTO, uri);
        PackageManager pm = cordova.getActivity().getPackageManager();
        int mailApps      = pm.queryIntentActivities(intent, 0).size();
        Boolean available;

        available = mailApps > 0;

        return available;
    }

    /**
     * Ask the package manager if the app is installed on the device.
     *
     * @param id
     *      The app id
     *
     * @return
     *      true if yes otherwise false
     */
    private boolean isAppInstalled(String id) {
        PackageManager pm = cordova.getActivity().getPackageManager();

        try {
            pm.getPackageInfo(id, 0);
            return true;
        } catch(PackageManager.NameNotFoundException e) {
            return false;
        }
    }

    /**
     * The name for the package.
     *
     * @return
     *      The package name
     */
    private String getPackageName () {
        return cordova.getActivity().getPackageName();
    }

    /**
     * Called when an activity you launched exits, giving you the reqCode you
     * started it with, the resCode it returned, and any additional data from it.
     *
     * @param reqCode     The request code originally supplied to startActivityForResult(),
     *                    allowing you to identify who this result came from.
     * @param resCode     The integer result code returned by the child activity
     *                    through its setResult().
     * @param intent      An Intent, which can return result data to the caller
     *                    (various data can be attached to Intent "extras").
     */
    @Override
    public void onActivityResult(int reqCode, int resCode, Intent intent) {
        command.success();
    }
}