Мазаалай Bot

DynamoDB Table Schema.md

index.js

'use strict';

String.prototype.clearFormat = function() {
    return this.replace(/<br>/g, '\n').replace(/<i>/g, '').replace(/<\/i>/g, '');
};

String.prototype.wordWrap = function(length) {
    var words = this.split(' ');
    var result = [];
    var current = words[0];

    for (var i = 1; i < words.length; i++) {
        if (words[i].length === 0) {
            continue;
        }

        if (current.length + words[i].length + 1 > length) {
            result.push(current);
            current = words[i];
        } else {
            current += ' ' + words[i];
        }

    }

    result.push(current);

    return result;
}

Array.prototype.chunk = function(n) {
    if (this.length === 0) {
        return [];
    }

    return [this.slice(0, n)].concat(this.slice(n).chunk(n));
};

const request = require('request');
const AWS = require('aws-sdk');

AWS.config.update({
    region: 'us-east-1'
});

const dynamodb = new AWS.DynamoDB.DocumentClient();
const snowball = new require('snowball')('English');

const PAGE_ACCESS_TOKEN = 'XXXXXXXXX';

function stemmer(word) {
    snowball.setCurrent(word);
    snowball.stem();

    return snowball.getCurrent();
}

function find(stem, callback) {
    dynamodb.query({
        TableName: 'Mazaalai',
        ConsistentRead: false,
        KeyConditionExpression: 'stem = :stem',
        ExpressionAttributeValues: {
            ':stem': stem
        }
    }, function(error, data) {
        if (!error) {
            callback(data.Items);
        }
    });
}

function get(word, callback) {
    dynamodb.get({
        TableName: 'Mazaalai',
        ConsistentRead: false,
        Key: {
            stem: stemmer(word),
            word: word
        }
    }, function(error, data) {
        if (!error) {
            callback(data.Item);
        }
    });
}

function createMessageElement(item) {
    var title = item.word;
    var subtitle = item.data.clearFormat();
    var buttons = null;

    if (subtitle.length > 80) {
        subtitle = subtitle.substr(0, 77) + '...';
        buttons = [{
            type: 'postback',
            title: 'Дэлгэрэнгүй',
            payload: JSON.stringify({
                command: 'detail',
                parameter: item.word
            })
        }];
    }

    return {
        title: title,
        subtitle: subtitle,
        buttons: buttons
    }
}

function sendResult(recipientId, items) {
    var data = {
        recipient: {
            id: recipientId
        },
        message: {
            attachment: {
                type: 'template',
                payload: {
                    template_type: 'generic',
                    elements: []
                }
            }
        }
    }

    items.forEach(function(item) {
        data.message.attachment.payload.elements.push(createMessageElement(item));
    });

    request({
        uri: 'https://graph.facebook.com/v2.6/me/messages',
        qs: {
            access_token: PAGE_ACCESS_TOKEN
        },
        method: 'POST',
        json: data
    }, function (error, response, body) {
        // TODO: implement later
    });
}

function sendMessage(recipientId, message) {
    request({
        uri: 'https://graph.facebook.com/v2.6/me/messages',
        qs: {
            access_token: PAGE_ACCESS_TOKEN
        },
        method: 'POST',
        json: {
            recipient: {
                id: recipientId
            },
            message: {
                text: message
            }
        }
    }, function (error, response, body) {
        // TODO: implement later
    });
}

exports.handler = (event, context, callback) => {
    if (event['body-json'].object !== 'page') {
        callback('forbidden');
        return;
    }

    event['body-json'].entry.forEach(function(pageEntry) {
        pageEntry.messaging.forEach(function(messagingEvent) {
            if (messagingEvent.message) {
                find(stemmer(messagingEvent.message.text.split(' ')[0].toLowerCase()), function(items) {
                    if (items.length === 0) {
                        sendMessage(messagingEvent.sender.id, 'Уучлаарай, таны хайсан үг олдсонгүй.');
                        return;
                    }

                    items.chunk(10).forEach(function (chunkedItems) {
                        sendResult(messagingEvent.sender.id, chunkedItems);
                    });
                });
            }

            if (messagingEvent.postback) {
                var payload = JSON.parse(messagingEvent.postback.payload);
                var i = 0;

                if (payload.command === 'detail') {
                    get(payload.parameter, function(item) {
                        item.data.clearFormat().wordWrap(320).forEach(function (chunkedData) {
                            setTimeout(function() {
                                sendMessage(messagingEvent.sender.id, chunkedData);
                            }, 200 * (i++)); // sleeps 200ms between messages to keep order
                        });
                    });
                }
            }
        });
    });

    callback(null, 'success');
};