FairEmail/app/src/main/java/eu/faircode/email/ActivityCompose.java

package eu.faircode.email;

/*
    This file is part of FairEmail.

    FairEmail is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    FairEmail is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.

    Copyright 2018-2020 by Marcel Bokhorst (M66B)
*/

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.text.Html;
import android.text.Spanned;
import android.text.TextUtils;

import androidx.core.app.TaskStackBuilder;
import androidx.core.net.MailTo;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import java.util.ArrayList;

public class ActivityCompose extends ActivityBase implements FragmentManager.OnBackStackChangedListener {
    static final int PI_REPLY = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_compose);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        getSupportFragmentManager().addOnBackStackChangedListener(this);

        if (getSupportFragmentManager().getBackStackEntryCount() == 0)
            handle(getIntent());
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        setIntent(intent);
        handle(intent);
    }

    @Override
    public void onBackStackChanged() {
        if (getSupportFragmentManager().getBackStackEntryCount() == 0) {
            Intent parent = getParentActivityIntent();
            if (parent != null)
                if (shouldUpRecreateTask(parent))
                    TaskStackBuilder.create(this)
                            .addNextIntentWithParentStack(parent)
                            .startActivities();
                else {
                    parent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(parent);
                }

            finishAndRemoveTask();
        }
    }

    private void handle(Intent intent) {
        Bundle args;
        String action = intent.getAction();
        if (Intent.ACTION_VIEW.equals(action) ||
                Intent.ACTION_SENDTO.equals(action) ||
                Intent.ACTION_SEND.equals(action) ||
                Intent.ACTION_SEND_MULTIPLE.equals(action)) {

            args = new Bundle();
            args.putString("action", "new");
            args.putLong("account", -1);

            Uri uri = intent.getData();
            if (uri != null && "mailto".equals(uri.getScheme())) {
                // https://www.ietf.org/rfc/rfc2368.txt
                MailTo mailto = MailTo.parse(uri.toString());

                String to = mailto.getTo();
                if (to != null)
                    args.putString("to", to);

                String cc = mailto.getCc();
                if (cc != null)
                    args.putString("cc", cc);

                String subject = mailto.getSubject();
                if (subject != null)
                    args.putString("subject", subject);

                String body = mailto.getBody();
                if (body != null) {
                    StringBuilder sb = new StringBuilder();
                    for (String line : body.split("\\r?\\n"))
                        sb.append("<span>").append(Html.escapeHtml(line)).append("<span><br>");
                    args.putString("body", sb.toString());
                }
            }

            if (intent.hasExtra(Intent.EXTRA_SHORTCUT_ID)) {
                String to = intent.getStringExtra(Intent.EXTRA_SHORTCUT_ID);
                if (to != null)
                    args.putString("to", to);
            }

            if (intent.hasExtra(Intent.EXTRA_EMAIL)) {
                String[] to = intent.getStringArrayExtra(Intent.EXTRA_EMAIL);
                if (to != null)
                    args.putString("to", TextUtils.join(", ", to));
            }

            if (intent.hasExtra(Intent.EXTRA_CC)) {
                String[] cc = intent.getStringArrayExtra(Intent.EXTRA_CC);
                if (cc != null)
                    args.putString("cc", TextUtils.join(", ", cc));
            }

            if (intent.hasExtra(Intent.EXTRA_BCC)) {
                String[] bcc = intent.getStringArrayExtra(Intent.EXTRA_BCC);
                if (bcc != null)
                    args.putString("bcc", TextUtils.join(", ", bcc));
            }

            if (intent.hasExtra(Intent.EXTRA_SUBJECT)) {
                String subject = intent.getStringExtra(Intent.EXTRA_SUBJECT);
                if (subject != null)
                    args.putString("subject", subject);
            }

            if (intent.hasExtra(Intent.EXTRA_HTML_TEXT)) {
                String html = intent.getStringExtra(Intent.EXTRA_HTML_TEXT);
                if (!TextUtils.isEmpty(html))
                    args.putString("body", html);
            } else if (intent.hasExtra(Intent.EXTRA_TEXT)) {
                CharSequence body = intent.getCharSequenceExtra(Intent.EXTRA_TEXT);
                if (body != null)
                    if (body instanceof Spanned)
                        args.putString("body", HtmlHelper.toHtml((Spanned) body, this));
                    else {
                        String text = body.toString();
                        if (!TextUtils.isEmpty(text)) {
                            String html = "<span>" + text.replaceAll("\\r?\\n", "<br>") + "</span>";
                            args.putString("body", html);
                        }
                    }
            }

            if (intent.hasExtra(Intent.EXTRA_STREAM))
                if (Intent.ACTION_SEND_MULTIPLE.equals(action)) {
                    ArrayList<Uri> uris = intent.getParcelableArrayListExtra(Intent.EXTRA_STREAM);
                    if (uris != null)
                        args.putParcelableArrayList("attachments", uris);
                } else {
                    Uri stream = intent.getParcelableExtra(Intent.EXTRA_STREAM);
                    if (stream != null) {
                        ArrayList<Uri> uris = new ArrayList<>();
                        uris.add(stream);
                        args.putParcelableArrayList("attachments", uris);
                    }
                }
        } else
            args = intent.getExtras();

        FragmentCompose fragment = new FragmentCompose();
        fragment.setArguments(args);

        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
        fragmentTransaction.replace(R.id.content_frame, fragment).addToBackStack("compose");
        fragmentTransaction.commit();
    }
}