loader.js

const AWS = require("aws-sdk")
AWS.config.update({ region: "us-east-1" })
const db = new AWS.DynamoDB()
const async = require("async")

var users = [["mickey mouse", "password", "mickey", "mouse", "mickeymouse@gmail.com", "upenn", "10-14-2002", ["news", "sports"]]]

var initTable = function (key, tableName, callback) {
  db.listTables(function (err, data) {
    if (err) {
      console.log(err, err.stack)
      callback("Error when listing tables: " + err, null)
    } else {
      console.log("Connected to AWS DynamoDB")

      var tables = data.TableNames.toString().split(",")
      console.log("Tables in DynamoDB: " + tables)
      if (tables.indexOf(tableName) == -1) {
        console.log("Creating new table '" + tableName + "'")

        var params = {
          AttributeDefinitions: [
            {
              AttributeName: key,
              AttributeType: "S",
            },
          ],
          KeySchema: [
            {
              AttributeName: key,
              KeyType: "HASH",
            },
          ],
          ProvisionedThroughput: {
            ReadCapacityUnits: 20, // DANGER: Don't increase this too much; stay within the free tier!
            WriteCapacityUnits: 20, // DANGER: Don't increase this too much; stay within the free tier!
          },
          TableName: tableName /* required */,
        }

        db.createTable(params, function (err, data) {
          if (err) {
            console.log(err)
            callback("Error while creating table " + tableName + ": " + err, null)
          } else {
            console.log("Table is being created; waiting for 20 seconds...")
            setTimeout(function () {
              console.log("Success")
              callback(null, "Success")
            }, 20000)
          }
        })
      } else {
        console.log("Table " + tableName + " already exists")
        callback(null, "already created")
      }
    }
  })
}

initTable("username", "users", function (err, data) {
  if (err) {
    console.log("error making table users")
  } else {
    if (data === "already created") {
      console.log("Table users already exists - adding dummy values")

      async.forEach(
        users,
        function (user, callback) {
          console.log("Uploading user: " + user[0])
          var params = {
            Item: {
              username: {
                S: user[0],
              },
              password: {
                S: user[1],
              },
              first_name: {
                S: user[2],
              },
              last_name: {
                S: user[3],
              },
              email: {
                S: user[4],
              },
              affiliation: {
                S: user[5],
              },
              birthday: {
                S: user[6],
              },
              interests: {
                SS: user[7],
              },
            },
            TableName: "users",
            ReturnValues: "NONE",
          }

          db.putItem(params, function (err, data) {
            if (err) callback(err)
            else callback(null, "Success")
          })
        },
        function () {
          console.log("Upload complete")
        }
      )
    } else {
      console.log("Successfully created table users")
    }
  }
})

initTable("sender", "friends", function (err, data) {
  if (err) {
    console.log("error making table friends")
  } else {
    if (data === "already created") {
      console.log("Table friends already exists - adding dummy values")

      const friends = [
        ["jren2", "test1", 0],
        ["test1", "test2", 1],
        ["test2", "test1", 1],
      ]

      async.forEach(
        friends,
        function (friend, callback) {
          console.log("Uploading friend: " + friend[0])
          var params = {
            Item: {
              sender: {
                S: friend[0],
              },
              receiver: {
                S: friend[1],
              },
              status: {
                S: friend[2],
              },
            },
            TableName: "friends",
            ReturnValues: "NONE",
          }

          db.putItem(params, function (err, data) {
            if (err) callback(err)
            else callback(null, "Success")
          })
        },
        function () {
          console.log("Upload complete")
        }
      )
    } else {
      console.log("Successfully created table friends")
    }
  }
})

initTable("post_id", "posts", function (err, data) {
  if (err) {
    console.log("error making table posts")
  } else {
    if (data === "already created") {
      console.log("Table prefixes already exists - adding dummy values")

      const prefixes = [
        ["j", ["jren2"]],
        ["jr", ["jren2"]],
        ["jre", ["jren2"]],
        ["jren", ["jren2"]],
        ["jren2", ["jren2"]],
      ]

      async.forEach(
        prefixes,
        function (prefix, callback) {
          console.log("Uploading prefix: " + prefixes[0])
          var params = {
            Item: {
              prefix: {
                S: prefix[0],
              },
              usernames: {
                SS: prefix[1],
              },
            },
            TableName: "prefixes",
          }

          db.putItem(params, function (err, data) {
            if (err) callback(err)
            else callback(null, "Success")
          })
        },
        function () {
          console.log("Upload complete")
        }
      )
    } else {
      console.log("Successfully created table users")
    }
  }
})

initTable("prefix", "prefixes", function (err, data) {
  if (err) {
    console.log("error making table prefixes")
  } else {
    console.log("successfully created table prefixes")
  }
})

initTable("group_id", "groups", function (err, data) {
  if (err) {
    console.log("error making table groups")
  } else {
    console.log("successfully created table groups")
  }
})

initTable("sender_uid", "messages", function (err, data) {
  if (err) {
    console.log("error making table messages")
  } else {
    console.log("successfully created table messages")
  }
})

initTable("news_id", "news", function (err, data) {
  if (err) {
    console.log("error making table news")
  } else {
    console.log("successfully created table news")
  }
})