/*
 * 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 org.apache.sling.cli.impl.mail;

import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.Properties;

import javax.mail.Address;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

public class Email {

    private String id;
    private InternetAddress from;
    private String subject;
    private String body;

    public Email(String id) {
        this.id = id;
        try (CloseableHttpClient client = HttpClients.createDefault()) {
            URI uri = new URIBuilder("https://lists.apache.org/api/source.lua/" + URLEncoder.encode(id, StandardCharsets.UTF_8)).build();
            HttpGet get = new HttpGet(uri);
            try (CloseableHttpResponse response = client.execute(get)) {
                try (InputStream content = response.getEntity().getContent()) {
                    if (response.getStatusLine().getStatusCode() != 200) {
                        throw new IOException("Status line : " + response.getStatusLine());
                    }
                    MimeMessage message = new MimeMessage(Session.getDefaultInstance(new Properties()), content);
                    subject = message.getSubject();
                    Address[] who = message.getFrom();
                    if (who.length > 0) {
                        from = (InternetAddress) who[0];
                    }
                    body = getContent(message);
                }
            }
        } catch (URISyntaxException | IOException | MessagingException e) {
            throw new IllegalArgumentException(e);
        }
    }

    public String getId() {
        return id;
    }

    public InternetAddress getFrom() {
        return from;
    }

    public String getSubject() {
        return subject;
    }


    public String getBody() {
        return body;
    }

    private String getContent(Message message) throws MessagingException, IOException {
        String result = "";
        if (message.isMimeType("text/plain")) {
            result = message.getContent().toString();
        } else if (message.isMimeType("multipart/*")) {
            MimeMultipart mimeMultipart = (MimeMultipart) message.getContent();
            result = getTextFromMimeMultipart(mimeMultipart);
        }
        return result;
    }

    private String getTextFromMimeMultipart(
            MimeMultipart mimeMultipart) throws MessagingException, IOException {
        StringBuilder result = new StringBuilder();
        int count = mimeMultipart.getCount();
        for (int i = 0; i < count; i++) {
            BodyPart bodyPart = mimeMultipart.getBodyPart(i);
            if (bodyPart.isMimeType("text/plain") || bodyPart.isMimeType("text/html")) {
                result.append("\n").append(bodyPart.getContent());
            } else if (bodyPart.getContent() instanceof MimeMultipart) {
                result.append(getTextFromMimeMultipart((MimeMultipart) bodyPart.getContent()));
            }
        }
        return result.toString();
    }

}