L13 websocket lambdas

lambdas/common/API_Responses.js

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+const Responses = {
+    _200(data = {}) {
+        return {
+            headers: {
+                'Content-Type': 'application/json',
+                'Access-Control-Allow-Methods': '*',
+                'Access-Control-Allow-Origin': '*',
+            },
+            statusCode: 200,
+            body: JSON.stringify(data),
+        };
+    },
+
+    _400(data = {}) {
+        return {
+            headers: {
+                'Content-Type': 'application/json',
+                'Access-Control-Allow-Methods': '*',
+                'Access-Control-Allow-Origin': '*',
+            },
+            statusCode: 400,
+            body: JSON.stringify(data),
+        };
+    },
+};
+
+module.exports = Responses;

lambdas/common/Dynamo.js

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+const AWS = require('aws-sdk');
+
+const documentClient = new AWS.DynamoDB.DocumentClient();
+
+const Dynamo = {
+    async get(ID, TableName) {
+        const params = {
+            TableName,
+            Key: {
+                ID,
+            },
+        };
+
+        const data = await documentClient.get(params).promise();
+
+        if (!data || !data.Item) {
+            throw Error(`There was an error fetching the data for ID of ${ID} from ${TableName}`);
+        }
+        console.log(data);
+
+        return data.Item;
+    },
+
+    async write(data, TableName) {
+        if (!data.ID) {
+            throw Error('no ID on the data');
+        }
+
+        const params = {
+            TableName,
+            Item: data,
+        };
+
+        const res = await documentClient.put(params).promise();
+
+        if (!res) {
+            throw Error(`There was an error inserting ID of ${data.ID} in table ${TableName}`);
+        }
+
+        return data;
+    },
+
+    async delete(ID, TableName) {
+        const params = {
+            TableName,
+            Key: {
+                ID,
+            },
+        };
+
+        return documentClient.delete(params).promise();
+    },
+};
+module.exports = Dynamo;

lambdas/common/S3.js

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+const AWS = require('aws-sdk');
+
+const s3Client = new AWS.S3();
+
+const S3 = {
+    async get(fileName, bucket) {
+        const params = {
+            Bucket: bucket,
+            Key: fileName,
+        };
+
+        let data = await s3Client.getObject(params).promise();
+
+        if (!data) {
+            throw Error(`Failed to get file ${fileName}, from ${bucket}`);
+        }
+
+        if (fileName.slice(fileName.length - 4, fileName.length) == 'json') {
+            data = data.Body.toString();
+        }
+        return data;
+    },
+    async write(data, fileName, bucket) {
+        const params = {
+            Bucket: bucket,
+            Body: JSON.stringify(data),
+            Key: fileName,
+        };
+
+        const newData = await s3Client.putObject(params).promise();
+
+        if (!newData) {
+            throw Error('there was an error writing the file');
+        }
+
+        return newData;
+    },
+};
+
+module.exports = S3;

lambdas/common/websocketMessage.js

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+const AWS = require('aws-sdk');
+
+const create = (domainName, stage) => {
+    const endpoint = `${domainName}/${stage}`;
+    return new AWS.ApiGatewayManagementApi({
+        apiVersion: '2018-11-29',
+        endpoint,
+    });
+};
+
+const send = ({ domainName, stage, connectionID, message }) => {
+    const ws = create(domainName, stage);
+
+    const postParams = {
+        Data: message,
+        ConnectionId: connectionID,
+    };
+
+    return ws.postToConnection(postParams).promise();
+};
+
+module.exports = {
+    send,
+};

lambdas/websockets/connect.js

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+const Responses = require('../common/API_Responses');
+const Dynamo = require('../common/Dynamo');
+
+const tableName = process.env.tableName;
+
+exports.handler = async event => {
+    console.log('event', event);
+
+    const { connectionId: connectionID, domainName, stage } = event.requestContext;
+
+    const data = {
+        ID: connectionID,
+        date: Date.now(),
+        messages: [],
+        domainName,
+        stage,
+    };
+
+    await Dynamo.write(data, tableName);
+
+    return Responses._200({ message: 'connected' });
+};

lambdas/websockets/default.js

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+const Responses = require('../common/API_Responses');
+
+exports.handler = async event => {
+    console.log('event', event);
+
+    return Responses._200({ message: 'default' });
+};

lambdas/websockets/disconnect.js

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+const Responses = require('../common/API_Responses');
+const Dynamo = require('../common/Dynamo');
+
+const tableName = process.env.tableName;
+
+exports.handler = async event => {
+    console.log('event', event);
+
+    const { connectionId: connectionID } = event.requestContext;
+
+    await Dynamo.delete(connectionID, tableName);
+
+    return Responses._200({ message: 'disconnected' });
+};

lambdas/websockets/message.js

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+const Responses = require('../common/API_Responses');
+const Dynamo = require('../common/Dynamo');
+const WebSocket = require('../common/websocketMessage');
+
+const tableName = process.env.tableName;
+
+exports.handler = async event => {
+    console.log('event', event);
+
+    const { connectionId: connectionID } = event.requestContext;
+
+    const body = JSON.parse(event.body);
+
+    try {
+        const record = await Dynamo.get(connectionID, tableName);
+        const { messages, domainName, stage } = record;
+
+        messages.push(body.message);
+
+        const data = {
+            ...record,
+            messages,
+        };
+
+        await Dynamo.write(data, tableName);
+
+        await WebSocket.send({
+            domainName,
+            stage,
+            connectionID,
+            message: 'This is a reply to your message',
+        });
+        console.log('sent message');
+
+        return Responses._200({ message: 'got a message' });
+    } catch (error) {
+        return Responses._400({ message: 'message could not be received' });
+    }
+
+    return Responses._200({ message: 'got a message' });
+};