'use-strict';
/**
* The handler function receives context and variables. It returns new variables to be used in your flow.
*
* @param {object} context - the context contains environment variables accessible as context.env.varName1
* @param {object} variables - the variables from your flow (the input parameters) accessible as variables.varName1
* @returns {object} - return values that will become available in your flow
* @throws ExecutionError
*/

const axios = require('axios');
var format = require('date-fns/format');
var parseISO = require('date-fns/parseISO');


function fetchConversation(offset, variables, context, entireConversation) {
    return axios({
        method: 'GET',
        url: `https://conversations.messagebird.com/v1/conversations/${variables.conversationId}/messages?limit=20${offset > 0 ? `&offset=${offset}`: ''}`,
        headers: {
            Authorization: 'AccessKey ' + context.env.TOKEN,
        },
    })
    .then((response) => {
        let newEntireConversation = [...entireConversation, ...response.data.items];
        if (response.data.totalCount > response.data.count + offset) {
            return fetchConversation(offset + 20, variables, context, newEntireConversation);
        }
        return newEntireConversation;
    })
    .catch((error) => {
        throw error.message;
    });
}

async function sendConversationToEmail(conversation, conversationId, recipientEmail, context) {
    let conversationThread = 'Here is the conversation summary:\n';
    let conversationAttachments = [];
    conversation.filter(elem => elem.type !== 'event' && elem.type !== 'interactive').forEach(elem => {
        let msg = `Date: ${format(parseISO(elem.createdDatetime), "PPpp")}\n`
        if (elem.content.text) msg += elem.content.text;
        else if (elem.content.email) msg += elem.content.email.content.text + `\n`;
        else if (elem.type === 'image') conversationAttachments.push(elem.content.image.url.split("https://messaging.messagebird.com/v1/files/")[1]);
        else if (elem.type === 'file') conversationAttachments.push(elem.content.file.url.split("https://messaging.messagebird.com/v1/files/")[1]);
        conversationThread += msg + '\n-------------------\n';
    })
    const response = await axios({
        method: 'POST',
        url: "https://conversations.messagebird.com/v1/send",
        headers: {
            'Authorization': 'AccessKey ' + context.env.TOKEN,
        },
        data: {
            "to": recipientEmail,
            "from": context.env.FREEMAIL_CHANNEL_ID,
            "type": "email",
            "content": {
                "email": {
                    "to": [{
                        "address": recipientEmail
                    }],
                    "from": {
                        "name": "MessageBird",
                        "address": "email@REPLACE-WITH-YOUR-INBOX-DOMAIN.inbox.ai"
                    },
                    "subject": `Forwarded conversation [conversationID:${conversationId}]`,
                    "content": {
                        "text": conversationThread
                    },
                    "attachments": conversationAttachments.map(attachment => ({
                        id: attachment
                    }))
                }
            }
        }
    })
}

exports.handler = async function(context, variables) {
    if (!variables.hasOwnProperty('conversationId')) {
        throw 'Conversation Id parameter is required';
    }
    if (!variables.hasOwnProperty('recipientEmail')) {
        throw 'recipientEmail parameter is required';
    }
    let offset = 0;
    try {
        const conversation = await fetchConversation(offset, variables, context, []);
        await sendConversationToEmail(conversation, variables.conversationId, variables.recipientEmail, context);

        return {
            status: 'success'
        }
    } catch (e) {
        throw 'Something went wrong';
    }
};